Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-4, 6, 9, 11- 20 are rejected under 35 U.S.C. 103 as being unpatentable over Laval et al. (US20170229868, herein Laval), in view of Colby et al. (US20050135031, herein Colby)
Regarding claim 1, Laval teaches An energy storage system, comprising: a controller; and an inverter and an on-grid/off-grid mode switch that are connected to the controller ([0009] transmitting the first communication may include publishing, via a field message bus of the microgrid, an anomaly event, in response to opening the recloser and/or switch. The recloser and/or switch system may notify the inverter, a controller of the microgrid, and a utility SCADA system of the anomaly event, [0011] The method may include transitioning the inverter from a grid-connected mode to an islanded mode, in response to the first communication); and a load connected to the on-grid/off-grid mode switch ([0041] The microgrid 120 may optionally include one or more loads L. In some embodiments, a load L may communicate with the communication network 115. As the nodes N and load L of FIG. 1A), wherein the inverter is configured to: in response to determining that the energy storage system is in an islanding state, send an islanding state message to the controller, freeze an output frequency of the inverter based on a preset frequency ([0056] the recloser/switch system RSS may receive, via the communications/network interface 160′ (FIG. 1D) of the recloser/switch system RSS, a command to intentionally transition to an islanded mode independently of any power disturbance of the utility grid 100. The recloser/switch R/S may then open (Block 220) in response to the command. In some embodiments, the recloser/switch system RSS may receive the command to intentionally transition to the islanded mode via a field message bus. Moreover, in some embodiments, the event may be a security event such as the detection of a potential security threat), and control an output current of the inverter based on an association relationship that an output voltage of the inverter is negatively correlated with apparent power of the inverter…, ([0072] an inverter I of the microgrid 120 may transition from an islanded mode to either (i) a current-source grid-following mode or (ii) a voltage-source grid-following mode. In the isochronous mode, the inverter I may provide voltage and frequency to the power system. Alternatively, the inverter I could provide Watts and VARS in the isochronous mode instead of providing voltage and frequency); the controller is configured to send a disconnection instruction to the on-grid/off-grid mode switch based on the islanding state message, wherein the disconnection instruction instructs the on-grid/off-grid mode switch to disconnect from a power grid corresponding to the on-grid/off- grid mode switch ([0063] the microgrid 120 includes a plurality of inverters I, the inverters I may be prioritized with respect to each other, to determine which of the inverters I will take over when disconnected from the grid 100. For example, a field message bus may have configured priorities for the inverters I. Prioritization could be based on a Quality of Service (QoS) rank of the inverters I. The field message bus thus has the ability to prioritize (e.g., order/rank) which inverter I will take over. Accordingly, the field message bus can coordinate the inverters, [0059] Blocks 220 and 230 may be grouped and referred to as transitioning from (a) a grid-connected mode to (b) an islanded mode, whereas Blocks 240 and 250 may grouped and referred to as transitioning from (b) an islanded mode to (a) a grid-connected mode) ; the controller is further configured to send a switching instruction to the inverter in response to receiving a disconnection complete message from the on-grid/off-grid mode switch, wherein the disconnection complete message indicates that the on-grid/off-grid mode switch has been disconnected from the power grid, and the switching instruction instructs the inverter to switch to a voltage source mode ([0059] Blocks 220 and 230 may be grouped and referred to as transitioning from (a) a grid-connected mode to (b) an islanded mode, whereas Blocks 240 and 250 may grouped and referred to as transitioning from (b) an islanded mode to (a) a grid-connected mode, [0064] the microgrid 120 may include multiple distributed energy resources DER, such as multiple batteries, that are behind the recloser/switch R/S. It may be desirable to prioritize the batteries for switching to a voltage-source mode so that the batteries do not fight each other and potentially cause a system failure, [0066] the voltage source when the microgrid 120 disconnects from the grid); and the inverter is further configured to switch to the voltage source mode in response to receiving the switching instruction …([0059] 220 and 230 may be grouped and referred to as transitioning from (a) a grid-connected mode to (b) an islanded mode, whereas Blocks 240 and 250 may grouped and referred to as transitioning from (b) an islanded mode to (a) a grid-connected mode, [0066] utility service provider or the customer could determine the order in which the batteries will become the voltage source when the microgrid 120 disconnects from the grid 100. This ranking/priority may be on the communications protocol of a field message bus that is used by the microgrid 120, [0067] it may be beneficial to open the recloser/switch R/S when a voltage drops below (or increases above) a predetermined percentage (e.g., 70%) of nominal).
Laval does not teach so that the output voltage of the inverter meets a preset range of a rated voltage, … and determining that the output voltage of the inverter meets the preset range of the rated voltage
Colby teaches so that the output voltage of the inverter meets a preset range of a rated voltage, … and determining that the output voltage of the inverter meets the preset range of the rated voltage ([0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Laval’s teaching of a microgrid connection transitioning the inverter from a grid connected mode to an islanded mode with Colby’s teaching of controlling the interconnection of a power inverter so that the output voltages matches within a preset tolerance. The combined teaching provides an expected result of a microgrid connection transitioning the inverter and controlling the inverter output voltages to match within a preset tolerance. Therefore, one of ordinary skill in the art would be motivated to improve safety and efficiency ensuring the voltage levels are acceptable for the system.
Regarding claim 2, the combination of Laval and Colby teach The energy storage system according to claim 1, wherein the inverter is configured to: control the output current of the inverter based on a first association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter, (Laval, [0066] when the microgrid 120 returns to the grid 100, there may be a handshake between the recloser/switch R/S and the battery/inverter to move back to current-source mode. Quickly switching back to the current-source mode upon reconnecting to the grid 100 may reduce the risk of equipment overheating, failure, [0040] Each inverter I may be configured to convert a variable Direct Current (DC) output of one or more distributed energy resources DER into a utility frequency Alternating Current (AC) that can be fed into a commercial electrical grid (e.g., the grid 100) or be used by a local, off-grid electrical network, [0061] When grid power is restored (Block 240), the recloser/switch system RSS may tell a control system (e.g., one of the nodes N) that power of the grid 100 is back on and to start preparing the microgrid 120 to reconnect to the grid 100, before the recloser/switch system RSS tells inverter(s) I (Block 250) about grid power restoration)
Colby further teaches to obtain a first stable output voltage of the inverter and first apparent power corresponding to the first stable output voltage wherein a variation range of the first stable output voltage is less than or equal to the preset range; adjust the first association relationship based on a second association relationship that the output voltage of the inverter is positively correlated with apparent power of the load, and a magnitude relationship between the first stable output voltage and the rated voltage, to obtain a third association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter; and control the output current of the inverter based on the third association relationship and the rated voltage, so that the output voltage of the inverter meets the preset range of the rated voltage (Fig. 8, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0009] a regulator circuit to control an inverter voltage to match an electrical system voltage by measuring x-y phasor components of the inverter voltage and the electrical system voltage, a synchronization detection circuit to detect synchronization of the inverter voltage with the electrical system voltage by calculating a voltage error based on the x-y phasor components, and a contactor control circuit to command contactor closure to interconnect the inverter with the electrical system responsive to detecting synchronization, [0036] generates current commands (IXCNTL and IYCNTL) based on the differences between measured and desired real and reactive power and from them generates a reference current waveform, IREF. The IREF signal, which can be generated in terms of x and y components, is then used to set a reference voltage, VREF, that is updated via the control to produce desired changes in the inverter current).
Regarding claim 3, the combination of Laval and Colby teach The energy storage system according to claim 2,
Colby further teaches wherein the inverter is configured to: adjust the first association relationship based on a magnitude relationship between the first stable output voltage and the rated voltage, to obtain a fourth association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter; control the output current of the inverter based on the fourth association relationship, to obtain a second stable output voltage of the inverter and second apparent power corresponding to the second stable output voltage, wherein a variation range of the second stable output voltage is less than or equal to the preset range; obtain, based on the first stable output voltage, the first apparent power, the second stable output voltage, and the second apparent power, the second association relationship that the output voltage of the inverter is positively correlated with the apparent power of the load; and adjust the fourth association relationship based on the second association relationship and the magnitude relationship between the first stable output voltage and the rated voltage, to obtain the third association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter (Fig. 8, [0060] Thus, the inverter's output is matched to the required (or desired) magnitude, frequency, and phase not by directly setting current and voltage phases and magnitudes but rather by referencing the inverter's x-y coordinate frame to a desired anchor point, e.g., the grid voltage, and controlling the real and reactive powers measured for the inverter in relation to desired real and reactive powers, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0009] a regulator circuit to control an inverter voltage to match an electrical system voltage by measuring x-y phasor components of the inverter voltage and the electrical system voltage, a synchronization detection circuit to detect synchronization of the inverter voltage with the electrical system voltage by calculating a voltage error based on the x-y phasor components, and a contactor control circuit to command contactor closure to interconnect the inverter with the electrical system responsive to detecting synchronization, [0036] generates current commands (IXCNTL and IYCNTL) based on the differences between measured and desired real and reactive power and from them generates a reference current waveform, IREF. The IREF signal, which can be generated in terms of x and y components, is then used to set a reference voltage, VREF, that is updated via the control to produce desired changes in the inverter current).
Regarding claim 4, the combination of Laval and Colby teach The energy storage system according to claim 2,
Colby further teaches wherein the inverter is further configured to obtain the first association relationship based on a minimum output voltage and a maximum output voltage of the inverter within the preset range of the rated voltage, maximum apparent power corresponding to the minimum output voltage, and minimum apparent power corresponding to the maximum output voltage (Fig. 8 [0008] A controlled disconnect of the inverter can be performed by ramping down inverter power, and subsequently commanding contactor opening to disconnect the inverter from the electrical system responsive to determining that the inverter power is below a defined threshold. The inverter can be stopped after opening the contactors, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output).
Regarding claim 6, the combination of Laval and Colby teach, The energy storage system according to claim 3,
Colby further teaches wherein the fourth association relationship indicates that; when the first stable output voltage is less than the rated voltage, maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the fourth association relationship is greater than maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the first association relationship; or when the first stable output voltage is greater than or equal to the rated voltage, maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the fourth association relationship is less than maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the first association relationship (Fig.8, [0008] A controlled disconnect of the inverter can be performed by ramping down inverter power, and subsequently commanding contactor opening to disconnect the inverter from the electrical system responsive to determining that the inverter power is below a defined threshold. The inverter can be stopped after opening the contactors, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output).
.
Regarding claim 9, the combination of Laval and Colby teach The energy storage system according to claim 3,
Colby further teaches wherein the inverter is configured to: determine a value of an association coefficient in the fourth association relationship based on the second association relationship and the magnitude relationship between the first stable output voltage and the rated voltage; and update the fourth association relationship based on the value of the association coefficient, to obtain the third association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter (Fig.8, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0036] voltage, VREF, that is updated via the control to produce desired changes in the inverter current, [0076] With this configuration, VXREF serves as the coefficient for generating the cosine (x) component of the VREF waveform from the REFX sinusoid and VYREF serves as the coefficient for generating the sine (y) component of the VREF waveform from the REFY sinusoid. Waveform generator 146 thus provides the ac output voltage VREF for Stand Alone and Synchronization mode operations (Step 170)) .
Regarding claim 11, the combination of Laval and Colby teach The energy storage system according to claim 2,
Colby further teaches wherein the inverter is configured to: obtain, based on the third association relationship, target apparent power corresponding to the rated voltage; and control the output current of the inverter based on the target apparent power, so that the output voltage of the inverter meets the preset range of the rated voltage (Fig.8, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output) .
Regarding claim 12, the combination of Laval and Colby teach The energy storage system according to claim 1, wherein the preset frequency comprises a rated frequency of the load, or an output frequency of the inverter in a case that the energy storage system is in the islanding state (Laval, [0040] Each inverter I may be configured to convert a variable Direct Current (DC) output of one or more distributed energy resources DER into a utility frequency Alternating Current (AC) that can be fed into a commercial electrical grid (e.g., the grid 100) or be used by a local, off-grid electrical network, [0039] The switch may be referred to as an “islanding switch,” as it can island the microgrid 120 from the grid 100, [0067] Accordingly, the recloser/switch R/S may open (Block 220) in response to the recloser/switch system RSS detecting a power anomaly. For example, a transient that trips the recloser/switch R/S could be referred to as a power disturbance. Moreover, the grid 100 could have a voltage or frequency issue that would be considered a power disturbance, even if it does not result in an outage. The voltage or frequency issue could be a voltage or frequency that goes undesirably high (or, alternatively, goes undesirably low). In particular, it may be beneficial to disconnect the microgrid 120 from the grid 100 before a power outage occurs. As an example, it may be beneficial to open the recloser/switch R/S when a voltage drops below (or increases above) a predetermined percentage (e.g., 70%) of nominal).
Regarding claim 13, the combination of Laval and Colby teach The energy storage system according to claim 1, wherein the inverter is specifically configured to: in response to that an operation mode is a current source mode, determine, based on the output voltage of the inverter, whether the energy storage system is in the islanding state (Laval, [0071] the islanded mode may then include changing from the voltage-source isochronous mode of the inverter I of the distributed energy resource DER to another mode of the inverter I of the distributed energy resource DER, in response to the second peer-to-peer or peer-to-multipeer communication. The other mode may be a current-source grid-following mode or a voltage-source grid-following mode, [0063] determine which of the inverters I will take over when disconnected from the grid 100 ).
Regarding claim 14, Laval teaches An on-grid/off-grid mode switching method, applied to an energy storage system, wherein the energy storage system comprises a controller, an inverter, an on-grid/off-grid mode switch, a power grid ([0009] transmitting the first communication may include publishing, via a field message bus of the microgrid, an anomaly event, in response to opening the recloser and/or switch. The recloser and/or switch system may notify the inverter, a controller of the microgrid, and a utility SCADA system of the anomaly event, [0011] The method may include transitioning the inverter from a grid-connected mode to an islanded mode, in response to the first communication), and a load ([0041] The microgrid 120 may optionally include one or more loads L. In some embodiments, a load L may communicate with the communication network 115. As the nodes N and load L of FIG. 1A), and the method comprises: in response to determining that the energy storage system is in an islanding state, sending, by the inverter, an islanding state message to the controller, freezing an output frequency of the inverter based on a preset frequency ([0056] the recloser/switch system RSS may receive, via the communications/network interface 160′ (FIG. 1D) of the recloser/switch system RSS, a command to intentionally transition to an islanded mode independently of any power disturbance of the utility grid 100. The recloser/switch R/S may then open (Block 220) in response to the command. In some embodiments, the recloser/switch system RSS may receive the command to intentionally transition to the islanded mode via a field message bus. Moreover, in some embodiments, the event may be a security event such as the detection of a potential security threat), and controlling an output current of the inverter based on an association relationship that an output voltage of the inverter is negatively correlated with apparent power of the inverter… ([0072] an inverter I of the microgrid 120 may transition from an islanded mode to either (i) a current-source grid-following mode or (ii) a voltage-source grid-following mode. In the isochronous mode, the inverter I may provide voltage and frequency to the power system. Alternatively, the inverter I could provide Watts and VARS in the isochronous mode instead of providing voltage and frequency), sending, by the controller, a disconnection instruction to the on-grid/off-grid mode switch, wherein the disconnection instruction instructs the on-grid/off-grid mode switch to disconnect from the power grid ([0063] the microgrid 120 includes a plurality of inverters I, the inverters I may be prioritized with respect to each other, to determine which of the inverters I will take over when disconnected from the grid 100. For example, a field message bus may have configured priorities for the inverters I. Prioritization could be based on a Quality of Service (QoS) rank of the inverters I. The field message bus thus has the ability to prioritize (e.g., order/rank) which inverter I will take over. Accordingly, the field message bus can coordinate the inverters, [0059] Blocks 220 and 230 may be grouped and referred to as transitioning from (a) a grid-connected mode to (b) an islanded mode, whereas Blocks 240 and 250 may grouped and referred to as transitioning from (b) an islanded mode to (a) a grid-connected mode); sending, by the controller, a switching instruction to the inverter in response to receiving a disconnection complete message from the on-grid/off-grid mode switch, wherein the disconnection complete message indicates that the on-grid/off-grid mode switch has been disconnected from the power grid, and the switching instruction instructs the inverter to switch to a voltage source mode ([0059] Blocks 220 and 230 may be grouped and referred to as transitioning from (a) a grid-connected mode to (b) an islanded mode, whereas Blocks 240 and 250 may grouped and referred to as transitioning from (b) an islanded mode to (a) a grid-connected mode, [0064] the microgrid 120 may include multiple distributed energy resources DER, such as multiple batteries, that are behind the recloser/switch R/S. It may be desirable to prioritize the batteries for switching to a voltage-source mode so that the batteries do not fight each other and potentially cause a system failure, [0066] the voltage source when the microgrid 120 disconnects from the grid); and switching, by the inverter, to the voltage source mode in response to receiving the switching instruction… ([0059] 220 and 230 may be grouped and referred to as transitioning from (a) a grid-connected mode to (b) an islanded mode, whereas Blocks 240 and 250 may grouped and referred to as transitioning from (b) an islanded mode to (a) a grid-connected mode, [0066] utility service provider or the customer could determine the order in which the batteries will become the voltage source when the microgrid 120 disconnects from the grid 100. This ranking/priority may be on the communications protocol of a field message bus that is used by the microgrid 120, [0067] it may be beneficial to open the recloser/switch R/S when a voltage drops below (or increases above) a predetermined percentage (e.g., 70%) of nominal).
Laval does not teach so that the output voltage of the inverter meets a preset range of a rated voltage, … and determining that the output voltage of the inverter meets the preset range of the rated voltage
Colby teaches so that the output voltage of the inverter meets a preset range of a rated voltage, … and determining that the output voltage of the inverter meets the preset range of the rated voltage ([0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances)
Regarding claim 15, the combination of Laval and Colby teach The on-grid/off-grid mode switching method according to claim 14, wherein controlling an output current of the inverter based on an association relationship that an output voltage of the inverter is negatively correlated with apparent power of the inverter comprises, (Laval, [0066] when the microgrid 120 returns to the grid 100, there may be a handshake between the recloser/switch R/S and the battery/inverter to move back to current-source mode. Quickly switching back to the current-source mode upon reconnecting to the grid 100 may reduce the risk of equipment overheating, failure, [0040] Each inverter I may be configured to convert a variable Direct Current (DC) output of one or more distributed energy resources DER into a utility frequency Alternating Current (AC) that can be fed into a commercial electrical grid (e.g., the grid 100) or be used by a local, off-grid electrical network, [0061] When grid power is restored (Block 240), the recloser/switch system RSS may tell a control system (e.g., one of the nodes N) that power of the grid 100 is back on and to start preparing the microgrid 120 to reconnect to the grid 100, before the recloser/switch system RSS tells inverter(s) I (Block 250) about grid power restoration):
Colby further teaches controlling, by the inverter, the output current of the inverter based on a first association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter, to obtain a first stable output voltage of the inverter and first apparent power corresponding to the first stable output voltage, wherein a variation range of the first stable output voltage is less than or equal to the preset range (Fig. 8, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0009] a regulator circuit to control an inverter voltage to match an electrical system voltage by measuring x-y phasor components of the inverter voltage and the electrical system voltage, a synchronization detection circuit to detect synchronization of the inverter voltage with the electrical system voltage by calculating a voltage error based on the x-y phasor components, and a contactor control circuit to command contactor closure to interconnect the inverter with the electrical system responsive to detecting synchronization, [0036] generates current commands (IXCNTL and IYCNTL) based on the differences between measured and desired real and reactive power and from them generates a reference current waveform, IREF. The IREF signal, which can be generated in terms of x and y components, is then used to set a reference voltage, VREF, that is updated via the control to produce desired changes in the inverter current).
Regarding claim 16, the combination of Laval and Colby teach The on-grid/off-grid mode switching method according to claim 15,
Colby further teaches wherein the method further comprises: adjusting, by the inverter, the first association relationship based on a second association relationship that the output voltage of the inverter is positively correlated with apparent power of the load, and a magnitude relationship between the first stable output voltage and the rated voltage, to obtain a third association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter; and controlling, by the inverter, the output current of the inverter based on the third association relationship and the rated voltage, so that the output voltage of the inverter meets the preset range of the rated voltage (Fig. 8, [0060] Thus, the inverter's output is matched to the required (or desired) magnitude, frequency, and phase not by directly setting current and voltage phases and magnitudes but rather by referencing the inverter's x-y coordinate frame to a desired anchor point, e.g., the grid voltage, and controlling the real and reactive powers measured for the inverter in relation to desired real and reactive powers, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0009] a regulator circuit to control an inverter voltage to match an electrical system voltage by measuring x-y phasor components of the inverter voltage and the electrical system voltage, a synchronization detection circuit to detect synchronization of the inverter voltage with the electrical system voltage by calculating a voltage error based on the x-y phasor components, and a contactor control circuit to command contactor closure to interconnect the inverter with the electrical system responsive to detecting synchronization, [0036] generates current commands (IXCNTL and IYCNTL) based on the differences between measured and desired real and reactive power and from them generates a reference current waveform, IREF. The IREF signal, which can be generated in terms of x and y components, is then used to set a reference voltage, VREF, that is updated via the control to produce desired changes in the inverter current). .
Regarding claim 17, the combination of Laval and Colby teach The on-grid/off-grid mode switching method according to claim 16,
Colby further teaches wherein adjusting the first association relationship based on a second association relationship that the output voltage of the inverter is positively correlated with apparent power of the load, and a magnitude relationship between the first stable output voltage and the rated voltage, to obtain a third association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter comprises: adjusting, by the inverter, the first association relationship based on a magnitude relationship between the first stable output voltage and the rated voltage, to obtain a fourth association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter; and controlling, by the inverter, the output current of the inverter based on the fourth association relationship, to obtain a second stable output voltage of the inverter and second apparent power corresponding to the second stable output voltage, wherein a variation range of the second stable output voltage is less than or equal to the preset range (Fig. 8, [0060] Thus, the inverter's output is matched to the required (or desired) magnitude, frequency, and phase not by directly setting current and voltage phases and magnitudes but rather by referencing the inverter's x-y coordinate frame to a desired anchor point, e.g., the grid voltage, and controlling the real and reactive powers measured for the inverter in relation to desired real and reactive powers, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0079] the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0009] a regulator circuit to control an inverter voltage to match an electrical system voltage by measuring x-y phasor components of the inverter voltage and the electrical system voltage, a synchronization detection circuit to detect synchronization of the inverter voltage with the electrical system voltage by calculating a voltage error based on the x-y phasor components, and a contactor control circuit to command contactor closure to interconnect the inverter with the electrical system responsive to detecting synchronization, [0036] generates current commands (IXCNTL and IYCNTL) based on the differences between measured and desired real and reactive power and from them generates a reference current waveform, IREF. The IREF signal, which can be generated in terms of x and y components, is then used to set a reference voltage, VREF, that is updated via the control to produce desired changes in the inverter current, [0008] A controlled disconnect of the inverter can be performed by ramping down inverter power, and subsequently commanding contactor opening to disconnect the inverter from the electrical system responsive to determining that the inverter power is below a defined threshold. The inverter can be stopped after opening the contactors).
Regarding claim 18, the combination of Laval and Colby teach The on-grid/off-grid mode switching method according to claim 17,
Colby further teaches wherein the method further comprises: obtaining, by the inverter based on the first stable output voltage, the first apparent power, the second stable output voltage, and the second apparent power, the second association relationship that the output voltage of the inverter is positively correlated with the apparent power of the load; and adjusting, by the inverter, the fourth association relationship based on the second association relationship and the magnitude relationship between the first stable output voltage and the rated voltage, to obtain the third association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter (Fig.8, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output, [0036] voltage, VREF, that is updated via the control to produce desired changes in the inverter current) .
Regarding claim 19, the combination of Laval and Colby teach The on-grid/off-grid mode switching method according to claim 15,
Colby further teaches wherein before the controlling the output current of the inverter based on a first association relationship that the output voltage of the inverter is negatively correlated with the apparent power of the inverter, the method further comprises: obtaining, by the inverter, the first association relationship based on a minimum output voltage and a maximum output voltage of the inverter within the preset range of the rated voltage, maximum apparent power corresponding to the minimum output voltage, and minimum apparent power corresponding to the maximum output voltage (Colby, Fig. 8 [0008] A controlled disconnect of the inverter can be performed by ramping down inverter power, and subsequently commanding contactor opening to disconnect the inverter from the electrical system responsive to determining that the inverter power is below a defined threshold. The inverter can be stopped after opening the contactors, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output).
Regarding claim 20, the combination of Laval and Colby teach The on-grid/off-grid mode switching method according to claim 17,
Colby further teaches wherein the fourth association relationship indicates that: when the first stable output voltage is less than the rated voltage, maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the fourth association relationship is greater than maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the first association relationship; or when the first stable output voltage is greater than or equal to the rated voltage, maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the fourth association relationship is less than maximum apparent power corresponding to the inverter within the preset range of the rated voltage in the first association relationship (Fig. 8 [0008] A controlled disconnect of the inverter can be performed by ramping down inverter power, and subsequently commanding contactor opening to disconnect the inverter from the electrical system responsive to determining that the inverter power is below a defined threshold. The inverter can be stopped after opening the contactors, [0079] The threshold value can be set to an empirically determined default value, or it can be configurable, or otherwise adjustable. In any case, the detection threshold is set low enough to avoid premature interconnection of the inverter 10 but high enough to account for measurement and control tolerances, [0005] a control circuit locks to the phase of the ac mains voltage and then adjusts the fundamental phasor components of the inverter's output voltage to match the measured fundamental phasor components of the grid voltage. Once matching is achieved within a defined tolerance, interconnecting contactors are commanded closed and, after verifying contactor closure, regulation of the inverter's output is changed over from voltage regulation to power/current regulation, wherein the inverter's output is controlled as a function of desired real and reactive power output).
Relevant Art Cited by Examiner
The following prior art made of record and not relied upon is cited to establish the level of skill in the applicant’s art and those arts considered reasonably pertinent to Applicant’s disclosure. See MPEP 707.05(c).
Laval, US20170229868 discloses a microgrid connection transition from grid to island mode.
Colby, US20050135031 discloses power inverter synchronization matching the output voltage of the inverter.
Dent, US20150295413 discloses a remote controlled photovoltaic string combiner including a grid tie inverter operating at different modes.
Allowable Subject Matter
Claims 5, 7-8, 10 are objected to as allowable subject matter. The following is an Examiner’s statement of reasons for allowance:
The reasons for allowance of Claims 5, 7-8, and 10 are that the prior art of record, including the reference(s) cited below, neither anticipates, not renders obvious the recited combination as a whole; including the limitation of:
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The prior art made of record Laval, Colby, and Dent neither anticipates nor render obvious the above-recited combinations for at least the reasons specified.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure.
Dent (US20150295413) discloses a remote controlled photovoltaic string combiner including a grid tie inverter operating at different modes.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to YVONNE T FOLLANSBEE whose telephone number is (571)272-0634. The examiner can normally be reached on Monday - Friday 1pm - 9pm.
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/YVONNE TRANG FOLLANSBEE/Examiner, Art Unit 2117
/ROBERT E FENNEMA/ Supervisory Patent Examiner, Art Unit 2117