Inverter with independent current and voltage controlled outputs
First Claim
1. A bimodal inverter operative to convert DC power from a battery to either or both of a current-controlled AC output and a voltage-controlled AC output, comprising:
- a switching matrix at least partially shared between the current-controlled and voltage-controlled outputs; and
a controller operative to cause the shared switching matrix to output one or both ofa current-controlled output selectively generating AC power having a predetermined current level within a predetermined current tolerance and suitable for backfeeding power to an electric utility grid, anda voltage-controlled output selectively generating AC power having a predetermined voltage level within predetermined voltage tolerance and suitable for directly powering AC loads;
wherein the controller is operative to cause the shared switching matrix to output the current-controlled output and the voltage-controlled outputs simultaneously; and
wherein the controller is operative to cause the shared switching matrix to output the current-controlled output if the voltage-controlled output is terminated; and
wherein the controller is operative to cause the shared switching matrix to output the voltage-controlled output if the current-controlled output is terminated.
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Accused Products
Abstract
Transformerless bimodal inverters provide grid-tie outputs for back-feeding solar-originated power from a battery to a utility power grid in a grid-tied mode, simultaneously or alternatively with providing a constant-voltage AC output for powering AC appliances or loads directly in a standalone mode. The inverters continue to operate in the standalone mode without interruption should the grid-tied mode cease, e.g., due to anti-islanding during a grid outage or other fault condition not affecting the standalone mode. Conversely, the inverters continue to operate in the grid-tied mode should the standalone mode trip out, e.g., due to a current overload or other condition not affecting the grid-tied mode.
88 Citations
19 Claims
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1. A bimodal inverter operative to convert DC power from a battery to either or both of a current-controlled AC output and a voltage-controlled AC output, comprising:
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a switching matrix at least partially shared between the current-controlled and voltage-controlled outputs; and a controller operative to cause the shared switching matrix to output one or both of a current-controlled output selectively generating AC power having a predetermined current level within a predetermined current tolerance and suitable for backfeeding power to an electric utility grid, and a voltage-controlled output selectively generating AC power having a predetermined voltage level within predetermined voltage tolerance and suitable for directly powering AC loads; wherein the controller is operative to cause the shared switching matrix to output the current-controlled output and the voltage-controlled outputs simultaneously; and wherein the controller is operative to cause the shared switching matrix to output the current-controlled output if the voltage-controlled output is terminated; and wherein the controller is operative to cause the shared switching matrix to output the voltage-controlled output if the current-controlled output is terminated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A bimodal inverter operative to convert DC power from a battery to a voltage-controlled AC output, comprising:
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a first half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; an inductor connected between a node between the switches of the first half-H-bridge and a neutral AC output terminal; a second half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; a first damped low-pass filter connected between a node between the switches of the second half-H-bridge and a first voltage-controlled AC output terminal; and a controller operative to control the first half-H-bridge to alternately connect the positive and negative battery terminals to the neutral AC output terminal through the inductor to provide an electronic center-tap of the battery; and wherein the controller is further operative to control the second half-H-bridge to alternately connect the positive and negative battery terminals to the first voltage-controlled AC output terminal through the first damped low-pass filter according to a bit-density modulation stream of binary bits chosen to approximate a sinewave voltage waveform. - View Dependent Claims (12, 13, 14)
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15. A bimodal inverter operative to convert DC power from a battery to a current-controlled AC output, comprising:
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a first half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; a first inductor connected between a node between the switches of the first half-H-bridge and a neutral AC output terminal; a second half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; a second inductor connected between a node between the switches of the second half-H-bridge and a current-controlled AC output terminal; and a controller operative to control the first half-H-bridge to alternately connect the positive and negative battery terminals to the neutral AC output terminal through the first inductor to provide an electronic center-tap of the battery; and wherein the controller is further operative to control the second half-H-bridge to alternately connect the positive and negative battery terminals to the current-controlled AC output terminal through the second inductor according to a bit-density modulation stream of binary bits chosen to approximate a sinewave current waveform.
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16. A bimodal inverter operative to convert DC power from a battery to either or both of a current-controlled AC output and a voltage-controlled AC output, the AC outputs sharing a neutral output terminal, comprising:
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a first half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; a first inductor connected between a node between the switches of the first half-H-bridge and the shared neutral AC output terminal; a second half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; a damped low-pass filter connected between a node between the switches of the second half-H-bridge and a voltage-controlled AC output terminal; and a third half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery; a second inductor connected between a node between the switches of the second half-H-bridge and a current-controlled AC output terminal; and a controller operative to control the first half-H-bridge to alternately connect the positive and negative battery terminals to the shared neutral AC output terminal through the inductor to provide an electronic center-tap of the battery; wherein the controller is further operative to control the second half-H-bridge to alternately connect the positive and negative battery terminals to the voltage-controlled AC output terminal through the damped low-pass filter according to a bit-density modulation stream of binary bits chosen to approximate a sinewave voltage waveform; and wherein the controller is further operative to control the third half-H-bridge to alternately connect the positive and negative battery terminals to the current-controlled AC output terminal through the second inductor according to a bit-density modulation stream of binary bits chosen to approximate a sinewave current waveform.
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17. A method of controlling a bimodal inverter operative to convert DC power from a battery to either or both of a current-controlled AC output suitable for backfeeding power to an electric utility grid and a voltage-controlled AC output suitable for directly powering AC loads, comprising:
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monitoring an AC current at the current-controlled AC output; comparing the monitored current to a desired current waveform; if the monitored current deviates from an instantaneous value of the desired current waveform by more than a predetermined current deviation, controlling a second half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery to reduce the current deviation; monitoring an AC voltage at the voltage-controlled AC output; comparing the monitored voltage to a desired voltage waveform; if the monitored voltage deviates from an instantaneous value of the desired voltage waveform by more than a predetermined voltage deviation, controlling a third half-H-bridge of semiconductor switches connected in series between positive and negative terminals of the battery to reduce the voltage deviation. - View Dependent Claims (18, 19)
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Specification