Parallel connected inverters

A method comprising:

• connecting first inputs of a first power converter to a DC power source, wherein the DC power source comprises an energy storage device, wherein the first power converter comprises a first converter circuit, a first controller, the first inputs, and first outputs;
• connecting second inputs of a second power converter to the DC power source, wherein the second power converter comprises a second converter circuit, a second controller, the second inputs, and second outputs;
• providing a first AC power from the DC power source to the first outputs by the first converter circuit, wherein the first AC power is set by the first controller;
• and
• providing a second AC power from the DC power source to the second outputs by the second converter circuit, wherein the second AC power is set by the second controller,
• wherein the first outputs and thr second outputs are connected in parallel to each other and connected to an AC network,
• wherein the first AC power is different from the second AC power,
• wherein the DC power source further comprises a plurality of solar power sources ,
• wherein each of a plurality of power devices comprises an input coupled to a respective solar power source of the plurality of solar power sources and an output coupled in series to one or more other power devices of the plurality of power devices to form a series string, and
• wherein the first inputs and the second inputs are connected to the series string.

A distributed power system comprising:

• an energy storage device comprising at least one battery;
• a first power converter comprising a first converter circuit, a first controller, first inputs, and first outputs;
• and
• a second power converter comprising a second converter circuit, a second controller, second inputs, and second outputs,
• wherein the first inputs and the second inputs are connected in parallel to each other and connected to the energy storage device,
• wherein the first converter circuit is configured to provide, from the energy storage device, a first alternating current (AC) power at the first outputs,
• wherein the second converter circuit is configured to provide, from the energy storage device, a second AC power at the second outputs,
• wherein the first outputs and the second outputs are connected in parallel to each other, the first outputs are across an AC network, and the second outputs are across the AC network,
• wherein the first controller is configured to set the first AC power provided by the first converter circuit,
• wherein the second controller is configured to set a second AC power provided by the second converter circuit,
• wherein the first AC power output is different from the second AC power output, and
• wherein each of the first controller and the second controller comprises:
• a voltage loop block configured to output a current reference signal based on a comparison of a voltage of the energy storage device to a reference voltage;
• and
• a current loop block configured to compare the current reference signal with a current signal proportional to a current signal of the energy storage device.

A method comprising:

• connecting first inputs of a first power converter to an energy storage device, wherein the energy storage device comprises a battery, wherein the first power converter comprises a first converter circuit, a first controller, the first inputs, and first outputs;
• connecting second inputs of a second power converter to the energy storage device, wherein the second power converter comprises a second converter circuit, a second controller, the second inputs, and second outputs;
• providing, by the first converter circuit, a first AC power from the energy storage device to the first outputs, wherein the first AC power is set by the first controller;
• providing, by the second converter circuit, a second AC power set by the second controller from the energy storage device to the second outputs, wherein the second AC power is set by the second controller;
• comparing, by a voltage loop block, a voltage of the energy storage device to a reference voltage;
• outputting a current reference signal based on the comparison;
• and
• comparing, by a current loop block, the current reference signal with a current signal proportional to a current signal of the energy storage device,
• wherein the first outputs and the second outputs are connected in parallel to each other and connected to an AC network, and
• wherein the first AC power is different from the second AC power.