Parallel-connected inverters with separate controllers having impedance current regulators

A distributed generation network, comprising:

• a) a plurality of power sources connected together in a distributed generation AC power network that is primarily inductive;
• b) a plurality of power converters, at least some of which are connected in parallel, each connected to one or more of said plurality of power sources;
• c) a plurality of control systems, each connected to at least one of said plurality of power converters and each including an impedance current regulator for generating an effective output resistance as a function of characteristics of AC power in the AC power network;
• and
• d) wherein each of said plurality of control systems controls said at least one of said plurality of power converters without the need for a centralized control system connected to said each control system.

An uninterruptible power supply (UPS), comprising:

• a) a distributed generation AC power network having a plurality of controlled current sources for providing power, wherein said plurality of controlled current sources are connected together in parallel;
• b) a plurality of control systems for controlling operation of said controlled current sources, wherein each of said plurality of control systems (i) is capable of controlling at least one of said controlled current sources without the need for a separate control system connected to said each control system and (ii) includes an impedance current regulator for generating an impedance current signal as a function of characteristics of AC power in the AC power network;
• and
• c) a switch for selectively connecting said distributed generation AC power network to a load.

An uninterruptible power supply (UPS), comprising:

• a) a distributed generation AC power network having a plurality of controlled current sources for providing power, wherein said plurality of controlled current sources are connected together in parallel;
• b) a plurality of control systems for controlling operation of said controlled current sources, wherein each of said plurality of control systems (i) is capable of controlling at least one of said controlled current sources without the need for a centralized control system connected to said each control system and (ii) includes an impedance current regulator for generating an impedance current signal as a function of characteristics of AC power in the AC power network;
• and
• c) a switch for selectively connecting said distributed generation AC power network to a load.

An AC power network, comprising:

• a) a utility AC power grid;
• b) a distributed generation AC power network connected to said AC power grid, wherein said network includes:
• i) a plurality of controlled current sources for providing power, wherein said plurality of controlled current sources are connected together in parallel;
• ii) a plurality of control systems for controlling operation of said controlled current sources, wherein each of said plurality of control systems controls operation of at least one of said controlled current sources without the need for a separate control system connected thereto and (ii) includes an impedance current regulator for generating an impedance current signal as a function of characteristics of AC power in the AC power network.

An AC power network, comprising:

• a) an AC power grid;
• b) a distributed generation AC power network connected to said AC power grid, wherein said network includes:
• i) a plurality of controlled current sources for providing power, wherein said plurality of controlled current sources are connected together in parallel;
• ii) a plurality of control systems for controlling operation of said controlled current sources, wherein each of said plurality of control systems controls operation of at least one of said controlled current sources without the need for a centralized control system connected thereto and (ii) includes an impedance current regulator for generating an impedance current signal as a function of characteristics of AC power in the AC power network.

An energy storage system, comprising:

• a) a plurality of energy storage devices, each for providing power;
• b) a plurality of power converters connected in parallel, wherein each of said plurality of power converters is connected to at least one of said plurality of energy storage devices;
• and
• c) a plurality of control systems connected to said plurality of power converters for controlling operation of said plurality of power converters, wherein said plurality of control systems including an impedance current regulator for generating an impedance current signal as a function of characteristics of power provided by said plurality of energy storage devices, wherein said plurality of control systems controls operation of said plurality of power converters without the need for a separate control system connected thereto.

An energy storage system, comprising:

• a) a plurality of energy storage devices, each for providing power;
• b) a plurality of power converters connected in parallel, wherein each of said plurality of power converters is connected to at least one of said plurality of energy storage devices;
• and
• c) a plurality of control systems connected to said plurality of power converters for controlling operation of said plurality of power converters, each of said plurality of control systems including an impedance current regulator for generating an impedance current signal as a function of characteristics of power provided by said plurality of energy storage devices, wherein said plurality of control systems controls operation of said plurality of power converters without the need for a centralized control system connected thereto.

An AC power network connected to an AC power grid for providing power to a load on an uninterrupted basis when said load is disconnected from the grid, the AC power network comprising:

• a) a plurality of power converters connected in parallel;
• b) a plurality of control systems connected to said plurality of power converters for controlling operation of said plurality of power converters, each of said plurality of control systems including an impedance current regulator for generating an impedance current signal as a function of characteristics of AC power in the AC power network, wherein said plurality of control systems are not connected to a high-speed communication system that controls operation of said plurality of control systems;
• and
• c) a switch for selectively connecting the AC power network to the grid.