Systems/methods for controlling residential renewable energy systems, such as a home solar and storage power system, resolve or avoid overloading that could arise as a result of new loads/sources in the home or existing loads drawing too much power. The systems/methods provide a power control…
A system and method includes suppling power to a utility grid with a plurality of fuel cell power plants, storing power generated by the plurality of fuel cell power plants with an energy storage system including one or more batteries, and maintaining a standby state-of-charge of the one or more…
A power distribution system includes a macrogrid controller configured to control one or more first loads associated with a macrogrid, wherein the one or more first loads include a microgrid comprising one or more second loads and a plurality of energy resource systems; and a microgrid controller…
A grid-forming photovoltaic (PV) system and method for both islanded connection and grid-connected mode is provided. An inverter converts PV array voltage to a voltage usable as a power source to an electric power system load. Active power-frequency droop controller regulates a modulator that…
Disclosed is a method for controlling battery charging/discharging current in an off-grid mode of a hybrid energy storage inverter that is based on photovoltaic and a lithium battery. If photovoltaic energy is sufficient and a battery is not fully charged, the photovoltaic energy is supplied to a…
Systems and methods for microgrid-power distribution management when distributed energy resources transition between operating modes. The system includes a fuel cell system that generates DC power and a multi-mode inverter system that operates in one of the operating modes based on an availability…
An energy storage converter, a control method and device for the energy storage converter, and a computer readable storage medium are provided. The control method includes: obtaining an operation state of a power grid; under the condition that the power grid operates in a normal state, controlling…
The disclosure is directed to an island network detection method using a voltage-impressing converter, and includes determining the frequency and phase of a voltage curve of a sub-network connected to a network connection point of the converter, and generating a voltage curve using a bridge circuit…
A power converter includes a power conversion circuit, a relay, and a controller. The power conversion circuit can be configured to implement conversion from a direct current to an alternating current. The relay can be configured to implement on-grid and off-grid switching. The controller can be…
A method for preventing unintentional islanding of loop networks when a distributed power source is providing power to the network when network power is lost. The method includes detecting loss of voltage to the network, opening the source side switching device in the transformers nearest both ends…
A system and a method for connecting electrical load(s) to a first power source and a second power source including a switching device and a controller. The switching device includes a first semiconductor device pair and a second semiconductor device pair. The controller configured to receive a…
A power supply system includes at least one group of power supply modules. The power supply module includes a first string, a first residual current detection circuit, an inverter circuit, and a first controller. The first residual current detection circuit is connected between the first string and…
A system and a method for connecting electrical load(s) to a first power source and a second power source including a switching device and a controller. The switching device includes a first semiconductor device pair and a second semiconductor device pair. The controller configured to receive a…
A universal control (UniCon) scheme for grid-connected converters is presented herein that allows operation automatically in grid-following, grid-firming, and grid-forming modes. The converter does not need information on the grid or connected sources and loads. The converter can set its own…
The present invention relates to a photovoltaic power generation system comprising: a plurality of PV modules; and a plurality of power generation efficiency optimization units, which are installed to correspond to the respective plurality of PV modules one-to-one, and include inverters to convert…
An electrical distribution system is configured to supply electric power to an electric load and includes a feeder, a battery energy storage system, an electrical switchgear device and an electronic controller. The switchgear device is configured to selectively connect the connection point to the…
The present application relates to a method for seamless switching between off-grid and grid-connected including: in a grid-connected state, when a host determines that utility power is abnormal, a grid-connected working mode is closed, a phase-locked source of the host is switched from the utility…
Unintentional islanding (UI) of a circuit of distributed energy resources (DERs) may leave area electrical power systems (EPS), external to the DER circuit, energized. Thus, UI detection methods have been developed to detect unintentional islanding and trigger a UI response. However, individual UI…
An islanding detection method includes: an alternating current frequency of an inverter is monitored. The alternating current frequency fluctuates within a preset range when in a normal mode. When an instantaneous shifting value of the alternating current frequency exceeds the preset range, a…
Disclosed are an on-grid/off-grid scheduling method and apparatus, and an energy storage power supply system. The method is applied to the system. The system includes an energy storage device; the energy storage device is connected to a direct current bus; one end of the direct current bus is…
A method, an apparatus, and a system for monitoring an islanding electricity generation unit are provided. The method includes determining an islanding electricity generation unit in a renewable energy station on the basis of collected electrical capacity at critical electrical nodes of the…
For the purpose of obtaining a power conversion apparatus of a three-level inverter system that can reduce a withstand voltage of an isolation transformer for a semiconductor driving circuit and secure long-term reliability under a situation in which a conversion target power supply voltage reaches…