Embodiments of this application provide a power system. An output terminal of a power supply or a DC-to-DC unit is cascaded. In addition, according to the power system provided in embodiments of this application, a quantity of cables from the power supply or the DC-to-DC unit to the DC-to-AC unit may be further reduced by cascading an output terminal of the power supply or the DC-to-DC unit and cascading an input of the DC-to-AC unit.

Disclosed herein are systems and methods for sliding mode control enabled hybrid energy storage. In a specific embodiment, the system can include: a photovoltaic power generation unit; a hybrid energy storage system, where the hybrid storage system can include a battery, a supercapacitor, where the supercapacitor provides excess power demand based on different loading conditions, and a rate limiter; a sliding mode controller, where the slide mode controller controls a current in a hybrid energy storage system; a supercapacitor charging control; and a proportional integral controller. In a specific embodiment, the method can include: decoupling an average and transient hybrid energy storage system current with a single rate limiter, where the decoupling includes a battery discharge rate; regulating a battery current with a first sliding mode controller; and regulating a supercapacitor current with a second sliding mode controller, where a supercapacitor provides excess power demand.

A distributed power system including multiple DC power sources and multiple power modules. The power modules include inputs coupled respectively to the DC power sources and outputs coupled in series to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the serial string to output power. A signaling mechanism between the inverter and the power module is adapted for controlling operation of the power modules.

The present disclosure provides systems and methods for flexible renewable energy power generation. The present disclosure also provides systems and methods for firming power generation from multiple renewable energy sources.

Provided is a system including: a management unit configured to manage a plurality of battery packs connected in parallel, in which the management unit is configured to control the plurality of battery packs to cause the plurality of battery packs to be discharged alternately so that a discharge rate of each of the plurality of battery packs becomes higher than the discharge rate in a case of discharging all of the plurality of battery packs. The plurality of battery packs include a plurality of left-hand side battery packs and a plurality of right-hand side battery packs, and the management unit is configured to manage the plurality of battery packs to cause at least one of the plurality of battery packs in each of the plurality of left-hand side battery packs and the plurality of right-hand side battery packs to be discharged at a time in order.

An inverter parallel system and a zero feed-in control method for the inverter parallel system are provided. The system includes at least one first inverter, at least one second inverter, a load, an electrical grid, a controller, and an electrical parameter measuring device. The controller includes a system control module, and the first inverter includes an inverter control module. The system control module is configured to determine a battery power reference value of an energy storage battery according to an electrical grid current reference value and an electrical grid current sampling value. The inverter control module is configured to control the first inverter, such that a feed-in current flowing into the electrical grid side is zero, and the second inverter operates in a maximum power point tracking state. Therefore, in the system, zero feed-in control may be achieved without energy management and without communication between inverters. Therefore, the need for installation of communication lines in the conventional wired communication is eliminated, system costs and installation difficulty are reduced, and the system can operate in the optimal state.

An embodiment converter includes a magnetic material, a first circuit including a first winding surrounding the magnetic material and a clamp circuit configured to reset a power conversion operation, the first circuit being configured to convert power received from a first input voltage source to provide the converted power to a load, and a second circuit including a second winding surrounding the magnetic material, the second circuit being configured to convert power received from a second input voltage source to provide the converted power to the load and to perform the power conversion operation being reset by the clamp circuit.

A wireless photovoltaic power system is provided. The wireless photovoltaic power system includes photovoltaic cell units that provide power. Each of the photovoltaic cell units include a photovoltaic cell. The wireless photovoltaic power system includes a first wireless power device that receives the power. The first wireless power device includes a coil that provides a magnetic field to wirelessly transfer the power to a second wireless power device. The first wireless power device provides a combinational implementation of a maximum power point tracking of the photovoltaic cell units and a power control of a load.

A control device (2) of an inverter converts electrical power generated by a solar cell (3) into alternating current power connecting to an electric power system (7). The control device includes: an alternating current voltage sensor (14) sensing a system voltage (Vr) of the electric power system; an MPPT executer (23) controlling a direct current voltage (Vdc) applied to the inverter (1) to cause the electrical power output from the solar cell (3) to be a maximum when the direct current voltage (Vdc) is higher than a lower limit (VL); a direct current voltage lower limit calculator 22 reducing the lower limit (VL) when the system voltage (Vr) is lower than a predetermined voltage; and an electrical power controller (25) controlling reactive power based on the system voltage (Vr), the reactive power being output from the inverter (1).

A grid connection power conversion device for connecting a distributed power supply to a three-phase commercial power system is provided. The power conversion device comprises an inverter, an instantaneous voltage detection circuitry to detect a maximum three-phase instantaneous voltage value of the commercial power system, a line voltage detection circuitry to detect a maximum value of each of three line voltages, an instantaneous voltage drop detection circuitry to detect an instantaneous voltage drop, and an output current control circuitry to control an output current value from the inverter. When the instantaneous voltage drop detection circuitry detects an instantaneous voltage drop, the output current control circuitry reduces the output current value from the inverter to an output current value corresponding to a minimum value among the four maximum voltage values which are the maximum three-phase instantaneous voltage value and the maximum values of the three line voltages.