Huawei Digital Power Technologies Co., Ltd.

Delta Electronics (shanghai) Co., Ltd

Mingxuan Dong

Li Chen

Kai Xin

Changyong Wang

Aibin Qiu

Yunfeng Liu

Yan Chen

Mingquan Zhao

Wenchao Li

Shuo Wang

Chaowei Guo

Meiqing Zhang

Jiuyang Zhou

This application provides an inverter, a power grid power supply system, and a method for controlling an excitation inrush current. The controller adjusts the output voltage of the conversion circuit based on a first phase that is of the output voltage of the conversion circuit and that is during reduction of the output voltage, the magnetic flux of the iron core in the transformer, an output voltage that is of the conversion circuit and that is after the output voltage is reduced, and the target voltage value, so as to increase the output voltage of the conversion circuit and keep the magnetic flux of the iron core less than the saturation magnetic flux.

Inverter, power grid power supply system, and method for controlling excitation inrush current

This application discloses examples of an energy storage system, a power conversion system, and a method for optimizing primary frequency modulation. In one example, when the power conversion system determines that a state of charge (SoC) value of a target energy storage battery does not meet a target SoC value and determines that a present frequency of a power grid falls within a frequency modulation constant band, the power conversion system determines, based on a preset mapping relationship between a SoC value and an active power, a first specified active power value corresponding to the SoC value of the target energy storage battery, and controls, based on the first specified active power value, the target energy storage battery to be charged or discharged, so that the SoC value of the target energy storage battery can reach the target SoC value.

Energy storage system, power conversion system, and method for optimizing primary frequency modulation

A method includes: performing one or more adjustments on a filter parameter based on battery information of the ESS that is at a first control moment, and performing one or more times of power filtering by the filter, until a power fluctuation rate determined based on a power obtained through filtering is less than or equal to a preset threshold; and determining, based on the power obtained through filtering, a given power of the ESS that is at the first control moment. During smooth control of a power, a relationship is established between battery information and a filter characteristic, so as to prevent a battery from quickly reaching a fully charged state or a fully discharged state.

Power control method and apparatus, and energy system

An energy storage system includes at least two power conversion systems PCSs, output terminals of the at least two PCSs are connected in parallel to connect to an alternating current power grid, and input terminals of the at least two PCSs are connected to an energy storage power supply. The first PCS is any one of the at least two PCSs. The voltage detection circuit detects a power grid voltage at a parallel connection point of the output terminals of the at least two PCSs. When determining, based on the power grid voltage at the parallel connection point, that islanding occurs in the alternating current power grid, the controller adjusts an angle of an output voltage of the first PCS to a reference angle, so that angles of output voltages of the at least two PCSs are the same.

Energy storage system, on/off-grid switching method, and power conversion system

The application relates to battery internal resistance detection device and method for power conversion device. The detection device includes a data acquisition module for acquiring a battery voltage and a battery current to obtain a DC voltage, an AC voltage, a DC current and an AC current, a first calculation module for receiving the AC current and the AC voltage at a certain instant to output a first internal resistance value and a battery capacitance, a second calculation module for receiving a plurality of DC currents and a plurality of DC voltages at multiple instants and the battery capacitance to output a second internal resistance value, and a selection module for receiving the first and second internal resistance value and selecting one of the first and second internal resistance value as battery internal resistance value. The application improves detection accuracy of battery internal resistance by combining DC and AC algorithms.

Battery internal resistance detection device and method

The present disclosure provides a power supply system method for an AC load. The system includes a power supply device and a DC/AC converter. An AC side of the DC/AC converter is coupled to an AC grid and the AC load through an AC bus. The power supply device outputs DC electric energy and is coupled to a DC side of the DC/AC converter through a DC bus. The power supply device includes an energy storage circuit and a controller. The energy storage circuit includes a first energy storage circuitry and a second energy storage circuitry. The controller is configured to control a conversion operation of the first energy storage circuitry to output a low-frequency power to the DC bus, and a conversion operation of the second energy storage circuitry to output a high-frequency power to the DC bus.

Power supply system and method for alternating current load

The present application provides a method of controlling an electrical power system and an apparatus using the same. The electrical power system includes a DC bus and a DC bus capacitor connected to the DC bus. The method includes: receiving a virtual DC bus capacitance value of the DC bus capacitor; detecting a DC bus voltage; calculating an expected value of a DC bus current based on the virtual DC bus capacitance value and the DC bus voltage; and adjusting the DC bus current, so that the DC bus current reaches the expected value and thus the DC bus capacitor is equivalent to the virtual DC bus capacitance value.

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Shanghai, China

Mingxuan Dong