Circulation power theory-based distributed parallel control method applied to miniature power grid system island mode

Abstract

The present invention provides a circulation power theory-based distributed parallel control method applied to a miniature power grid system island mode. The method is characterized in that a distributed power generation and energy storage unit in a miniature power grid system is connected with an AC bus via an inverter and operates in a parallel mode in the island mode, and by taking a communication network as the basis in a parallel operation mode, the controllers of the inverter units in the miniature power grid system form a whole control system. According to the method of the present invention, the circulation active power and the circulation reactive power of an inverter parallel system in the parallel operation mode of the miniature power grid system can be restrained effectively, the situation that the parallel system has the optimal dynamic performance and transient response capability is guaranteed, the reliability of the system is improved, at the same time, the steady-state errors of the frequencies and the amplitudes of the output voltages of the inverter units are eliminated, and the inverter units share the public load power evenly according to the occupied proportions of the respective power capacities of the inverter units in the parallel system, so that the method has a very strong practicality.

Description

technical field [0001] The invention relates to a distributed parallel control method based on circulation power theory and realized by using a communication network in the island mode of a micro-grid system, and relates to the island mode operation of the micro-grid system and the parallel connection of multiple distributed power generation units and energy storage units The working mode, especially in the micro-grid system composed of new energy sources such as solar energy and wind energy, belongs to the field of new energy. The invention also relates to the parallel operation mode of a plurality of inverter units (such as UPS, etc.), and belongs to the application field of inverter power supplies. technical background [0002] As the prices of fossil fuels such as oil and coal continue to rise, countries around the world are taking various measures to deal with the challenges brought about by the energy crisis. At present, the whole world is actively promoting the const...

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Problems solved by technology

[0010] (3) Always start with E * As a benchmark, due to the individual differences of each inverter unit, there is a fixed amplitude error between the inverter output voltages, resulting in the E-Q control cannot completely eliminate the inverter circulating reactive power

[0011] (4) When each inverter unit shares the common load power according to different proportions, the performance of the traditional droop control method to suppress the circulating current will drop sharply, so it has great limitations in the application of the microgrid island mode

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