Control method of quality control system of micro source internetworking electric energy

Abstract

The invention discloses a control method for a quality control system of micro source internetworking electric energy. A primary side of the coupling voltage transformer on a serial active power filter side of a UPQC (unified power quality controller) is connected with a larger current-limiting inductor in parallel, and a direct-current large-capacitance side of the UPQC is connected with a photovoltaic generating power supply in parallel. Due to effects of cooperative control, the photovoltaic power supply is internetworked for power generation during normal operation, active power is provided for a power grid by the parallel active power filter of the UPQC, and the harmonic current from a load side and the voltage fluctuation and harmonic voltage from the power grid side are governed and compensated by the UPQC. In the case of short-circuiting failure on the load side, the main circuit of the UPQC stops operating, a secondary side of the coupling voltage transformer is subjected to high impedance, and the current can be limited by the parallel current-limiting large inductor. By adopting the method, the functions of failure current limitation, harmonic treatment, voltage support, photovoltaic power generation and the like can be realized during micro grid internetworking operation, and the optimized protection and operation of the quality of electric energy in micro grid internetworking can also be realized.

Description

technical field [0001] The invention relates to an intelligent distribution network micro-source grid-connected and power quality control multi-converter system and a control method thereof. Background technique [0002] Microgrid is a distributed micro-grid technology based on renewable energy, which has attracted more and more attention in recent years. However, when the microgrid is connected to the grid, due to the intermittent and unstable micro-sources and the use of a large number of power electronics, the power quality indicators inside the microgrid and at the access point of the distribution network are poor. At the same time, when a large number of distributed power sources are put into use, it will bring many power quality problems. This will cause great harm to some equipment that requires high power supply quality, and will also have a bad impact on the power quality of the large power grid. In order to solve this problem, there are higher requirements for po...

AI Technical Summary

Problems solved by technology

[0005] Existing power quality control devices, short-circuit current limiting devices, and photovoltaic power generation devices cannot take into account power quality control, fault current limiting, and photovoltaic power generation, which increases the cost of microgrid construction

At the same time, when the solid-state current limiter is in normal operation, the T1-T8 tubes and DC inductors have current flowing for a long time, resulting in long-term loss and waste of resources.

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