Active Distribution Network Distributed Generation and Active Filter Coordinated Control System

Abstract

The invention relates to a distributed generation (DG) of an active power distribution network and a coordinate control system of an active power filter (APF). The control system divides the active power distribution network into multiple regional power grids. A DG is at least included in each regional power grid. APFs are installed at points of common coupling (PCC) of the regional power grids. Each DG and each APF control output through respective grid-connection inverter local control strategy. The control system comprises a DG and APF grid-connection end local controller, a DG source net composite controller and a regional device coordinate controller. According to invention, GD grid-connection end rest capacity can be fully used; electric power quality at the PCC is improved, so investment cost of an electric power quality compensation device is reduced; the DGs and the APFs in the regions are coordinately controlled; interference to the electric power quality at the grid-connection points by the harmonic compensation current of the DGs is reduced; overall electric power quality level of each node in the active power distribution network is improved; and the distributed generation and the coordinate control system have the excellent engineering application prospect.

Description

technical field [0001] The invention relates to a control system, in particular to a coordinated control system of a distributed power supply of an active distribution network and an active filter, and belongs to the technical field of power quality. Background technique [0002] In recent years, with the use of nonlinear loads such as power electronic devices and distributed generation systems connected to the distribution network, the harmonic content of the grid current has increased sharply. Power quality problems. Larger harmonic currents will directly threaten the operation safety of distribution network transformers. Among the existing technical means, APF technology is an effective means to control the harmonic pollution of the power grid, but limited by the construction and maintenance costs, it is difficult to connect a large number of APF devices in the distribution network. At the same time, considering that DG and APF have similar forms of grid-connected inver...

AI Technical Summary

Problems solved by technology

[0004] The existing composite control strategy involving DG grid-connected power generation and power quality management can make full use of the DG power electronic interface capacity to realize compensation for the power quality of key nodes in the system, but the harmonic compensation current output by DG will interfere with its grid connection point poor power quality, worsen the working condition of other equipment at the DG parallel point, and reduce the service life of the equipment

At the same time, due to the fluctuation of the output power of the DG, it is impossible to ensure sufficient remaining capacity for the compensation of the power quality of key nodes at all times. It needs to cooperate with APF to improve the power quality of each node in the active distribution network.

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