Multiport unified power quality conditioner (UPQC) applied to active power distribution network and method

Abstract

The invention discloses a multiport unified power quality conditioner (UPQC) applied to an active power distribution network and a method. A dynamic voltage restorer is arranged at a bus connection line for connecting adjacent buses; in multiple lines connected with the buses, the head end of each line is serially connected with a corresponding dynamic voltage restorer; each dynamic voltage restorer is in parallel connection with a DC link capacitor; one bus is connected with an active power filter, and the active power filter is connected with the dynamic voltage restorer for providing active power support for each dynamic voltage restorer; the dynamic voltage restorers at the lines comprehensively restore fall or temporary rise of voltage at each node; when transformers operate in a banked mode, output of the transformers is balanced via the dynamic voltage restorers at the bus connection lines; and the multiport unified power quality conditioner can be directly arranged inside a substation. The UPQC can effectively realize control on voltage deviation of each node of the line, power balancing when the transformers operate in a banked mode can be realized, and effective banked operation can be ensured.

Description

technical field [0001] The invention relates to the field of power grids, in particular to a multi-port unified power quality controller suitable for active distribution networks and a coordinated control method thereof. Background technique [0002] my country's long-distance distribution network transmission lines have long-term problems of excessive line loss and large user voltage deviation. In recent years, the penetration rate of distributed power in the distribution network has been increasing. Distributed power generation can effectively alleviate the problems of power supply shortage and excessive line loss in traditional distribution networks. The voltage amplitude of the traditional distribution network decreases along the power transmission direction, so the voltage deviation at the end is the most serious. However, the access of distributed power generation has changed the structure of the original distribution network, and there is a two-way power flow in the...

AI Technical Summary

Problems solved by technology

The researchers proposed to use the unified power flow controller to control the balance of transformer output, so as to avoid the serious inconsistency of the transformer output and even the occurrence of power reverse transmission during the parallel operation, resulting in the failure of the parallel supply

This method can effectively avoid the reverse power that occurs during the parallel supply operation, but it does not consider the excessive current of the bus connection caused by the change of the transformer output after the parallel supply operation, which will further cause the action of the corresponding relay protection device and cause the failure of the parallel supply operation

Images