State Grid Jiangsu Power Co., LTD. 500 kV Wujiang static synchronous compensator (STATCOM) access system function test completed (72 hours of trial operation ended), the world's largest capacity of IGBT-based dynamic reactive power compensation device officially put into operation.

In recent years, the economic development of southern Jiangsu is rapid, and its electricity demand is mainly met by 500 kV AC lines and ±800 kV DC outside the area, and the AC/DC channel load is heavy, and once the power grid failure is easy to cause huge reactive power loss, it will not be able to support the stability of the system.

"Grid voltage is like human blood pressure, too high or too low will affect the normal operation of the system, and even destroy the health of the equipment." The reactive power in the system is an important factor affecting the voltage, and an efficient and stable reactive power compensation device can reliably control the 'blood pressure' of the grid." Shaojianwei, head of the Wujiang change team, introduced.

IGBT (Insulated Gate BipolarTransistor) is an insulated gate bipolar transistor, which is the core device of energy conversion and transmission, commonly known as the "CPU" of power electronics. It is reported that the IGBt-based STATCOM device is the latest technical representative of reactive power compensation, which can quickly respond to dynamic reactive power by judging system faults, and then maintain the system voltage level. It can play a significant role in preventing the system voltage collapse, improving the system voltage stability and improving the power quality of the grid.

Previously, STATCOM devices in other provinces in China only participated in reactive power coordination control in substations. State Grid Jiangsu Power for the first time connected Wujiang STATCOM to the automatic dispatching voltage control system for control, and studied and formulated the operation control strategy and dispatching operation procedures of Wujiang STATCOM. The effect of reverse regulation between STATCOM and fixed capacitor reactor is reduced, and the optimal control of reactive voltage is realized.

The project was approved to start on November 28, 2017, and three sets of STATCOM with ±100 meV were installed in the 220 kilovolt equipment area of the 500 kilovolt Wujiang Substation, with a total capacity of 300 meV and a maximum output capacity of 450 mev under fault condition. The smooth start-up of the STATCOM device will provide fast reactive power control for the southern Suzhou power grid, which is an important remedy for voltage collapse caused by system overload or major accidents.

"The total capacity of the STATCOM device started this time is second to none in China and is in the world's leading level. Compared with traditional reactive power compensation devices, it has a wider voltage regulation range and faster compensation speed." Gao Lei, deputy director of the power grid technology center of Jiangsu Electric Science and Technology Institute, said that this power grid system innovation technology will become a tool to stabilize the Jiangsu regional power grid.