A DC voltage control method and control system of a flexible ring network controller

Abstract

The invention relates to an active power control method of a flexible ring network controller and a control system thereof. The method comprises the steps that: a constant DC voltage side generates a DC voltage reference value Udcref; the DC voltage reference value Udcref is generated into an active current reference value of idref-opp after a DC voltage controller PI link; the active current reference value of idref-opp is transmitted by a communication optical fiber to a constant active power side convertor station; the constant active power side convertor station generates an active power reference signal Pref; the constant active power side convertor station receives the active current reference value of idref-opp and transmits the same into an active power controller to serve as an additional control signal; and the constant active power side convertor station generates a positive sequence d axis current reference value id*. According to the active power control method in the technical scheme provided by the invention, the DC voltage signal of a constant DC voltage side convertor station is generated into the additional signal of the active power controller of a constant power control side convertor station via inter-station communication, and the transmission active power of the flexible ring network controller is quickly regulated by the coordination control of the convertor stations of both ends.

Description

technical field [0001] The invention relates to a control strategy of a flexible ring network controller, in particular to a DC voltage control method and a control system of a flexible ring network controller. Background technique [0002] The flexible ring network controller is back-to-back flexible DC, and its control system has a symmetrical structure. Commonly used outer loop controllers include: constant DC voltage control, constant active power control, constant reactive power control, constant AC voltage control, etc. Constant DC voltage control is very important. For the flexible ring network controller system, one end must adopt constant DC voltage control to balance the active power of the flexible ring network controller system and maintain the stability of the DC side voltage. When the active power of the AC systems on both sides of the flexible ring network controller is unbalanced, it will cause fluctuations in the DC voltage. At this time, the active current ...

AI Technical Summary

Problems solved by technology

[0003] When the flexible ring network controller needs to increase or decrease the DC voltage in a short period of time due to changes in operating conditions, when the command value of the DC voltage changes suddenly, the original control strategy only relies on the converter station on the side of the constant DC voltage to adjust the DC voltage , there is a certain time delay in the response of the DC voltage change, and there are disadvantages

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