Method for screening sub-synchronous resonance risk based on series compensation effect coefficients

Abstract

The invention discloses a method for screening a sub-synchronous resonance risk based on series compensation effect coefficients in the technical field of electric power system operation and control. The method comprises the steps that (1) according to a multi-machine alternating current system with a series compensation alternating current line, all electric generators are equivalent to a series branch of a power source and an inductor; (2) according to the well equivalent multi-machine alternating current system in the step (1), an instant three-phase short circuit ground fault is triggered on the series compensation alternating current line, and when the multi-machine alternating current system recovers the steady state, CIF values of series compensation effect coefficients of the electric generators are calculated; (3) if the CIF value of the series compensation effect coefficient of one electric generator is larger than or equal to a TCIF value, the sub-synchronous resonance risk exists in the electric generator; if the CIF value of the series compensation effect coefficient of the electric generator is smaller than the TCIF value, the sub-synchronous resonance risk does not exist in the electric generator. According to the method, the calculated amount is small, the amount of information required for calculation is small, and the electric generator with the sub-synchronous resonance risk can be effectively and accurately judged.

Description

technical field [0001] The invention belongs to the technical field of power system operation and control, and in particular relates to a subsynchronous resonance risk screening method based on a series compensation action coefficient. Background technique [0002] Series capacitor compensation technology is widely used in AC transmission systems because it is a fast, effective, low-cost and relatively safe method to increase system steady-state and transient stability. In power grids in Northwest China, Inner Mongolia, and Northeast my country, the topological structure in which generator sets are connected to the main grid through series-compensated AC lines is very common. However, the LC resonant circuit formed between the series compensation capacitor (C) and the line inductance (L) will amplify the disturbance signal at the subsynchronous frequency, and when the disturbance signal is transmitted to the generator end, it will excite the The relative torsional vibration...

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Problems solved by technology

Due to the above two conditions, the following two consequences will be caused: 1) In the stage of grid planning, the detailed parameters of the generator and its shafting module are not known, and in more cases, only the approximate capacity and voltage level of the generator are known , then it will be difficult to apply the frequency scanning method for screening; 2) In a multi-generator system, the workload of repeating equivalent work is very heavy

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