Thyristor soft switch switching circuit of static reactive power compensator and control method

Abstract

The invention relates to a thyristor soft switch switching circuit of a static reactive power compensator and a control method. The thyristor soft switch switching circuit comprises a power grid, a thyristor control reactor TCR, a thyristor switching capacitor TSC and a control circuit, wherein the thyristor control reactor TCR and the thyristor switching capacitor TSC are connected in parallel and are then accessed to the power grid, and the control circuit comprises a phase detection module, a reactive detection and control amount calculation module, signal generators 1# and 2# and driving circuits 1-4. According to the thyristor soft switch switching circuit, thyristor TC and TL control on the TSC and the TCR is realized respectively through taking a power grid voltage phase as reference, and a period and a phase for TC and TL conduction triggering are determined according to magnitude of target control amount. The thyristor soft switch switching circuit does not includes an energy consumption resistor, a bridge diode rectification unit is additionally arranged, only one thyristor is employed for the TSC or the TCR, and bidirectional electric energy control can be realized.

Description

technical field [0001] The invention relates to the field of reactive power control of a grid, in particular to a thyristor soft switch switching circuit and a control method of a static reactive power compensator. Background technique [0002] Reactive power compensation is the main way to control the reactive power balance of the power grid, and it is also the key to ensure the safe, stable and reliable operation of the power grid. Static Var Compensator (SVC) is the most widely used reactive power compensation equipment in the current power grid. It includes Thyristor Controlled Reactor (TCR) and Thyristor Switched Reactor (TSC). The former plays the role of continuously adjusting inductive reactive power. , the latter provides discrete capacitive reactive power, and the combination of the two can realize continuous reactive power control. [0003] In the power system, SVC is generally installed in the converter station, the secondary side of the transformer, etc., and t...

AI Technical Summary

Problems solved by technology

[0003] In the power system, SVC is generally installed in converter stations, secondary sides of transformers, etc., and the working voltage level and current capacity are large. For the semiconductor switch-thyristor, too high voltage is likely to cause the switch to turn on momentarily. Excessive current impact will also cause voltage impact at the moment the switch is turned off. Voltage or current overshoot is extremely detrimental to the safe operation of the thyristor, which will lead to frequent accidents and serious economic losses.

In addition, the self-turn-off process of the thyristor needs to experience a long forward and reverse blocking time, which is prone to large turn-off loss and may lead to turn-off failure

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