Multi-infeed direct current transmission system commutation failure control method

Abstract

The invention discloses a commutation failure control method for a multi-infeed direct-current power transmission system. The method comprises the following steps: calculating commutation bus voltage of an adjacent direct-current power transmission system under a fault; calculating a direct current reference value for ensuring that the target direct current power transmission system does not generate subsequent commutation failure; judging whether successive commutation failure occurs in the adjacent direct-current power transmission systems or not; and establishing a target direct-current power transmission system inverter station controllable domain for avoiding successive commutation failure of adjacent direct-current power transmission systems so as to adjust a direct-current instruction value and an advanced trigger angle adjusting quantity to implement control. According to the method, the interaction influence of the subsequent commutation failure and the successive commutation failure is considered, and the subsequent commutation failure of the target DC power transmission system can be effectively inhibited and the successive commutation failure of the target DC power transmission system can be avoided through the coordination control between the DC current instruction value and the lead trigger angle.

Description

technical field [0001] The invention relates to the field of power system protection and control, in particular to a commutation failure control method for a multi-feed direct current transmission system. Background technique [0002] With the continuous promotion of high-voltage direct current transmission technology in China, the current-source high-voltage direct current transmission technology based on grid commutation has become an important technical means of power transmission due to its advantages of large capacity and good economy. East China Power Grid and Southern Power Grid have formed A typical multi-DC infeed grid pattern. The failure of the AC system of the receiving end power grid may affect the multi-circuit DC system at the same time, causing the commutation failure of multiple DC circuits at the same time, thus affecting the stability of the power grid. [0003] After commutation failure in the inverter station, under the continuous action of the DC contr...

AI Technical Summary

Problems solved by technology

The failure of the AC system of the receiving end power grid may affect the multi-circuit DC system at the same time, causing the commutation failure of multiple DC circuits at the same time, thus affecting the stability of the power grid

[0003] After commutation failure in the inverter station, under the continuous action of the DC controller, the reactive power consumption of the inverter station will increase. At this time, the inverter station of the DC transmission system will absorb more reactive power from the AC system at the receiving end. It is not conducive to the recovery of the first commutation failure, and there is a risk of causing subsequent commutation failures in the inverter station; at the same time, due to the tight coupling between multiple DC drop points, if the adjacent DC absorbs too much reactive power, the affected Therefore, there is a risk of causing successive commutation failures of adjacent DC

Existing research mainly focuses on changing the DC current command value I d-ord Or increase the leading firing angle β ord The setting value is used to reduce the risk of commutation failure, but the coordinated control between different control variables is not considered. While suppressing the subsequent commutation failure, its controller response may affect the adjacent DC transmission system through reactive power and voltage coupling. , causing successive commutation failures of other DC inverter stations

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