Commutation failure suppression method for high-voltage direct-current power transmission system based on energy storage type chain STATCOM

Abstract

The invention discloses a commutation failure suppression method for a high-voltage direct-current power transmission system based on an energy storage type chain STATCOM. The power transmission system comprises a sending-end power grid; the sending-end power grid is connected with the receiving-end power grid through a direct-current power transmission line; and the energy storage type chain STATCOM is connected in parallel with an alternating current bus of a receiving end power grid. The energy storage type chain STATCOM device is adopted, the energy storage technology and the reactive compensation technology are combined, and when a receiving end alternating-current power grid breaks down, an effective supporting effect can be provided for receiving end bus voltage of a high-voltage direct-current power transmission system, the commutation failure probability of an HVDC system is reduced, and the operation stability of an alternating-current and direct-current system is improved; damping of an interconnection system can be remarkably enhanced, power oscillation is suppressed, and power recovery of a direct-current power transmission system after a fault is promoted.

Description

technical field [0001] The invention relates to a direct current transmission system, in particular to a method for suppressing commutation failure of a high voltage direct current transmission system based on an energy storage type chain STATCOM. Background technique [0002] Commutation failure, as the most typical system failure of direct current transmission system (HVDC), has become one of the major problems facing the development of high voltage direct current transmission system. The short-circuit fault of the receiving-end AC system near the DC landing point will cause the bus voltage drop of the high-voltage DC inverter station. If the fault is not cleared in time, it may cause commutation failure in the DC transmission system. In addition, once the high-voltage DC system fails and causes a blockage, it will cause an instantaneous shortage of the power supply of the receiving-end grid, which will have a great impact on the power balance and normal power supply of th...

AI Technical Summary

Problems solved by technology

[0008] The present invention uses the energy storage type chained STATCOM in the high-voltage direct current transmission system, which can avoid the serious double frequency fluctuation of the capacitor voltage of the STATCOM sub-module caused by the excessive reactive power output, and the complex voltage equalization control strategy of the cascaded unit capacitors. The support effect of compensating reactive power grid voltage is limited, and it has more advantages in maintaining bus steady-state voltage, suppressing voltage sag level, damping power oscillation and suppressing phase jump

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