UPFC reactive compensation method capable of reducing commutation failures

Abstract

The invention discloses a UPFC reactive compensation method capable of reducing commutation failures, comprising the steps of setting up a detailed power grid model; separately performing transient simulation under various typical faults, and respectively calculating an inversion side converter station blow-out angle and a converter station AC bus voltage; according to conditions which may cause commutation failures, determining the constraint limits of the blow-out angle and the converter station bus voltage, and a fault set of commutation failures which may be caused by a current power grid; increasing a parallel side compensation reference value, and determining whether the parallel side compensation reference value exceeds an adjusting limit; and determining a new fault set, determining whether the fault set is empty, and finally obtaining a UPFC reactive compensation scheme applied to an actual power grid. The method performs simulation control on a current power grid to determine an appropriate UPFC compensation scheme, and can cover various faults, and reduce the AC power grid fault influence to extra-high voltage direct current, and fault lines which may cause commutation failures, thereby improving extra-high voltage DC access power grid safety and stability.

Description

technical field [0001] The invention relates to the technical field of power system control, in particular to a reactive power compensation method for a unified power flow controller that reduces commutation failures. Background technique [0002] Commutation failure is one of the common faults in HVDC transmission systems. When the commutation between the two bridge arms is over, if the valve that has just exited conduction fails to recover its blocking capability during a period of time under the action of reverse voltage, Or the commutation process has not been completed during the reverse voltage, and the commutated valve will reverse the phase to the valve that was originally scheduled to withdraw from conduction when the valve voltage changes to positive, which is called commutation failure. The failure of commutation will lead to the decrease of DC voltage and the increase of DC current. If the control measures are not taken properly, it will also cause continuous com...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is: by simulating the current power grid, determine a suitable scheme for using a unified power flow controller (UPFC) as a reactive power compensation device to reduce commutation failure, and then apply it to the actual power grid to increase the system The short-circuit ratio reduces the sensitivity of the system to faults, solves the problem of the weak receiving-end grid's ability to resist external faults, can be applied to the control of various fault situations in the system, and reduces the complexity of control during faults, and the cost is low

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