Coordinated control method for low-voltage current-limiting link of multi-circuit direct-current system

Abstract

The invention discloses a coordinated control method for a low-voltage current-limiting link of a multi-circuit direct-current system, and relates to the technical field of power system control, and the method comprises the steps: firstly, comprehensively considering two factors of active power and reactive power, and evaluating the influence degree of each circuit direct-current system on an alternating-current and direct-current hybrid power grid; secondly, calculating reactive voltage sensitivity among converter stations of each direct current system; and finally, determining a control strategy and related parameters of the low-voltage current-limiting link coordination control method based on the calculation result. The reactive interaction influence among the multi-circuit direct current systems is considered, the risk of commutation failure caused by reactive interaction can be effectively reduced, and thus coordination recovery of the multi-circuit direct current systems is promoted.

Description

technical field [0001] The invention belongs to the technical field of power system control, and in particular relates to a coordinated control method for a low-voltage current-limiting link of a multi-circuit direct current system. Background technique [0002] my country's energy center and load center of gravity present the characteristics of reverse geographical distribution. In order to effectively solve the problem of cross-regional energy transmission, the high-voltage direct current transmission system based on grid-commutated converters has been obtained due to its advantages in large-capacity long-distance transmission. a wide range of applications. Multiple direct currents are densely connected to the same AC grid, forming a much more complex multi-infeed system, which poses new challenges to the safe and stable operation of the power system. Commutation failure is one of the most common faults in DC transmission systems. Single commutation failure and continuous ...

AI Technical Summary

Problems solved by technology

Multiple DCs are intensively connected to the same AC grid, forming a much more complex multi-infeed system, which poses new challenges to the safe and stable operation of the power system

Commutation failure is one of the most common faults in DC transmission systems. Single commutation failure and continuous commutation failure will have adverse effects on DC line power transmission, reactive voltage stability, transient stability, etc.

In the multi-infeed DC system, due to the complex reactive power interaction among the various DC systems, the transient characteristics during the DC restoration process of this circuit will affect the recovery of other DC systems and even cause additional commutation failures.

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