Reactive power control method and device of direct-current transmission layering connecting system

Abstract

The invention discloses a reactive power control method and device of a direct-current transmission layering connecting system. The reactive power control method comprises the steps that two or more relatively independent reactive power control functions are configured for two or more relatively independent alternating-current power grids at a direct-current transmitting end or receiving end, so that control over the voltage of an alternating-current bus of a power grid or reactive power exchange on an alternating-current system side is achieved; one or more power grid reactive power coordination control modules are configured for the portions, needing coordination, of the two or more alternating-current power grids, and coordination control is conducted on the situation that an absolutely minimum filter of each power grid cannot fulfill the starting power fall-back function, the voltage control function and the valve set trigger angle instant increase function; after coordination control processing is accomplished, a pole / double-pole power fall-back instruction value is generated to be sent to a pole / double-pole power control module, a Gamma angle increment value is generated to be sent to a valve set control module, and filter switching instructions are generated to be sent to filter switching control modules of the two alternating-current power grids. The reactive power control method and device of the direct-current transmission layering connecting system are applicable to reactive power control of the direct-current transmission layering connecting system under different operating conditions.

Description

technical field [0001] The invention belongs to the field of high-voltage / ultra-high voltage direct current transmission control, and in particular relates to a reactive power control method and device for a layered access system of direct current transmission. Background technique [0002] HV / UHVDC hierarchical access systems are divided into series type and parallel type, among which the series type is as follows: figure 1 As shown, the high-pressure valve group is connected to the 500kV AC grid, and the low-voltage valve group is connected to the 1000kV AC grid. [0003] There is only one power grid on the AC side of the conventional UHV DC sending end or receiving end, and the control system is equipped with only one reactive power control module, and the reactive power control is only controlled for the AC filter field of one power grid. [0004] For the UHV DC layered access system, the AC side of the sending end or the receiving end may be connected to two or more AC...

AI Technical Summary

Problems solved by technology

The conventional DC reactive power control method only controls the AC filter field of one power grid, and does not have the ability to coordinate the control of two or more power grid AC filters.

[0006] In the past, the unified reactive power control method of the conventional UHV DC receiving end is no longer applicable to the hierarchical access system, so it is necessary to design a new reactive power control method and device suitable for the hierarchical access system

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