Active commutation hybrid converter topological structure and control method thereof

Abstract

The invention discloses an active commutation hybrid converter topological structure and a control method thereof. The active commutation hybrid converter topological structure comprises a three-phase six-bridge arm circuit, an upper bridge arm auxiliary valve, a lower bridge arm auxiliary valve, a controllable switch module and a selection unit, wherein each phase of bridge arm circuit of the three-phase six-bridge arm circuit comprises an upper bridge arm and a lower bridge arm, and the upper bridge arm or the lower bridge arm is provided with a thyristor valve; the first end of the upper bridge arm auxiliary valve is connected with the cathode end of the thyristor valve of each phase of each upper bridge arm; the first end of the lower bridge arm auxiliary valve is connected with the anode end of the thyristor valve of each phase of each lower bridge arm; the first end of the controllable switch module is connected with the second end of the upper bridge arm auxiliary valve and the second end of the lower bridge arm auxiliary valve; the selection unit comprises two connecting ends and at least two selection ends, and the connecting ends are connected with the second end of the controllable switch module; and the first selection end is connected with the anode end of the thyristor valve of each upper bridge arm, and the second selection end is connected with the cathode end of the thyristor valve of each lower bridge arm. By implementing the active commutation hybrid converter topological structure and the control method, the occurrence of commutation failure is avoided, and the stability and safety of power grid operation are ensured.

Description

technical field [0001] The invention relates to the technical field of commutation in power electronics, in particular to an active phase commutation hybrid converter topology and a control method thereof. Background technique [0002] The traditional line commutated converter high voltage direct current (LCC-HVDC) transmission system has the advantages of long-distance large-capacity transmission and controllable active power, and is widely used in the world. As the core equipment of DC power transmission, the converter is the core functional unit to realize the conversion of AC and DC power, and its operation reliability largely determines the operation reliability of the UHV DC grid. [0003] Since traditional converters mostly use semi-controlled device thyristors as the core components to form a six-pulse bridge commutation topology, each bridge arm is composed of multi-level thyristors and their buffer components connected in series. Commutation failures are prone to ...

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Problems solved by technology

[0004] In view of this, the embodiment of the present invention provides a hybrid converter topology with active commutation and its control method to solve the problem that commutation failure affects the stable and safe operation of the power grid

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