Steady-state testing device and steady-state testing method for modularized multi-level converter valves

Abstract

The invention provides a steady-state testing device and a steady-state testing method for modularized multi-level converter valves. The device comprises a load electric reactor, a sample valve, an auxiliary valve, a water cooler, a direct-current power supply, a controller and a protection device. Current alternating components and current direct components of the electric reactor can be controlled individually. The structure of a steady-state testing circuit is simple. The steady-state testing device and the steady-state testing method have the advantages that the auxiliary valve and the sample valve are controlled to be unlocked and locked in a charging phase and a testing phase, support capacitors in the auxiliary valve and the sample valve are charged in different phases, and steady-state testing of the modularized multi-level converter valves is realized; charging and energy supplement of the support capacitors in the auxiliary valve are performed only through N output interfacesin the direct-current power supply, and additional direct-current power supplies are not needed for charging of the support capacitors in the sample valve, so that the cost of the whole test circuitis low; the actual working conditions of the modularized multi-level converter valves can be represented completely.

Description

technical field [0001] The present invention relates to Background technique [0002] Compared with AC transmission and traditional DC transmission, flexible DC transmission has unique advantages in operation performance. With the continuous development of modular multi-level flexible DC transmission converter valve technology, the construction of flexible DC transmission projects and flexible DC transmission networks is also accelerating. As one of the core equipment of modular multi-level flexible direct current transmission, the performance of the flexible direct current transmission converter valve determines the operation reliability and stability of the flexible direct current transmission system. The reliability of valves (ie, modular multilevel converter valves) has become one of the necessary measures to ensure the reliability of HVDC flexible transmission systems. [0003] The smallest functional unit of a modular multilevel converter valve is a sub-module. There...

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Problems solved by technology

[0004] In order to overcome the shortcomings in the prior art that the current AC component and the current DC component of the load reactor cannot be controlled separately and cannot completely reproduce the actual operating conditions of the modular multilevel converter valve, the present invention provides a modular multilevel A steady-state test device and method for a converter valve. The steady-state test device includes a load reactor, a sample valve and an auxiliary valve connected through the load reactor, and a water cooling device for providing cooling water to the auxiliary valve and the sample valve. DC power supply for charging the supporting capacitor in the auxiliary valve, sending unlocking command and blocking command to the auxiliary valve and the sample valve through optical fiber, and controlling the phase angle of the respective output voltages of the auxiliary valve and the sample valve and the output voltage of the DC power supply The control device and the protection device used to protect the steady-state test device when the steady-state test device fails, and realize the modularization by unlocking or blocking the auxiliary valve and the test valve during the charging phase and the test phase Steady-state test of multi-level converter valves, and can fully reproduce the actual operating conditions of modular multi-level converter valves

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