A steady-state test device and method for a modular multilevel converter valve

Abstract

The invention provides a steady-state test device and method for a modular multi-level converter valve. The device includes a load reactor, a sample valve, an auxiliary valve, a water cooling device, a DC power supply, a control device and a protection device, and the reactor The AC component of the current and the DC component of the current can be controlled separately, and the structure of the steady-state test circuit is simple. The steady-state test method provided by the present invention realizes modularization by unlocking or locking the auxiliary valve and the sample valve during the charging stage and the test stage, and charging the supporting capacitors in the auxiliary valve and the sample valve at different stages. Steady-state test of the level converter valve; the present invention only charges and supplements the support capacitor in the auxiliary valve through the N output interfaces provided by the DC power supply, and does not need to separately set up another DC power supply for the test valve. The charging of the supporting capacitor makes the cost of the whole test circuit lower, and the invention can fully reproduce the actual operating conditions of the modularized multilevel converter valve.

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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