Closed loop test system of flexible direct current transmission control protection system

Abstract

The invention discloses a closed loop test system of a flexible direct current transmission control protection system. The closed loop test system of the flexible direct current transmission control protection system comprises a real-time digital simulator and a control protection device of a flexible direct current transmission device based on modularized multi-level, wherein the alternating voltage and current signal output end of the real-time digital simulator is connected with the alternating analog quantity input end of the control protection device, the direct voltage and current signal output end of the real-time digital simulator is connected with the direct analog quantity input end of the control protection device, the switching state signal output end of the real-time digital simulator is connected with the switching value input end of the control protection device, and the switching merge-joint command signal output end of the control protection device is connected with the switching value input end of the real-time digital simulator. The closed loop test system of the flexible direct current transmission control protection system has the advantages of being simple, flexible, and capable of conveniently and rapidly achieving tests on a whole flexible direct current transmission actual control protection system device based on the modularized multi-level.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a closed-loop test system based on a modular multi-level flexible DC transmission control and protection system. Background technique [0002] With the advancement of power electronic devices and control technology, the flexible DC capacity and voltage level are getting higher and higher. Flexible DC transmission based on modular multi-level is more and more widely used because of its many advantages such as easy realization of new energy grid connection, black start, power inversion, and construction of multi-terminal DC systems. [0003] In the R&D and functional testing phases of modular multi-level flexible DC transmission devices, closed-loop tests are required to simulate field conditions to adjust and verify the steady-state and dynamic performance of the control system. The common method of closed-loop test is to build a physical prototype. The meth...

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Problems solved by technology

[0006] (2) The model of the flexible DC transmission device based on modular multi-level is relatively complex. As the capacity increases, the number of sub-modules increases, resulting in higher and higher costs for building a dynamic model system;

[0007] (3) Flexible DC transmission based on modular multi-level is used for multi-terminal flexible DC transmission based on modular multi-level and access to new energy (such as wind power access). It is almost impossible to completely simulate the entire system test by building a prototype

[0008] Due to the above reasons, it is very uneconomical to use the dynamic model test method to test the function and dynamic performance of the control and protection system based on modular multi-level flexible DC transmission, and the construction period for changing the dynamic model equipment and parameters is long, which is harmful to the whole A complete simulation of a flexible DC system is often not possible

At present, the testing of control and protection based on modular multi-level flexible DC transmission mainly relies on offline simulation for simulation, but the scheduling system, execution cycle, and operating parameters of offline simulation cannot be prepared to simulate actual control and protection equipment, and cannot accurately simulate control and protection. Steady-state and dynamic performance of the system, not a good guide for practice

At present, based on the actual control and protection device of modular multi-level flexible DC transmission, there is no good test method

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