Testing system for detecting characteristics of offshore wind power flexible direct current transmission converter

Abstract

The invention discloses a testing system for detecting characteristics of an offshore wind power flexible direct current transmission converter. The testing system comprises a rectifier side unit and a master control module connected with the rectifier side unit, wherein the master control module comprises an alternating voltage and current sensor, a direct voltage sensor, a direct voltage control module, an alternating voltage control module, a reactive power control module, an active power control module, a loop current control module, a frequency control module, an alternative switch, a one-out-three switch, a first adder and a second adder. The current is directly controlled by employing double closed loops, the d-axis current and the q-axis current are respectively controlled based on d and q models of a convertor station so as to control the active power and reactive power, the steady state error in a controlling unit is reduced, and the dynamic characteristics of the controlling unit are perfected; and moreover, a main circuit of the testing system has a simple topological structure, and the testing system is suitable for a medium / low-power system.

Description

technical field [0001] The invention relates to a test system in the technical field of electric power conversion, which belongs to the field of wind power converter control, in particular to a test system for testing the bus voltage and current characteristics and power control characteristics output by the rectifier end of the converter, so as to obtain better Test system for rectification effect. Background technique [0002] Flexible DC transmission technology uses voltage source converters and insulated gate bipolar crystals with self-shutoff capability. Since the fully-controlled power electronic device IGBT is used as the switching device, the system has the ability to self-shut off current and can work in passive In the inverter mode, the receiving end system can be a passive network; the control is flexible and convenient, and the active power and reactive power can be controlled simultaneously and independently; the pulse width modulation control technology is adop...

AI Technical Summary

Problems solved by technology

However, this solution still has the following disadvantages for actual product development and testing: 1) The main circuit part of the system is connected in star form, and there is no common DC side, which brings certain difficulties to active power transmission; 2) The test system only verifies its trigger algorithm 3) The main circuit is a cascaded multi-level structure, which is suitable for high-voltage and high-power system design. For small and medium power systems, the structure is too complicated and the system cost too high

In summary, the experimental system design scheme cannot be used as a general platform for converter product design, development and performance testing, and the main circuit topology is too complex to be suitable for small and medium power systems

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