Network voltage disturbance generating device and control method thereof

Abstract

The invention provides a network voltage disturbance generating device, which comprises a three-phase bridge type PWM (Pulse Width Modulation) rectifier and a three-H-bridge three-phase four-wire-system PWM inverter, wherein the alternating current side of the rectifier is connected with an electric network through an L type filter; the direct current side of the rectifier is connected in series with the direct current side of the three-H-bridge three-phase four-wire-system PWM inverter; an LC filter is connected to the alternating current side of the three-H-bridge three-phase four-wire-system PWM inverter; the output end of the LC filter is connected with an isolation transformer; and the secondary side of the isolation transformer is connected with a load. The invention further provides a control method suitable for the device. Due to the adoption of the device provided by the invention, the simulation of a network voltage amplitude, frequency disturbance and an electric network harmonic phenomenon can be realized, bilateral flow of energy can be realized, and active energy transmitted by tested solar-powered grid-connected equipment is fed back to the electric network; and the control method is easy and convenient to implement, and a target reference value can be accurately tracked; and moreover, quick response and small steady-state errors are realized, so that electric network disturbance can be simulated accurately.

Description

technical field [0001] The invention relates to the technical field of electrical equipment and electrical engineering, in particular to a grid voltage disturbance generating device and a control method thereof. Background technique [0002] With the massive application of new energy, the micro-grid composed of new energy-based distributed power generation is developing rapidly, and the grid-connected converter, as a bridge connecting the large power grid and the micro-grid, is also popularized. Whether the grid-connected converter can work stably directly affects the safety of the distributed generation system. How to evaluate the performance of the grid-connected converter has become an important research topic. Most of the current voltage disturbance generation platforms use back-to-back dual PWM AC-DC converters for simulation, which have the following defects: [0003] 1. Most voltage disturbance generating devices adopt a topology structure in which three-phase half-b...

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Problems solved by technology

[0003] 1. Most voltage disturbance generating devices use a topology structure in which three-phase half-bridge rectifiers and three-phase half-bridge inverters are connected back to back. This structure is not easy to achieve different three-phase voltages due to the possibility of mutual influence between the output three-phase voltages. Accurate simulation of symmetrical faults, and its inverter-side control strategy is more complex

[0004] 2. Part of the voltage disturbance generating device adopts a topology structure of three single-phase AC-DC converters connected in parallel. Although this structure can better realize the required simulation functions, it uses more devices and is not economical.

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