Study On Control Technology Of Low Power Anti-islanding Protection Testing Device

Detecting the anti-islanding protection function of the grid inverter is the goal of this paper. Besides, the topology and control technology of low power anti-islanding protection testing device is studied. The low power anti-islanding protection testing device developed, which gets a good effect in practical application, has high value of engineering application.The traditional anti-islanding protection testing device, RLC load, consumes a large amount of electricity, is huge, needs to manually matching, operates complexly, wastes a lot of time. To solve above problems, the voltage source PWM AC/DC/AC converter with LC filter is proposed as the main circuit topology of low power anti-islanding protection testing device, which is composed of the simulating converter and the grid-connected converter. The former converter is responsible for simulating linear load, and the latter grid-connected converter sends back the recycling energy to the power grid efficiently to achieve the goal of low power.Besides, the control technology of low power anti-islanding protection testing device is studied. With the mathematical model under two-phase static coordinate system, repetitive PI control strategy of the simulating converter is put forward. Repetitive control strategy ensures accuracy of the steady state of the converter, and PI control strategy provides a good dynamic response. Meanwhile, to the grid-connected converter, dual closed-loop control strategy is proposed, which contributes to steady-state performance and anti-interference performance. The PR controller is adopted in current inner loop, and the dc voltage outer loop adopts traditional PI controller. The analysis of simulation result under Matlab, verifies the effectiveness of the controller design.In addition, a set of 50 k W low power anti-islanding protection testing device is developed, and main circuit, hardware system and software system are designed in detail. Compared with traditional RLC testing device, it was applied to anti-islanding testing protection experiment with the same pv inverter. Through analyzing experimental data, it’s concluded that new anti-islanding testing device has the same effect with traditional RLC load, shows the effectiveness of proposed main circuit topology and control technology.