国家自然科学基金面上项目(51877035).Project Supported by National Natural Science Foundation of China(51877035)
Key Laboratory of Modern Power System Simulation and Control Renewable Energy Technology,Ministry of EducationNortheast Electric Power University
Dynamic voltage restorer (DVR) is a power electronic device connected in series with source and load, which is used to rapidly compensate voltage fluctuation in the power system. However, due to the energy storage equipment, the conventional DVR based on voltage source inverters (VSIs) has some shortcomings. And DVR based on direct AC/AC conversion with pulse width modulation (PWM) has the shortages of commutation problem and voltage balance of flying capacitor. Therefore, this paper proposes a single-phase DVR based on bipolar direct AC/AC conversion. The AC/AC converter topology with PWM used in the proposed DVR has the characteristics of common grounding between the input and output ports. In addition, the proposed DVR can achieve bipolar voltage regulation under a simple control strategy and solve the commutation problem during operation effectively. In order to verify the engineering value of the proposed DVR, a 1 kW experimental platform has been built to verify its rationality and effectiveness on the basis of theoretical analysis.