Harmonic Research Of Electric Vehicle Charging Station In Shenzhen Power Grid

During recent years, with the development of the cars in China, cars’ oil consumption hasbeen about35%of the total national consumption. The oil consumption of cars is a seriousthreat to the whole country and cause the environmental pollution at the same time. Theelectric vehicles (EVs), which are driven by electricity instead of gasoline, is the direction ofthe development in the auto industry. In order to satisfy the demand of the EVs, there must belots of charging stations constructed around the country. However, as a power electronicdevice, the charging station will produce harmonics, which will make a bad affection on thepower grid. It is very necessary to take eyes on the new power quality problem introduced bythe EV charging stations and must find an effective way to mitigate it.This thesis focus on the harmonic problems of the EV charging stations which haveoperated in Shenzhen already. The main work include:1. Introduce the proposal of the EV charging station, involving the scope, principle andstructure in detail;2. Monitor the harmonic of the EV charger in the field. Analyze the variation of theharmonic produced by the charger during the4charging processes and establish themagnitude-frequency model of the charger;3. Set up the simulation model of the EV charging station and simulate the harmonicproduced by the station under different conditions. Evaluate the effectiveness of theharmonic on the power grid;4. Put forward the approaches of the harmonic mitigation in the EV charging station.Compare the availability of two approaches.Theoretic analysis, field measurement and simulations are applied in this thesis to studythe characteristics of the harmonics in the EV charging stations. The effect of the harmonics isevaluated to propose the mitigating strategies. The simulation results show that the validity ofthe strategies, which is very important for the construction of the EV charging stations inShenzhen.