earticle

영어

At present, the technology of the distributed power grid gradually become mature. The focus of the study is from controlling power quality to reducing the loss of power grid, improving the network efficiency and reducing the cost. In the link of distributed generation grid connected power generation, the loss of the switching device is an important factor affecting the efficiency of grid connection. This paper puts forward a systematic solution to this problem. Firstly, as for topology structure of grid connected controller, aiming at the research on NPC, a traditional topology which is energy-saving and low loss, we present an improved NPC topology with a more continuous flow state. At the same time for this topology, the corresponding control strategies are designed in this paper. It makes the switching device of the grid connected controller have more freedom of switch and make the system can achieve the precise control of the switch tube ,which can achieve the balance of system device lose heat so as to solve the problem of local high temperature from inverter. The system is verified by grid connected test, the power adjustable PWM strategy can be used to achieve different working states without affecting the output current of the system. Through the comparison between light and heat sensors finds that the topology and control strategy proposed in this paper are successfully completed by the new hardware topology and control strategy to achieve the loss balance of the system switching devices.