| As the fossil energy is exhausted, it becomes more and more urgent to speed up the development and utilization of new energy. The solar photovoltaic power generation has incomparable advantage compared with other power. It has been an important research direction of the field. The development prospects are very broad. A inverter is an important part of photovoltaic grid power generation system, but with the increase of power consumption and the improvement of reliability requirements, a single inverter can not always meet the ideal requirements. So, the inverter parallel technology arises at this moment. It can effectively solve the problem. At the same time, along with the updating of digital signal processing chip (DSP), some advanced or improved control strategy can be applied to the inverter parallel system. Based on this background, this paper studies the photovoltaic grid inverter parallel control technology in detail, and it has a very important practical significance for photovoltaic power generation.In this paper, the inverter parallel system model is established based on the single inverter model, then the circulation of the parallel system and the power characteristic are analyzed thoroughly, this paper introduces two parallel ways, including interconnection line connection and free interconnection line connection, the latter is mainly studied. Considering the limitations of traditional PQ control strategy and the specific photovoltaic grid field, an improved free of interconnection lines parallel control method is put forward, then the overall control scheme, parallel system hardware and software design based on TMS320F2812 DSP control core are designed. Finally, it compares the traditional PQ control method with the improved PQ control method by simulation. Simulation results show that it can get a good current-sharing and power-sharing with the improved PQ control strategy, and the system has high stability and good dynamic response. |
PDF Full Text Request