Study On Network Control Strategy And Low Voltage Ride Through Capability Of Pv System

With further increase of energy pressure, the development of solar photovoltaic energy is bound to become a major area of development strategy in China. However,since the output of solar PV is volatile, these innate factors largely inhibited the massive parallel operation of solar photovoltaic power, so researches on solar photovoltaic power grid control strategies and LVRT control strategy will have great significance in promoting the further development of solar photovoltaic. This paper is based on the actual situation and it is highly targeted, in which solar photovoltaic power grid control strategies and LVRT control technology are fully researched.Firstly, by learning relevant literature, a comprehensive understanding of the issue of the status and development of solar photovoltaic power generation is received, which leads to the topic of network control strategy and LVRT control strategy. A photovoltaic cell model is established and MATLAB is applied in simulation analysis of PV output characteristics with changes in ambient temperature and light intensity. Variable step MPPT method is studied to control PV system, and an inverter model is also established for photovoltaic power DC voltage control strategies.Then solar photovoltaic power grid control strategy is described in brief, a PI control strategy model and deadbeat control strategy model are established and the control principle is studied. By way of simulation analysis of the effectiveness of the proposed control method, comparative analysis of different physical environment is applied in different control methods PI control and deadbeat control features and suggestions.Finally, a detailed analysis of photovoltaic power LVRT capability requirements is made, which promote the understanding of purpose and scope of capabilitiesphotovoltaic power LVRT. The common LVRT control strategy features is summarized and energy parallel resistor method can improve the feasibility of low-voltage ride through capability,and by the method of simulation analysis to verify the proposed method. In order to reduce additional investment, deadbeat control method is proposed and low voltage ride through capability enhancement is produced to control the duty cycle of the control signal when the power grid voltage drop. In the process, active power is reduced and reactive power is increased. Related simulations also confirmed the feasibility of this approach.