Research On The Droop Control Of Microgrid With Photovoltaic Power Generation

In order to guarantee human energy safe, reliable and friendly supply, while to protect the ecological environment human must depend on to survive, human must reduce the use of fossil fuels and develop clean and efficient renewable energy. Solar energy as a renewable energy source, the radiated energy can be converted into energy we need, its development and use receive the world's attention. At present, the vast majority of photovoltaic power generation system can achieve grid connected operation, But with such a large number of power system connected to the grid, if continue to use the traditional constant power grid operation will affect the system inertia. Inertia reduces means that the system anti impact capability becomes weak and poor stability, meanwhile, with a large number of micro power access, power quality will also be a hit. In order to provide high quality electric energy and minimize the impact of grid connected photovoltaic on grid inertia, this paper main in the following two aspects are studied.In order to make the micro network can take the initiative to participate in the adjustment of the system voltage, frequency, guarantee the stability of the system,the article improves the traditional droop control, power controller using P- f droop control and Q- ?U droop control combined control method, Q represents the reactive power of distributed power output,? U represents the change value of the distributed power output voltage, the control method combines the traditional droop control active power is proportional to the equilibrium according to the capacity, while using the Q- ?U droop control and ?U recovery mechanism combined method, can well improve the reactive power distribution among multiple distributed power supply. Inner ring USES the voltage and current double loop controller,current controller uses the proportion link to improve the system response speed, voltage controller using PI control to stabilize the load voltage. through designing controller parameters make its output impedance is perceptual, use improved power controller and voltage current double loop control combined can realize he traditional droop control in the low voltage power distribution network, reduce the impact of distributed power on power grid at the same time guarantee the reactive power allocation is proportional to the equilibrium according to the capacity, effectively improve the stability of the network.A detailed analysis of the main circuit, control circuit and the main parameters of the system selection of design, design of photovoltaic DSP chip TMS320F2812 control network based on micro power generation device, control method is verified by the experiments.