Research On Capacity Configuration And Inverter Of Wind-Solar Complementary Power Generation System

Both wind and solar energy have the characteristics of low energy density and strong randomness.Independent wind power and solar power generation cannot obtain stable power output.By utilizing the natural complementary of wind energy and solar energy,and wind energy and solar power generation in energy storage and reverse the versatility of variable links,it is possible to apply wind and solar power generation system in the technical.Taking grid-connected wind and solar power generation system as the research object,this paper mainly focuses on the configuration optimization of capacity of wind and solar power generation system and wind power based on LCL grid-connected inverter control technology.For the optimization of the capacity of the grid-connected wind-solar complementary system of the hybrid energy storage device with supercapacitor-battery,the traditional one-step intelligent optimization algorithm for the optimization of the capacity of the wind-storage system cannot fully consider the environmental sensitivity factors such as wind speed,illumination and temperature.And economic characteristics and electrical characteristics of components such as wind turbines,photovoltaic cells,and batteries.In this paper,the hierarchical optimization method combining HOMER software and genetic algorithm is used to optimize the capacity of the wind-storage power generation system with the minimum computational cost of the HOMER simulation software for optimizing the objective function.The environmental sensitivity factors such as wind speed,illumination and temperature,and the economic characteristics and electrical characteristics of components such as wind turbines,photovoltaic cells,and storage batteries can be fully considered,so that the wind-solar hybrid power generation system can meet the scheduling and planning requirements of the power grid.Combined with the battery capacity obtained from the primary optimization,the genetic algorithm is used to further optimize the power and capacity optimization of the battery and supercapacitor hybrid energy storage system,so as to obtain the optimal system capacity optimization configuration.The optimized system output meets the needs of grid scheduling and local load.The periodic and non-periodic of the grid fixed harmonic current flowing through the line impedance will PCC connection point.There are high and low frequency power grid background harmonic,the grid-connected inverter is composed of power electronic devices,and its working process needs high-frequency pulse width modulation(PWM),which will generate a large number of high-frequency harmonics on the switchgear and cause a large interference to the power grid.Therefore,LCL filter needs to be introduced at the output of grid-connected inverter to suppress high and low frequency harmonics.In order to ensure safe,stable and high-quality power output,These background harmonics through the phase-locked loop control loop so that grid-connected inverter current and harmonic components.In order to analyze the LCL grid-connected inverter more comprehensively,this paper establishes the LCL inverter equivalent model from two aspects of the control strategy and parameter design,and Detailed analysis of the stability of the repetitive control system,error convergence and other control system performance,taking into account the presence of non-periodic background harmonics in the grid voltage,theintroduction of grid voltage feedforward control,based on grid voltage feedforward control with Pole placement method for multi-state variables.The simulation control of the combination of pole placement and repetitive control of grid voltage feedforward is carried out to verify the effectiveness and feasibility of the integrated control strategy.