Research On Power Control Technology Of Photovoltaic Grid-connected Energy Storage System

Solar photovoltaic power generation has gradually become the main new energy power generation mode,and the application of power electronic devices in the field of photovoltaic power generation has also become a major research hotspot.In order to improve the utilization rate of solar energy resources,a new control method of thermal energy storage power for grid connected photovoltaic power generation without countercurrent is proposed,which is suitable for the occasions where the demand for hot water is relatively fixed,such as families and small factories,and PWM is used The rectifier controls the output power.In this paper,the topology of single-phase current source PWM rectifier and single-phase voltage source PWM rectifier is analyzed in principle.Through the analysis and comparison,it is found that current source PWM rectifier is more suitable for the application of this subject,so as to further analyze and study its modulation process.In addition,the single-phase current source PWM rectifier is simulated by Matlab / Simulink,and the conclusion is that the DC side power can be linearly adjusted.Secondly,according to the overall structure design and requirements,this paper mainly designs the power part of the rectifier controller hardware circuit,the control part of the circuit and the detection part of the circuit in detail,including the schematic design,the main device selection and parameter description.In addition,based on the analysis of software requirements,this paper designs the related part of the software,and realizes the function of some modules in the software design.This paper also designs a new design method of H-bridge driving circuit based on CPLD,which is mainly aimed at the design of H-bridge driving signal of single-phase current source PWM rectifier.The current source PWM rectifier H-bridge is set with superimposed current time to prevent DC side open circuit,and it can realize the flexible setting of switching frequency and the setting of PWM waveform duty cycle through bus interface,which has great practicability in engineering application ?Finally,the power control experiment of single-phase current mode PWM rectifier in photovoltaic grid connected energy storage system is carried out.The experimental results show that under the control method,topology and control sequence of the experimental system,the harmonic current at the grid side can be well suppressed,and the power at the output side can be continuously adjusted.