Memory Element Circuit And Its Application In The Control Of Microgrid Photovoltaic Converter

Since the successful discovery of memristor(MR)with memory function,the research and application of memristor has aroused a research boom in academia.Because of its excellent performance in memorizing the number of charges flowing through it,the memory element is expected to become the basic circuit element of the new type of neuromorphological computing,which can bring revolutionary changes to the field of microelectronics.At present,foreign competition and research have entered a white-hot stage,but the technical problems and practical applications of memristors are still an opportunity for us.In this paper,a novel circuit network of memristor,memcapacitor and meminductor are designed based on varactor diode.And a general circuit model of memory elements is proposed by unifying the circuit topologies of three memory elements.Memory circuits are applied to PI control and maximum power point voltage control of microgrid photovoltaic system converters.Firstly,this paper briefly introduces and combs the advancement and development of memory elements,summarizes the research status and application of memory elements,and gives a brief overview of the main control methods of microgrid converters.Secondly,according to the working principle and characteristics of varactor diode,a grounded memristor with fewer devices is designed,and and the working characteristics of the grounded memristor are analyzed.Based on the current-voltage conversion characteristics of transconductance operational amplifier,the analog circuits of grounded memcapacitor and floating-ground memristor,memcapacitor and meminductor are designed respectively.Summarizing the similarity of floating-ground circuit topology,a general memory element circuit is proposed,which can show different performance of memory elements by position transformation of several devices.The electrical characteristics of the three memory elements are analyzed and verified by simulation and hardware experiment platform.The results show that the circuit model designed accords with the characteristics of the memory elements.Thirdly,based on the resistance and capacitance characteristics of the memristor and memcapacitor,the series-parallel circuits with the same and opposite polarities of the MR and MC are designed.The theoretical analysis and simulation prove that the memristor based on varactor still has the characteristics of memristor and memcapacitor when they are combined,and the calculating formula of composite memristor and memory capacitance value is given.The method is the same as the calculation method for series-parallel connection of common resistance capacitors.Fourthly,VD-MR and VD-MC are used in PI control circuit instead of traditional resistors and capacitors,which can automatically adjust the proportion and integral coefficient.At the same time,the replaced controller is applied in Buck circuit.The simulation results show that the PI controller using VD-MR and VD-MC can automatically adjust the proportion and integral coefficient,quickly stabilize the output of the circuit and reduce the fluctuation.Finally,the characteristics of VD-MR and VD-MC and the output of Buck circuit controlled by VD-MR are verified by RTDS real-time simulator.In RTDS/RSCAD,the simulation model of micro-grid system including photovoltaic power generation,storage battery and diesel generator module is established.The PI regulating circuit of VD-MR is applied to DC side voltage control of maximum power point tracking in photovoltaic system.