Power Decoupling Control Of Single Phase Electric Springs

Currently,the world is moving towards cleaner energy to combat climate change.Renewable Energy Sources(RESs)would play an increasingly important role.The International Energy Agency believes that RES such as solar,wind,and biomass will meet 20% of our electricity needs by 2040.Microgrids and buildings,in particular,will play an important role in future grids and help integrate RES in an extremely decentralized manner.However,the intermittency of RES brings about grid instability and power balance problems between generation and demand.Energy storage devices like batteries are part of the solution,but currently,they are expensive and their disposal is bad for the environment.Therefore,it is necessary to explore other avenues to compensate for the intermittent shortcomings of RES.Demand management of loads is also being explored as a means of adjustment.In fact,demandside management may be necessary to create sustainable and competitive microgrids.This paper leverages power electronics to form smarter loads so that they can accommodate the intermittency of RES without interrupting service.The concept of Electric Spring(ES)introduced in recent years classifies loads,one is called a critical load,the other is called a non-critical load,and the series combination of ES and noncritical load is called smart load.Critical loads are sensitive to voltage and power fluctuations,while non-critical loads can operate even at the point of voltage and power fluctuations,such as water heaters,etc.By controlling smart loads,it is possible to regulate the voltage and power of critical loads that are sensitive to voltage and power fluctuations,while transferring power fluctuations to non-critical loads.This paper firstly presents an overview of ES topologies(ES-1,ES-2,ES-3,and hybrid ES);followed by an in-depth study of ES control strategies and their valuable smart grid applications,with progress in the following areas.Since the main goal is the efficient management of microgrids with high renewable energy penetration,this paper proposes a simple power decoupling control for single-phase ES-2 topology,which overcomes the shortcomings of existing ES controls.The control strategy does not depend on circuit parameters,is simple and easy to implement,and fast dynamic response.Then,according to the instantaneous power theory,the paper discusses the instantaneous power calculation method of single-phase ES in detail,deduces the power mathematical model of single-phase ES,and proposes the direct power control strategy of single-phase ES based on the switch table.The control system has a simple structure and fast dynamic performance.In order to describe the model proposed by ES,the unpredictable power generated by RES is divided into two parts,that is,the part absorbed by ES-2 also changes,so the other part is injected into the controllable grid by a simple and accurate method both at steady-state and RES transients.This is typically achieved by placing two current loops that regulate the load current drawn by the load on the d-and q-axes,respectively,complementing the loops with active damping put in place via feedback of ES output current.It is believed that this type of bearing is suitable for distributed power generation,especially in domestic homes.The proposed control is supported by theoretical background.Finally,this paper builds a simulation model of power decoupling control of single-phase ES under different conditions on the MATLAB/Simulink simulation platform and introduces the model building process in detail.The simulation results verify the correctness and effectiveness of the power decoupling control strategy proposed in this paper.