| Solar and other renewable energy have aroused widespread concern with theglobal energy crisis intensifies. Due to the advantages of non-pollution, lowinvestment, low loss, high system reliability, photovoltaic power has become animportant form of renewable energy generation. The output of PV power generationbecomes randomness because of the uncertainty of the location, ambient temperature,light intensity and other factors. With the popularity of electric vehicles and thecontinuous development of the Vehicles to Grid(V2G)technology, plug-in electricvehicles(PHEVs) can provide spinning reserve capacity for the grid in peak shaving,achieve strong guarantee for the load shifting. The loads and V2G capacity of PHEVsbecome randomness because of the randomness of charging and discharging time,battery state of charge, and the number of electric vehicles. The uncertainties of theoutput of the PV and the V2G capacity have cause serious effect to safe and stableoperation of the power system. The PV-PHEVs hybrid energy supply system is buildand the randomized optimize the decision-making and fuzzy control methods for thehybrid energy supply system is proposed, through depth study of the principle ofphotovoltaic power generation and V2G technology and coordination optimizationand control between PV and PHEVs.PV-PHEVs hybrid energy supply system consists of photovoltaic system andPHEVs. Hybrid energy supply system through PEHVs energy storage devices, withV2G technology, It can make full use of photovoltaic power generation to achieve theeconomic stability of operation of the power system with V2G technology through theenergy storage function of PEHVs.Aimed at the randomness of the output of the PV and the V2G capacity,stochastic optimization and decision-making model of the PV-PHEVs hybrid energysupply system is proposed based on the theory of chance constrained. TheOptimization Model uses the form of probability to describe the randomness of theoutput of the generation system and the V2G capacity on purpose of reducing electricpower costs. It uses the sample average approximation (SAA) to handle the chanceconstrained stochastic optimization decision-making model into computabledeterministic nonlinear optimization problems and particle swarm optimization tosolve the problems because of the difficulty for calculating the chance constrained.The results of numerical example shows that the stochastic optimization model based on chance constraint can maximize the use of photovoltaic power generation andachieve the economic of hybrid power supply system.In order to make the system to operate according to the optimal decision scheme,based on the fuzzy theory, the hierarchical fuzzy control strategy model of thePV-PHEVs hybrid power supply system is proposed. Using hierarchical fuzzycontroller, the control strategy control the output of PV power generation and V2G, aswell as external power injection to make full use of renewable energy powergeneration. Hierarchical fuzzy controller can depict the fuzzy characteristic ofvariables of input and output according to the corresponding membership function andfinally get the optimal control by reasoning decision scheme. Compare with theconventional fuzzy control, hierarchical fuzzy control strategy can reduce the numberof fuzzy rules to make the system more accurately and efficiently.The PV-PHEVs hybrid power supply system proposed in this paper can take fulladvantage of the output of PV power generation and V2G though the stochasticoptimization decision-making and fuzzy control. Therefore, the stochasticoptimization decision-making and fuzzy control method of PV-PHEVs hybrid energysupply system has the important practical significance to the economic security andstable operation of power system and they are the special reference to theestablishment of other forms of mixed energy supply system. |
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