The optional dispatch of microgrid is a new complex issue with both important economic benefits and social benefits.In order to ensure the microgrid with distributed power to operate in a more economical,flexible and environmental way,and the advantages of distributed generation can be fully played,according to the problem of optimal scheduling of microgrid,this paper proposes a multi-objective optimization function model of microgrid with electric vehicle which is used as a load and power generation unit at the same time,which aims to maximize the economic benefit and minimize the environmental cost of multi-objective optimization of microgrid.In the process of optimization,this paper introduces the structure of double chain and the adjustment strategy of dynamical rotation angle,proposes a new modified quantum genetic algorithm,and compares with the traditional genetic algorithm and the fundamental quantum genetic algorithm.Finally,a numerical examples are provided to verify the effectiveness and feasibility of the proposed model,strategy and algorithm.

Economic benefit of the micro-grid is key to attract users and ensure the micro-grid be popularized in the power system,and economic operation is important to realize economic benefit of the micro-grid.In allusion to research status and insufficiencies of economic optimal operation of the micro-grid at home and abroad,this paper has discussions in three as-pects including distributed micro-grid system,demand-side management strategy for electric vehicle micro-grid and co-gener-ation of cooling heat and power based on the multi-objective optimal operation model of the micro-grid. It points out the multi-objective optimal model and optimization algorithms for the micro-grid are future research emphasis,and co-genera-tion of cooling heating and power,vehicle-to-grid (V2G)and the new-typed energy storage will become research focuses.

Grid voltage unbalance brings great damage to doubly-fed induction wind generator (DFIG) and traditional control methods cannot completely solve this problem.According DFIG operation principle under unbalanced voltage,based on interconnection and damping assignment passivitybased control (IDA-PBC),port controlled Hamiltonian-withdissipation (PCHD) model for grid-side converter controller design is proposed in this paper.Positive and negative sequence grid-side converter IDA-PBC controller based on PCHD is deduced.Grid-side current values in three control targets are calculated to eliminate the second harmonics in grid-side current,output power and output reactive power.Optimal coordinated control targets of grid-side and rotor-side are given in combination of rotor-side control strategy.Simulation and experiment results show feasibility and effectiveness of the proposed control scheme.

In order to eliminate the influences of sudden chang in light intensity and load on photovoltaic (PV) system,and improve the stability and immunity of PV system,by analyzing the principle and advantages of virtual DC generator (VDG),we adopted the VDG in PV system control strategy,and applied the dual stage control strategy system of MPPT+VDG to the DC microgrid.The simulation results of Matlab/Simulink show that if the load or the light intensity is respectively mutated,the fluctuation amplitude of bus voltage of PV system with MPPT+VDG control is 55 V or 71 V,respectively,it is obviously smaller than that of the PV system with MPPT control that the fluctuation amplitude of bus voltage is 97 V and 101 V,respectively.Moreover,on the DC microgrid with MPPT+VDG control of PV system at mutation of the load or light intensity,the fluctuation amplitude of bus voltage with double stage control of 26.7 V or 17.7 V is smaller than that of common control of 28.5 V or 20 V,and the battery switching frequency of 2 or 0 times is significantly less than the common control of battery switching frequency of 4 or 2 times.The simulation results show that the proposed control strategy can improve the stability and immunity of PV system.

为了实现分布式电源组成的微网能以更为经济、灵活和环保的方式运行,充分发挥分布式电源的发电优势。针对微网优化调度的问题,提出以电动汽车同时作为负荷和发电单元且计及制热收益的微网多目标优化模型,以经济效益最大化、环境成本最小化作为微网多目标优化问题。应用非劣排序遗传算法NSGA-II,进行多目标优化求解,求得Pareto前端解,从而获得微网最优调度策略。通过算例验证了所提模型、策略和算法的有效性。

In order to solve microgrid ubiquitous three-phase load imbalance,a detailed analysis of the microgrid three-phase unbalanced load characteristics,a new method for the calculation of three-phase load microgrid was proposed,and used an improved quantum genetic algorithm the model optimization solution.Quantum optimization algorithms used in the introduction of double chain structure and dynamics of the rotation angle adjustment strategy proposes a new improved quantum genetic algorithm,obtained the right solution and solve to obtain access to the best three-phase load program.Finally,an example demonstrated the effectiveness and feasibility of the proposed model,strategies and algorithms.

Aiming at the larger bus voltage fluctuation,more frequent battery control mode switching and richer redundant power of DC microgrid in normal hierarchical control,a strategy of variable power control is proposed.For the islanded DC microgrid consisting of photovoltaic cells,batteries and loads,it is designed to take the difference between its photovoltaic output power and load power as the reference to regulate the power and direction of battery charge/discharge and its operating mode.The effectiveness and feasibility of the proposed strategy are verified by the simulative results with MATLAB/Simulink,which shows that,the balanced power and stable voltage of microgrid are realized and its control performance is better than that of the hierarchical control.

Z源三电平逆变器将具有独特性能的Z源拓扑和高性能的三电平逆变器相结合,能够充分发挥两者的优势.由于Z源三电平逆变器的拓扑结构相比两电平逆变器更加复杂,为了避免并网控制策略中复杂的坐标变换和解耦过程,进而提高系统效率,将准PR控制引入Z源三电平并网逆变器中.在理论分析的基础上,将准PR控制和SVPWM调制算法相结合,设计出了系统完整的控制策略,实现了Z源三电平逆变器在两相静止αβ坐标系下对电网交流信号的无静差跟踪,简化了传统的系统控制结构,提高了系统的性能.最后在Matlab/Simulink仿真软件中建立了Z源三电平并网逆变器的的仿真模型.仿真结果表明,相比于传统的两电平逆变器,该三电平逆变器输出的电压更接近正弦波,谐波畸变率更低,系统的鲁棒性更强.