This paper presents in the first place, the state of art relating to the methods to solve optimal power flows (OPF) and its application in electrical microgrids. Afterwards, a mathematical algorithm based on the gradi...This paper presents in the first place, the state of art relating to the methods to solve optimal power flows (OPF) and its application in electrical microgrids. Afterwards, a mathematical algorithm based on the gradient method is proposed for the application of OPF in a low power microgrid, in order to improve the voltages profiles and consequently reduce the active power losses. Finally, the proposed algorithm is implemented in a low power microgrid to demonstrate the effectiveness of the method.展开更多
Microgrid (MG) integrated with Distributed Generation (DG) provides several benefits like reliable, secure, and high efficient of energy supply, while minimizing power loss, deferring expansion of power distribution i...Microgrid (MG) integrated with Distributed Generation (DG) provides several benefits like reliable, secure, and high efficient of energy supply, while minimizing power loss, deferring expansion of power distribution infrastructures, and reduced carbon emission of energy supply etc. to the communities. Despite of the several benefits, there are several challenges existing due to the integration of different characteristics and technology of DG sources in MG network. Power Quality (PQ) issue is one of the main technical challenges in MG power system. In order to provide improved PQ of energy supply, it is necessary to analyse and quantify the PQ level in MG network. This paper investigates the detail of PQ impacts in a real MG network carried out through an experimental analysis. Voltage and frequency variations/deviations are analysed in both on-grid and off-grid mode of MG operation at varying generation and varying load conditions. Similarly unbalance voltage and current level in neutral are estimated at unbalanced PV generation and uneven load distribution in MG network. Also current and voltage THD are estimated at different PV power level. Finally the results obtained from the analysis are compared to that of Australian network standard level.展开更多
针对新能源可靠供电中的供需平衡问题,提出一种计及局部阴影工况的光储直流微电网能量管理。首先,针对光伏阵列在局部阴影等弱光照工况下,传统最大功率点跟踪方法在功率捕捉能力与能源利用效率方面的不足,利用蝠鲼优化算法(manta ray fo...针对新能源可靠供电中的供需平衡问题,提出一种计及局部阴影工况的光储直流微电网能量管理。首先,针对光伏阵列在局部阴影等弱光照工况下,传统最大功率点跟踪方法在功率捕捉能力与能源利用效率方面的不足,利用蝠鲼优化算法(manta ray foraging optimization,MRFO)的全局与局部搜索优势,提出一种结合MRFO的自适应电导增量法(manta ray foraging optimization-adaptive variable step-incremental conductance,MRFO-AVS-INC),以在特殊工况下实现对光伏出力的有效跟踪;其次,针对系统集成中存在的多源扰动问题,在储能系统的能量管理与控制方面,提出一种考虑蓄电池工作状态的改进下垂控制方法,通过引入蓄电池的荷电状态(state of charge,SOC)和健康状态(state of health,SOH)等参数,实现下垂系数的自适应调节,从而合理分配各蓄电池的输出功率;最后,在不同光照条件下对光储系统进行仿真验证。仿真结果表明,与基于粒子群算法的自适应变步长电导增量法(particle swarm optimization-adaptive variable stepincremental conductance,PSO-AVS-INC)及传统INC相比,MRFO-AVS-INC方法在收敛速度与跟踪稳定性方面表现更优;改进的自适应下垂控制有效实现了储能单元之间的状态均衡,延长了储能系统的整体使用寿命。展开更多
文摘This paper presents in the first place, the state of art relating to the methods to solve optimal power flows (OPF) and its application in electrical microgrids. Afterwards, a mathematical algorithm based on the gradient method is proposed for the application of OPF in a low power microgrid, in order to improve the voltages profiles and consequently reduce the active power losses. Finally, the proposed algorithm is implemented in a low power microgrid to demonstrate the effectiveness of the method.
文摘Microgrid (MG) integrated with Distributed Generation (DG) provides several benefits like reliable, secure, and high efficient of energy supply, while minimizing power loss, deferring expansion of power distribution infrastructures, and reduced carbon emission of energy supply etc. to the communities. Despite of the several benefits, there are several challenges existing due to the integration of different characteristics and technology of DG sources in MG network. Power Quality (PQ) issue is one of the main technical challenges in MG power system. In order to provide improved PQ of energy supply, it is necessary to analyse and quantify the PQ level in MG network. This paper investigates the detail of PQ impacts in a real MG network carried out through an experimental analysis. Voltage and frequency variations/deviations are analysed in both on-grid and off-grid mode of MG operation at varying generation and varying load conditions. Similarly unbalance voltage and current level in neutral are estimated at unbalanced PV generation and uneven load distribution in MG network. Also current and voltage THD are estimated at different PV power level. Finally the results obtained from the analysis are compared to that of Australian network standard level.
文摘针对新能源可靠供电中的供需平衡问题,提出一种计及局部阴影工况的光储直流微电网能量管理。首先,针对光伏阵列在局部阴影等弱光照工况下,传统最大功率点跟踪方法在功率捕捉能力与能源利用效率方面的不足,利用蝠鲼优化算法(manta ray foraging optimization,MRFO)的全局与局部搜索优势,提出一种结合MRFO的自适应电导增量法(manta ray foraging optimization-adaptive variable step-incremental conductance,MRFO-AVS-INC),以在特殊工况下实现对光伏出力的有效跟踪;其次,针对系统集成中存在的多源扰动问题,在储能系统的能量管理与控制方面,提出一种考虑蓄电池工作状态的改进下垂控制方法,通过引入蓄电池的荷电状态(state of charge,SOC)和健康状态(state of health,SOH)等参数,实现下垂系数的自适应调节,从而合理分配各蓄电池的输出功率;最后,在不同光照条件下对光储系统进行仿真验证。仿真结果表明,与基于粒子群算法的自适应变步长电导增量法(particle swarm optimization-adaptive variable stepincremental conductance,PSO-AVS-INC)及传统INC相比,MRFO-AVS-INC方法在收敛速度与跟踪稳定性方面表现更优;改进的自适应下垂控制有效实现了储能单元之间的状态均衡,延长了储能系统的整体使用寿命。
