为减轻分布式电源接入对城市配电网产生的负面影响,国内外制定了一些分布式电源并网准则,以保证分布式电源的安全有效接入,但这些并网规则的制定依据并没有明确给出。为此,以天津城区典型的35kV 高压、10kV中压和400V低压配电网为例,计算分析接入分布式电源对城市配电网线路载流量和母线电压的影响,给出分布式电源并网规则中关于接入容量和接入电压等级要求的依据,并讨论分布式电源接入配电网后对电压偏差、频率偏差、谐波及三相不平衡度等方面的电能质量的影响及其要求和依据。
In order to mitigate the adverse impact of integration of distributed generators (DGs ) to distribution systems, some rules for interconnecting DGs with electric power systems are made all over the world to guarantee the safe and effective integration of DGs. However, no definite basis are given for these rules. Therefore, case studies of Tianjin distribution networks of 35kV high voltage, 10kV medium voltage and 400V low voltage are conducted, and the influences of DGs on line maximum capacity and bus voltage are calculated, through which the theoretical bases of the capacity and voltage level of DG integration are obtained, and requirements for power quality of DG integration in terms of voltage deviation, frequency deviation, harmonics, and three-phase imbalance are set up.