Distributed Power Access and Grid Voltage Deviation Analysis
Dec 15, 2017
In recent years, the distributed generation technology represented by wind power and photovoltaic power generation has been rapidly developed and vigorously promoted. On the one hand, the environmental friendliness and recycling of distributed power sources have helped to cope with the energy crisis and environmental pollution. On the other hand, people have also noticed that distributed generation has strong output power due to its natural conditions Randomness and volatility, large-scale distributed generation into the grid, will have a serious impact on the quality of the power supply of existing power systems.
Since distributed power supply generally has the characteristics of small stand-alone capacity and decentralized layout, it usually has direct access to the distribution network. There are mainly three ways to access the distribution network: low-voltage side of distribution transformers, decentralized access of medium-voltage lines and bus-side green access of high-voltage substations. The traditional centralized power distribution network, generally radial structure, the power distribution lines in the unidirectional flow from the load to the load. Under steady-state operation, the voltage is gradually reduced along the direction of power flow on the distribution line. Access to distributed power supply, the distribution feeder on the transmission power is reduced (in the load side has a power supply, reducing the power supply on the original power supply requirements), and distributed power output reactive power support, making The voltage at each load node on the distribution feeder is raised, resulting in voltage deviation at some load nodes.
Voltage deviation reflects the degree of deviation of the actual voltage from the system rated voltage. Voltage deviation is too large for many electrical equipment and power grid security and stability and economic operation will have a tremendous risk, it is necessary to study the distributed power access distribution network caused by the voltage deviation. In this paper, starting from the mechanism of voltage deviation, taking into account the particularity of the voltage deviation of distribution network, the distribution of voltage deviation generated by distributed power supply under different access conditions is analyzed and the use of distributed power supply to suppress Voltage deviation.
