2nd China International Youth Conference on Electrical Engineering (CIYCEE 2021)

368 / 2021-11-10 18:17:52

Study on Energy Storage for Improving Power Supply Ability at the End of Distribution Network

Energy Storage, Power Supply Ability, End of Distribution Network

Power system and automation > Smart grid and utility applications

As a new technical means, energy storage technology has potential application value in delaying the expansion and upgrading of distribution equipment, providing reactive power support, improving power quality and so on. However, because the traditional distribution network is a single power supply system with radial structure, its corresponding distribution network protection and automation devices are only designed for one-way power flow. The bidirectional power supply capability of energy storage makes it have both load characteristics and distributed power supply characteristics. After the energy storage system is connected to the distribution network, the topology and power flow direction of the original network will be changed. It has a great impact on the voltage distribution of traditional distribution network, the action of relay protection devices and the economy of power grid operation. The access of energy storage system will transform the traditional distribution network from passive network to multi power active network. The energy storage output in a certain range can reduce the line loss, improve the node voltage, and solve the problem of low terminal voltage caused by too long power supply radius. However, when the energy storage capacity is too large, the control mode is improper or the output is too much, it will not only cause the waste of power grid assets, high maintenance cost and decline of economic value, but also cause the reverse current of power grid. Some lines, resulting in local node voltage exceeding the upper limit due to excessive rise. These will seriously threaten the safe and stable operation of the power grid. At the same time, if the energy storage system is lack of reasonable control methods, the uncertainty of its operation state will cause many problems, such as difficult relay protection coordination, loss of selectivity, reduced sensitivity and so on. Therefore, comprehensively considering various application scenarios, studying the capacity configuration and operation control method of distributed energy storage, and improving the power supply capacity of distribution network on the premise of ensuring the safe and stable operation of power grid will become a key proposition Then, based on the distribution network with energy storage, post evaluate the improvement effect of its power supply capacity, form a complete industrial chain of energy storage capacity allocation, operation control and effect evaluation, and realize new income growth with systematic services. .