计及波浪能并网的弱区域配电网继电保护方案研究

Research on relay protection scheme of distribution network for weak area with wave energy integration

为解决波浪能发电单元接入给配电网继电保护带来的误动、拒动问题。本文提出采用分区纵联差动保护配合自适应过流保护的继电保护改进方案。在分析波浪能发电特点的基础上建立波浪能发电模型,并分析其在配电网不同位置并网后给配网继电保护动作的可靠性和选择性带来的影响;接着分析含波浪能发电的配电网故障计算方式,分析不同故障下波浪能发电的处理方案;然后提出采用保护范围系数取代传统三段式保护的可靠系数的自适应电流保护方案,实现配电网保护整定值根据故障点位置实时调整,并提出基于波浪能不同接入点的配电网分区纵差保护方案,形成基于分区纵差配合自适应过电流保护的继电保护方案,最后通过实例仿真验证,表明该方案能够实现波浪能在配电网不同位置并网的配电网继电保护准确动作。

In order to solve the problem of misoperation and refusal of relay protection caused by the access of the wave energy generating unit to the distribution network.This paper proposes a relay protection improvement scheme using partitioned longitudinal differential protection and adaptive overcurrent protection.Based on the characteristics of power generation,the wave energy generation model is established,and the impact on the reliability and selectivity of the relay protection action after the grid connection at different locations in the distribution network is analyzed.Then the fault calculation method of distribution network with wave energy generation is analyzed,and the treatment schemes of wave energy generation under different faults are analyzed.Then an adaptive current protection scheme is proposed to replace the reliability coefficient of the traditional three-stage protection by using the protection range coefficient,which realizes the real-time adjustment of the protection setting value according to the location of the fault point,and a zonal longitudinal differential protection scheme for distribution network based on different wave energy access points is proposed.A relay protection scheme based on zonal longitudinal difference and adaptive overcurrent protection is formed.The simulation results show that the scheme can realize the accurate action of the relay protection of the distribution network with wave energy connected at different locations in the distribution network.