Relay protection device is an important part to ensure the safe and stable operation of power system. With the rapid increase of the number of substations and relay protection devices,the daily inspection workload of the operation and maintenance personnel has become saturated,which can not guarantee the high quality and no dead angle inspection every time and brings hidden dangers to the reliable operation of the protection devices. In this paper,an intelligent inspection technology of protection device based on convolution neural network image recognition algorithm is proposed. With the help of the cameras installed in the front and back of the cabinet,the unmanned or few people inspection of the protection device can be realized. Firstly,the intelligent inspection system of the protection device is introduced,and the intelligent inspection items that can be realized is analyzed. The conclusion that convolution neural network can be used for image recognition is drawn. Secondly,taking the platen state recognition as an example,the training sample set and test sample set required by the inspection items are introduced,and the convolution neural network level of the inspection items is given. Then the training sample set is used to train the convolution neural network of different inspection items,and finally each network is tested. The test results show that the neural network image recognition rate of each inspection item is above 96%,even 98%,and the recognition effect is good.

针对双母线接线的母差保护,在母联死区发生故障时,因无法自动识别母线运行状态,导致故障跳闸缺乏选择性且实际故障母线切除时间长的问题,提出一种快速隔离母联死区故障的母线保护原理.新原理将母联断路器两侧CT同时接入母线保护,通过增加母联间隔比率差动,调整小差差流计算方法,使得故障时母线保护装置可自动识别母联断路器分合状态,并准确辨识故障位置,从而提高母联死区保护故障时故障切除的快速性和选择性.仿真结果表明:该方法实现了故障切除的快速性或最小范围隔离故障,提高了母线设备运行状态的自动化以及母线保护装置的智能化水平.

差动速断保护作为比率差动保护的补充,在变压器发生严重区内故障时可以快速切除故障,但CT(电流互感器)饱和可能引起差动速断保护误动.为此,结合一起由于CT饱和导致的差动速断保护误动案例,对保护动作原因、CT饱和原因及电流波形特征进行分析,提出了一种基于采样值差动原理的差动速断保护抗饱和优化措施.仿真测试和波形回放等试验结果表明,优化后的差动速断保护抗饱和性能明显提高,并且速断的动作特性在金属性故障、 转换性故障、 永久性故障等情况下均不受影响.

就地化分布式变压器保护采用子机模式,通过环网传输交流采样、开入量及参数等信息,环网的信息异常将直接影响保护装置的可靠运行.为了解决各种环网异常情况下变压器保护装置不正确动作的问题,以220 kV变压器保护子机配置模式为例,分析了环网可能存在的各类异常情况.并有针对性地提出处理原则及解决方案,基于该方案搭建测试环境,验证了方案的合理性和可行性.该环网异常方案可有效提高就地化分布式变压器保护装置运行的稳定性和可靠性.