In order to improve the test efficiency and test accuracy of the engineering stability control system, a automated test system solution for the stability control system based on distributed collaborative testing and virtual device communication is proposed, which can adapt to different test situations including multiple stability control stations and single stability control station. The paper introduces the principles and implementation methods of the four key technologies which used in the stability control system test system in detail: wireless collaborative testing technology, virtual simulation of stability control device technology, test case generation technology and test report generation technology. Then a detailed explanation about the realization process of the key technology is introduced through the stability control engineering examples.

电力系统中普遍存在的浪涌冲击会导致继电保护设备采样中出现飞点数据,继而引发保护设备误动作.常规的飞点检测算法主要适用于智能变电站SV(采样值)模式,对于1.2 kHz采样率、采样回路有RC低通的模式,无法可靠识别该类飞点波形.对浪涌电流的不同异常波形及故障波形进行仿真分析,提出了一种新的飞点检测算法.该算法既能可靠识别浪涌电流的飞点特征,避免飞点干扰造成继电保护设备误动作,又能在发生故障时可靠快速开放继电保护设备正确动作.

The correctness of security control system strategy is very important to ensure the stability of power system. Aiming at the problem that the current security control strategy verification method is not enough to match the increasingly complex large power grid, this paper proposes a cyclic verification method of security control system strategy table based on constraints and whole process dynamic simulation. Firstly, the method is improved based on the traditional security control strategy model to make the strategy model meet certain generalization ability; And on the basis of this model, the cyclic dynamic verification of the strategy table is realized based on the constraint conditions and the whole process dynamic simulation, which not only ensures the high accuracy of strategy verification for the security control strategy of complex large power grid, but also ensures that the power system is stable and controllable. Finally, based on a certain regional power system, the optimal verification of strategy table verification experiment is realized. The experimental results show that the average processing time of the proposed method is 10.32s, and it can effectively guarantee the controllability and stability of power grid.

Aiming at the problems of imperfect dynamic verification of power grid security and stability control strategy and high test cost, a reliability test method of power grid security control system based on BP neural network and dynamic group simulation is proposed. Firstly, the fault simulation results of real-time digital simulation system (RTDS) software are taken as the data source, and the dynamic test data are obtained with the help of the existing dispatching data network, wireless virtual private network, global positioning system and other communication resources; Secondly, the important test items are selected through the minimum redundancy maximum correlation algorithm, and the test items are used to form a feature set, and then the BP neural network model is used to predict the test results. Finally, the dynamic remote test platform is tested by the dynamic whole group simulation of the security and stability control system. Compared with the traditional test methods, the proposed method reduces the test cost by more than 50%. Experimental results show that the proposed method can effectively complete the reliability test of power grid security control system based on dynamic group simulation, and reduce the test cost.

In order to solve the problem of incomplete test items or inability to work due to the lack of test conditions for the stability control devices of some substations during the joint debugging and testing of the stability control system engineering, a virtual stability control device platform was researched and developed. According to the data frame format of the communication content between the stability control devices, special software is developed to virtually send and receive these communication messages, and the messages are converted from Ethernet format and El format through the protocol conversion device to realize real-time communication between the control client and the stability control device. Practical application shows that the virtual stability control device platform can not only communicate with stability control devices of different manufacturers, but also flexibly virtualize various types of stability control device communication messages, which is convenient to operate and has good practicability.

在分析阻抗法测距技术与行波测距技术优缺点的基础上,提出一种新的嵌入式行波测距方法.通过将行波测距模块化,并以独立插件方式集成到线路保护装置中,既实现了完整的线路保护功能,还实现了完整的行波测距功能.并且行波测距模块复用线路保护装置的电流采样通道、光纤通信通道,共享线路保护故障数据与行波测距数据,提高了行波测距的准确性.

Abstract Photovoltaic grid-connected interface devices are an important class of smart devices in microgrids. The authenticity and reliability of the data they acquire, as well as the safety and stability of operation, are related to the safe and reliable operation of the entire microgrid system. However, in the context of microgrid intelligence and informatization, information / network attacks will become the norm, making network-dependent information interaction methods subject to various security risks. The photovoltaic grid-connected interface device involves an open operating environment and is extremely vulnerable to network attacks. The attack information will occupy the space or resources of the photovoltaic grid-connected interface device, making the photovoltaic grid-connected interface device unable to respond to other important requests or instructions in a timely manner, and in severe cases, will cause the device to be paralyzed and affect the normal system operation. Aiming at the above problems, this paper presents an attack detection method based on the gradient-upgraded decision tree model, and gives a detailed design process of attack detection model of the photovoltaic grid-connected interface device. That is, the important data flow in the photovoltaic grid-connected interface device is used as the input of the gradient-upgraded decision tree model, and then the gradient-upgraded decision tree model detect or classify flows, finally, intercept the data flow with attack behavior and give a warning prompt, and forward data without attack behaviors normally.

Based on the distributed parameter model of transmission line , the optimization algorithm for two-terminal fault lo-cation is presented by adopting the electrical quantities at two terminals for the calculation of fault location .This algorithm makes a detailed analysis on the relationship for each point between its voltage and current when there has a line fault .Mean-while, this method also utilizes the resistive character of resistance to determine the fault location , which is not affected by the influence of line load , system impedance and transition resistance , and finally obtains a relatively high accuracy .

In smart substation, synchronized sampling is the key issues for the relay protection. Protection device depends on the synchronization of external clock source, when sampling data is transmitted via Ethernet for process level. Sampling synchronization method based on voltage vector (SSMBVV) for busbar differential protection is proposed. When the original synchronization method loses effectiveness and the sampling of merging unit (MU) is out of step, sampling data can be synchronized through the phase difference of voltage vector, which can make busbar differential protection keep on working. The synchronization principle is analyzed, the system wiring diagram is introduced, and the implementation details for SSMBVV are given i.e. calculating the time difference between each MU sampling through the positive sequence voltage; synchronizing the sampling data using quadratic interpolation; synchronization process should be quitted when three-phase PT break is happening. The effectiveness and feasibility of the synchronization method are verified by results of RTDS simulation.