Protective relays have been designed with different technologies resulting in electromechanical, solid-state, and numerical devices. Speed and reliability are the two most important characteristics of a protective relay. Other capabilities such as monitoring and recording are supposed to be of secondary priority. The new technology using combination of field-programmable analog arrays (FPAAs) and digital technologies seems to be a breakthrough and has the potential to provide better performance than the present-day numerical relays. The use of FPAAs for designing and implementing overcurrent relay is investigated. The modeling and simulation of a protected system using Matlab are described. Hardware implementation using FPAAs is described. The practical test for different types of fault conditions is presented. The practical results show the ability of the new protection to response to the steady-state fault condition fastly and also can obtain different types of Time–Current characteristics with high accuracy. Also two types of characteristics Inverse Definite Minimum Time type IDMT type and very-inverse type are implemented, the protection system is tested in a fault of line-to-line type and the results show the ability to discriminate the fault condition and isolate the faulted section only, the remaining network can operate normally.

中文翻译：

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过流保护继电器的设计与实现

保护继电器采用不同的技术设计，产生机电、固态和数字设备。速度和可靠性是保护继电器的两个最重要的特性。其他功能，如监控和记录，应该是次要的。结合现场可编程模拟阵列 (FPAA) 和数字技术的新技术似乎是一项突破，并且有可能提供比当前数字继电器更好的性能。研究了使用 FPAA 设计和实现过电流继电器。描述了使用 Matlab 对受保护系统进行建模和仿真。描述了使用 FPAA 的硬件实现。给出了针对不同类型故障条件的实际测试。实际结果表明，新型保护能够快速响应稳态故障条件，并且能够高精度地获得不同类型的时间-电流特性。还实现了反向有限最小时间类型IDMT类型和非常反向类型的两种特性，保护系统在线到线类型的故障中进行了测试，结果表明能够区分故障条件并隔离故障仅部分，其余网络可正常运行。