SZH-2型数字低周继电器拒动可能性探讨

SZH 2型数字低周继电器采用CMOS集成电路,外加抗干扰电容,其特点是频率和时间测量精度高、试验方法简单、动作可靠、抗干扰性强。但由于内部设计电路不合理使之在一定的条件下会发生拒动现象。针对该继电器的内部原理图结合具体试验对改进前的继电器进行了动作行为分析和实际试验结果对比,同时对改进后的动作行为进行了细致的分析论证,结果表明改进前该继电器在动作过程中会因所取电压短时降低(到闭锁电压定值以下)而被永久闭锁使继电器拒动,直到系统频率和电压均恢复正常之后才能够解除闭锁。改进后所有功能不变,并消除了拒动现象.

Analysis of the trip-rejection possibility of SZH-2 digital low-frequency relay

SZH-2 digital low-frequency relay, which employs with CMOS circuit and anti-interference capacitor, has many special characteristics, such as high measuring accuracy of frequency and time, simple test method, good trip reliability and strong anti-interference. Because of the unreasonable design of inside circuit, the original relay would reject to trip at some special circumstances. In according to its inside principal diagram and the test, a comparison of the trips analysis and the real test result is made. The result shows that the original relay could be locked when the voltage reduced shortly below the setting value until the system frequency and voltage restored to standard status. The advanced relay trip actions are also precisely analyzed and proved that there is not trip-rejection or the change of the function.