一种改进的微机保护装置研究

Study on an improved microcomputer protective device

为了解决传统微机保护装置在电力系统断电恢复的瞬间无法快速有效地对已存在显性故障采取相应保护动作的问题,引入一种新型微机保护装置的研究。首先在硬件上利用蓄电池在电力系统断电时给整个微机保护装置供电,并且控制脉冲输出对跳闸电容进行充电,配合电容电压监测电路,时刻保证其电压值达到驱动断路器的临界电压。另外软件上设计了两种算法。一种适用于系统断电恢复时刻的“快速算法”,以保证能快速地切除断电恢复瞬间的故障。另一种适用于系统正常工作时的“精确算法”,以保证整个装置在正常运行时的可靠性。针对不同的情况,分别使用不同的算法,共同构成新型微机保护装置的保护算法。仿真实验表明:所设计的新型微机保护装置相比于传统的微机保护装置,能在更短的时间内切除电力系统断电恢复瞬间已存在的显性故障,并且不影响正常运行时保护动作的可靠性。

In order to solve the problem that a traditional microcomputer protection device cannot quickly and effectively take appropriate protective action to an apparent fault when a power system is restored,this paper introduces research on a new type of microcomputer protection device.First,the battery is used on the hardware to supply power to the whole microcomputer protection device when the power system is cut off,and the pulse output is controlled to charge the tripping capacitor,and the capacitor voltage monitoring circuit is used to ensure that the voltage reaches the critical voltage of the driving circuit breaker at all times.In addition,two algorithms are designed on the software.A“fast algorithm”is suitable for the system power failure recovery time algorithm,to ensure that the power failure recovery moment fault can be quickly cut off.Another“accurate algorithm”is applied to ensure the reliability of the whole device in normal operation.According to different situations,different algorithms are used to form the protection algorithm of the new microcomputer protection device.The experimental results show that compared with a traditional microcomputer protection device,the new microcomputer protection device can cut out the apparent fault existing at the moment of power system power failure recovery in a shorter time,and does not affect the reliability of the protection action in normal operation.