近区电压优先原则的数字化实现方案

Digital implementation of the principle for selecting synchro-voltage in 3/2 breaker system

3/2断路器接线的一次系统的运行方式多种多样,采用同期合闸方式时,每台断路器两侧的同期电压并非固定。在实际工程中,同期电压的取法采用的是"近区电压优先原则",并使用相关的隔离开关和断路器的辅助触点来实现电压的切换。这种做法使同期回路的接线复杂,同期电压选择可靠性不高,另外也不利于同期合闸装置和保护的一体化。该文叙述了一种基于可编程逻辑器件的近区电压优先原则的数字化实现方案,在不牺牲系统稳定性的前提之下,简化了同期回路的接线,同时也增强了同期合闸装置和保护的可结合度,是对这一问题的一种新思考。

The diverse operator modes of the 3/2 breaker systems don′t make the U-line and the U-bus of an open breaker fixed. In engineering application, the selection of the synchronism voltage is usually according to the principle that the nearest voltages are prior. Traditionally, the relevant auxiliary contacts of the switches and breakers are used to switch the synchro-voltage, which results in the complexity of the synchro-check circuit. This kind of implementary scheme also makes the integration of protection system and the synchro-check recloser almost impossible .Although engineers try different ways to decrease the complexity of the synchro-check circuit, many of those are still not satisfactory. This paper describes a digital implementation of synchro-voltage selecting principle based on programmable logic device (PLD), which can decrease the complexity of the synchro-check circuit and increase the combination with the protection system. This is a new thought on the problem.