低压断路器机械特性状态监测方法研究

Research on Condition Monitoring Method of Mechanical Characteristics of Low-Voltage Circuit Breaker

低压断路器作为低压配电系统中重要的保护装置,主要用于切断和接通负荷电路以及断开故障电路,以保证系统安全稳定运行。断路器内部机械部件的可靠运行对其操作性能至关重要,随着操作次数的增加,断路器的机械特性将逐渐退化,最终破坏操作机构的正常运动,进而引起合分闸失败,甚至对配电系统造成影响。为了准确监测低压断路器的机械特性,提出基于操作机构运动特性的低压断路器机械特性状态监测方法。首先,根据操作机构的运动特性分析机构合分闸过程中的旋转特征,并选取能够反映操作机构性能的特征量;其次,定量分析触头磨损、机构磨损和分闸弹簧断裂对机构性能的影响,通过实时监测特征量的变化实现机械部件性能的诊断;最后,通过定量计算触头超程性能退化对分闸能量和机构性能的影响,实现触头超程状态的监测。实验结果表明,所提方法能够有效监测低压断路器机械部件的状态信息,实现触头超程状态的准确评估,为低压断路器机械特性状态监测与诊断提供一种新方法。

As an important protective device in low-voltage distribution system, low-voltage circuit breaker is mainly used to cut off and connect load circuit and cut off fault circuit to ensure the system safe operation. The reliable operation of its internal mechanical components is very important to the operating performance of the low-voltage circuit breaker. With the increase of the number of operations, the mechanical characteristics of the circuit breaker gradually deteriorate, and eventually destroy the normal movement of the operating mechanism, and then cause the failure of closing and opening, and even affect the distribution system. In order to accurately monitor the mechanical characteristics of low-voltage circuit breaker, a condition monitoring method for mechanical characteristics of low-voltage circuit breaker based on the motion characteristics of operating mechanism is proposed. Firstly, according to the motion characteristics of the operating mechanism, the rotation characteristics of mechanism in the process of closing and opening are analyzed, and the characteristics that can reflect the performance of the operating mechanism are selected. Secondly, the effects of contact abrasion, mechanism abrasion and opening spring fracture on the performance of the mechanism are quantitatively analyzed, and the performance monitoring and diagnosis of mechanical parts are realized by monitoring the changes of characteristic quantities in real time. Finally, the influence of contact overtravel performance degradation on opening energy and mechanism performance is quantitatively calculated to realize the monitoring of contact overtravel state. The experimental results show that the proposed method can effectively monitor the state information of the mechanical components of lowvoltage circuit breaker, realize the accurate evaluation of the contact overrange state, and provide a new method for the monitoring and diagnosis of the mechanical characteristics of low-voltage circuit breaker.