Condition Monitoring Of Circuit Breakers Research Articles

Comprehensive condition assessment of circuit breakers in a power network for maintenance scheduling

AbstractEnhancing preventive maintenance (PM) by using condition monitoring of circuit breaker (CB) can reduce maintenance costs, if enough information about the condition of this expensive equipment are provided. Here, using recorded coil current data of CBs in a power system network and on the basis of their calculated failure probability function, an algorithm is developed for comprehensive CB condition assessment. For this purpose, first, CBs are prioritized according to their cumulative failure probability functions. Second, by introducing healthy/reference CBs and comparing them with the CB with the highest priority, the condition of the latter is assessed that whether it needs maintenance or not. At last, by creating two sets of reference CBs with healthy/reference features and/or mechanisms and comparing them with the features and/or mechanisms of the CB with the highest priority, the failure part of the considered CB that needs to be repaired will be identified. The proposed methodology is straightforward, completely rule‐based and relies just on recorded data and the results have enough clarity and reliability.

Prioritizing CBs Maintenance and Identifying Mandatory Maintenance at Higher Priorities

Preventive maintenance (PM) based on condition monitoring of circuit breakers (CBs) provides proper and timely maintenance of CBs and reduces their failure rate as well as network costs. Condition monitoring of CB considers functional age (not natural age) of CB. This functional age depends on CB erosion. In this paper, CB condition assessment is obtained by monitoring the coil current and its duty cycles. Then, the maintenance priority between CBs of a power network is achieved using self-evaluation decision-making algorithm (SEDMA). This algorithm works in such a way that both the performance of CB is tracked by itself over time as well as compared to other CBs. First, this means the condition of the CB is measured by itself, and if the condition of the CB deteriorates over time, the CB will be given priority for repair. Second, the CB is compared offline with other CBs, and owing to the CB failures compared to other CBs, the priority of CB repair will be finalized. Then, using sensitivity analysis, it is determined whether the CB with the highest priority needs to be repaired or not, and the failure level of each CB will be specified. The case study in this paper concerns about two similar CBs. Also, the effect of improving the condition of the CB will be determined by performing maintenance operations. Eventually, it will be clear which CB has a higher priority for maintenance and whether this higher priority justifies the need for maintenance or not.

Research on Intelligent Communication System for Circuit Breaker Condition Monitoring

Based on the research of vacuum circuit breaker condition monitoring, a circuit breaker state monitoring intelligent communication system using ZigBee + SWM61850 communication configuration is proposed. Under the IEC61850 modelling specification, the state monitoring intelligent electronic device (IED) model is constructed. Combined with the experimental system, data read and write service and message transmission operation of the insulating gas monitoring logic node are simulated. At the same time, the communication system can avoid signal interference in complex electromagnetic environment, reduce data transmission delay, and share real-time monitoring data to multiple functional nodes. These features are beneficial for the improvement of equipment status warning, protection actions, and comprehensive performance evaluation. The communication system integrates the control command transmission with the on-site measurement mode. Simultaneously, the system uses the monitoring data as a constraint for implementing the adjustment operation mode. And the operational stability of the power equipment can be further improved.

Contact Force Monitoring and Its Application in Vacuum Circuit Breakers

Condition monitoring of circuit-breaker (CB) operating mechanisms is one the most important aspects of predictive maintenance. This paper proposes a contact force monitoring scheme for 10 $\sim$ 35-kV vacuum CB. With specially designed force sensors and a signal-processing method, we can accurately find the instants of contact touch and separation. With the indirectly measured contact touch-and-separation instants, we can measure the opening speed, closing speed, and open gap over the travel of each phase. The accuracy of our online monitoring scheme is compared with the conventional offline methods that can directly obtain the instants of contact touch and separation by measuring the connectivity of the contacts. The results show that the accuracy of the scheme proposed in this paper is satisfactory and it can meet the engineering requirements of online condition monitoring of CBs. By introducing a set of new force sensors, some additional information that is useful for overall condition assessment of CB operating mechanism can also be extracted; this will help us to find new ways to improve our CB condition monitoring systems.

A New Method for Mechanical Fault Recognition of Extra-high Voltage Circuit Breaker

It is of important to recognize the mechanical fault for extra-high voltage Circuit Breakers (CBs) in GIS, when the condition monitoring of CBs is realized. In this paper, a new efficiency fault recognition method is provided, by using improved Support Vector Machines (LibSVMs). The recognition methods, ANN and LibSVM are compared on their recognition accuracy, and the results show that the LibSVM is more efficient than ANN. The algorithm of LibSVM is improved by using Genetic Algorithm (GA), and the GA-LibSVM can obtain higher recognition accuracy than usual LibSVM for mechanical fault recognition of CB.

Design of trip current monitoring system for circuit breaker condition assessment

A distributed system, which supports circuit breaker maintenance and asset management, is described. It uses a client/server architecture for propagating expert knowledge from switchgear maintenance experts directly to maintenance operatives for on-site circuit breaker condition assessment and diagnosis. Prior research in the field of distribution level circuit breaker condition monitoring has shown the trip coil of a circuit breaker yields a current profile that, when tripped, can subsequently be interpreted as an indicator of plant health. Exploiting existing circuit breaker test equipment, a centralised archive of asset condition is built from routine tests permitting experts to examine trends in the data and pass their definition of the operating conditions to personnel in the field. This provides diagnostic support to engineers in the field. The system is currently in use as the subject of a pilot study conducted by SP PowerSystems intended to improve its ongoing maintenance and asset management activities.