Present Federal regulations which specify maximum instantaneous circuit breaker settings for the short-circuit protection of coal mine trailing cables are discussed. Characteristics of mine power systems, which limit short-circuit current in dc trailing cables and minimum expected short-circuit currents for dc 300 and 600 V trailing cables, are analyzed. New maximum instantaneous circuit breake...

The state of the energy-absorption branch MOV in hybrid DC circuit breaker (DCCB) has a very important impact on short fault breaking operation breaker. Therefore, it is necessary to evaluate MOV, which also called “sleep component”. Due DCCB being placed indoors, aging mainly caused by short-circuit impulse current. this paper focuses study characteristics MOV. dynamic simulation system was bu...

To reduce the pressure on contacts and circuit breaker and realize the zone selective interlocking (ZSI) function above the instantaneous protection threshold (e.g., >10In), the short circuit current needs to be early detected. The state-of–art of early short circuit detection (ESCD) method is reviewed. Based on the equivalent model of the short circuit, a new method based on the current and it...

The assurance of the reliability for the transformation substations is one of primary goals of the manufacturers and distributors of electricity. Therefore, a proper monitoring and maintenance program is required. The circuit breaker is a complex device, subject to the thermal and mechanical stresses during the normal or fault currents switching. The substations are frequently equipped with SF6...

Circuit breakers (CBs) are very important elements in the power system. They are used to switch other equipment in and out of service. Circuit breakers need to be reliable since their incorrect operation can cause major issues with power system protection and control. Today’s practice in monitoring circuit breaker operation and status in real time is reduced to the use of Remote Terminal Units ...

-This paper presents an overview of resource optimization approach for transmission system maintenance selection and scheduling. The approach is based on failure rate estimation and risk reduction calculation followed by resource optimization. It also presents probabilistic models developed for circuit breakers and power transformers. An effort is made to quantify the effect of maintenance usin...

Low-cost step-up/step-down converter accepts 2V to 16V inputs 10 Visible-laser driver has digitally controlled power and modulation 11 High-voltage circuit breaker protects to 26V 13 Dual comparator forms temperature-compensated proximity detector 15

Low-cost step-up/step-down converter accepts 2V to 16V inputs 10 Visible-laser driver has digitally controlled power and modulation 11 High-voltage circuit breaker protects to 26V 13 Dual comparator forms temperature-compensated proximity detector 15