DC Circuit Breaker vs. AC Circuit Breaker
AC circuit breaker is the main power control equipment of substation. Both DC circuit breaker and on-load voltage regulator refer to the transformer tap switch voltage regulation mode. The difference is that the non-excited voltage regulator does not have the ability to change gears with load.
The working quality of circuit breaker directly affects the safe operation of power system. We need to understand the difference between AC and DC circuit breakers from different aspects. In this article, ATO industrial atomation will explore the differences between the two.
Structure:
AC high voltage circuit breaker comprises a shell, a high voltage porcelain flask arranged on the shell, a three-phase high-voltage input end and a three-phase high voltage output end. The shell is provided with a linear electromagnetic actuator, an active electrode, a fixed electrode and a controller. The linear electromagnetic actuator comprises an iron core, a coil, a permanent magnet, an armature, a push rod and an electromagnetic positioning lock, and a push rod is arranged between the active electrode and the linear electromagnetic actuator.
The topology principle of PV DC circuit breaker is complex and diverse. According to the difference of the key on-off devices in DC circuit breaker, DC circuit breaker can be divided into three types: mechanical DC circuit breaker, all solid state DC breaker, and hybrid DC circuit breaker combining mechanical switch and solid state switch.
Feature:
AC circuit breaker adopts three-phase pillar structure, with stable and reliable breaking performance, no combustion and explosion risk, maintenance free, small size, light weight and long service life.
The development of DC breaker is difficult in two aspects, first, DC system current does not have natural zero crossing, can not apply mature arc extinguishing technology in AC circuit breaker. Secondly, the inductive components in DC system store huge energy, which significantly increases the difficulty of DC fault current opening.
Application:
AC high voltage circuit breaker is the main power control equipment of the substation, when the system is running normally, it can cut off and connect the line and various electrical equipment no-load and load current; When the system fails, it and relay protection cooperate, can quickly cut off the fault current, in order to prevent expanding the scope of the accident. Therefore, AC high-voltage circuit breakers with high working quality can ensure the safe operation of the power system.
DC circuit breaker is a combination of power electronic devices, is used to realize the DC off is the current zero crossing. DC solar circuit breakers can be divided into mechanical DC circuit breakers, solid state DC circuit breakers and hybrid DC circuit breakers. The control of power electronic devices and DC arc extinguishing are the key technologies of DC circuit breaker.
