Non-arcing hybrid DC circuit breaker and method for achieving non-arcing breaking and closing

Abstract

The invention discloses a non-arcing hybrid DC circuit breaker and a method for achieving non-arcing breaking and closing belonging to the technical field of DC circuit breakers. The non-arcing hybrid DC circuit breaker CB comprises a silicon controlled rectifier SCR, a mechanical switch K, a power supply side capacitor C1, a load side capacitor C2, a resistor R, diodes D1 and D2 and a current limiting inductor L, wherein a positive electrode and a negative electrode of the silicon controlled rectifier SCR are connected with two ends of the mechanical switch K. The non-arcing hybrid DC circuit breaker simultaneously meets an arcing electric field intensity condition and an arcing voltage condition of dielectric breakdown when designed aiming at the arc generation requirements; a certain safety allowance is considered; no arc is generated in the breaking and closing processes; the condition that a DC arc is difficult to extinguish after being generated is thoroughly avoided; a mechanical contact is not corroded; a fully-controlled power device and an additional auxiliary mechanical switch are not needed; the control is simple; the cost is low; and the reliability is high.

Description

technical field [0001] The invention belongs to the technical field of DC circuit breakers, in particular to a hybrid DC circuit breaker without arcs and a method for realizing opening and closing without arcs. Background technique [0002] The low-voltage DC power system is mainly used in rail transit, ships, aviation and other occasions. The medium-high voltage DC transmission system is mainly used in long-distance high-power transmission and networking of asynchronous AC systems. It has the advantages of less line investment, no system stability problems, and adjustment Fast, reliable operation and other advantages. Although the operating characteristics of DC systems in different application places are obviously different, they all require the core power equipment of DC circuit breakers. [0003] Existing DC circuit breakers are mainly divided into mechanical type, power electronic all-solid-state type and hybrid type combining mechanical and power electronics. Among t...

AI Technical Summary

Problems solved by technology

Among them, the mechanical and hybrid types mostly focus on how to extinguish the arc, but the lack of a natural zero-crossing point makes it more difficult to extinguish the DC arc than the AC arc, and the erosion of the contacts by the arc leads to frequent maintenance of the circuit breaker, which reduces the reliability of the system. sex

The all-solid-state DC circuit breaker composed of power electronic devices can break without arc, but it is limited by the capacity of power devices. When it is used in the high-voltage field, a large number of devices need to be connected in series and parallel, resulting in complex structure and control, low reliability, and system failure. Disadvantages such as large loss during operation and high cost

Chinese invention patent CN103632895A "A DC circuit breaker" proposes a DC circuit breaker topology and its control method without arc breaking, but the invention patent does not clarify how to ensure that no arc is generated during breaking; and this DC circuit breaker Multiple auxiliary mechanical switches are required to cooperate, resulting in complex control and reduced reliability; there is a problem of closing arc

Images