Compact direct-current circuit breaker of shared branch and control method of compact direct-current circuit breaker

Abstract

According to the branch-sharing compact direct-current circuit breaker and the control method thereof provided by the invention, when the circuit breaker is in normal through-flow, the current is conducted through the main mechanical switch of the through-flow loop, and the loss of the direct-current circuit breaker is extremely low; according to the direct-current circuit breaker, the quick operating mechanism is adopted to drive the mechanical switch, fault current can be cut off in a short time, the reclosing function is achieved, faults are isolated, and a flexible direct-current system is protected. According to the control method, the commutation branch and the energy absorption branch are shared, oscillation current with the amplitude gradually increased is generated by the commutation branch, the oscillation current is superposed on the current of the main loop to generate a current zero crossing point, and finally the current is cut off by the mechanical switch. And one circuit breaker can be used for switching on / off and isolating fault current of all external lines on one bus. It is guaranteed that only one direct-current circuit breaker needs to be configured for each direct-current bus, the cost and the size of the direct-current circuit breaker in a direct-current power grid are greatly reduced, and technical guarantee is provided for construction of the direct-current power grid.

Description

technical field [0001] The invention belongs to the technical field of electric power equipment, in particular to a compact DC circuit breaker with a shared branch and a control method thereof. Background technique [0002] At present, DC circuit breakers mainly include mechanical DC circuit breakers and hybrid DC circuit breakers. Among them, mechanical circuit breakers have become the preferred technical solution for DC circuit breakers due to their small on-state loss. With the significant increase in demand for distributed DC power supply systems for new energy sources, especially in offshore wind power flexible multi-terminal DC systems, the grid erection space resources are limited, the offshore platform’s carrying capacity is limited, its fault current is large and its rising rate is fast. The volume space, weight, breaking capacity, breaking speed and cost of circuit breakers are extremely demanding. like figure 1 As shown, the traditional DC circuit breaker can on...

AI Technical Summary

Problems solved by technology

The number of DC circuit breakers that need to be configured in the DC grid is huge, and the DC circuit breakers are expensive and have a large space, which leads to a substantial increase in the construction cost of the DC grid and cannot be applied to the flexible multi-terminal DC system.

Images