A Hybrid Fast DC Circuit Breaker

Abstract

The invention provides a hybrid type rapid direct current breaker, comprising: a main flow branch, a current transferring branch and an energy consumption branch. All are connected in parallel. The main flow branch comprises a rapid mechanical switch unit and a main branch sub-module unit. The two units are in series connection. The current transferring branch comprises valve module units in successive cascade connection with each valve module unit comprising a plurality of semiconductor modules in series connection. The energy consumption branch comprises energy consumption components in successive cascade connection. According to the invention, the design of the breaker structure is such a design featuring the electrical topology corresponding to modularization. This means that for the application requirement of different voltage grades, the structure can be expanded to do so. As the breaker adopts a single platform supporting structure, all functional units can be integrated onto the platform, therefore, making the equipment highly integrated, small in size, and strongly resistant to earthquakes. Highly reliable and flexible in structure, better electric compatibility can be achieved. With the breaker, it is possible to rapidly cut off the current in fault when the direct current system meets a fault.

Description

technical field [0001] The invention relates to a circuit breaker, in particular to a hybrid rapid direct current circuit breaker used for current interruption of a high-voltage direct current transmission system. Background technique [0002] The current characteristics of direct current make current breaking obviously different from alternating current breaking. Since there is no current zero crossing point in direct current, there are many problems when relying on traditional mechanical switches to break direct current, such as arc extinguishing, insulation and mechanical structure design For this reason, a circuit breaker for breaking DC current is required. According to the arc extinguishing method, there are generally mechanical DC circuit breakers, solid-state semiconductor DC circuit breakers and hybrid DC circuit breakers. The mechanical circuit breaker uses self-excited oscillation to realize the current zero-crossing point, and at the same time uses nonlinear ene...

AI Technical Summary

Problems solved by technology

The semiconductor switch of the circuit breaker adopts a half-bridge circuit design, that is, the single-stage semiconductor component is composed of two fully-controlled devices, which determines that the short-circuit current withstand capacity of the circuit breaker is directly determined by a single fully-controlled semiconductor device. There is no organic combination of modular design and structural design. The high-speed switch described in this patent does not use modular component design. Modular design of voltage levels, DC projects with different voltage levels need to design different circuit breaker structures

The international patent WO 2013 / 127463 A1 applied by ALSTOM also describes a hybrid circuit breaker composed of a semiconductor switch, a charging capacitor branch and a non-linear protection energy consumption branch. The key components of the breaker to break the fault current have large capacitance and structural volume. The overall equipment structure design is complex and requires a large structural space, and it is obviously difficult to realize the DC current zero-crossing design. Therefore, in hundreds of There are obvious defects in the application of kV DC engineering

The international patent WO 2013 / 045238 A1 applied by SIEMENS company, the device described in the patent is a hybrid circuit breaker composed of numerous semiconductor component switches, resistance capacitor devices, nonlinear energy consumption components and mechanical switches, the electrical design is complex, and the control and protection system It is also very complicated. The design is analyzed from the perspective of engineering practical application, and it only stays in the conceptual design stage. Therefore, it does not have the value of heroic implementation in high-voltage DC engineering applications.

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