Method for breaking high-voltage (HV) superconducting current-limiting direct current (DC) circuit breaker

Abstract

The invention provides a method for breaking a high-voltage (HV) superconducting current-limiting direct current (DC) circuit breaker. The method comprises the following steps: when a HVDC side is in short-circuit fault and current / current rising steepness rises rapidly and reaches a critical value of a current limiter, a superconducting material quenches immediately, impedance rises steeply, short-circuit current is limited within set values, and meanwhile, an instruction is sent to an ultra-quick mechanical switch; the ultra-quick mechanical switch acts immediately, enables contacts to separate at an ultrahigh rigid separating speed so as to form a physical gap and generate electric arcs, and immediately sends a breaking instruction to a power electronic switch; the power electronic switch quickly breaks the short-circuit current and enables the electric arcs between the contacts to be extinguished, so as to form an isolated fracture; when the contacts are separated to final open positions and current in a lightning arrester is attenuated to zero, the HV superconducting current-limiting DC circuit breaker completes a whole breaking process, and a HVDC transmission power grid is isolated from a faulty line. The method has the advantages that the cost performances of different components are taken into account comprehensively, so that the cooperation is optimized; the number of components and devices is reduced as much as possible, so that the size is reduced, the weight is reduced, and the reliability is improved.

Description

technical field [0001] The invention relates to a circuit breaker, in particular to a high-voltage superconducting current-limiting DC circuit breaker and a breaking method thereof. Background technique [0002] Reliable and efficient power supply and the exploitation and utilization of renewable resources pose great challenges to improve power transmission modes. Based on the advantages of low loss, long-distance, high-power transmission, more efficient connection of renewable energy into the grid, and flexible operation, high-voltage direct current transmission has received new attention. In particular, the emergence of flexible DC transmission technology based on voltage source converters makes the preparation and development of multi-terminal HVDC grids possible and more and more attractive. A DC circuit breaker with the functions of quickly breaking DC fault current and isolating faults is an essential and crucial component for realizing a multi-terminal high-voltage D...

AI Technical Summary

Problems solved by technology

This is undoubtedly a great progress, but there are still some defects; such as the large number of power electronic components required, and many standby backup components are required from the perspective of safety and reliability; the volume is large, the control system is complicated, the price is expensive, and the protection and control coordination is not yet available. It needs to be considered; the type test items need to be further discussed and determined; especially the reliability and operation of power grids with different topological structures need to be tested.

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