Intensive bridge-type multi-port hybrid DC circuit breaker and control method

Abstract

The invention provides an intensive bridge type multi-port hybrid direct current circuit breaker and a control method. The circuit breaker comprises a first direct current bus, a second direct currentbus, a main current disconnection branch circuit, n upper current connection branch circuits, n lower current connection branch circuits and n ports, wherein n is an integer not less than 2; each upper current connection branch circuit and each lower current connection branch circuit are connected in series to serve as a group of series branch circuits; each port corresponds to one group of series branch circuits and is connected to a common connection point of the corresponding upper and lower current connection branch circuits; the main current disconnection branch circuit is connected in parallel with each group of series branch circuits; the two ends of the main current disconnection branch circuit are provided with the first direct-current bus and the second direct-current bus respectively; the main current disconnection branch circuit comprises a plurality of current disconnection units connected in series; each current disconnection unit is connected in parallel with a lightning arrester by a main current disconnection switch; each upper current connection branch circuit is connected in series with a diode by a first auxiliary switch; and each lower current connection branch circuit is connected in series with a second auxiliary switch by a fast mechanical switch, and then is connected in parallel with the diode. The natural current conversion characteristics of the diodes are utilized, so that the cost is greatly reduced.

Description

Technical field [0001] The invention relates to the technical field of power electronics, in particular to an intensive bridge type multi-port hybrid DC circuit breaker and a control method. Background technique [0002] DC circuit breakers are one of the key equipment for the construction of flexible DC grids. At present, DC circuit breakers used in flexible DC grids are mainly divided into mechanical DC circuit breakers based on conventional switches, solid-state DC circuit breakers based on pure solid-state power electronic devices and Hybrid DC circuit breaker combining mechanical switch and power electronic switch. Among them, the hybrid DC circuit breaker has both the current passing capacity of a mechanical switch and the current breaking capacity of a solid-state switch, so it has broad application prospects. In research on hybrid DC circuit breakers, in 2012, ABB Group announced that it had developed the world's first hybrid high voltage DC circuit breaker. After that,...

AI Technical Summary

Problems solved by technology

However, in the prior art mentioned above, figure 1 The hybrid DC circuit breaker shown in the figure minimizes the number of power electronic devices used, which leads to defects in the current interruption function. There are problems such as the inability to break the bus failure, and the successive failures of multiple lines. Due to the very serious failure of the DC bus failure , which is extremely harmful, so when the DC bus fails, the circuit breaker loses its protective effect; figure 2 The hybrid DC circuit breaker shown still uses more main breaking branch devices, and the cost of implementation is higher

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