Method for testing short circuit of medium-voltage busbar of EMU train

Abstract

The invention relates to a method for testing the short circuit of a medium-voltage busbar of an EMU (electric multiple units) train. The method comprises the steps of (1) setting multiple auxiliary converters in the train, setting N coupling switches on the medium-voltage busbar, wherein the auxiliary converters are connected in parallel for output, the coupling switches are switched on in normalworking, and the medium-voltage busbar connects the whole train, (2) firstly confirming whether a short circuit fault is an auxiliary converter internal fault once the vehicle has the short circuit fault and reducing a fault range, (3) allowing a vehicle to start an external short-circuit test program if the auxiliary converter has no internal fault, switching off the N coupling switches, dividing the medium-voltage busbar into N+1 segments, and then inputting the auxiliary converters to judge a faulty busbar segment, and (4) switching off one or two adjacent coupling switches after confirming the faulty busbar segment, switching on coupling switches which are not adjacent to the faulty busbar segment to ensure the normal working of a medium-voltage load of a busbar segment which is not in short circuit. According to the method, a line fault point can be refined, the fault influence range is reduced, even the fault influence can be avoided, and the vehicle operation is maintained to the maximum extent.

Description

technical field [0001] The invention relates to a short-circuit test method for a rail vehicle, in particular to a short-circuit test method for a medium-voltage busbar of an EMU. Background technique [0002] In recent years, the development of high-speed railways is changing with each passing day. As a means of carrying people on high-speed railways, EMUs have become the first choice for people to travel. As an important part of the EMU, the auxiliary converter is responsible for providing cooling for high-voltage traction components and providing power for passenger comfort loads such as passenger room air-conditioning systems, kitchens, and electric boilers. Once a fault such as a short circuit occurs in the auxiliary power supply system, how to minimize the impact range is one of the main guidelines for auxiliary system design. [0003] Usually, multiple auxiliary converters for EMUs provide medium voltage for vehicles. Two or more contactors are installed on the mediu...

AI Technical Summary

Problems solved by technology

[0004] The first way is to install multiple contactors on the entire medium-voltage busbar. Once a short circuit occurs in a certain busbar section, the contactor will be closed, and the power supply will be extended by other auxiliary converters. The extended auxiliary converter will also stop due to short circuit. Until there is only one auxiliary converter left in the whole row to supply power to the medium-voltage loads of the three vehicles, this method will expand the impact area of ​​the short circuit and cause poor availability

[0005] The second method is to install only one contactor on the entire medium-voltage bus. Once a short circuit occurs in a certain bus section, the contactor will open, and the traction power, auxiliary converter and medium-voltage bus of the half-train unit will be directly lost.

[0006] If a short circuit occurs in the two methods, it is impossible to distinguish whether the short circuit occurs inside the auxiliary converter or on the busbar, which will always cause the loss of the medium voltage busbar (at least 4 vehicles), and even expand the scope of the fault

Images