High-redundancy synchronous signal switching method for intelligent rectifier bridge

Abstract

The invention provides a high-redundancy synchronous signal switching method for an intelligent rectifier bridge. The method comprises the steps of obtaining the three-phase synchronous signals from all rectifier bridges; if the synchronization signal for driving a trigger pulse comes from the local, immediately starting the synchronization signal switching after the local synchronization signal fails; if the synchronization signal for driving the trigger pulse comes from other intelligent rectifier bridges, determining that the local synchronization signal is normal; if the phase deviation ofthe synchronization signal for driving the trigger pulse and the local same-phase synchronization signal exceeds a preset threshold value, starting the synchronization signal switching; if the localthree-phase synchronous signal fails and the synchronous signal for driving the trigger pulse is not from the local, selecting the synchronous signal for driving the trigger pulse according to the synchronous signal information provided by an online controller; if the synchronization signal switching is started through the method in the step S3, pausing to receive the synchronization signal coordination of the online controller within one second after the switching. According to the invention, the fault response speed of a high-redundancy synchronization scheme is improved, and the reliabilityof the system is improved.

Description

technical field [0001] The invention belongs to the field of power conversion, in particular to a method for switching high-redundancy synchronous signals of an intelligent rectifier bridge. Background technique [0002] like figure 1 As shown, high-power power electronic devices usually need to use multiple thyristor three-phase rectifier bridges to output in parallel. Conventional smart rectifier bridges can generate trigger pulses by themselves according to the control angle data output by the controller, and the trigger pulses used to drive generally use local One phase in three-phase synchronization. The test shows that for 50Hz power frequency signals, the time deviation of the same phase synchronous signal of different intelligent rectifier bridges is very small, about 10 μs, and the time deviation of synchronous signals of different phases is still large even if 120° time compensation is added, which may reach more than 50 μs . Therefore, the smart rectifier bridg...

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Problems solved by technology

[0008] However, the synchronous disconnection fault response of this scheme is slower than that of the conventional scheme. The intelligent rectifier bridge where the fault source is located needs to judge the fault and transmit it to other intelligent rectifier bridges to start switching through communication, which adds a communication delay compared with the conventional scheme.

Moreover, if the controller receives the synchronous fault information later than the smart rectifier bridge, the synchronous phase information coordinated by the controller will not be refreshed in time, and the synchronous phase information coordinated by the controller has a higher priority than the self-selected synchronous phase, which may cause synchronous phase switching further delay, resulting in a large disturbance in the output of the smart rectifier bridge

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