A Common DC-Bus-Configured Traction Motor Emulator Using a Virtually Isolated Three-Phase AC-DC Bidirectional Converter

Abstract

An industrial drive testing, with a 'real-machine' can pave way, for some serious issues to test-bench and motor. A slight disturbance in control logic amid testing, can damage the physical machine or drive. Such dangerous testing conditions can be avoided by supplanting real motor with a power electronic converter based 'Motor Emulator' (ME) test-bench system. The conventional ME comprises of two-stage three-phase AC-DC-AC conversion with first-stage AC-DC as emulator and second-stage DC-AC as regenerating unit. This two-stage power conversion, require independent control algorithm, burdening control complexity as well as the number of power electronic switches are quite significant. Hence, to economize and downsize conventional multistage ME system, this paper experimentally validates a common DC-bus-configured ME system with only the AC-DC regenerative emulator stage. A virtually isolated bidirectional two-level three-phase AC-DC converter is proposed as the regenerative emulator converter in a common DC-Bus-configured ME system. The Proposed converter's operating principle along with mathematical design and control strategy are also presented. To validate the operation of the proposed converter as a common DC-bus-configured emulator, a permanent magnet synchronous motors (PMSM) of 7.5 kW is emulated and its experimental results are presented here.