Abstract: An ac drive controller including a phase assembly for each phase of a polyphase supply to a motor, each phase assembly including an invertor module and a corresponding filter module. The electrical interconnections between each filter module and each invertor module occur through electrically conductive clips and corresponding bus bars to which the electronic switching devices in the invertor are also connected. The filter and invertor module interconnections are located as close as possible to the points where the electronic switching devices are connected to the buses to minimize stray reactances while allowing for simplified assembly and servicing of the controller.