ZVS inverters for brushless DC motors in EMA applications

Electromechanical actuators (EMAs) are being examined as a replacement for the hydraulic systems used in thrust vector control and propellant control valves on space vehicles. In these high power electromechanical systems, the flow of energy from the source to an electric motor is regulated by a three-phase inverter. The use of zero-voltage-switching techniques in this inverter can reduce electromagnetic interference and improve efficiency. Zero voltage switching can be achieved by augmenting the inverter with a waveshaping circuit. This paper discusses the use of zero-voltage-switching techniques in three-phase inverters for EMA systems which utilize a brushless DC motor