The high frequency PWM current-source inverter: its inherent problems and their remedies

Current source inverters (CSI) with high frequency pulsewidth modulation (PWM) have been investigated for a short time. These investigations show that the circuit topology, the demands on the switching elements as well as the problems occurring with this type of inverter are in most aspects dual to those of the well-known voltage source inverters (VSI). Some of the major problems associated with this new form of CSI are: filter resonances, demands on the PWM, interaction of inverter and AC-source/load, stress of the semiconductors, snubbers for the semiconductors, and overvoltages. The cause of these problems, as well as methods to overcome them, are discussed. The investigations were carried out on a 10 kVA experimental ASM-drive. Results of that drive are presented