Papers by Keyword: Current Source Inverter

Abstract: This paper proposes a new regular sampled pulse width modulation (PWM) for three-phase current source inverters. The theoretical basis of the proposed modulation strategy is described, including dwell time calculations and switching sequence selection. This strategy is well suited for digital implementation, and enjoys all the flexibilities and degree of freedoms as in space vector modulation. In addition, it ensures a minimum number of switching transitions per fundamental cycle, unlike other PWM methods. It is therefore promising for high-power medium-voltage applications. The validity of the proposed modulation strategy has been confirmed using simulation and experimentation. To furthermore substantiate the superiority of the proposed modulation strategy against other PWM methods, its performance is compared to sinusoidal PWM, selective harmonic elimination, and space vector modulation.

Abstract: This paper presents a new csi-hvusspwm technology with many advantages such as the better output waveforms and the high utilization ratio of dc voltage based on the study of the csi-spwm technology and csi-tpwm technology. Theoretical derivation and modulation principle of csi-hvusspwm technology are described in detail. Finally, the simulation results validate the feasibility and effectiveness of this novel technology.

Abstract: For high-power current source inverter work object is a nonlinear time-varying systems, which could easily lead to the inverter voltage and current output waveform distortion, this paper firstly proposes a new variable-rate reaching sliding mode control scheme to solve the above problems existing in current source inverter system. In this scheme, we construct the variable structure model of the system, determine the sliding surface, give the variable-rate reaching control law and deduce the sliding domain. At last, the simulation result proves the validity and superiority of the scheme.

Abstract: A generalized three-phase multilevel current-source inverter (MCSI) topology is proposed by implanting the generalized N-level current cells into a three-phase MCSI topology which is derived from the three-phase multilevel voltage-source inverter (MVSI) topology through dual conversion. In the generalized three-phase MCSI topology, each intermediate dc-link current level can be automatically balanced without adding any external circuits, thus a true multilevel structure is provided. Output current of each phase is independently modulated because of being supplied with two DC current-sources. This allows the wealth of existing knowledge relating to the operations, modulations and control strategies of multilevel VSI to be immediately applied to such multilevel CSI. Simulation results of 5-level and 7-level CSI systems are presented to verify the proposed three-phase MCSI topology.

Abstract: This paper describes a simple fault protection system for Current Source Inverter built with normally-on SiC JFETs. Because all transistors are in on-state after loss of the gate drive(s) supply, list of possible fault modes is extended in reference to standard inverters. That is also why an additional normally off switch is introduced in the DC link. Operation principles of the protection system which follows the drain-source voltages of JFETs and the current of the DC link are presented. The 2kVA/100kHz model of the inverter equipped with the proposed system is validated via various laboratory tests including short-circuits and the auxiliary supply turn off.