Resonant DC Link Circuit Research Articles

Matlab/Simulink Modeling of Parallel Resonant DC Link Soft-Switching Four-leg SVPWM Inverter

This paper suggests the use of the traditional parallel resonant dc link (PRDCL) circuit to give soft switching to the Four-leg Space Vector Pulse Width Modulation (SVPWM) inverter. The proposed circuit provides a short period of zero voltage across the inverter during the zero-vectors occurrence. The transition between the zero and active vectors accomplished with zero- voltage condition (ZVC), this reduces the switching losses. Moreover, the inverter output voltage Total Harmonic Distortion (THD) not affected by circuit operation, since the zero voltage periods occur simultaneously with zero-vector periods. To confirm the results, balanced and unbalanced loads are used. Matlab/Simulink model implemented for simulation.

Matlab/Simulink Modeling of Parallel Resonant DC Link Soft-Switching Four-leg SVPWM Inverter

This paper suggests the use of the traditional parallel resonant dc link (PRDCL) circuit to give soft switching to the Four-leg Space Vector Pulse Width Modulation (SVPWM) inverter. The proposed circuit provides a short period of zero voltage across the inverter during the zero-vectors occurrence. The transition between the zero and active vectors accomplished with zero- voltage condition (ZVC), this reduces the switching losses. Moreover, the inverter output voltage Total Harmonic Distortion (THD) not affected by circuit operation, since the zero voltage periods occur simultaneously with zero-vector periods. To confirm the results, balanced and unbalanced loads are used. Matlab/Simulink model implemented for simulation.

A novel three-phase, current-fed ZCS-PWM converter incorporating a single resonant DC link soft commutation snubber

This paper presents a novel prototype three-phase current-fed PWM converter with a switched-capacitor-type resonant DC link commutation circuit operating with a new optimum PWM pattern strategy, designed with consideration for a low-pass filter. This converter can operate based on the principle of zero current soft-switching commutation. First, the steady-state operating principle of this converter with a new resonant DC link snubber circuit is described in relation to an equivalent operating circuit, together with the practical design procedure of the switched-capacitor-type resonant DC link circuit. Second, the three-phase current-fed PWM converter with the switched-capacitor-type resonant DC link circuit is discussed from a theoretical viewpoint based on a design example. An actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open-loop control scheme so as to obtain a new optimum PWM pattern. Finally, an experimental setup of this converter is demonstrated in a laboratory to confirm the zero current soft-switching commutation of this converter. Comparative evaluations between current-fed hard-switching PWM and soft-switching PWM converters are implemented from the viewpoint of PWM converter characteristics. © 2000 Scripta Technica, Electr Eng Jpn, 132(3): 57–67, 2000

A Novel Three-Phase Current-Fed ZCS-PWM Converter Incorporating A Single Resonant DC Link Soft Commutation Snubber

This paper presents a novel prototype three-phase current-fed PWM converter with switched-capacitor type resonant DC link commutation circuit operating with a new optimum PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft-switching commutation.In the first place, the steady-state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operating circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit. In the second place, the three-phase current-fed PWM converter with the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard-switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

Low-loss quasi-parallel resonant DC link inverter with advanced PWM capability

A low-loss quasi-parallel resonant DC link (L2QPRDCL) circuit with advanced PWM capability is proposed for soft switching a three-phase PWM inverter. This L2QPRDCL has minimum voltage stress for the devices, and an advanced PWM capability due to the variable zero voltage duration of the DC-link over a wide range. Owing to there being scarcely any freewheeling current in the L2QPRDCL during the zero voltage period, low-loss operation in the resonant circuit can be obtained. As a result, the proposed L2QPRDCL inverter is applicable to the highpower range. Operational principles and detailed analyses are presented. By adopting the non-nearest four vectors (N2FV) selection law in the space vector PWM technique, the narrow pulse problem originating from the link operation, which should be considered in those inverters having resonant DC-links, can be eliminated. Experimental results are also presented to verify the link operation and the performance of the selected space vector PWM method.

Quasi-parallel resonant DC link inverterwith improved PWM capability

A quasi-parallel resonant DC-link (QPRDCL) circuit with improved PWM capability is proposed for the zero voltage switching (ZVS) three phase PWM inverter. The circuit has minimum voltage stresses and improved PWM capability due to the flexible selectability of the on/off instants of the resonant link.

PAM GTO inverter with quasi resonant dc link

This paper presents a technique for realizing PAM capability in the case of a resonant dc link three phase inverter equipped with GTO thyristors. A new quasi resonant dc link circuit together with a sinusoidal PAM for an inverter fed drive are proposed in order to reduce the power losses in the machine and in the inverter. An improved dynamic behavior is also discussed in the paper. The harmonic analysis of the output voltage is presented for different operation modes.