A single-phase fully-regenerative converter for chopper controlled dc drives

High performance dc servo-drives are often supplied from four-quadrant choppers to ensure low armature current ripple and large control loop bandwidths. In order to allow for continued regenerative braking, the dc link voltage is regulated within limits and the energy produced during braking is dissipated in resistances.;The performance of the complete converter with a single phase ac mains is analysed in terms of operation in both motoring and braking modes. The advantages of the scheme are presented and its characteristics are compared to the standard chopper configuration and to the conventional phase-controlled converter systems. It is shown that the system exhibits high power factor and efficiency and is very compact.;In the proposed scheme the energy produced during regeneration is re-injected into the ac mains supply. The scheme consists of adding to each diode of the front end rectifier a transistor capable of conducting the reverse current, and suppressing the dc link capacitor.