Inverter operation of fully controlled converter

In fact, for most operating conditions, t, is discontinuous. This makes prediction of performance difficult. Analysis is simplified if continuity of armature current can be assumed. Analysis for both continuous and discontinuous current is presented in the following sections. Developed by Therithal info, Chennai. Toggle navigation BrainKart. Posted On : C Motor Drive The basic circuit for a single-phase separately excited dc motor drive is shown in Fig.

Basic Equation I The armature circuit of the de motor is represented by its back voltage eg, armature resistance Ra, and armature inductance LaasshowninFig. Back voltage: Note that the inductance La does not absorb any average voltage.

From equations 2 and 6, the average speed is In single-phase converters, the armature voltage ea and current t, change with time. Classification of Load Torques. When these diodes are switched with Thyristors, then it becomes phase control rectifier. The main application of these rectifiers is involved in speed control of DC motor.

A phase control Thyristor is activated by applying a short pulse to its gate terminal and it is deactivated due to line communication or natural.

And each kind includes a semi, full and dual converter. Single Phase Controlled Rectifiers are classified into different types. The basic working principle of a PCR circuit is explained using a single phase half wave PCR circuit with a RL load resistive shown in the following circuit. Thus, the 3-pulse converter acts as an inverter and a rectifier.

The figure below shows a six-pulse bridge controlled converter connected to a three-phase source. Using the same converter configuration, it is possible to combine two bridges of the six-pulse to obtain a twelve or more pulses converter.

When commutation is not available, two diodes will conduct at any particular time. Furthermore, to obtain a voltage drop across the load, two diodes must be at positioned at opposite legs of the bridge. For example, diodes 3 and 6 cannot be ON at the same time. Therefore, the voltage drop across the DC load is a combination of line voltage VL from the three-phase source. It is important to note that more the number of pulses, the greater the utilization of the converter.

In addition, the fewer the number of pulses the lesser the utilization of the converter. Pavan Lalwani. Himanshu Vasishta. Akshay Magre. Pradeep Kshetrapal.

Richa Maheshwari. Power Electronics - Pulse Converters Advertisements.