DC Motor Drives

Single Phase Fully Controlled Rectifier Control of DC Motor: The Single Phase Fully Controlled Rectifier Control of DC Motor is shown in Fig. 5.26(a). Motor is shown by its equivalent circuit. Field supply is not shown. When field control is required, field is fed from a controlled rectifier, otherwise from an uncontrolled rectifier. The ac […]

Controlled Rectifier Fed DC Drives: Controlled Rectifier Fed DC Drives are used to get variable dc voltage from an ac source of fixed voltage. Controlled Rectifier Fed DC Drives are also known as Static Ward-Leonard drives. Figure 5.25 shows commonly used Controlled Rectifier Fed DC Drives and quadrants in which they can operate on Va-Ia

Armature Voltage Control using Transformer: Variable voltage for the dc motor control can also be obtained by either using an auto-transformer or a Armature Voltage Control using Transformer with tappings (either on primary or on secondary) followed by an uncontrolled rectifier as shown in Fig. 5.23. A reactor is connected in the armature circuit to

Ward Leonard Method of Speed Control: Known after the name of its inventor Ward Leonard Method of Speed Control (1891), it consists of a separately excited generator feeding the dc motor to be controlled. The generator is driven at a constant speed by an ac motor connected to 50 Hz ac mains. The driving motor

Speed Control of DC Motor Drives: The Speed Control of DC Motor Drives can be any of the following methods: Armature voltage control Field flux control Armature resistance control Speed-torque curves of dc motors for these methods of speed control are shown in Figs. 5.16 to 5.18. Armature voltage control is preferred because of high

Transient Analysis of DC Motor: Starting, braking, reversing speed changing and load changing are the Transient Analysis of DC Motor which commonly occur in an industrial drive. One is interested in knowing how current, torque and speed of the driving motor change with time when under these transient operations. One is also interested in knowing

DC Motor Braking Methods: The need for electric braking was explained earlier, the motor works as a generator developing a negative torque which opposes the motion. Three types of DC Motor Braking Methods are Regenerative braking; Dynamic or Rheostatic braking; and Plugging or reverse voltage braking. 1. Regenerative Braking: In regenerative braking, generated energy is supplied

DC Shunt Motor Starter Design: Maximum current that a DC Shunt Motor Starter Design can safely carry during starting is limited by the maximum current that can be commutated without sparking. For normally designed machines, twice the rated current can be allowed to flow and for specially designed machines it can be 3.5 times. At

Types of DC Motor: The commonly used Types of DC Motor are shown in Fig. 5.1. In a separately excited motor, the field and armature voltages can be controlled independent of each other. In a shunt motor, field and armature are connected to a common source. In case of a series motor, field current is