How does torque control work on a DC motor?

How does torque control work on a DC motor?

Complete torque control may be dependent on the use of an external torque reference circuit or control that has flexibility and adjustability to compensate for any drive/motor shortcomings. 3.) DC Drives – Velocity (Speed) Control: To regulate DC motor speed, the drive will normally control the armature voltage.

How does a constant torque variable frequency drive work?

Without speed feedback from the motor, drives rely on electrical feedback in the form of current and voltage as well as phase angle vector analysis between the two to regulate the speed loop. For example, if speed drops, the drive will have to increase voltage through its IGBT gating control on the output to effect a speed increase.

How is torque related to current and power?

The torque is the product of the flux and the torque-producing current, i.e. the component of current which is in phase with the voltage. In DC motors and AC induction motors, the magnetising current is usually constant regardless of torque, unless a special energy-saving control is applied at reduced torque.

What’s the relationship between current and DC motor?

To further simplify the torque equation, the number of poles (P), the number of coils (Z), and the geometric factors (2πA) can be combined to form the torque constant, k T, which is specific to the motor. This simplifies the torque equation to:

Can a straight torque control cause maximum speed?

Straight torque control can have the undesirable effect of causing run-up to maximum speed in the event of web breakage or load loss unless the drive includes a “Max speed or voltage limiting” function..

How does a DC drive control the speed of the motor?

DC Drives – Velocity (Speed) Control: To regulate DC motor speed, the drive will normally control the armature voltage. How well it does this depends on what feedback signal is used to represent the motor speed.

What are the characteristics of a d.c.motor?

In order to effectively design with D.C. motors, it is necessary to understand their characteristic curves. For every motor, there is a specific Torque/Speed curve and Power curve. The graph above shows a torque/speed curve of a typical D.C. motor.

How to calculate the torque of an electric motor?

For three phase AC motor torque formula: T = 1.732 x V x I x pf / (2 x pi x N (rpm) / 60) V => Input AC Voltage in volts (line to line voltage) I => Input AC Current in amps. Also while reducing the motor power the torque will be reduced.

How can I increase the torque of my induction motor?

In order to increase the starting torque, extra resistance should be added to the rotor circuit at start and cut out gradually as motor speeds up. The maximum torque is directly proportional to square of rotor induced emf at the standstill.

Why do you need a reaction torque sensor?

A reaction torque sensor often is required to carry significant extraneous loads, such as the weight of a motor or, at least, some of the drive line.

How is load torque related to motor speed?

Load Torque: For a fixed voltage, the speed of the motor is inversely affected by the load. Increase in load torque = decrease in speed If you have any questions about this relationship, or how the theory applies to a ‘real-world’ motor, please contact our sales engineers to help with your application.

How to design a full state feedback controller?

Since all of the state variables in our problem are very easy to measure (simply add an ammeter for current, a tachometer for speed, and a potentiometer for position), we can design a full-state feedback controller for the system without worrying about having to add an observer. The control law for a full-state feedback system has the form .

How to calculate the settling time of a DC motor?

By ignoring the effect of the first pole (since it is faster than the other two poles), the dominant poles correspond to a second-order system with = 0.5 corresponding to 16% overshoot and = 100 which corresponds to a settling time of 0.040 seconds.