Electrical Machines

Speed Control of a DC Compound Motor

A compound motor is a combination of a series and a shunt-wound motor.

Compound-wound motor (long shunt)
Compound-wound motor (long shunt)
Compound-wound motor (short shunt)

The Speed-torque characteristics for a compound motor

Compound motor characteristics

Speed Control of a DC Compound Motor

Speed is controlled by variable resistors in the shunt field and armature circuit. The series winding may be arranged that it aids the shunt field (cumulative compound) or opposes it (differential compound).

Speed control of a DC compound motor (long shunt type)

Cumulatively compounded motors are similar in characteristics to series motors, while differential compounded motors are similar to shunt motors as shown in the figure below:

Characteristics of cumulatively & differential compounded motors

Starting a DC Compound Motor

The compound motor is started with the help of a dc face-plate starter.

Applications of DC Compound Motors

Compound motors are used in applications where a wide speed range is needed but the differentially compounded types are rarely used as they tend to be unstable. The cumulatively compounded types are suitable for heavy machine tools.

John Mulindi

John Mulindi is an Industrial Instrumentation and Control Professional with a wide range of experience in electrical and electronics, process measurement, control systems and automation. In free time he spends time reading, taking adventure walks and watching football.

View Comments

Recent Posts

Hydraulic System: Function, Components, Advantages & Drawbacks  

Hydraulic systems are built in such way that they are able to move large loads…

3 weeks ago

The Role of Precision PCB Design in Aerospace Innovation

Image source: Unsplash Innovation in aerospace engineering is accelerating, driven by rising demands for safer,…

3 weeks ago

Bittele Electronics: Setting the Pace in Turnkey PCB Assembly

Image source: Freepik From consumer electronics, IoT, automotive, industrial control, healthcare, communication systems to aerospace;…

3 weeks ago

The Role of Industrial and Domestic Biomass Boilers

Image source: Unsplash What is Biomass Energy? Biomass energy, a form of renewable energy derived…

3 weeks ago

The Essential Role of Water Turbines in Harnessing Hydroelectric Power

Hydro Turbine, Image source: Energy Education Understanding Hydroelectric Power Hydroelectric power is one of the…

4 weeks ago

Common Types of Differential Pressure Flowmeters

The term ‘flow’ can generally be applied in three distinct circumstances: Volumetric flow is the…

1 month ago