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

Control Architectures for Smart EV Charging: Meeting NEC 2023, Demand Response, and Safety Standards

An Expert’s Guide to EV Load Management and NEC Compliance Smart EV charging control architectures…

3 weeks ago

How Residential Battery Backup Protects Your Home During Power Outages

Frequent power failures due to severe storms, aging grid infrastructure, and other unpredictable natural disasters…

4 weeks ago

How Temperature Sensors Are Transforming IoT in Smart Devices

The rise of smart devices and the Internet of Things (IoT) has revolutionised the way…

1 month ago

The Growing Importance of Battery Technology in Sustainable Energy

Battery technology has become essential to the global transition to sustainable energy, fundamentally changing transportation…

2 months ago

Hydraulic System: Function, Components, Advantages & Drawbacks  

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

3 months 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 months ago