This article describes the Applications of DC Generators, including applications of Separately Excited DC Generators, Shunt Wound DC Generators, Series Wound DC Generators, and Compound Wound DC Generators.
What is a DC Generator?
A DC generator converts mechanical energy into direct current (DC). The working principle of a DC generator is based on Faraday’s law of electromagnetic induction. As per this law, the electromotive force (EMF) is induced in a conductor when it moves in a magnetic field.
DC generators are categorized based on field excitation methods:
- Separately Excited DC Generators
- Shunt Wound DC Generators
- Series Wound DC Generators
- Compound Wound DC Generators
Each type has distinct applications, which are detailed below.
Applications of DC Generators
1. Application of Separately Excited DC Generators
Separately excited DC generators have an independent field winding. The armature current and field current are independent. They are costlier than self-excited DC generators because of separate excitation sources.
Common applications include:
- Electroplating and Electroformin: Separately excited DC generators provide a constant and controlled current supply for precise metal deposition.
- Testing Laboratories: Separately Excited DC Generators provide stable and wide adjustable voltage ranges, therefore they are used in laboratories to conduct experiments and research.
- Battery Charging: They are used for charging systems that require controlled voltage.
- Excitation of Alternators: They provide the required DC excitation for synchronous alternators in power generation systems.
- Supply Source of DC Motors: The separately excited DC generators generate a stable voltage with any variation in field excitation. They are used to supply DC voltage to DC motors to control the speed, For Example- Ward Leonard Systems of speed control.
2. Application of Shunt Wound DC Generators
The field winding of a Shunt-wound DC generator is connected in parallel to the armature. It provides a stable output voltage.
Common applications include:
- Lighting Systems: These generators are used in streetlights, trains, and ships, where a steady voltage supply is required for uninterrupted illumination.
- Small Power Systems: They are used for workshops and small-scale industries.
- Battery Charging: They provide a constant voltage therefore the power supply is reliable for charging batteries in vehicles.
- Field Excitation for Alternators: Shunt wound DC generators are used for excitation for synchronous alternators.
- Emergency Backup Systems: These are used as a backup power source to supply power during power outages.
3. Application of Series Wound DC Generators
The field winding of a Series wound DC generator is connected in series with the armature winding. They deliver high current at low voltage.
Common applications include:
- Arc Welding: Series wound generators are used for arc welding applications, as they can supply a high current for arc welding.
- Voltage Boosters: They are used in transmission systems to compensate for voltage drops.
- Railway Electrification: They are used to power traction motors to deliver high torque at low speeds.
- Excitation Systems: Series wound generators are used to excite the magnetic field of alternators, where a large current is required.
- Heavy-Duty Starting Applications: Series wound generators are used for running heavy-duty engines or machinery that require a high current at the start.
4. Application of Compound Wound DC Generators
Compound wound DC generators have the features of shunt and series wound generators and offer better voltage regulation. They are used in those applications which require a stable output voltage under varying load conditions.
Common applications include:
- Power Supply Systems: Compound wound DC generators are used in elevators, hoists, and cranes because they provide stable voltage under varying loads.
- Marine Applications: They are used in ships for lighting and auxiliary power for reliable operation in harsh environments.
- Traction Systems: They are used in electric locomotives and trams, where stable voltage is required for consistent operation under load fluctuations.
- Rolling Mills and Industrial Applications: Compound wound DC generators are used in rolling mills, presses, and other industrial machines that require a constant power supply under varying load conditions.
- Emergency Power Systems: They are used as a backup generator for critical systems to deliver stable power during load fluctuations.
- Arc Lamps: Compound wound DC generators are used for supplying power to arc lamps used in cinema projectors and searchlights.
Nowadays, the Applications of DC Generators are limited because of technological advancement of AC generators.