What is a Power Generator?

Do you know what the use of a power generator is? In this article, we intend to define the power generator for you and introduce its types. So, stay with us to achieve good and comprehensive results from this text.

First, let’s go to the definition of a power generator.

What is a Power Generator?

A power generator is a device that generates electricity and power, preventing interruptions in daily activities or disruptions in work operations. Generators are available in various physical and electrical forms for different applications.

Choosing the best power generator for complex work requirements is a meticulous process that requires precise calculations and should be carried out by the relevant expert to ensure the consumer gets the maximum efficiency at a reasonable cost. We will continue to provide information about generators to ensure you have the best choice in this field. Read on to find out what a city power grid generator key is.

How Does a Generator Work?

A power generator is a device that converts mechanical energy obtained from an external source into electrical energy as output. It’s important to note that a generator doesn’t produce electrical energy itself.

Instead, it utilizes the supplied mechanical energy to create motion and generate an electric current in wire coils within an electrical circuit, producing electricity as the system’s output. This flow constitutes the electric charge supplied by the generator.

The mechanism of a generator can be understood by grasping the operation of a water pump, which induces water flow but doesn’t actually create water; it simply directs the flow of water.

Power generators consist of two main parts: the moving part is called the rotor, and the stationary part is called the stator. Rotors are also classified structurally into two categories: smooth-pole machines and salient-pole machines.

These devices are conventionally categorized based on electrical power in kilovolt-amperes (KVA) or kilowatts (KW). In fact, both the engine must have the power to produce this force (also referred to as horsepower) and the generator must be able to deliver this output with the driving force generated by the engine.

Types of Generator Engines

Types of generator engines can be categorized based on fuel consumption as follows:

– Diesel Gensets

– Gas Gensets

– Dual Fuel Gensets

Main Components of a Generator

The main components of an electric generator are categorized as follows:

1. Engine

2. Generator

3. Fuel System

4. Voltage Regulator

5. Cooling and Exhaust System

6. Lubrication System

7. Battery Charger

8. Control Panel

9. Main Frame

1. Engine

This part is the most vital component of a diesel generator and provides all the mechanical power needed for the generator to operate. The engine in a diesel generator must be chosen very precisely.

Because the mechanical power supplied by an engine can determine the electrical output power of the generator, thus providing electrical power for the diesel generator’s operation. When selecting a diesel generator engine, other factors such as the level of noise produced by the generator and the volume of the fuel chamber are also important considerations.

Diesel engines require electrical power for startup and power generation. Therefore, in most cases, a power source that produces direct current (DC) voltage of around 12 to 24 volts is used to start the engine. This power source can be either an electric motor or a number of batteries that supply this voltage.

2. Generator

The generator is the heartbeat of power production in a diesel generator, taking its primary energy from the engine and generating electricity. The type of generator is determined by our needs. For example, for high-power production, we need an induction generator. The construction of the generator, including the type of rotor and stator winding, and its excitation current, determines the operation of the diesel generator.

4. Fuel System

The fuel tank usually has sufficient capacity to maintain operation for an average of 6 to 8 hours. For small generator units, the fuel tank is often part of the generator base. For commercial applications, it may need to be separate and installed on an external fuel tank stand.

Common components of the fuel system include:

– Pipe connection from the fuel tank to the engine

– Direct fuel supply from the tank to the engine and direct return from the engine to the tank

– Overflow connection from the fuel tank to the drain pipe

– Fuel pump that transfers fuel from the main storage tank to the day tank. The fuel pump typically operates electrically.

– Fuel-water separator, which separates water and foreign matter from the liquid fuel to protect other generator components against corrosion and contamination.

– Fuel injector cleans and sprays liquid fuel into the engine combustion chamber as needed.

5. Voltage Regulator

The voltage regulator is responsible for adjusting the generator’s output voltage, which is achieved through the operation of components such as the regulator, exciter coil, and stabilizing rotor.

6. Cooling System

Cooling generator components is crucial in diesel generators because excessive and prolonged heating can damage parts, affecting the device’s performance. Some diesel generators use liquid cooling, while others use hydrogen gas for cooling purposes.

7. Lubrication System

In diesel generators, there are many mechanical components constantly in operation and motion. Therefore, it is necessary for these components to be lubricated for better efficiency. Typically, the oil level of the generator should be checked every 10 hours of operation, and the oil should be replaced every 500 hours.

8. Battery Charger

The operation of the generator starts with the battery. This component not only charges the battery but also indicates the level of charge. The power of this charger is proportional to the generator’s output power.

9. Control Panel

This part is responsible for the electrical control of the entire system. The parts that need to be controlled include:

– Generator control, which involves controlling all parameters involved in the generator, including voltage, current, and frequency.

– Engine control, where parameters such as speed, brightness level, oil pressure, coolant temperature, etc., need to be measured and controlled.

– On/Off panel, an automatic on/off system present in some diesel generators.

10. Engine Generator Frame/Chassis

The diesel generator can be portable or stationary. Generally, all the above equipment is placed on a platform or chassis.

Generator Exhaust System

Due to the production of toxic exhaust fumes in diesel generators, there is a need for a system to control and separate this exhaust from other parts. For this purpose, this system is located at the engine exhaust outlet. Diesel generators, depending on the requirements, come with additional equipment such as:

– Control board with automatic start during city power outages

– Jacket Water Heater System

– Tropical Radiator (for tropical regions)

– Battery and automatic battery charger

– Elastic shock absorbers between the engine and chassis, as well as between the generator and chassis

– Soundproof and waterproof canopy (enclosure)

Types of Generators

According to their application, manufacturers recommend four types:

– Standby

– Prime

– Continuous

– Multi-purpose

Standby Generator

This type of generator automatically supplies power to subscribers in the event of a city power outage. While some standby generator models may only need to operate for a few hours per month, others, like prime generators, must operate continuously. When a standby generator kicks in, it may operate under specific conditions, such as 10% overload.

Common applications include providing emergency power to hospitals, factories, offices, etc., without being connected to the grid.

Prime Generator

Primarily used in locations requiring temporary power, such as campsites, exhibitions, mining explorations, and camps. These generators should not be used in power plant applications.

They can supply various loads for unlimited periods. These generators are typically capable of providing 100% peak demand and are also available with a 10% overload capacity for a limited time.

(This classification (Rating) may not be applicable to all generator models. Its general applications include serving as a reference power generator and providing remote communication for mines, construction sites, exhibition grounds, festivals, etc.)

Continuous Generator

A continuous generator is used for power plant or national grid applications, capable of providing continuous power output at a steady load up to its rated capacity for unlimited durations. It cannot handle additional loads beyond its rating. For proper selection, consult authorized distributors (in accordance with ISO8528, BS5514, DIN6271, ISO3046, AS2789).

This rating is not applicable to all generator models. General applications include generators that continuously supply constant loads or parallel with the main and continuous network feeders for a maximum allowable level of 8760 hours per year. Additionally, it may be used for network support/peak load (even through actions for 200 hours per year).

Coupled Diesel Generator

Coupling refers to the process of connecting a diesel engine and generator together, installing them on a metal chassis, and placing a control panel next to them.

Structure and Operation Basis of Synchronous Generator

In a synchronous generator, a DC current is applied to the rotor winding to produce a magnetic field. Then, the generator rotor is rotated by the main drive to create a rotating magnetic field in the machine. This magnetic field induces a three-phase voltage in the stator winding of the generator.

Two terms are widely used in describing the winding wires, one being the field winding and the other armature winding.

Field Windings:

Field windings are the wires that produce the main magnetic field in the machine. These windings are located in the rotor for synchronous machines.

What is a Power Generator?


A synchronous generator rotor is essentially a large electromagnet. The magnetic poles in the rotor can be either salient or non-salient. A salient pole is a magnetic pole protruding from the rotor surface. On the other hand, a non-salient pole is a magnetic pole that is flush with the rotor surface. A non-salient rotor is typically used for machines with 2 or 4 poles.

While salient pole rotors are used for 4 poles or more because the magnetic field in the rotor is variable, they are made of thin layers to reduce losses. A constant current must be applied to the field circuit in the rotor to reduce losses. As the rotor rotates, a special arrangement is needed to deliver DC power to its field coils. Two methods are available for this:

1. Providing DC power from an external source to the rotor with slip rings and brushes.

2. Supplying DC power from a DC power source directly mounted on the shaft of synchronous generators.

In a machine, two terms are commonly used to describe the winding wires, “field windings” and “armature windings.”

Field Windings:

Field windings, also known as field coils, are responsible for generating the main magnetic field in the machine. This is while armature windings are the coils where the main voltage is induced. In synchronous machines, field windings are located in the rotor.


A synchronous generator rotor is essentially a large electromagnet that includes magnetic poles, which can be either salient or non-salient. In a salient pole, the magnetic pole protrudes from the rotor’s surface, whereas in a non-salient pole, the magnetic pole is flush with the rotor’s surface. Non-salient rotors are typically used for machines with 2 or 4 poles.

However, slip rings and brushes pose challenges for the field windings of synchronous machine rotors when applying DC voltage. They require more maintenance as the brushes need regular checking to prevent wear. Also, voltage drops in the brushes can cause significant power losses along with field currents.

Due to these issues, slip rings are widely used in smaller synchronous machines, as there is no more economical way to apply field current.

In larger motors and generators, brushless exciters are used to transfer DC field current to the machine. A brushless exciter is a small AC generator with its field circuit on the stator and its armature circuit on the rotor.

The output of the three-phase generator exciter is rectified, and direct current is obtained by a three-phase rectifier circuit mounted on the generator shaft, directly applied to the main DC field circuit.

DC Field Current Control

By controlling the DC field current obtained from the exciter generator (mounted on the stator), the field current on the main machine can be precisely adjusted without the need for slip rings and brushes. Due to the absence of mechanical connection between the rotor and stator, the pilot exciter requires less maintenance compared to slip rings and brushes.

To ensure that the generator operates completely independently of external excitation sources, a small pilot exciter is usually included in the system. This pilot exciter is a small AC generator with permanent magnets, mounted on the rotor shaft, and has a stator winding.

This exciter generates the necessary energy for the exciter field circuit, which in turn controls the main machine’s field circuit. By installing a pilot exciter on the generator shaft, there is no longer a need to supply external electrical power for the generator to operate.

Many synchronous generators equipped with brushless exciters also have slip rings and brushes. Therefore, an additional source of DC field current is available in case of emergency.

Stator of Synchronous Generators:

The stator of synchronous generators is typically constructed in two layers: a self-distributed winding layer with small steps to reduce the harmonics of voltages and output currents.

Considering that the rotor rotates at the speed of the magnetic field, electrical power is generated at a frequency of 50 or 60 Hz. The generator must rotate at a constant speed to produce the desired power. For example, to generate power at a frequency of 60 Hz in a two-pole machine, the rotor must rotate at a speed of 3600 revolutions per minute, and to generate power at a frequency of 50 Hz in a four-pole machine, the rotor must rotate at a speed of 1500 revolutions per minute.

The induced voltage in the stator depends on the flux in the machine, the frequency or rotational speed, and the structure of the machine. The internally generated voltage is directly proportional to the flux and speed, but the flux itself depends on the current in the rotor field circuit. The internal voltage is not equal to the output voltage, and several factors contribute to the difference between these two, including:

– Distortions present in the magnetic field due to the current in the stator, known as armature reaction.

– Self-induced voltage in the armature coils.

– Resistance of the armature coils.

– The effect of the shape of the rotor’s protruding poles.

Regarding which generator to use for mining rigs, using gas generators for miners has the advantage of lower cost and easier access to their fuel. Digital currency mining generators also need to remain active stably for a long time, so using diesel fuel can be problematic and dealing with their fuel can be risky, making it better to use gas generators.

In terms of lifespan and durability, these two types of devices do not differ much, but economically, servicing diesel generators is more cost-effective. However, in terms of depreciation and useful life, it should be said that diesel generators have a longer lifespan and also have less depreciation.

Comparison of Gas and Diesel Generators for Miners

Advantages of Gas Generators:

– Clean fuel that contributes to environmental preservation.

– Easier access to fuel compared to diesel.

– Lower fuel costs and higher fuel efficiency.

– No need for fuel storage due to its availability in the gas network.

– No unpleasant odors compared to other fuels.

Disadvantages of Gas Generators:

– Access to gas may decrease in the event of natural disasters.

– The occurrence of serious hazards in case of pipeline explosions.

– Non-renewable nature of natural gas as a source.

– High initial cost of the equipment.

AC Generators or Alternators:

AC generators, or alternators, operate based on the principle of electromagnetic induction and consist of an armature coil and a magnetic field, similar to DC generators. However, there is a significant difference between them. In DC generators, the armature rotates while the field system remains static, whereas in alternators, the armature is stationary, and the internal magnetic field is rotating.


An alternator is a simple generator without a commutator that produces alternating current. This type of electrical current is highly efficient for power transmission, which is why most large electrical generators are AC type. There are two specific conditions where AC generators differ from DC generators.

Comparison of Gasoline and Diesel Generators for Miners

Advantages of Gasoline Generators:

– Clean fuel contributing to environmental preservation.

– Easier access to fuel compared to diesel.

– Lower fuel costs and higher fuel efficiency.

– No need for fuel storage due to availability in the gas network.

– Absence of unpleasant odors compared to other fuels.

Disadvantages of Gasoline Generators:

– Access to gas may decrease during natural disasters.

– Possibility of serious hazards in case of pipeline explosions.

– Non-renewable nature of natural gas as a source.

– High initial cost of the equipment.

AC Generators or Alternators:

AC generators, also known as alternators, operate based on the principle of electromagnetic induction and consist of an armature coil and a magnetic field. However, there is a significant difference between them. In DC generators, the armature rotates while the field system remains static, whereas in alternators, the armature is stationary, and the internal magnetic field rotates.


An alternator is a simple generator without a commutator that produces alternating current. This type of electrical current is highly efficient for power transmission, which is why most large electrical generators are AC type. There are two specific conditions where AC generators differ from DC generators.

The terminals of the armature coil extend outward. For slip rings, solid rings, which replace the commutator and field coils, energy is supplied from an external DC source and mounted on the shaft of the generator to be operated by the generator itself.

AC generators have low speeds and are constructed with a large number of poles, around 100 poles, both to improve the frequency range and to easily achieve the desired frequency. Alternators are started by high-speed turbines. The frequency of the current taken by the AC generator is equivalent to half the number of poles and the rotation speed of the armature per second.

Due to the possibility of sparking between brushes and slip rings and the mechanical risk of short circuits, a short circuit may occur. Alternators are constructed with a stationary coil that rotates around a rotor. This rotor consists of several magnetic field iron bars. Their operation principle has also been described exactly like AC generators.

Generators with high voltage are directly connected to the power grid without the need for a step-up transformer. This design uses a cable as the stator coil, which is a new idea. High-voltage generators are suitable for any application in thermal and hydroelectric power plants.

High efficiency, lower maintenance costs, less losses, and fewer environmental impacts (due to the materials used) are the advantages of this type of generator. A high-voltage generator operates at high voltage and low current compared to regular generators.

The maximum output voltage of these generators is limited using cable technology, which currently, considering the advanced cable manufacturing technology, can be designed up to a level of 400 kilovolts. The conductor used in high-voltage generators is rotary, whereas in regular generators, this conductor is triangular.

Due to a more uniform electric field in high-voltage generators, the dimensions of the coil are determined based on the system voltage and the maximum generator power. In these types of generators, the outer layer of the cable is connected to the ground along the entire length of the cable, limiting the electric field along the cable and eliminating the need for field control at the end region of the coil.

The presence of partial discharge in any area of the winding increases the safety of operators or repairmen. Connections and terminations are usually made in accessible spaces on-site, so the location of these connections may vary from one power plant to another.

However, these connections are outside the stator core. For example, connections and terminations may be made under the generator or outside the stator frame. Thus, these connections and terminations do not suffer from issues arising from vibrations and oscillations typical of conventional machines.

In the current design of high-voltage generators, two types of cooling systems exist. The rotor and end windings are air-cooled, while the stator is water-cooled. The water cooling system includes XLPE pipes placed within the stator core. Water flows through these pipes, keeping the stator core cool.

Comparing short-circuit currents in power plants equipped with high-voltage generators to those with conventional generators shows that because reactive transformer reactance is eliminated in power plants with high-voltage generators, fault currents are smaller.

An induction generator is a type of electrical generator that operates mechanically and electrically similar to an induction motor. These generators produce electrical power when their shaft rotates at a higher speed than the synchronous frequency of an induction motor. Induction generators are primarily used in wind turbines and some micro-hydro structures and are simpler compared to other types of generators. These generators are powerful and do not require brushes or commutation.

Induction generators are not self-excited, meaning they require an external source to produce rotating magnetic flux, and the power used for this purpose is called active excitation current. The external source can be from the power grid or the generator itself. The rotating magnetic flux of the stator induces current in the rotor and generates a magnetic field.

Comparison of Permanent Magnet Alternators (PMA) and Brushed DC Motors for Home Wind Turbines

Permanent Magnet Alternators (PMA):

Permanent Magnet Alternators (PMA) consist of a set of electric iron cores and a set of permanent magnet cores. Typically, the permanent magnet cores are mounted on the rotor, while the electric iron cores are mounted on the stator. Permanent magnet motors and generator technology have advanced significantly in recent years, resulting in the production of rare earth iron cores. Usually, the coils are wound in standard Y or Delta three-phase configurations.

Permanent Magnet Alternators can be highly efficient, ranging from 60% to 95%. Unlike motors, generators do not require three-phase control. Their power can easily be equalized, and they can charge a battery bank effortlessly.

Brushed DC Motors:

Brushed DC motors are commonly used for home wind turbine applications. In Brushed DC motors, electric iron cores rotate on the rotor with the help of a commutator. This action creates a unified output power. A Brushed DC motor can have a good efficiency of up to 700%.

There are many advantages to using Brushed DC motors. One of these advantages is the lack of need for gears and battery charging even in low winds. Additionally, these motors are easily accessible.

We appreciate your accompanying us until the end of this article. You can certainly contact ElectroShield’s experts for purchasing industrial electrical equipment through our contact section.

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