Understanding Shunt Generators and Their Types

A shunt generator is a type of generator where the field winding is connected in parallel with the armature. This design allows the field current to flow independently of the armature current.

The field winding is typically connected to a separate source of DC power, such as a battery or a separate DC generator. This setup enables the field current to remain constant, regardless of the armature current.

Shunt generators are often used in applications where a constant voltage is required, such as in power supplies or lighting systems. They can also be used in conjunction with other types of generators to provide a stable power source.

In a shunt generator, the field winding is typically made of a few turns of heavy-gauge wire, which provides a high degree of stability and reliability.

Check this out: Can a Ac Motor Be Used as a Generator

The working principle of a DC shunt generator is based on electromagnetic induction, where the field winding is connected in parallel to the armature conductors. This allows the generator to produce a DC output.

The field winding includes a number of windings with a thin wire having high resistance, and a small current supplies the field winding while a huge current supplies the armature winding. The shunt field current is 'Ish' and armature current is 'Ia'.

The load current is 'IL' and the armature current can be provided through Ia = IL + Ish. The shunt field current Ish can be calculated through Ish (Shunt field current) = V/Rsh, wherever Rsh is shunt field resistance.

The DC shunt generator diagram shows the connection of load beyond the armature. The terminal voltage can be provided through V = Eg – Ia Ra – Vbr, and the developed power within the DC generator is Eg Ia.

The working principle of a DC shunt generator is based on electromagnetic induction, where the connection of the field winding is shunt towards the armature.

In this type of generator, the conductor is turned within a permanent magnetic field, which induces an electromagnetic force within the conductors arranged under the magnetic field influence.

Check this out: Dc Electromagnetic Generator

This induced emf is utilized for generating energy, which can be used through other mechanical devices.

The flow of current-induced throughout the armature winding is irregular, so the armature winding output is irregular as well.

AC is changed into DC due to the commutator, resulting in a DC output within the DC shunt generator.

The electromagnetic force induced within the conductors is based on the electromagnetic Faraday’s law, which states that an electromagnetic force will be induced within the conductors once a conductor is turned within the magnetic field.

This principle is the foundation of how a DC shunt generator works, allowing it to convert mechanical energy into electrical energy in the form of DC power.

The DC shunt generator diagram is a crucial part of understanding how it works. It shows the field windings connected in parallel through the armature conductors.

The field winding includes a number of windings along with a thin wire including high resistance. This is a key characteristic of a DC shunt generator.

Readers also liked: How Is a Shunt Wound Dc Generator Connected

The connection of load can be done beyond the armature, as shown in the diagram. A small current will supply throughout the field winding.

A huge current supply will be there throughout the armature winding. This is due to the high resistance of the field winding.

The shunt field current is 'Ish', while the armature current is 'Ia' and the load current is 'IL'.

You might enjoy: Direct Current Electric Generator

There are three main types of shunt generators: DC shunt generators, AC shunt generators, and compound shunt generators.

A DC shunt generator is a type of shunt generator that uses a DC power source and is commonly used in applications where a stable DC voltage is required.

AC shunt generators, on the other hand, use an AC power source and are often used in applications where a variable AC voltage is needed.

Compound shunt generators combine the characteristics of both DC and AC shunt generators, offering a range of voltage and current outputs.

The shunt wound DC generator is a type of generator that excites by residual magnetism in poles. The field windings are connected to the armature conductors parallelly to produce the needed magnetic field for excitation.

The field windings in a shunt generator have the same voltage as the terminals, and the actual value of this voltage depends on the load and its speed. A high shunt winding resistance is preferred to keep the shunt current low.

Armature current Ia consists of two parts: shunt field current Ish and load current IL. This is represented by the equation Ia=Ish+Il.

The generated power and power delivered to the load are determined by the generated EMF (Eg) and the armature current (Ig). The maximum effective power for the load is achieved when the load current (IL) is at its maximum.

Compound wound generators are a type of DC generator that combines both series and shunt field windings. They are designed to overcome the disadvantages of series and shunt wound generators.

The circuit of a compound wound generator includes both series and shunt field windings, with a series winding connected in series with the armature and a shunt winding connected in parallel with the armature.

Compound wound generators can be further divided into two types: short-shunt compound and long-shunt compound.

The short-shunt compound type has only the shunt field winding in parallel with the armature, while the long-shunt compound type has the shunt field winding in parallel with both the series field winding and the armature.

Here are the key characteristics of compound wound generators:

The output voltage and EMF of a compound wound generator depend on the load current, with the output being proportional to the inverse of the load current in the shunt type.

A DC shunt generator can produce a voltage even in the absence of a current 'If' due to residual magnetism within the material pole.

The magnetization curve of a DC shunt generator increases suddenly when the magnetic circuit is unsaturated.

The curve flattens out when the magnetic circuit saturates.

There is a critical field resistance, Rc, that lets a generator be self-exciting.

The voltage can be increased once the whole resistance within the field is low as compared to the critical resistance or Rc.

For the rated machine speed, the critical resistance can be verified from the curve of magnetization by drawing a tangent line towards the magnetization curve starting from the source.

To perform a load test on a DC shunt generator, you'll need a few specific components, including a M.C type Ammeter, a M.C type Voltmeter, wire wound rheostats, and a digital tachometer. These tools will help you measure the generator's internal and external load characteristics.

The experiment involves connecting the generator to a load, and using the ammeter and voltmeter to measure the current and voltage output. You'll also need to use the rheostats to control the load, and the digital tachometer to measure the generator's speed.

The nameplate details for the motor and generator are crucial in understanding its specifications, including the voltage, speed, current, and output.

Readers also liked: What Size Inverter Generator Do I Need