What is wave winding?
Wave winding is a method of winding coils in electric motors and generators. Learn about the different types of wave winding configurations and their applications in industry.
In wave winding, the armature coils are connected in such a way that the finishing end of one coil is connected to the starting end of the other coil, with a certain distance between them. This results in only two parallel paths being created between the positive and negative brushes, regardless of the number of poles in the machine. The number of brushes used in this type of winding is equal to the number of parallel paths.
This type of winding is mainly used in high voltage, low current machines because it allows for a greater number of turns of wire to be used in the armature coils, which increases the voltage output of the machine. This is beneficial in applications where a high voltage is required but a low current is sufficient, such as in generators. However, it is worth noting that wave winding may result in increased losses due to the increased resistance of the armature coils.
Types of Wave winding:
The wave winding is further classified as:
- Simplex wave windings
- Duplex wave windings
- Retrogressive wave windings
- Progressive wave windings
Simplex Wave Windings:
In simplex wave winding, the conductors of all the coils are connected in series, resulting in only one path between the positive and negative brushes. This type of winding is mainly used in high voltage, low-current generators.
Duplex wave windings:
In duplex wave winding, the conductors of the coils are divided into two equal groups and connected in series, resulting in two parallel paths between the positive and negative brushes. This type of winding is mainly used in machines that require high voltage and high current, such as some types of motors.
Retrogressive wave winding:
Retrogressive wave winding is a type of wave winding in which the conductors of the coils are connected in a specific way that causes the current to flow in the opposite direction in one of the parallel paths. This is achieved by connecting the finishing end of one coil to the starting end of the next coil in a manner such that after one complete rotation of the armature, the coil falls into a slot that is left of its starting slot.
This type of winding is mainly used in machines that require a high voltage and a high current, such as some types of motors. The retrogressive connection ensures that the current flows in the opposite direction in one of the parallel paths, which can result in more efficient operation of the machine.
Progressive wave windings:
Progressive wave winding is a type of wave winding in which the conductors of the coils are connected in a specific way that causes the current to flow in the same direction in both parallel paths. This is accomplished by connecting the finishing end of one coil to the starting end of the next coil in such a way that the coil falls into a slot to the right of its starting slot after one complete rotation of the armature.
This type of winding is mainly used in machines that require a high voltage and a high current, such as some types of motors. The progressive connection ensures that the current flows in the same direction in both parallel paths, which can result in more efficient operation of the machine.
Advantages of wave winding:
- It requires fewer brushes than lap winding, which simplifies the design and reduces cost.
- In cases of poor contact with the commutator, wave winding machines continue to operate satisfactorily.
- Wave winding does not require an equalizer ring, simplifying the design and reducing cost.
- Wave winding is less costly and requires less maintenance compared to lap winding machines.
- Wave winding is well-suited for high-voltage and low power machines.
- Wave winding is better suited for machines with power ratings less than 50 KW.
- Wave winding is more efficient in terms of commutation, as it does not require an equalizer ring.
- It is less complex and cheaper to manufacture than lap windings.
- Wave windings are suitable for low-power, high-voltage machines.
- As there are only two parallel paths in a wave wound machine, it is less prone to commutation issues and less likely to damage the machine.
- As wave winding does not require an equaliser ring, commutation is more consistent in a wave winding machine.
- The maintenance requirement for a wave winding machine is less as compared to a lap winding machine.
- The design of the wave winding machine is simpler and more robust.
Disadvantages of wave winding:
- It cannot be used in machines with a higher current rating because it has only two parallel paths.
- Wave winding may result in increased losses due to the increased resistance of the armature coils.
- It is not suitable for high current machines as the current density is high, and it can cause commutation problems.
- The wave winding is less efficient than other types of winding, such as lap winding at high current.
- As the wave winding has only two parallel paths, if one of the brushes develops poor contact with the commutator, the machine will not operate satisfactorily.
- The cost of wave winding machines is generally higher than that of lap winding machines.
- Wave winding is less suitable for high power machines, such as large motors, as they require a large current, and wave winding is not efficient enough to handle such large currents.
- Wave winding machines are less reliable and have a shorter lifespan than lap winding machines.
- Wave winding machines are less robust and more susceptible to wear and tear.
- Wave winding machines are less efficient in terms of energy consumption as compared to lap winding machines.
Applications of wave winding include:
- The applications of wave winding include low current and high voltage machines because wave winding is specifically designed to provide high voltage output with low current. It is accomplished by connecting the armature coils in a specific way that creates only two parallel paths between the positive and negative brushes.
This allows for a greater number of turns of wire to be used in the armature coils, which increases the voltage output of the machine. This makes wave winding suitable for applications where a high voltage is required, but a low current is sufficient.
