AC Asynchronous Motor Windings and Technical Parameters

Technical Parameters of Motor Windings

• Polar Pitch (YP): This is the distance between the axes of two continuous poles.
• Coil Width (YK): This is the number of coil bobbins that exist within a coil.
• Slip: This is the challenge that exists between the rotor and the stator.
• Slots per Pole and Phase (Kpq): This must be checked against the calculation to determine if the coil can or cannot be used.

Concentric and Lap Winding Characteristics

Winding Groups and Types

What is the extent of a group, and what type of windings are used? It is the number of slots that are active between the smallest group's coil sides and will be occupied by various other groups. This is typically seen with concentric windings.

Coil Width and Polar Pitch Relationship

How would you define the width of the coil and its relationship to the polar pitch? In a lap (imbricated) winding of a single layer, the coil width should be odd. If the polar pitch is even, the coil width must necessarily be shortened to an odd value.

Data for Concentric Winding Outlines

What data are needed to draw the outline of a single-layer concentric winding?

• Winding type: Concentric or lap (imbricated)
• Number of slots
• Number of poles
• Connection type (for consequent poles or pole-by-pole)
• Number of phases

Starting Mechanisms in Single-Phase Motors

How does the start-up occur in a single-phase motor? Because a single-phase motor requires a starting mechanism, we produce a phase gap. This is achieved using a capacitor that creates a discrepancy of 90 degrees, or an auxiliary winding that causes a gap between 80° to 85°.

Classification of AC Asynchronous Motors

Single Layer Lap Windings

What happens when the passage of a single-layer lap winding has an even polar pitch value? We must necessarily shorten it to an odd value, such as shortening by 1 or 3.

Double Layer Lap Windings

What happens when a two-layer lap winding has an even polar pitch value? Nothing specific happens because it can be both odd and even; it can be shortened as desired or when necessary.

Solving Single Layer Concentric Windings

How do you solve a single-layer concentric winding when the number of coils for a unit group is more than half? The coils are in the same phase, alternating between three rolls and two rolls. The total number of coils for one phase (BF) is the value of the number of coils per group multiplied by the number of groups.

Dahlander Connection and Speed Control

What is a Dahlander coil connection, and how are the groups of coils distributed? It is used for a two-speed motor. This is achieved through internal connection changes where the coils in each phase have two halves. The relationship between different speeds is obtained by switching the polarity from 2 to 1.

The connection of the groups will be interconnected between groups. For the groups and interconnected pairs to close, the coil halves are connected, joining the end of the last group with the next even/odd group pair. One polarity is formed by applying the input current at the start of the phases, and the final phase ends exit. The other polarity is formed by applying the input current to the midpoints of these principles, which will serve as the final output stages.