DC machine wave and lap winding with numerical analysis

 Classification of DC machine windings

DC machine wave and lap winding with numerical analysis [figure 1]

Classification

Mainly DC machine have two type of winding

 1) wave winding

 2) Lap winding

Wave winding

In DC machine armature coil connected to series with commutator  with distributed  two parallel path with respect of number of pole called wave winding. Wave winding is a High voltage winding.

DC machine wave and lap winding with numerical analysis [figure 2]

Lap winding

And, In DC machine armature coil connected to series with commutator  with distributed two or more parallel paths as the number of pole called Lap winding. Lap winding is called Low voltage. Some time difficult to remember which winding is high voltage and which one is Low voltage. So we are find a short tips , their are.

Low =Lap

High=wave (sea wave is always High).

DC machine wave and lap winding with numerical analysis [figure 3]

Mathematical Analysis

In  way two winding classifications are done because their voltage rating is different with respect of different current rating but the power will be same as well as torque and speed remain same with power.

When DC machine required for low voltage rating then preferred lap winding and DC machine required for high voltage then use wave winding.

This theory will better understand with some numerical model and some assumed parameter of DC machine.

We know, A is number of parallel paths 

When Wave winding is use the A =2

And lap winding is use the A=NUMBER OF POLE(P)

At first we need some assumed data 

P=4 ,Z=1000, Φp = 0.02 wb ,N=1500 RPM

So, Eg (lap)= Φp  Z N P/60 A= (0.02×1000×1500×4)/(60×4)= 500 volt

Eg (wave)= Φp  Z N P/60 A=(0.02×1000×1500×4)/(60×2)= 1000 volt

The numerical analysis says that the generated e.m.f in lap winding is 2 times greater then the wave winding.

Next we see the current behaviour of lap and wave winding.

Current in coil is Ic

Ic(lap)=a Ic=4Ic

Ic(wave)=a Ic=2Ic

The current in coil says that the current in wave winding is 2 Times more than the lap winding.

Power(lap)=Eg (lap) .Ic(lap) = 500.4Ic = 2000Ic

Power(wave)=Eg (wave) .Ic(wave) = 1000.2Ic = 2000Ic

After the conclusion the numerical analysis and theoretical analysis is justified.

If both winding has different voltage a current rating the power always same in nature.

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