“Conserve Energy” is the mantra for engineers. Machine design plays a vital role in energy conservation and we have designed a new theoretical machine called ‘Motarator’ performs the function of D.C motor and gets 50 to 70% of energy from the inbuilt D.C.generator.‘Motarator’ is similar in construction to that of the D.C. motor in the stator side (poles). The armature of the ‘Motarator’ has two types of winding .One for the motor; which is in the outer periphery of the armature and the other for the generator, which is in the inner slots made specially. These slots are placed by vectorial field orientation study. The rectifier circuit rectifies the generated a.c and is filtered and fed as input or can be used for auxiliary purpose. Cent percent efficiency will run the machine without supply. Power consumption in the world is steeply rising. To meet the demands production has to be increased or else the machine should be in such a way that it should consume less power. Taking into account, to meet the power demands in industries we have designed a new special theoretical machine called ‘Motarator’, which conserves about 70% of the energy. The machine makes use of the principles of both motor and generator, although its main purpose is as a motor.
Salient features of ‘Motorator’:
Q Armature:
The armature of the ‘Motorator’ has two rows of slots .The upper slots are made to hold the conductors of the motor. The lower slots are made to hold the generator winding. The position for the generator slots are selected suitably by Vectorial field orientation study in the armature so that the armature reaction due to the motor current is nullified by the generator current. The armature are laminated and stacked up to reduce the eddy current loses.
Slots
1.The slots for the motor are of semi closed type.
2. The slots for the generator are of full closed type.
Windings:
Lap winding is used in this kind of special machine to take heavy loads
Two commutator
‘Two commutators’ each on either side of the machine is placed to externally connect both the motor & the generator. The commutators segments are separated by mica insulators as Shown.
Shaft:
A material of good mechanical and magnetic property is selected with key way to externally connect the mechanical load.
Brushes
Two sets of brushes are placed over the commutators to tap & to supply power to the motorator. The brushes are made of carbon.
Stator
Poles:
Laminated poles are built in the stator over which laminated pole shoes attached. This combination provides the uniform flux over the air gap.
Yoke:
The yoke is made up of cast iron so that it provides good mechanical strength and path for the magnetic flux. Foot mountings are provided to avoid mechanical vibrations which affects the machine performance.
Rectifier & Filter
The rectifier and filter are placed outside the machine. This is basically a bridge rectifier connected to a ∏ section filter which rectifies the generated a.c to d.c & filter the ripples.Here the rectifier uses thyristors to control the input power. Improved version filters will be used in industries to avoid losses.
CONCEPT
It’s difficult to imagine a motor and a generator in the same machine. So for study consider a motor-generator set. Now the motor in the set have to serve for two types of loads.
They are
- Mechanical load
- Electrical load
Mechanical load
The mechanical load taken by the motor in the set is due to armature weight of the generator.
Electrical load
When the generator of the set rotates emf is generated and current flows when it is connected to the load. Now the generator armature is actually a current carrying conductor placed inside the magnetic field. So it will tend to rotate in the opposite direction. This opposing force will act as load to the motor. This load is taken as electrical load.
So the motor has to supply enough force & torque to overcome the loads so as to make the generator to run at its rated rotations per minute.
Coming back to our “Motarator” it is similar or equivalent to a motor and generator set. Taking into account of the above points the motor of the machine has to supply only for the electrical load and not for the mechanical load of the generator of the machine as there is no separate armature for the generator .So the Motarator
- can be able to run a mechanical load whose weight is equal to that of the armature of the generator
- And can be able to generate power similar to a generator.
Operation
The ‘Motorator’ has both the operations of motor & generator and works on the “Principle of faraday’s law”. In the beginning supply is given to the motor and is made to run to take the mechanical load. Until the motor takes the load the generator conductors are kept floating (no output current). After it takes the load the generator conductors are connected externally through the commutator and brushes, and the generated A.C is converted to pulsating D.C. using the rectifier circuit and is filtered to D.C. This current is again fed to the motor. Thus nearly 70% of the motor supply is generated by the inbuilt generator & 30% from the make up supply. There by conserving the energy. The electrical energy generated from the motor can also be used for auxillary purpose.
DISCUSSIONS AND RESULTS:
From the discussions we can say that machine can serve for both electrical and mechanical load. But the speed of machine may be marginally reduced due to armature reaction. By field orientation control this can be suitably rectified.
Advantages
1. Nearly 75% of the input is supplied by the machine itself.
2. Input supplied to the motor is greatly reduced.
3. Greatly suitable for constant speed motor
Shortcoming
Any system will have some shortcomings and so does ‘Motorator’ has,
1. The speed of the motor will be reduced marginally.
2. Initial cost for the construction of machine is more.
3. Maintenance is difficult. (Due to fully closed slots).
Conclusion
This is the era of the ‘rise of the machines’. New machines are pouring into the industries with various applications and motorator will show a new path in energy conservation which is one of the main fields of its application. In the future, High level research and development on motarator will surely open up new and promising avenues in science and industrial technology. The motorator is bound to make a definite impact and it is a giant leap for mankind
Reference:
Websites
Books
A course in Electrical technology
B.L.Thereja
Power Electronics
Joseph Vithayathil
Electrical machine design
A.K.Sawhney
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