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#1 Ward Leonard Generator Repair & Service


Ward Leonard Speed Control For Ships Machinery Operations

Ward Leonard speed control method is utilized to control the speed of a DC motor. Henry Ward Leonard introduced the new Ward Leonard control system in 1891. Essentially, it’s a basic armature control method that consists of a direct current (DC) motor M_1 with the power coming from a DC generator G. This systems allows controlling the DC motor M_1 if different voltage is applied across its armature. The variable voltage is achieved when a motor-generator set consisting of a motor M_2 (regardless whether it AC or DC) in direct combination with the generator G. This system is a very widely applied way of controlling the speed of a DC motor.  

Ward Leonard Principle

Ward Leonard System of Speed Control

A basic model of a Ward Leonard motor can be seen in the picture.

Generator G powers the motor M_1 and that motor is controlled. DC supply lines connect the shunt field of motor M_1.The motor M_2 drives the generator and M_2’s speed is constant. The output voltage produced by the generator starts the M_1 motor’s rotation. When that voltage fluctuates, that affects the speed of the motor which also varies. By controlling the generator‘s output voltage, the M_1 motor’s speed is also controlled. What controls the output voltage is the field regulator that is linked to DC supply lines across the generator to control field excitation. The direction in which motor M_1 rotates can be switched by the generator’s excitation current and it can be carried out by reversing switch R.S. However, the motor-generator set must rotate in the same direction. 

Advantages of Ward Leonard Speed Control System


1.      The system runs very smoothly over a broad range of speed (from zero to normal).

2.      Speed control is easily enabled regardless of the direction of the rotation of the motor.

3.      It allows the motor to run with uniform acceleration.

4.      Speed regulation is very good.

Relative disadvantages of Ward Leonard Speed Control System


1.      For many, the system is on the pricey side due to the fact that two additional machines are necessary (motor-generator set).

2.      The general efficiency of Ward Leonard system is not enough, and more so when it’s lightly loaded.

Applying Ward Leonard System


When a broad and sensitive speed control of a DC motor is required, in both directions, the Ward Leonard speed control system is applied. The main uses of this system are seen in colliery winding engines, mine hoists, cranes, steel rolling mills, electric excavators, paper machines and so on.  

Ward Leonard Generator Repair


If you think or know there’s a problem with your Ward Leonard generator or any other component, feel free to call Propulsion Controls Engineering in San Diego. We offer you fast and highly reliable solutions for any problems you could have with your power systems. Our team will put all their knowledge and skill to make the downtime as short as possible. Contact us today and get an invaluable service at very affordable prices. 

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