User talk:Spaceel

I am looking for some information about the use of War Leonard Control in the field of EE.

If anyone know something about it, please put some here.

Reply
I have put Ward leonard control on my watch list. I suggest that you read Harry Ward Leonard more carefully. Other related articles include:

Adjustable-speed drive

Brushed DC Electric Motor

Electric motor

Electronic speed control

Motor controller

Thyristor drive

When you post to discussion pages, please sign your post by putting 4 tildes at the end (like this: ~ ). C J Cowie 14:30, 13 October 2007 (UTC)

Introduction
Ward Leonard Control, also known as Ward Leonard Drive System, is widely used motor speed control system that was introduced by Harry Ward Leonard in 1891. Applications of the control system include elevators and many others. Even though the system started to be replaced from 1980s, many variations still remain in use and are also considered to be Ward Leonard Control. Spaceel 00:28, 15 October 2007 (UTC)

Basic Concept
A Ward Leonard control system has a electrical generator and a electric motor. Prime mover feeds a constant DC current to a generator. The generator is connected to the armature of the motor. The speed of motor is controled by varying the voltage feeded from generator. Fig 1 shows the Ward Leonard control system, with the Vgf feeding the generator and Vmf feeding the motor. Spaceel 00:28, 15 October 2007 (UTC)

Mathmetical Approach
Before going into the equations, first conventions should be set up, which will follow the convention Datta used. The first subscripts 'g' and 'm' each represents generator and motor. The superscripts 'f', 'r',and 'a', correspond to field, rotor, and armature.

Wi = plant state vertor K = gain t = time constant J = polar moment of inertia D = angular viscous friction G = rotational inductance constant s = laplace operator

eq 1: The generator field equation Vgf = RgfIgf + LgfIgf

eq 2: The equation of electrical equilbrium in the armature circuit -GgfaIgfWgr + (Rga + Rma)Ia + (Lga + Lma)Ia + GmfaImfWmr = 0

eq 3: Motor torque equation -TL = JmWmr+DmWmr

With total impedence, Lga + Lma, neglected, the transfer function can be obtained by solving eq 3 TL = 0.

eq 4: Transfer function $$\frac{W_m^r(S)}{V_g^f(S)} = \cfrac{K_BK_v/D_m}{(t_g^fs+1)[t_ms+\cfrac{K_m}{D_m}]}$$

$$K_B = \tfrac{G_m^faV_m^f}{R_m^f(R_g^a+R_m^a)}$$

$$K_v = \tfrac{G_g^faW_g^r}{R_g^f}$$

$$t_m = \tfrac{J_m}{D_m}$$

$$t_g^f = \tfrac{L_g^f}{R_g^f}$$

$$K_m = D_m+K_B^2(R_g^a + R_m^a)$$

Spaceel 00:29, 15 October 2007 (UTC)

Image copyright problem with Image:Ward-Leonard Control.jpg
Thank you for uploading Image:Ward-Leonard Control.jpg. However, it currently is missing information on its copyright status. Wikipedia takes copyright very seriously. It may be deleted soon, unless we can determine the license and the source of the image. If you know this information, then you can add a copyright tag to the image description page.

If you have any questions, please feel free to ask them at the media copyright questions page. Thanks again for your cooperation. NOTE: once you correct this, please remove the tag from the image's page. STBotI 15:53, 7 October 2007 (UTC)