Speed control of DC Motor

The DC  motor  are versatile motors among the  available  electrical  motors due to  their  superior  characteristics. These motors  give a smooth speed control  over a wide  range. The  main advantage so using DC  motors  in industrial applications include ability of  providing  high starting torque  required  specially in traction applications possible  speed control over  wide range  both above and below  the  base  speed  simplicity and easiness in speed control methods and importantly less expensive than those of AC motors. The men  disadvantage with DC motors  is the  presence of commutate which  limit  its use in high speed applications and require more maintenance than  AC motors .

a.Controlled rectifies or phase controlled  converters which give a variable de  output  from a  fixed  ac voltage .

b.Choppers  which  provide  variable  dc output  voltage  from a fixed  dc input  voltage.