how to design dc motor which takes small time to simulate

i want to design a dc motor,though already there exists a inbuild model of dc motor,but still its taking to much time to simulate. thats why i want to make my own model,but nt as a transfer function,becoz transfer function takes input as signal,nt as electrical power supply.can this be made?

[Walter Roberson]

Is this for plain Simulink, or for SimPower ?

[Krishnendu Mukherjee]

simpower

[Krishnendu Mukherjee]

lots of simulink model is there which takes voltage input as constant block.but i want that model in simpower which will take input of a dc voltage source.any one plz help