This invention uses winding connection control and bidirectional on/off switches to supply reasonable level voltage to a motor without a booster. This invention also can raise the speed of the motor to double (or higher) of its original speed in order to free up the rooms in the slots for the additional winding. Besides lowering the battery requirement at starting, this invention can also increase the energy recovery when decelerating at low speed due to the additional turns of the motor winding-2 that produces higher voltage at low speed for charging the battery, hence higher miles per gallon.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
 This invention was made with United States Government support under Contract No. DE-AC05-00OR22725 between the United States Department of Energy and U.T. Battelle, LLC. The United States Government has certain rights in this invention.