Utah vehicle engineering company Raser Technologies recently announced that it has entered into an agreement with international vehicle technology developer FEV in an effort to integrate Raser’s electric motor and electronic drivetrain technology with traditional internal combustion engines. (read the article here) The goal of the project is a plug-in hybrid electric vehicle having 100 mpg fuel economy.
Raser owns one U.S. patent and several pending patent applications relating to AC induction electric motor systems. Such systems typically include an electric motor and a “drive” or “controller” to provide an AC waveform to drive the motor. Many AC motors are made to run from a DC power source with the drive acting as an interface between the two types of electrical energy. However, complex and inefficient switching devices are necessary for the drive to convert DC power to an AC waveform. U.S. Patent No. 6,847,186 seeks to solve this problem by eliminating the need for those switching devices.
A rotary motor has a rotating part, or rotor, and a stationary part called a stator, with an air gap between them. In an AC system, the stator has coils supplied with AC current to produce a rotating magnetic field to power the rotor. Raser’s patented system widens the gap between the stator and the rotor, which has the effect of increasing inductance – the ratio of magnetic flux to current (changes in current create changes in magnetic flux, which generate electromotive force). Thus, the motor itself is transformed into an inductor. The inductance is connected in series with a capacitor, generating alternating current between the motor and the capacitor. The result is a resonant circuit formed by the motor (inductor) and the capacitor. When power is applied, the circuit oscillates and produces AC waveform without the need for complex devices to convert DC to AC.