Four-Quadrant Resonant Drive with Ports for Other Electrical Equipment

A new quasi-resonant converter, called the unipolar series resonant converter ("USRC"), will be adapted as a four-quadrant drive for electric vehicles ("EVs"). With zero current and voltage switching, it will high modulation frequency (over 30 khz), thus driving a motor silently and efficiently throughout the speed range. The USRC produces any waveform required by any type of EV motor. It produces clean sinusoidal voltages, thus liminating induction motor overrating, noise and losses due to harmonics. The USRC can also receive any type of power, such as DC from batteries and AC from an engine generator, without any hardware change or need for other conversion or interface hardware. Finally, due to the use of high frequency modulation and the elimination of external filters, the USRC drive will be smaller and less costly than alternatives. Due to the USRC's extraordinary conversion flexibility, it can also become the heart of the entire electrical system of the EV. Without other conversion or interface hardware, it can link together the prime source (engine generator), storage (batteries or flywheels), propulsion motor and auxiliary loads (lights, wipers), in spite of highly disparate types of power. For example, a battery charger would not be necessary. Anticipated Benefits: In addition to the benefits described above, the resulting designs and technologies can be used by industry and the government in the following applications: variable-speed drives and actuators, variable-speed generation systems, inverters for photovoltaic cells, fuel cells and batteries, frequency changers, uninterruptible power supplies and power conditioners.