An avid home machinist, Dr. Larry Meiners of Rapid City , SD , had a garage full of three-phase machine tools operating through a variety of phase converter technologies. His need for a more versatile phase converter that delivered better power quality and efficiency led to the founding of a new technology company, Phase Technologies, LLC, and the development of Phase Perfect® digital phase converters. Dr. Meiners, a professor of electrical engineering at a local university, applied the latest advances in solid state power switching technology to phase converters, which have been in use for nearly a century.
Much like automobiles, modern electrical equipment has evolved into sophisticated machines with integrated computer controls and other solid state devices to enhance performance, efficiency and reliability. This equipment needs clean, balanced electrical power to operate properly. In the past, phase converters in most cases could not compete with utility three-phase installation in terms of power quality and efficiency but have been widely used because installation of three-phase service may be prohibitively expensive or not available in many locations. Phase Perfect® digital phase converters have changed that dynamic by producing three-phase power that is actually superior to utility three-phase in power quality while operating at 95-98% efficiency.
Dr. Meiners developed and patented a design that relies on solid state power switching components so that the converter has no moving parts. The input module has electronic power factor correction which draws the single-phase current in sinusoidal fashion and actually corrects the power factor of the load so the utility sees a load that operates at unity power factor. Because much of the current required by across-the-line starting of induction motors is reactive power, the converter can supply this reactive power, reducing the chance of line disturbances.
Proprietary software in the controls of the converter is constantly monitoring the phase conversion process, ensuring that the output voltages are perfectly balanced under all load conditions. The system is capable of supplying large momentary currents of up to five times its rated steady state current for load conditions such as motor starting and instant reversing. The three-phase voltage generated by the converter is a sine wave with less than 3% total harmonic distortion, better than the harmonic standards for computer grade power. The controls also protect the converter and load from undervoltage, overvoltage and faults. Consequently, a Phase Perfect® digital phase converter can operate virtually any type of load, even multiple loads, with pure, balanced three-phase power.
Phase Perfect® operates at 95-98% efficiency. Because it always supplies balanced voltage which can increase the efficiency of three-phase systems, the losses of the converter are likely offset by increased efficiency of the operated load. Unlike an idling rotary phase converter, a digital phase converter that is energized with no load consumes very little power.
Phase Perfect® digital phase converters are available in a variety of models up to 40 KVA in capacity and offer an affordable alternative to utility three-phase installation.
