NEW BERLIN, WI, June 11, 2004 ABB Inc., the leading power and automation technology group, has published the latest edition of its ABB industrial drive for test bench applications, covering the market-leading technologies from its AC drives business.ABB ‘s new industrial drive series, the ACS800, is used in virtually all test bench applications, including chassis dynamometers, engine test stands, and transmission tests. The drives series features proprietary open-loop Direct Torque Control technology that eliminates the need for installing encoders and enables the drives to calculate the state (torque and flux) of the motor 40,000 times per second, making the motor controllers trip-less. The absence of a required encoder can also reduce capital costs by up to 25 percent, when compared to flux vector PWM (Pulse-Width-Modulated) drives.”Because this open-loop control of speed or torque is so precise, the drives can adapt to and handle changes in load immediately,” according to John Tisdale, sales manager for ABB Inc., Automation Technologies, Low-Voltage Drives. The ability to provide full torque at zero motor speed, as well as high-operating torque at low speeds, enables the drives to respond immediately and precisely to load changes as they vary.A DTC flux optimization feature automatically adapts the motor flux to the load, so that the ACS800 drive provides only the amount of power needed. When the motor is not fully loaded, this increases energy savings quickly. A one percent increase in efficiency of a one-megawatt motor can save more than $ 3,000 per year