21. Instead of using a set of switched capacitors, an unloaded synchronous motor can supply reactive power. 22. Unlike synchronous motors , induction generators are load-dependent and cannot be used alone for grid frequency control. 23. This machine, using the standard synchronous motor , uses less than 1.5 amps at 115VAC 60 Hz. 24. The propulsion is realized by a permanent magnet synchronous motor with an electrical driven variable-pitch propeller. 25. Launch lift hills use mostly linear synchronous motors or linear induction motors but sometimes use drive tires. 26. Permanent magnet synchronous motors have quite limited field-weakening speed range due to the constant magnet flux linkage. 27. Usually, they are driven by AC-synchronous motors . 28. Wicked was the first LSM ( linear synchronous motor ) launched roller coaster to utilize a flywheel inverter. 29. Most had two pole synchronous motors . 30. Despite years of development, there is still no working mass transit system employing linear induction or synchronous motors .
