Characteristics of a Heteropolar Linear Synchronous Machine with Passive Secondary

Test results are presented for a novel form of heteropolar linear synchronous machine. The results show that the machine is capable of providing both thrust and lift force at relatively high efficiencies and power factors.A simple control scheme is described that enables independent variation of lift and thrust to be made. This is accomplished by the use of ‘constant-current’ supplies and operation at a fixed torque angle of 90°.Design formulas are derived, and performance predictions obtained from them are shown to agree well with the test results.