U. S. missile actuators employ REPM (rare earth permanent magnet) BLDCM (brushless D. C. motor). We are the first in China to propose square - wave REPM BLDCM for Chinese missile actuator.We found it necessary to desi...U. S. missile actuators employ REPM (rare earth permanent magnet) BLDCM (brushless D. C. motor). We are the first in China to propose square - wave REPM BLDCM for Chinese missile actuator.We found it necessary to desisn such square - wave motor with a method different from traditional ones. Traditionai methods for designing permanent - msanet BLDCM are based on sinusoidal gap magnetic density distribution and sinusoidal winding back EMF(electromotive force). They are not suitable for REPM square - wave motor which has square gap magnetic density distribution and trapezoidal winding back EMF. Table 1 gives for comparison the design formulas of inductive potential, armature current, electromagnetic torque, and no - load speed of REPM square - wave motor and of traditional permanent magnet BLDCM respectively. It is important to note that the elechromagnetic torque coefficient of REPM square - wave motor is about 5% higher than that of traditional BLDCM.We developed a prototroe of REPM square - wave motor. Its specifiations are: rated power = 30W, rated D. C. voltage = 48V, rated speed = 1000r/min. Its operation pattern is star - form three - phase six - state.Fig.1a shows test curves relating current I and efficiency n to output torque T respectively. Fig. 1b shows test curves relating input power P1 tal output power P2 to T respectively. The desisn error of rated torque is within 1. 7%. The prototype also achieves 17 500r/s2 starting acceleration and 0. 154 W/g power density and thus actuator performance is improved. All these indicate that our proposed design method is valid.展开更多
文摘U. S. missile actuators employ REPM (rare earth permanent magnet) BLDCM (brushless D. C. motor). We are the first in China to propose square - wave REPM BLDCM for Chinese missile actuator.We found it necessary to desisn such square - wave motor with a method different from traditional ones. Traditionai methods for designing permanent - msanet BLDCM are based on sinusoidal gap magnetic density distribution and sinusoidal winding back EMF(electromotive force). They are not suitable for REPM square - wave motor which has square gap magnetic density distribution and trapezoidal winding back EMF. Table 1 gives for comparison the design formulas of inductive potential, armature current, electromagnetic torque, and no - load speed of REPM square - wave motor and of traditional permanent magnet BLDCM respectively. It is important to note that the elechromagnetic torque coefficient of REPM square - wave motor is about 5% higher than that of traditional BLDCM.We developed a prototroe of REPM square - wave motor. Its specifiations are: rated power = 30W, rated D. C. voltage = 48V, rated speed = 1000r/min. Its operation pattern is star - form three - phase six - state.Fig.1a shows test curves relating current I and efficiency n to output torque T respectively. Fig. 1b shows test curves relating input power P1 tal output power P2 to T respectively. The desisn error of rated torque is within 1. 7%. The prototype also achieves 17 500r/s2 starting acceleration and 0. 154 W/g power density and thus actuator performance is improved. All these indicate that our proposed design method is valid.
