In t.g.Habetler no beat of direct torque control method,because of the large amount of calculation
and is not easy to achieve,therefore developed a series of simplified no beat directly Ac motor -
South Korea SPG ac motor series Ac motor - South Korea SPG ac acmotortrading.blogspot.com motor series Torque control,typically torque tracking prediction method.In this method,the paper analyzes the low speed torque ripple,torque ripple sawtooth asymmetric conclusions. Non-zero voltage vectors and the function of zero voltage vector rotating torque change is different,the former can make torque increase or decrease,while the latter is always decreased torque.In addition,in different speed range of the two counter rotating torque effect produced by the rate is changing.In torque predictive control method,the voltage vector in space position is fixed,the synthesis in the middle of the two single voltage vector,but the voltage vector is not effect the whole sampling period,but there is a certain duty cycle,in a sampling period can be divided into non zero voltage vector and zero voltage vectors.If the next sampling period of zero voltage vector and zero voltage vector to produce torque changes calculated torque error is equal to the three phase induction motor price cycle. To eliminate the torque error,achieve the goal of no beat torque control.Even appear calculated voltage vector effect time beyond the sampling period,also the full voltage vector can be used gasoline generator spare parts in place of,so it is very easy to implement,from the point of the experimental results,the torque ripple of the sawtooth basically symmetrical and explain the torque pulsation has been greatly reduced.Flux method considered by accurate control or change slowly,without considering the magnetic chain of beat control,in the literature on the flux and predictive control.