| 摘要 |
<p>A method of controlling slip frequency of an induction motor exhibiting exact and excellent control response characteristics. In determining a slip frequency (fs) and an exciting flux frequency ( omega 0) by using hardware elements, control error and control delay are reduced by determining these two parameters through a software processing using a processor for vector control. For this purpose in the speed control routines (101 to 104), a slip quantity (A) and a remainder ( alpha ) obtained by the running of the routine of this time are calculated by dividing by a routine start frequency (CV) the value obtained by addition of the remainder ( alpha ') calculated by the running of the routine of the preceding time and a slip frequency that is obtained by dividing the product of a secondary current instruction (I2) and a proportional constant (K2) by the excitation flux instruction ( PHI ). In the current control routine (201 to 205) executed on a period shorter than that of the speed control routine, a slip distribution data ( omega s) and a remainder ( beta ) of this time are calculated by dividing the value obtained by addition of a slip quantity to be calculated and the remainder ( beta ') of the preceding time by the number (n) of times of starting the current control routine. Furthermore, data ( omega r) that represents an actual motor speed is added to the calculated slip distribution data in order to obtain an exciting flux frequency ( omega 0).</p> |
