| 摘要 |
PROBLEM TO BE SOLVED: To precisely find an optimal counter balance value of a drive system of a pump jack in actual working conditions of the pump jack. SOLUTION: In the counter balance (C balance) adjusting method of the pump jack of a induction motor drive, the pump jack is operated for n cycles with arbitrary C balance weight. In up stroke(US) and in down stroke(DS), each average of the secondary current momentary maximum value (the secondary maximum average) is found. Weight of 49, 50, C balance are changed, then each secondary maximum average in US and DS is found. By means of the optimal C balance arithmetic unit 53 by a regression line equation method, it is found that the regression line equation to the US secondary current maximum value and the change of C balance weight by using the secondary maximum average in US, and it is found that the regression line equation to the DS secondary current maximum value and the change of C balance weight by using the secondary maximum average in DS. The optimal C balance weight is found from the intersection. |
