| 摘要 |
PURPOSE:To avoid giving a shock to a control system by inputting a speed actual value to an acceleration/deceleration operator for a period while the direction of a field current is changed, and by causing a speed command value outputted by said acceleration/deceleration operator to follow said speed actual value. CONSTITUTION:When a command contact 32 during field changing is turned ON, a speed actual value N detected by a speed detector 13 is inputted to an acceleration/ deceleration operator 31 and a speed command value N* outputted by said acceleration/ deceleration operator 31 is caused to follow said speed actual value N. This state continues until the direction of a field current of a DC motor 4 is changed and said reverse field current rises to a specified value. That is, the input deviation value to a speed regulator 14 during a zero-hold period is zero. Therefore, the deviation value inputted to the speed regulator 14 at the moment when said command contact 32 during field changing is turned OFF and the zero-hold of said acceleration/ deceleration operator 31 and speed regulator 14 is released, i.e., at the point of time of starting a regenerative braking operation, is zero. Accordingly, there is no possibility that an excessive current command value giving a shock to a control system is outputted. |
