| 摘要 |
PURPOSE:To accelerate a variable speed pump rapidly after the recovery of service power from suspension even when speed decreases due to the time of momentary stoppage, and to conduct stable operation by mounting an acceleration compensation computing element and compensating torque on instantaneous stoppage. CONSTITUTION:An acceleration compensation computing element 11 uses head H, an effective-power command value P0, the speed of revolution N and a short detecting signal Vd as inputs, compensates torque at the time of momentary stoppage, and arithmetically operates a compensation power value P*0 corresponding to the compensated torque. An adder-subtracter 8 arithmetically operates R*0-P(an effective component) and an adder-subtracter 9 Q0(a reactive- power command)-Q(a reactive component). A current pattern computing element 7 takes in (P*0 and (Q0-Q), and computes an output current command for a cycloconverter 3 while preparing a current pattern corresponding to the output current command. An automatic phase shifter 6 takes in the current pattern, controls the cycloconverter 3, and acquires an output current command value. |
