| 摘要 |
<P>PROBLEM TO BE SOLVED: To extract a phase current which is difficult to be inspected by a one-shunt current detection system by estimation. <P>SOLUTION: A current detection block 42 detects current values i<SB>dcA</SB>and i<SB>dcB</SB>of a maximum voltage phase and a minimum voltage phase by sampling a bus bar current flowing between an inverter for feeding a current to a motor and a DC power supply. An intermediate-phase current estimation block 43 estimates a current value i<SB>mid</SB>of an intermediate voltage phase from current command values i<SB>d</SB><SP>*</SP>and i<SB>q</SB><SP>*</SP>on dq-axes, and from a rotor position θ. A phase current calculation block 44 calculates three-phase current values (i<SB>u</SB>, i<SB>v</SB>and i<SB>w</SB>) from output values (i<SB>dcA</SB>and i<SB>dcB</SB>) of the detection block 42 during a period when the current values of the maximum voltage phase and the minimum voltage phase are exactly detected at the detection block 42. Meanwhile, during a period when the current values of the maximum voltage phase and the minimum voltage phase are not exactly detected at the detection block 42, the phase current calculation block calculates three-phase current values from a detection value (i<SB>dcA</SB>or i<SB>dcB</SB>) of the detection block 42 and an estimation value i<SB>mid</SB>of the estimation block 43. <P>COPYRIGHT: (C)2011,JPO&INPIT |
