| CPC H02P 21/18 (2016.02) [H02P 21/24 (2016.02)] | 9 Claims |
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1. An estimation device comprising:
a bus current detector to detect a value of a bus current that is a current flowing through a DC bus of a voltage-source inverter driven by a plurality of gate pulse signals generated on a basis of a voltage command;
a processor to execute a program; and
a memory to store the program which when executed by the processor performs:
a phase current determination process of performing a determination process for determining values of a plurality of phase currents supplied from the voltage-source inverter to an AC motor on the basis of values of the bus current detected by the bus current detector and states of the plurality of gate pulse signals;
a time difference calculation process of calculating a time difference between a first current detection time identified as a time of detection of the bus current used in a previous determination process by the phase current determination process and a second current detection time identified as a time of detection of the bus current used in a present determination process by the phase current determination process; and
an estimation process of estimating at least one of a position and a speed, of the AC motor on the basis of the values of the plurality of phase currents determined by the phase current determination process and the time difference calculated by the time difference calculation process.
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