Control device of permanent magnet type rotating electrical machine

A controller of a permanent magnet type rotating electrical machine, the controller comprising:

• magnetic pole position detector which detects a magnetic pole position of the permanent magnet type rotating electrical machine;
• an inverter connected to a direct current power supply, and which performs PWM control of switching elements based on a carrier wave and performs electric power conversion;
• a middle point level judge which:
• detects a middle point potential between a switching element connected to an anode side of the inverter and a switching element connected to a cathode side of the inverter,
• compares the middle point potential and a reference potential,
• outputs as Hi, when the middle point potential is higher than the reference potential, and
• outputs as Lo when the middle point potential is lower than the reference potential;
• and
• a magnetic pole position origin point correction amount operator:
• keeping both of a d-axis current command value and a q-axis current command value at zero in dq vector control in a state where the permanent magnet type rotating electrical machine is rotating;
• counts a time during which an output of the middle point level judge is Hi and calculates a duty value from a ratio with a carrier wave cycle;
• converts the calculated duty value corresponding to a three-phase signal and the magnetic pole position directly into a two-axis rotating coordinate system and calculates duty value corresponding to a two-phase signal;
• calculates a magnetic pole position origin point correction amount from the two-phase signal, and
• performs a magnetic pole position origin point correction using the calculated magnetic pole position origin point correction amount, and without using a PN voltage of the connected direct current power supply.