Whole Speed Range Sensorless Motor Solution

This solution aims to help customers implement the low-speed sensorless control function for IPM motor, which is difficult to develop, into their various equipment easily.
Suitable for applications that require torque and high efficiency at zero/low speeds.
In addition to the conventional high-voltage version (AC200V), a low-voltage version (DC24V) has been newly released. Please use according to the voltage of your motor.

Benefits of Adopting Whole Speed Range Sensorless Solution

Torque Output at Zero/Low-Speed Range

By adopting position estimation with pulse voltage^*1, it can output the rated torque at zero to low speeds (around hundreds of rpm), which conventional sensorless vector control^*2 could not support.

*1: At zero/low speeds. At high speeds, drives by switching to position detection with BEMF observer.
*2: Renesas sample software “Sensorless Vector Control for Permanent Magnet Synchronous Motor (R01AN6307)”

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Improving Magnetic Pole Position Estimation Error and Reducing Estimation Time

Having the initial magnetic pole position estimation function, this solution enables quick position estimation within 0.2 seconds regardless of the motor position.
In addition, achieves magnetic pole position estimation errors under ±10deg (equivalent to GP INV).
⇒Enables quick startup and smooth motor control.

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Optimizing Current Consumption

Since motor positions can be estimated even at the low-speed range, this solution enables motor drive with minimum necessary current according to the load at low-speed range, which the conventional sensorless vector control^*1 didn’t support.
⇒Can improve energy efficiency and reduce current consumption, suitable for battery applications.

*1: Renesas sample software “Sensorless Vector Control for Permanent Magnet Synchronous Motor (R01AN6307)”

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Control Algorithm

• Low-speed range: By injecting a high-frequency pulse voltage (around 1/2 of carrier frequency), the magnetic pole position and speed are estimated from the variation of the motor current.
• Mid to high-speed range: Stops injecting a high-frequency pulse voltage and switches estimation method of the magnetic pole position and speed to the method using inductive voltage, which is proportional to the rotation speed.

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Function and Specification

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Configuration of Whole Speed Range Sensorless Motor Solution

• Provide software and development support tools required for sensorless control for IPM motor over the whole speed range.
• Evaluation of 3-phase IPM motors with positive polarity and high-voltage versions can be performed by providing an IPM motor and a high-voltage inverter board.

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Deliverables

High Voltage Version (AC220V, RX66T)

• Application Note
  RX Family Sensorless Vector Control for IPMSM over the Whole Speed Range Rev.1.00 (PDF | English, 日本語)
• Sample Software
  RX Family Sensorless Vector Control for IPMSM over the Whole Speed Range Rev.1.00 (ZIP | English, 日本語)
• CPU Card
  RX66T CPU Card
• Communication Board
  MC-COM

Low Voltage Version (DC24V, RX26T)

• Application Note
  Sensorless Vector Control for IPMSM over the Whole Speed Range for MCK (PDF | English, 日本語)
• Sample Software
  Sensorless Vector Control for IPMSM over the Whole Speed Range for MCK - Sample Code (ZIP | English, 日本語)
• Motor Control Kit (MCK)
  RX26T MCK
• Communication Board
  MC-COM