Spin your Brushless motor in one minute using sensorless vector control algorithm on RX23T MCU

Nowadays, engineers are having tough time designing products, which comply with stricter energy and motor efficiency regulations. Even products in the moderate price range require highly precise and highly efficient inverter control. Sensorless vector control is taking the limelight because it can be highly efficient while keeping costs relatively down. Sensorless field oriented control requires heavy computing, and existing CPUs are insufficient… Equipment sizes are also shrinking, so available board space is becoming smaller… Brushless motor control required specific expertise & knowledge that are fundamental to meet deadlines…Tuning new and unknown brushless motors can take weeks… Finally, understanding in depth a sensorless vector control algorithm requires precious time and resources often missing…

That is why, Renesas designed specific MCU line-up to address such needs.

The kit called YROTATE-IT-RX23T is fully available on the RS Website, feel free to test it!

In this article and the document attached, you will:

• Discover the technical details of the 3-phase inverter kit based on RX23T, 5V microcontroller, FPU on-chip
• Understand the key features and benefits of the kits.
• See the existing compatible power stage: 60V_DC/100A and 300V_DC/10A
• Get the list of motors tuned and driven using the existing Field Oriented Control Software
• See how to get started with the existing PC GUI and kit.
• Discover how work the auto-tuning and self-identification firmware.
• Learn how to drive quickly your own motor using Renesas RX23T kit using the isolated PC GUI.

Let's have a look at the three tutorials prepared for you to drive very different kinf of motors:

a) The first one is designed and produced by BSH and used in washer:

 Please watch this video: How to drive your own High Voltage 300V_DC Brushless Washing Machine Motor using RX23T kit ?

b) The second one is use for e-bike application, the motor is a Crystalyte one: What if you could spin your 40A Brushless e-bike motor using RX23T kit ?

c) The thirs one is a high speed, low voltage motor from Maxon: How to drive your High Speed 40000RPM Permanent Magnet Motor for Turbine using RX23T kit?

Renesas designed the RX23T inverter kit for electronic developers, and any engineers willing to incorporate new 3-phase Permanent Magnet Motor as quickly as possible, with the little expertise needed.

Thanks to the intuitive PC GUI and a flexible inverter board based on RX23T, within a few clicks, each specific motor can start to spin. The GUI displays waveforms of internal program variables while the motor is rotating, to graphically check the behaviour of the control. Displaying waveforms of internal variables not only improves debugging efficiency, but also makes it easier to detect anomalous behaviour, helping to ensure safety.

Tuning a motor so quickly and generating automatically the list of parameters for the sensorless vector control algorithm is a major step forward for the designers with or without expertise in this field.

Furthermore, the RX23T/RX24T software is solving issues with processing speed when controlling multiple inverters and other issues with a single stroke. The use of an FPU (Floating Point Unit) vastly improves computing performance, code efficiency, and maintainability of source code. Motor control is more precise, and processing time is vastly reduced. There is no need for the complicated scaling that is required with fixed-point calculations. The royalty-free source code is more readable and easier to maintain, and development time is greatly shortened. The RX23T/RX24T MCU offering up to up to 160 DMIPS and 340 CoreMark with built-in FPU makes scaling unnecessary.

Thanks to the independent testing laboratory Langer EMV Technik, it was proven that the RX23T and RX24T microcontrollers reached the highest noise immunity for a 32-bit MCU. As the operating voltage is 5V, it allows the designer to get qualified their PCB quickly for Electro-Magnetic Compatibility.

Finally, the software running on the RX microcontroller is highly proven and already in Mass Production, driving motors at low & high speed and for low to very high torque.

The PC GUI allowed us to drive motor from 100RPM up to 40.000RPM, and up to 5N.m torque for specific motors.

The two examples below are showing such capabilities: high-speed turbine up to 40.000RPM (on the left) and with the same software, a propeller down to 100RPM (on the right).

Enjoy !   Kind regards - Vincent