Inverter Solution Kits for Brushless AC Motor ControlSeptember 01, 2014 by Jeff Shepard
Renesas Electronics Europe today announced its new RX111 motor control kits. These inverter reference solution kits are designed to drive any 3-phase permanent magnet synchronous motors (PMSM), also called brushless ac motors. The RX111 inverter kits enable engineers to save time by eliminating the need to tune their motor parameters and evaluate the best tuning algorithm coefficients. As a result, they can rotate a permanent magnet ac motor in less than one minute and accelerate their time to market.
The new RX111 inverter kits aim to revolutionize the integration of 3-phase motors in equipment. Based on Renesasâ€™ 32-bit RX family of MCUs running at 3V, they deliver 50DMIPS at 32MHz. The RX111 reference kits are designed for equipment requiring medium and high dynamics and a low-cost bill of materials. The kits provide up to 7A maximum at 24Vdc and have been tested with more than 30 different motors. Additionally, an external power stage is available on demand that is fully-compatible with the existing RX220 and RX62T inverter kits. The new RX111 solution kits provide the dynamics required to drive motors with a high level of accuracy.
The availability of the new RX111 kits completes the latest step in Renesas Electronicsâ€™ business strategy of providing a wide range of innovative solutions comprising both hardware and software. The companyâ€™s existing kits have seen considerable success and broad adoption by designers and engineers, for whom they provide cost savings and faster time to market. Renesas will be launching additional kits over the coming months to continue the implementation of this strategy. Many of the kits will be showcased on Renesasâ€™ stand at electronica in November (Hall A6, Stand 243). With the Renesas trade fair theme â€˜Connect with Tomorrowâ€™, the kit solutions will be a central focus at this yearâ€™s electronica in Munich.
Renesas has developed the two design tools based on RX111 MCUs to respond to a challenge encountered by engineers: tuning the embedded software to the application requirements, especially for sensorless field oriented control algorithms. The inverter kits provide: Auto-tuning of the current proportional-integral (PI) coefficients: Kp, Ki; Identification of intrinsic motor parameters: Rs, Ls, Lm; Real-time visualization of the motor phase, current and step response; and Dynamic modification of the PWM frequency and control loop.
The kits include an intuitive PC graphical user interface (GUI), providing engineers with a ready to use inverter reference prototype that enables them to drive their own motors in a few clicks. The solution kits also feature a sensorless vector control algorithm, which is used to accurately control the speed and the torque. This algorithm uses flux weakening to achieve rotation speeds higher than the nominal speed of the motor. Finally, two flux estimator blocks are implemented to ensure high flexibility in terms of motor types and application requirements.
Each kit contains the YROTATE-IT inverter board, a 24Vdc permanent magnet ac motor, a CD-ROM including the embedded software source code, the PC GUI, the board schematics, the bill of materials, Gerber files, user manual, quick start guide and the power stage schematics/Gerber files.