In keeping with TI’s philosophy of making motor control more accessible and easier to use by design engineers, TI is proud to announce the release of its newest motor control technology, InstaSPIN-BLDC. Targeted at low cost BLDC applications, InstaSPIN-BLDC is a sensorless control technique based on the premise that “simple is better”. In field tests with over 50 different motor types, InstaSPIN-BLDC was able to get each motor up and running in less than 20 seconds! The reason for this incredible robustness is because InstaSPIN-BLDC doesn’t require any knowledge about motor parameters to work, and you only need to adjust a single tuning value.
Unlike other sensorless BLDC control techniques based on back-EMF zero-cross timing, InstaSPIN-BLDC monitors the motor’s flux to determine when to commutate the motor. With the help of a free GUI (see figure), the user can watch the flux signal in a plot window, and set the “Flux Threshold” slider to specify at what flux level the motor should be commutated. Optimal commutation can be verified by observing the phase voltage and current waveforms, which are also displayed.
In addition to its ability to work with just about ANY BLDC motor, InstaSPIN-BLDC has demonstrated incredible resilience to speed transient perturbations. With zero-cross timing, you are always using PAST information to predict FUTURE commutation events. But InstaSPIN-BLDC monitors a real-time flux waveform to determine the appropriate time to commutate. Abrupt speed changes will be reflected in the flux waveform in real time, so that it will still cross the specified threshold value at exactly the right time to commutate.
Using flux for commutation vs. back-EMF zero-cross timing also enables more stable operation at lower speeds. Unlike the flux signal, the back-EMF signal amplitude diminishes at lower speeds, resulting in poor signal-to-noise performance. InstaSPIN-BLDC enables smoother operation at low speeds, and provides more reliable motor starting, even under heavy loads.