Pomiary prądu i prędkości w układach sterowania wolnoobrotowych silników BLDC

• Autorzy: Fręchowicz A. , Heyduk A.

Warianty tytułu

EN

Speed and current measurements in control systems for low-speed BLDC motors

• Języki publikacji: PL

Abstrakty

EN

BLDC motors become more and more popular for direct drive systems without clutches and mechanical gearboxes. For small devices like mobile robots and wheelchairs they need to be low-speed motors. They need a proper control system, providing fast and accurate response to commands and disturbances. Usually they are equipped with cascade control systems with outer speed feedback control loop and inner current feedback control loop. These loops need fast and precise measurements of two input signals - speed and current values. The paper presents some practical experiences from design and laboratory tests of a low speed wheelchair drive. For low-speed motors period measurements fed directly from digital Hall sensors are much better than frequency measurements because they give much faster response. But they are very sensitive to the accuracy of Hall sensor displacement. The fastest reactions to speed changes can be achieved using a back EMF measurements with maximum value phase selection. The key to successful measurements is an application of low-pass analogue filters on the voltage inputs. Current measurements are heavily disturbed by strong pulse disturbances in transistor switching time instants. Much better accuracy can be achieved when the measurements are done in the middle of the PWM pulse. It can be achieved using a symmetrical modulation technique instead of the asymmetrical one. Additional hardware interrupt allows for precise readout synchronization.

Słowa kluczowe

PL

silnik bezszczotkowy prądu stałego; silnik elektryczny; silnik wolnoobrotowy; maszyna elektryczna; pomiar prądu; pomiar prędkości obrotowej; układ sterowania

• Wydawca: Sieć Badawcza Łukasiewicz - Górnośląski Instytut Technologiczny
• Czasopismo: Maszyny Elektryczne : zeszyty problemowe
• Rocznik: 2011
• Tom: Nr 2(90)
• Strony: 123--128
• Opis fizyczny: Bibliogr. 4 poz., rys.

Twórcy

autor

Fręchowicz A.

autor

Heyduk A.

• Politechnika Śląska, Gliwice

Bibliografia

• [1]. Bonert R.: Digital Tachometer with Fast Dynamic response Implemented by a Microprocessor. IEEE Trans. on Industry Applications, vol. 19, No. 6, 1983.
• [2]. Brock S., Zawirski K.: Speed Measurement Method for Digital Control System. Proc. of European Conf. on Power Electronics and Applications, EPE'2001, Graz, 2001.
• [3]. Hagel R.: Miernictwo elektryczne wielkości nieelektrycznych metodami elektrycznymi, Część II. Metody pomiarowe. Skrypt Politechniki Śląskiej, Gliwice 1982.
• [4]. Miłek M. Miernictwo wielkości nieelektrycznych metodami elektrycznymi. Wyd. PZ. Zielona Góra 1998.