• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1449-1455
• /
• 2017

The vector control technique using low-resolution Hall-effect sensors has been widely used especially in consumer electronics. Due to electrical and/or mechanical unevenness related to binary-type Hall sensors, the calculated or estimated position information has discontinuities so called bumps, which causes the deterioration of vector control performance. In order to obtain a linearly changing position signal from low-precision Hall-effect sensors, this paper proposes a simple bumps in position signal removal algorithm that consists of a first-order observer with low-pass filtering scheme. The proposed algorithm has the feature of no needs for system parameters and additional estimation processes. The validity of the proposed method is verified through simulation and experimental results.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.4
• /
• pp.931-938
• /
• 2016

Application of vector control scheme for consumer products is enlarging to improve control performance. For the field-oriented control, accurate position detection is essential and generally requires expensive sensors. On the other hand, cost-reduction is important in home appliances, so that binary-type Hall-effect sensors are commonly used rather than using an expensive sensor such as an encoder. The control performance is directly influenced by the accuracy of the position information, and there exist non-uniformities related to Hall sensors in electrical and mechanical aspects, which result in distorted position information. Therefore, to get high-precision position information from low-resolution Hall sensors, this paper proposes a new position estimator consisting of a Kalman filter and feedforward compensation scheme, which generates a linearly changing position signal. The efficacy of the proposed scheme is verified by simulation and experimental results carried out with a 48-pole permanent magnet motor.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.4
• /
• pp.889-897
• /
• 2016

This paper presents an improved approach for compensating rotor position signal displacement in brushless DC (BLDC) motors with misaligned hall-effect sensors. Typically, the hall-effect sensors in BLDC motors are located in each phase and positioned exactly 120 electrical degrees apart. However, limitations in mechanical tolerances make it difficult to place hall-effect sensors at the correct location. In this paper, a position error compensator to counteract the hall-effect sensor positioning error is proposed. The proposed position error compensator uses least squares error analysis to adjust the relative position error and back-EMF information to reduce the absolute offset error. The effectiveness of the proposed approach is verified through several experiments.

• Journal of Magnetics
• /
• v.21 no.2
• /
• pp.173-178
• /
• 2016

Six-step commutation control widely used in brushless DC (BLDC) motor can be applied to consequent pole permanent magnet (CPPM) belt starter generator (BSG) with trapezoidal back electromotive force (EMF) in the starter state. However, rotor position detection with three Hall sensors in BLDC motor can hardly be employed in CPPM BSG due to asymmetric flux distribution in each pole side of CPPM BSG. This paper presents a low-cost rotor position detection method for CPPM BSG in which six Hall sensors are proposed to be used based on the analysis of flux distribution by 3D FEA. In the method, the six Hall sensors are divided into three groups and two signals in each group are combined through performing logic operations. In addition, offset angle between back EMF and the related Hall signal can be compensated by moving the Hall sensors. Experiments of a 2 kW CPPM BSG prototype have also been performed to verify the proposed method.

• Proceedings of the KIEE Conference
• /
• 1995.07c
• /
• pp.1431-1433
• /
• 1995

This paper describes the characteristics of Si Hall sensors fabricated on a SOI(Si-on-insulator} structure, in which the SOI structure was forrmed by SDB(Si-wafer direct bonding) technology. The Hall voltage and the sensitivity of implemented Si Hall devices show good linearity with respect to the applied magnetic flux density and supplied current. The product sensitivity of the SDB SOI Hall device is average $600V/A{\cdot}T$. In the temperature range of 25 to $300^{\circ}C$, the shifts of TCO(Temperature Coefficient of the Offset Voltage) and TCS(Temperature Coefficient of the product Sensitivity) are less than ${\pm}6.7{\times}10^{-3}/^{\circ}C$ and ${\pm}8.2{\times}10^{-4}/^{\circ}C$, respectively. From these results, Si Hall sensors using the SOI structure presented here are very suitable for high-temperature operation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.05a
• /
• pp.227-229
• /
• 1995

Using thermal oxide SiO$_2$ as a dielectrical isolation layer, SOI Hall sensors without pn junction isolation have been fabricated on Si/SiO$_2$/Si structures. The SOI structure was formed by SDB (Si- wafer direct bonding) technology. The Hall voltage and the sensitivity of Si Hall devices implemented on the SDB SOI structure show good linearity with respect to the appled magnetic flux density and supplied current. The product sensitivity of the SDB SOI Hall device is average 600V/V.T. In the trmperature range of 25 to 300$^{\circ}C$, the shifts of TCO(Temperature Coefficient of the Offset Voltage) and TCS(Temperature Coefficient of the Product Sensitivity) are less than ${\pm}$ 6.7x10$\^$-3/ C and ${\pm}$8.2x10$\^$04/$^{\circ}C$, respectively. These results indicate that the SDB SOI structure has potential for the development of Hall sensors with a high-sensitivity and high-temperature operation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2003.11a
• /
• pp.315-317
• /
• 2003

This paper deals with the position control of an AC servo motor using linear hall-effect sensors. The price of these is very low, but it is possible to make position control of motor similar to a control using an encoder. This paper introduces the design of motor using linear hall-effect sensors and shows the results of control.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.3
• /
• pp.205-210
• /
• 2013

This paper presents a novel hall sensor fault detection and fault-tolerant control method for a high-speed permanent magnet synchronous motor (PMSM) drive system. A phase locked loop (PLL) type position estimator is used with a conventional interpolation based rotor position estimator to reduce position errors due to misalignment of hall sensors. The expected trigger time of hall sensor's output is used for detecting hall sensor fault condition and the PLL type position estimator is reconfigured for fault-tolerant control at the hall sensor fault condition. The proposed method can minimize current ripples during the transition from sensored control using hall sensors to sensorless control. Experimental results have been proposed to prove the validity of the proposed method.

• Journal of Sensor Science and Technology
• /
• v.6 no.4
• /
• pp.265-273
• /
• 1997

The TMA gas sensors are fabricated with the ZnO-based thin films grown by a RF magnetron sputtering method. We investigate the surface carrier concentration, Hall electron mobility, electrical resistivity and sensitivity according to temperature variation and TMA gas concentration. The ZnO-based thin film sensors prepared by sputtering in oxygen showed higher surface carrier concentration, higher Hall mobility, higher sensitivity, and lower electrical resistivity than sensors prepared by sputtering in argon. The doping ZnO-based thin film sensors showed the same electrical properties in comparison with nondoping sensors. In case of sputtering on the oxygen gaseous atmosphere, the ZnO-based thin film sensors doped with 4.0 wt.% $Al_{2}O_{3}$, 1.0 wt.% $TiO_{2}$, and 0.2 wt.% $V_{2}O_{3}$ showed the highest surface carrier concentration of $5.95{\times}10^{20}cm^{-3}$, Hall electron mobility of $177\;cm^{2}/V{\cdot}s$, lowest electrical resistivity of $0.59{\times}10^{-4}{\Omega}{\cdot}cm$ and highest sensitivity of 12.1(working temperature, $300^{\circ}C$, TMA gas, 8 ppm).

• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.154-156
• /
• 2007

This paper proposes new vector control method that using two rectangular hall sensors instead of using the expensive encoder and resolver. The proposed method is similar to T-method. But the proposed method measures the speed using two hall sensors signals instead of encoder signal. The proposed new speed estimation method is stable under the rated speed range. This algorithm will be able to moderate prices of the whole system and apply for the unfit place for use encoder and resolver.