A new direct torque control for AC motors with over modulation ability

Sugai, Masaru; Umeno, Takatoshi; Amano, Yasushi

doi:10.1109/iemdc.2011.5994782

Cited by 13 publications

(3 citation statements)

References 8 publications

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“…Using a similar approach, VcN is calculated when U5 and U6 are applied sequentially, as shown in (9).…”

Section: Calculation Of the Fundamental Componentmentioning

confidence: 99%

“…A comparison of various motor drives shows direct torque control (DTC) drive has several advantages and the torque response is much faster than any AC or DC drive [8]. However, with a conventional DTC, the square wave or the six-step mode required at high speeds is not possible [9]. Therefore, to achieve an accurate seamless transformation between the conventional DTC and the six-step operation, several studies are now being conducted.…”

Section: Introductionmentioning

confidence: 99%

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A Novel Seamless Direct Torque Control for Electric Drive Vehicles

Umeno¹,

Amano²,

Sugai³

2011

Journal of Power Electronics

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Electric drive vehicles (EDV) have received much attention recently because of their environmental and energy benefits. In an EDV, the motor drive system directly influences the performance of the propulsion system. However, the available DC voltage is limited, which limits the maximum speed of the motors. At high speeds, the inverter voltage increases if the square wave (SW) voltage (six-step operation) is used. Although conventional direct torque control (DTC) has several advantages, it cannot work in the six-step mode required in high-speed applications. In this paper, a single-mode seamless DTC for AC motors is proposed. In this scheme, the trajectory of the reference flux changes continuously between circular and hexagonal paths. Therefore, the armature voltage changes smoothly from a high-frequency switching pattern to a square wave pattern without torque discontinuity. In addition, because multi-mode controllers are not used, implementation is more straightforward. Simulation results show the voltage pattern changes smoothly when the motor speed changes, and consequently, torque control without torque discontinuity is possible in the field weakening area even with a six-step voltage pattern.

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“…Using a similar approach, VcN is calculated when U5 and U6 are applied sequentially, as shown in (9).…”

Section: Calculation Of the Fundamental Componentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Novel Seamless Direct Torque Control for Electric Drive Vehicles

Umeno¹,

Amano²,

Sugai³

2011

Journal of Power Electronics

View full text Add to dashboard Cite

show abstract

“…Thus, the proposed method uses only SPWM technique and yet realizes the SPWM operation below the base speed and square wave operation above the base speed. This avoids the torque discontinuity which normally occurs while switching between the sine triangle and any other PWM technique to square wave [8,9]. The proposed strategy is implemented on a small low power, low voltage prototype motor in the lab.…”

Section: Introductionmentioning

confidence: 99%

A Torque Discontinuity Free New Hybrid PWM Approach for High Speed Induction Motor Drives

Rehman

Mahmood

Shah

2014

Advances in Power Electronics

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This paper designs a hybrid speed controller in which a Sine Triangle Pulse Width Modulated (SPWM) inverter is used below the base speed and a square wave inverter is employed above the base speed. The two inversion techniques complement each other for their advantages and disadvantages below and above the base speed. This paper proposes a unique strategy for the transition between SPWM and square wave by simply setting the frequency of the carrier signal equal to zero. The proposed methodology in a way uses only one inversion technique and realizes a seamless transition from the SPWM to square wave compared to conventional method in which modes are simply switched from SPWM to square wave and vice versa when the speed changes above and below the base speed, respectively. Computer simulations show that the proposed technique has smoother torque transition and thus a better speed response compared to conventional approach of inverter mode switching around the base speed. The performance of proposed hybrid approach is also validated on a small prototype induction motor through experimental results.

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