Four-Level Hysteresis-Based DTC for Torque Capability Improvement of IPMSM Fed by Three-Level NPC Inverter

Abstract

Direct torque control (DTC) is considered one of the simplest and fastest control strategies used in motor drives. However, it produces large torque and flux ripples. Replacing the conventional two-level hysteresis torque controller (HTC) with a four-level HTC for a three-level neutral-point clamped (NPC) inverter can reduce the torque and flux ripples in interior permanent magnet synchronous motor (IPMSM) drives. However, the torque will not be controlled properly within the upper HTC bands when driving the IPMSM in the medium and high-speed regions. This problem causes the stator current to drop, resulting in poor torque control. To resolve this problem, a simple algorithm based on a torque error average calculation is proposed. Firstly, the proposed algorithm reads the information of the calculated torque and the corresponding torque reference to calculate the torque error. Secondly, the average value of torque error is calculated instantaneously as the reference torque changes. Finally, the average value of the torque error is used to indicate the operation of the proposed algorithm without the need for motor speed information. By using the proposed algorithm, the torque can be controlled well in all speed regions, and thus, a better stator current waveform can be obtained. Simulation and experimental results validate the effectiveness of the proposed method.

Improved Rotor Flux and Torque Control Based on the Third-Order Sliding Mode Scheme Applied to the Asynchronous Generator for the Single-Rotor Wind Turbine

“…DFTC is wellknown for its robust strategy, simple algorithm, and fast-flux/torque response, which requires no modulation techniques, current control, or coordinate transformation [44]. This method has been applied to several electric machines such as induction motor [45], a brushless DC electric motor [46], interior permanent magnet synchronous motor [47], five- The stability condition is given by:…”

“…DFTC is well-known for its robust strategy, simple algorithm, and fast-flux/torque response, which requires no modulation techniques, current control, or coordinate transformation [44]. This method has been applied to several electric machines such as induction motor [45], a brushless DC electric motor [46], interior permanent magnet synchronous motor [47], five-phase induction motor [48], brushless doubly-fed machine [49,50], permanent magnet synchronous motor (PMSM) [51], six-phase induction motor [52], and five-phase PMSM [53,54]. In [55], the DFTC control scheme reduced the electromagnetic torque, stator current, and rotor flux compared to the FOC method.…”

A developed combined control method for induction machine drives based on PWM

“…As can be seen from Figure 4, the conventional three-level electromagnetic torque and two-level stator flux hysteresis controllers are used in the proposed CC system. To improve the performance of the proposed control method, a four-level electromagnetic torque hysteresis controller could be used in the proposed CC system (Hakami and Lee, 2020). It is also possible to use a constant switching frequency controller instead of the conventional three-level electromagnetic torque hysteresis controller (Alsofyani and Idris, 2016).…”

Investigations of hysteresis based direct torque controlled and field oriented controlled IPM drives for electric vehicle applications

“…Wang et al, 2017). Although less current distortions and smoother output torque can be achieved with PWM based DTC drives, the superior features of HB-DTC drives such as less burden on the processor, eliminating the need for a position sensor, less component in practical system, and simpler implementation due to less complexity of the HB-DTC strategy render them quite common even in recent studies (Mohan et al, 2016;Hakami and Lee, 2020;Xu, Odavic et al, 2021;Ben Mahdhi et al, 2022).…”