Inverter-fed Interior Permanent Magnet Synchronous Motor Research Articles

Model-Free Predictive Current Control for Three-Level Inverter-Fed IPMSM With an Improved Current Difference Updating Technique

Parameter mismatches in conventional model predictive current control (MPCC) would worsen torque and THD performance. To eliminate the parameter dependence of MPCC, this letter proposes a model-free predictive current control (MFPCC) for a three-level inverter-fed interior permanent magnet synchronous motor (IPMSM). Firstly, to increase the current difference updating frequency in the diode neutral-point-clamped (NPC) three-level inverter, a synchronous updating method is proposed in a manner where the number of updated current differences during one sampling period is increased up to 6. Secondly, for the sake of computational burden alleviation, a candidate vector selection algorithm is introduced in such a way that the number of candidate vectors is reduced to only 7–9. Then, the problem of neutral-point voltage fluctuation which is inherent to the three-level NPC inverter is investigated, and a reasonable replacement method incorporating the redundancy characteristic of small vectors is developed. Finally, experimental results verify that the system robustness against mismatched parameters can be greatly enhanced by use of the proposed control scheme; meanwhile, steady-state performance and dynamic-state response of the system can be improved to some extent as well.

Three-Level Inverter-Fed Direct Torque Control of IPMSM With Torque and Capacitor Voltage Ripple Reduction

This paper proposes a new direct torque control (DTC) method for a three-level neutral point clamped (3L-NPC) inverter-fed interior permanent magnet synchronous motor (IPMSM) drive. Theoretically, in comparison to a two-level inverter, a 3L-NPC inverter is advantageous for reducing the torque and flux ripples in DTC drives. Nonetheless, the ripples can still be excessive and detrimental if low switching frequencies are desired. To reduce the torque and flux ripples while maintaining a low average switching frequency, a switching table-based DTC scheme employing two voltage vectors in each sampling period is proposed in this paper. A duty ratio calculation method with minimal parameter dependence is developed, taking into account the dynamic torque and flux characteristics of an IPMSM. In addition, the problems of neutral point voltage fluctuations and smooth voltage vector switching, which are inherited from the 3L-NPC inverter, are addressed. Simulation and experimental results are presented to prove the effectiveness of the proposed method.

IPMSM 드라이브에서 전류 기울기 정보를 이용한 데드타임 및 인버터 비선형성 효과의 간단한 제거 기법

A simple on-line elimination strategy of the dead time and inverter nonlinearity using the current slope information is presented for a PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive. In a PWM inverter-fed IPMSM drive, a dead time is inserted to prevent a breakdown of switching device. This distorts the inverter output voltage, resulting in a current distortion and torque ripple. In addition to the dead time, inverter nonlinearity exists in switching devices of the PWM inverter, which is generally dependent on operating conditions such as the temperature, DC link voltage, and current. The proposed scheme is based on the fact that the d-axis current ripple is mainly caused by the dead time and inverter nonlinearity. To eliminate such an influence, the current slope information is determined. The obtained current slope information is processed by the PI controller to estimate the disturbance caused by the dead time and inverter nonlinearity. The overall system is implemented using DSP TMS320F28335 and the validity of the proposed algorithm is verified through the simulation and experiments. Without requiring any additional hardware, the proposed scheme can effectively eliminate the dead time and inverter nonlinearity even in the presence of the parameter uncertainty.

IPMSM 파라미터 변화에 영향 받지 않는 데드타임 및 인버터 비선형성 보상기법

In a PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive, a dead time is inserted to prevent a breakdown of switching device caused by the short-circuit of DC link. This distorts the inverter output voltage resulting in a current distortion and torque ripple. In addition to the dead time, nonlinearity exists in switching devices of the PWM inverter, which is generally dependent on operating conditions such as the temperature, DC link voltage, and current. The voltage disturbance caused by the dead time and inverter nonlinearity directly influences on the inverter output performance, and it is known to be more severe at low speed. In this paper, a new compensation scheme for the dead time and inverter nonlinearity under the parameter variation is proposed for a PWM inverter-fed IPMSM drive. The overall system is implemented using DSP TMS320F28335 and the validity of the proposed algorithm is verified through the simulation and experiments.

Modeling and Simulation Technique of Two Quadrant Chopper and PWM Inverter-Fed IPMSM Drive System and Its Application to Hybrid Vehicles

This paper presents a state space model of a two quadrant chopper and PWM inverter-fed Interior Permanent Magnet Synchronous Motor (IPMSM) drive system and its application to hybrid vehicles. The drive system has two different state equations for motoring and regenerating action. This paper presents a common state equation by using State Space Averaging method. Using this model of the IPMSM drive system, detailed simulation and controller design of the drive system, including PWM inverter switching, are given. The validity of this model and usefulness, according to a comparison among Maximum Torque/Ampere control, Maximum Torque/Flux control, and Maximum Efficiency optimization, are confirmed from simulation results.

매입형 영구자석 동기전동기 구동용 인버터 스위칭 소자의 개방 고장 진단

This paper deals with a fault diagnosis algorithm for open faults in the switching devices of PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive. The proposed diagnostic algorithm is realized in the controller using the informations of three-phase currents or reference line-to-line voltages, without requiring additional equipments for fault detection. Under switch open fault conditions, the conventional dq model used to control an AC motor cannot directly be applied for the analysis of drive system, since three-phase balanced condition does not hold. To overcome this limitation, a fault model based on the line-to-line voltages is employed for the simulation studies. For comparative performance evaluation through the experiments, the entire control system is implemented using digital signal processor (DSP) TMS320F28335. Simulations and experimental results are presented to verify the validity of the proposed diagnosis algorithm.

Fuzzy-logic-controller-based cost-effective four-switch three-phase inverter-fed IPM synchronous motor drive system

This paper investigates the performance of a fuzzy-logic-controller (FLC)-based cost-effective drive system of interior permanent-magnet synchronous motor (IPMSM) for high-performance industrial applications. In this paper, the FLC is used as a speed controller and the motor is fed from a four-switch three-phase (4S3Ph) pulsewidth-modulation (PWM) inverter instead of a conventional six-switch three-phase (6S3Ph) inverter. This reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms and interface circuits to generate six PWM logic signals. Furthermore, the proposed control approach reduces the computation for real-time implementation. The closed-loop vector control scheme of the proposed 4S3Ph-inverter-fed IPMSM drive incorporating the FLC is implemented in real time using the digital signal processor (DSP) TI TMS320C31 for a prototype 1-hp motor. The robustness of the proposed FLC-based 4S3Ph-inverter-fed IPMSM drive is verified by theoretical and experimental results at different operating conditions. A comparison of the proposed 4S3Ph-inverter-fed IPM drive with a conventional 6S3Ph inverter system is also made in terms of performance and harmonic analysis of the stator current. The proposed inverter-fed IPMSM drive is found quite acceptable considering its performance, cost reduction, and other inherent advantageous features.