Chunyan Lai

University of Windsor · Department of Electrical and Computer Engineering

To solve the torque minimization problem of redundant manipulators, a bi-criteria scheme is investigated in this paper. Different from previous researches, inertia-inverse is considered corresponding to global kinetic energy minimization of robot mechanisms via this scheme. Such a scheme could be finally formulated as a general quadratic programm (...

Accurate model of permanent magnet synchronous machine (PMSM) is significant for high-performance control. The machine model can be affected by various factors such as magnetic saturation and core loss effect especially in the deep saturation and high-speed regions. This paper proposes a data-driven based machine modeling and compensation approach...

This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines (PMSMs). The concept of virtual position-offset injection is mathematically transforming the machine model to a virtual frame with a position-offset. The virtual frame temperature estimation model...

Virtual current sensors (VCSs) are promising solutions for accurate current measurement in high performance and low cost permanent magnet synchronous machine (PMSM) drives. They not only help identify faults in hardware current sensors, but also ensure the continuous operation of PMSM drive system with reduced hardware current sensor counts. Howeve...

For permanent magnet synchronous machines (PMSMs), magnetic saturation is a key challenge to parameter estimation and saturation modeling using polynomials is popular with dq- axis inductances estimated independently. However, dq-axis inductances are mathematical terms derived from stator frame and are indeed correlated, which is not fully explor...

For permanent magnet synchronous machines (PMSMs), high performance control strategies rely on sensors to obtain accurate information of rotor position and speed. However, mechanical sensors are expensive and susceptible to harsh environment. Therefore, various sensorless control strategies have been proposed and intensively investigated for decade...

For permanent magnet synchronous machine (PMSM) drive, accurate magnet temperature is critical. The popular model-based magnet temperature estimation can be affected by core loss effect especially in the high-speed conditions. The paper proposes a novel hybrid approach for accurate magnet temperature modeling and estimation, in which the estimation...

For the dual three-phase interior permanent magnet synchronous machines (DT-IPMSMs), open-phase fault can cause current unbalance and degrade the drive performance. This article proposes a fault tolerant maximum torque per ampere (FT-MTPA) control for DT-IPMSMs, which can maximize the ratio of the average torque to the stator current and minimize t...

For the permanent magnet synchronous machine (PMSM), parameter estimation can be greatly affected by the measurement uncertainty, but few efforts are made to reduce the uncertainty level for estimation performance improvement. Therefore, this article proposes an efficient and robust incremental Bayesian learning approach for PMSM parameter estimati...

Permanent magnet synchronous machine (PMSM) drives with better efficiency are highly demanded, and accurate flux linkage and inductance models or maps are critical to achieve such drives. However, precise modeling and estimation of these parameters should employ redundant data and are affected by magnetic saturation and inverter distortion. This pa...

The maximum torque per ampere (MTPA) is popular control strategy for interior permanent synchronous machines (PMSMs) and MTPA point is dependent on the magnetic saturation and magnet temperature. This paper proposes a novel MTPA control method combining offline model and online compensation model for interior PMSM control. In the proposed approach,...

For interior permanent magnet synchronous machine (IPMSMs), maximum torque per ampere (MTPA) control aims to find the MTPA angle to maximize the control objective (the ratio of output torque to stator current). This paper proposes a novel online polynomial curve fitting technique for fast and accurate MTPA angle detection, which is motivated by the...

Accurate parameters are critical to permanent magnet synchronous machine (PMSM) drive. This paper investigates accurate flux linkages, inductances and PM flux linkage estimation for PMSM with core loss compensation. With conventional model, core loss will induce the flux linkage error especially in the deep saturation region. Hence, this paper firs...

This paper proposes a current injection-based simultaneous stator winding and permanent magnet (PM) temperature tracking technique for dual three-phase permanent magnet synchronous machines (PMSMs). The estimation models involving winding and PM temperatures are derived for different control strategies with the cancellation of inductances. To impro...

Fault tolerance is critical to real-time control of dual three-phase interior permanent magnet synchronous machine (IPMSM). This paper proposes an efficient decoupled design for fault tolerant control (FTC) of dual three-phase IPMSMs to improve the average torque and minimize current root mean square (RMS) for torque ripple and loss reduction under...

This paper proposes an efficient maximum torque per square ampere (MTPSA) control for the interior permanent magnet synchronous machines (IPMSMs). The objective of the MTPSA control is to find the optimal current angle, denoted as MTPSA angle, to maximize the ratio of the output torque to the square of the stator current. The proposed MTPSA control...

For permanent magnet synchronous machine (PMSM), torque ripple is a critical issue especially under low-speeds. Torque ripple minimization (TRM) control aims to find the optimal currents to be injected to cancel the existing torque ripple. This paper proposes an optimal current modeling technique for TRM control. In the proposed technique, torque h...

This paper proposes an optimized current harmonic minimization approach for dual three-phase permanent magnet synchronous machines (PMSMs) with consideration of inverter voltage limit. The current harmonic model is firstly derived to analyze the dominant current harmonic components in dual three-phase PMSM drive. Dual reference frame (DRF) model is...

For dual three-phase interior permanent magnet synchronous machines (IPMSMs), open-phase fault can result in significant average torque reduction and harmonics in the output torque and speed, which prevent the machines from reliable and safe operation. Indeed, these adverse effects are mainly due to the significant harmonics in the stator currents...

This paper investigates efficiency optimization in a permanent magnet synchronous machine (PMSM) drive system including the motor and the power converter. At first, the motor drive efficiency model based on the input and output power is proposed. In this model, the input power is calculated from the DC link voltage and current measurements, and the...

This article proposes a closed-loop decoupled current control for torque ripple minimization (TRM) of permanent magnet synchronous machines (PMSMs) by using the speed measurements. In the proposed control, a decoupled scheme is developed to control the harmonic currents for TRM, in which the control of phase angle and magnitude is decoupled to simp...

Comprehensive parameters testing and analysis are critical to high-performance modeling and control of permanent magnet synchronous machines (PMSMs). In this paper, a novel decoupled approach for dual three-phase PMSM (dual-3P-PMSM) parameter estimation including winding resistance, machine inductances and PM flux linkage is proposed for comprehens...

Accurate temperature information is crucial to dual three-phase permanent magnet synchronous machines (PMSM) drives. Therefore, this paper proposes two efficient models for permanent magnet (PM) temperature estimation of dual three-phase PMSMs. The proposed models are derived through current injection in the reference frame that does not contribute...

This paper proposes a novel dual dc injection-based maximum torque per ampere (MTPA) control algorithm for dual three-phase permanent magnet synchronous machines (PMSMs). The proposed analytical model to achieve optimal current angle takes magnetic saturation and temperature effects into account. In taking consideration of two effects, a set of sma...

Emerging demands in sustainable energy and power conversion applications are calling for high frequency and high efficiency switching devices. Gallium nitride (GaN) as one type of wide bandgap material has shown its potential in applications where high frequency, high efficiency, and small size are of significance. In this paper, recent progress ma...

Integrated battery charging (IBC), multiplexing the motor windings as line inductors for charging the electric vehicle battery pack, can improve the onboard charging capability without increasing the weight and cost. However, during the charging operation, currents flowing in the stator winding definitely generate a magnetic field, which may demagn...

To prevent motor failures caused by thermal overloading, accurate knowledge of stator winding temperature is of significance. The proposed stator winding temperature tracking is a stator resistance‐based estimation technique for dual three‐phase permanent magnet synchronous machines. In the proposed approach, a dual DC signal‐injection‐based method...

This paper investigates the use of the phase angle of the measured speed harmonics for efficient permanent magnet (PM) temperature estimation of permanent magnet synchronous machine (PMSM). Based on the mechanical model of a PMSM, a linear estimation model is derived to model the relationship between the PM temperature and the phase angle of the sp...

To develop a high–performance and reliable control for dual three–phase permanent interior magnet synchronous machine (IPMSM), accurate knowledge of machine parameters is of significance. This paper proposes an improved recursive least square (RLS) algorithm and current injection–based parameter estimation method for dual three–phase PMSM with cons...

This paper investigates open-phase fault modeling and fault tolerant control (FTC) of dual three-phase permanent magnet synchronous machines. A comprehensive fault model that considers both the permanent magnet torque and reluctance torque under the open-phase fault is proposed at first. This model shows that under open-phase fault the average torq...

Permanent magnet (PM) synchronous machines (PMSMs) with concentrated windings (CW) exhibit high content of space harmonics leading to non-sinusoidal distribution of PM flux linkage and phase inductances in addition to the non-sinusoidal wave shape of the induced EMF. The ideal single reference frame based PMSM model considers these parameters to be...

The 3-phase windings of interior permanent magnet synchronous machines (IPMSMs) used in electric vehicles (EVs) for traction can also be utilized for charging the battery. This integrated charging technology eliminates the on-board charger, leading to significant reduction in overall weight and cost of the EV. However, during integrated charging, t...

Torque ripple has been a critical issue for high-performance applications using permanent magnet synchronous machines (PMSMs). An efficient approach to minimize torque ripple is to control the stator current to follow an optimized current reference, which will produce an extra torque ripple to cancel the existing one. This paper proposes a multiple...

Power electronics and motor drive components existing in a conventional electric vehicle (EV) drivetrain employed to propel the EV can also be used to charge the battery under level 3 fast charging capacity. This integrated battery charging technology can be realized by employing the winding inductances of the three-phase interior permanent magnet...

Vector space decomposition (VSD) model has been widely utilized for dual three-phase permanent magnet synchronous machine (dual-PMSM) control, in which two DQ frames, DQ1 and DQ2, are introduced to facilitate controller design. Existing studies show that harmonic current injection in DQ2 frame can increase the output torque for a given peak phase c...

This paper investigates permanent magnet (PM) temperature modelling and estimation for permanent magnet synchronous machines (PMSMs) by using the measured speed harmonic. At first, a linear temperature model is derived to demonstrate that the magnitude of the speed harmonic decreases linearly as the PM temperature increases. To achieve this linear...

Merits such as reduced weight, overall and operational costs of the electric vehicle (EV) while providing level 3 charging capability, are propelling research on integrated charging (IC) technology for EVs. Since the same interior permanent magnet synchronous machine (IPMSM) is used during IC and traction conditions, it is important to understand t...

Merits such as reduced weight, overall and operational costs of the electric vehicle (EV) while providing level 3 charging capability, are propelling research on integrated charging (IC) technology for EVs. Since the same interior permanent magnet synchronous machine (IPMSM) is used during IC and traction conditions, it is important to understand t...

Permanent magnet (PM) temperature is crucial to high-performance control and condition monitoring of the permanent magnet synchronous machines (PMSMs). Thus, this paper proposes a non-invasive PM temperature estimation approach based on the PMSM steady-state equation. Firstly, a linear temperature model, dependent solely on the PM temperature, is d...

This paper explores the use of speed harmonic for accurate and fast maximum-torque-per-ampere (MTPA) control of interior permanent magnet synchronous machines (IPMSMs). A novel MTPA angle calculation approach is proposed, in which the MTPA angle is directly calculated from the phase angle of the speed harmonic that is induced by an injected harmoni...

The beneficial nature of employing power electronics and drive components in conventional electric vehicle (EV) towards level 3 charging capability has propelled research activities towards integrated charging (IC) technology. However, alternating magnetic fields produced in the air-gap by AC charging currents and the stationary nature of the rotor...

Permanent magnet (PM) temperature is critical to ensure high-performance and reliable control of permanent magnet synchronous machines (PMSMs) for electric vehicle (EV) applications. High-frequency (HF) voltage injection based approach has been shown to be capable of magnet temperature estimation under all-speed range with simple implementation. Th...

Understanding the merits of using an interior permanent magnet synchronous machine (IPMSM) for propulsion in all-electric vehicles and challenges in conventional electric machine design approach, this paper proposes a novel model based design approach for three-phase IPMSMs. Firstly, a novel bottom-up IPMSM design methodology involving closed-form...

This paper proposes a novel gradient descent based maximum torque per ampere (MTPA) control algorithm for interior permanent magnet synchronous machines (IPMSMs) by using the measured speed harmonics. The proposed approach does not require machine parameters and thus is not influenced by the machine and drive nonlinearities. Hence, the proposed app...

Torque ripple has been a critical issue in permanent magnet synchronous machines (PMSMs). After PMSMs are designed, an efficient way for torque ripple minimization is to inject an optimized harmonic current into the machine to produce an additional torque ripple to cancel existing torque ripple resulted from the imperfection of machine design and m...

This paper investigates the torque ripple modeling and minimization for interior permanent magnet synchronous machines (PMSMs). At first, a novel torque ripple model is proposed, in which the torque ripples resulted from the spatial harmonics of permanent magnet flux linkage, time harmonics of stator currents and the cogging torque are included. Ba...

Torque ripple modelling and minimization for interior permanent magnet synchronous machines (IPMSMs) requires accurate information of the inductances which vary nonlinearly due to magnetic saturation. However, existing approaches fail to consider the magnetic saturation and thus their performance is limited under different load conditions. Therefor...

Optimal stator current design has been widely investigated for torque ripple minimization of permanent magnet synchronous machines (PMSMs). The optimal current design requires accurate machine parameters including the permanent magnet flux and $dq$ -axis inductances, which are varying during machine operation due to machine uncertainty. Therefore,...

In this paper, an analytical torque ripple model for interior permanent magnet synchronous machine (IPMSM) is introduced at first, which can be used to estimate the torque ripple. Then, the inductance variation due to magnetic saturation is analyzed through experimental investigations, which demonstrates that magnetic saturation has a great influen...

Rotor magnet flux linkage is critical to monitor the state of the permanent magnet in a permanent magnet synchronous machine (PMSM). This paper proposes a novel online magnet flux linkage estimation approach by using measured speed harmonics. The proposed approach is based on the PMSM’s mechanical equation, so it is not influenced by magnetic satur...

This paper investigates torque ripple minimization for permanent magnet synchronous machine (PMSM), and proposes a closed-loop fuzzy logic based current controller by using the magnitude of the speed harmonic as the feedback control signal. The speed harmonic can be obtained from machine speed measurement, so the proposed approach does not require...

This manuscript presents an analytical model of eddy current losses in an interior permanent magnet motor (IPM) due to carrier frequency and harmonic current in maximum torque per ampere (MTPA) control operation. The influence of pulse width modulation (PWM) and motor design parameters has been considered to evaluate the increase in losses due to c...

For permanent magnet synchronous machines (PMSMs), accurate magnet flux linkage information is critical for permanent magnet condition monitoring and drive performance improvement. This paper proposes a novel particle filter based magnet flux linkage estimation approach by using the harmonics in the machine speed. In the proposed approach, the harm...

Understanding the significance of precise torque control of electrical machines and the importance of accurate motor parameter determination to achieve the control precisely, this manuscript proposes a new method of identifying varying parameters of permanent magnet synchronous machines through a two-step on-line estimation algorithm incorporating...

This paper investigates the torque ripple modeling and minimization for interior permanent magnet synchronous machine (PMSM). At first, a novel torque ripple model is proposed. In this model, both spatial harmonics of magnet flux linkage and current time harmonics induced by machine drive are considered, which includes the torque ripples resulted f...

The spatial harmonic of magnet flux is a major cause of torque ripple in permanent magnet synchronous machines (PMSMs), and it is temperature-dependent. Thus, this paper investigates torque ripple modeling and minimization for PMSMs considering magnet temperature variations. Firstly, experimental studies are conducted to demonstrate that the torque...

In this era of electrified transportation, inadequate fast-charging infrastructure and limited driving ranges in vehicles due to current energy storage technology remain bottlenecks in motivating consumers to rapidly shift to these electrified vehicles. Mass integration of these vehicles into the grid in the future would result in huge stress on th...

The study of the interaction between an interior permanent magnet (IPM) motor and a pulsewidth modulated (PWM) converter is increasingly becoming important, especially in the case of high-speed drives owing to the losses caused by modulation. Considering the significance of machine-converter interaction, this paper proposes a novel method to calcul...

This paper studies the online parameter estimation of permanent magnet synchronous motor (PMSM) with the consideration of magnetic saturation and proposes a novel current injection method to estimate parameters, including winding resistances, dq-axis inductances, and rotor flux. During the current injection, the inductances will vary due to magneti...

To develop a high-performance and reliable permanent magnet synchronous machine (PMSM) drive for electric vehicle (EV) applications, accurate knowledge of the PMSM parameters is of significance. This paper investigates online estimation of PMSM parameters and VSI nonlinearity using current injection method in which magnetic saturation is also consi...

In permanent magnet synchronous machine, high-frequency (HF) signal injection has been extensively investigated for permanent magnet temperature (PMT) estimation, in which PMT is estimated from the temperature-dependent HF resistance. Existing studies require prior knowledge on the HF resistance and neglect the fact that PMT is temporally correlate...

During integrated charging (IC) operation employing permanent magnet machines, the magnetic field produced by the sinusoidal AC current passing through the stator windings, a) affects the effective winding inductance used in the charger circuit as a function of different stator winding combinations; and b) produces oscillating torque of varying mag...

The concept of integrated battery charger is attracting attentions these days. To design a motor drive system with an integrated charging capability, the machine windings are usually reconfigured to be used as the AC side inductors. Along with the switches from the drive circuitry, the AC side inductors form the voltage front-end to improve the pow...

In this paper, a novel current tracking strategy for switched reluctance motor (SRM) is proposed, analyzed and verified. The relationship between pulse-width modulation (PWM) duty ratio and current variation in SRM over a cycle is investigated. The results demonstrate that an analytical resolution for calculating the duty ratio to achieve accurate...

Recently, permanent magnet synchronous machines (PMSMs) are widely used in electrified vehicle applications due to their high efficiency and high torque density characteristics. Hence, in an approach towards fault prognosis through online monitoring, it is of paramount importance to analyze inter-turn short-circuit fault whose occurrence is expecte...

The concept of electrified vehicles (EVs) is the best old "new" idea that has been around for the last century. Designs have changed to make EVs popular, but until now, no design has captured the public's imagination or gained market traction. This is because consumers need more than facts about EVs; they need to be wooed into making a bigger commi...

To solve the torque minimization problem of redundant manipulators, a bi-criteria scheme is investigated in this paper. Different from previous researches, inertia-inverse is considered corresponding to global kinetic energy minimization of robot mechanisms via this scheme. Such a scheme could be finally formulated as a general quadratic program (Q...