Author
Frank C. Doran
Bio: Frank C. Doran is an academic researcher. The author has contributed to research in topics: Induction motor & Servo drive. The author has an hindex of 3, co-authored 5 publications receiving 234 citations.
Topics: Induction motor, Servo drive, Servo, Servomechanism, Inverter
Papers
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TL;DR: In this paper, the position of the rotor flux is measured in the direct scheme and estimated in the indirect scheme, all of which are all machine-parameter dependent, and analytical expressions are derived to evaluate the effects due to parameter sensitivity.
Abstract: Vector control schemes are used in inverter-fed induction motor drives to obtain high performance. Crucial to the success of the vector control scheme is the knowledge of the instantaneous position of the rotor flux. The position of the rotor flux is measured in the direct scheme and estimated in the indirect schemes. Since the estimation of the flux position requires a priori knowledge of the induction motor parameters, the indirect schemes are all machine-parameter dependent. Changes in temperature and saturation levels of the machine vary the machine parameters and, hence, indirectly influence both the steady state and the dynamic operation of the drive system. Analytic expressions are derived to evaluate the effects due to parameter sensitivity. The simulation is experimentally verified on a drive system.
216 citations
TL;DR: In this article, a method of sensing line voltages from the base drive signals of the transistor inverter circuit is described, which is used in parameter adaptation for inverter-fed induction motor drives.
Abstract: Most high-performance inverter-fed induction motor drive systems require signals corresponding to the input voltages of the motor for parameter adaptation. Low-performance systems require the signals for stabilization. The voltage signals are used in the controller circuit and therefore require isolation. Isolation of the voltage signals is not a cost-effective solution in low-power motor drive systems. The fact that the base drive signals to the transistor inverter are isolated makes them the ideal choice for the reconstruction of the motor line voltages. A method of sensing line voltages from the base drive signals of the transistor inverter circuit is described. A step-by-step derivation of the voltage sensing algorithm is given which leads to a simple realization. The synthesized voltages are used in parameter adaptation for inverter-fed induction motor drives. The sensing scheme has been implemented on a laboratory prototype, providing experimental results which are presented.
17 citations
TL;DR: In this article, a simplified thermal model of vector-controlled induction motor servos rated between 1 and 15 kW is proposed to predict thermally safe load cycles for induction motor drives.
Abstract: Advances in the available performance of induction motor-inverter systems permit these drive systems to meet progressively more demanding performance criteria. High-performance servos require the induction motor to produce high torque and power. The severely repetitive load cycles stress the motor's insulation with high operating temperatures. The traditional rating of the induction motor based on ac line operation is not useful under these circumstances. In spite of the complexity of the thermal problem, an approximate thermal calculation procedure will allow servo designers and users alike to predetermine thermally safe load cycles for induction motor servo drives. Study is directed to the formulation of a simplified thermal model of vector-controlled induction motor servos rated between 1 and 15 kW and to the subsequent use of this model to predict thermally safe load cycles. A set of normalized curves relating duty cycle and torque is presented for the available classes of motor insulation. Theoretical results are supported by experimental verification on an existing vector-controlled induction motor servo system.
6 citations
01 Jan 1987
TL;DR: In spite of the complexity of the thermal problem, an approximate thermal calculation procedure will allow servo designers and users alike to predetermine thermally safe load cycles for induction motor servo drives.
Abstract: Advances in the available performance of induction motor-inverter systems permit these drive systems to meet progressively more demanding performance criteria. High-performance servos require the induction motor to produce high torque and power. The severely repetitive load cycles stress the motor's insulation with high operating temperatures. The traditional rating of the induction motor based on ac line operation is not useful under these circumstances. In spite of the complexity of the thermal problem, an approximate thermal calculation procedure will allow servo designers and users alike to predetermine thermally safe load cycles for induction motor servo drives. Study is directed to the formulation of a simplified thermal model of vector-controlled induction motor servos rated between 1 and 15 kW and to the subsequent use of this model to predict thermally safe load cycles. A set of normalized curves relating duty cycle and torque is presented for the available classes of motor insulation. Theoretical results are supported by experimental verification on an existing vector-controlled induction motor servo system.
1 citations
01 Jan 1987
TL;DR: In this article, a simplified thermal model of vector-controlled induction motorservos rated between 1 and 15kW was proposed to predict thermally safeloadcycles for high-performance servos.
Abstract: Advances intheavailable performance ofinduction motor- inverter systems permit these drive systems tomeetprogressively more demanding performance criteria. High-performance servosrequire the induction motortoproducehightorqueandpower.Theseverely repetitive loadcycles stress themotor's insulation withhighoperating temperatures. Thetraditional rating oftheinduction motorbasedonac lineoperation isnotuseful underthesecircumstances. Inspite ofthe complexity ofthethermal problem, anapproximate thermal calculation procedure willallowservodesigners andusersalike topredetermine thermally safeloadcycles forinduction motorservodrives. Studyis directed totheformulation ofa simplified thermal modelofvector- controlled induction motorservos rated between 1and15kW andtothe subsequent useofthis modeltopredict thermally safeloadcycles. A set ofnormalized curvesrelating dutycycle andtorque ispresented forthe available classes ofmotorinsulation. Theoretical results aresupported by experimental verification on an -existing vector-controlled induction motorservosystem.
Cited by
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TL;DR: In this article, the performance of the two control schemes is evaluated in terms of torque and current ripple, and transient response to step variations of the torque command, where secondary effects introduced by hardware implementation are not present.
Abstract: Field-oriented control and direct torque control are becoming the industrial standards for induction motors torque control. This paper is aimed at giving a contribution for a detailed comparison between the two control techniques, emphasizing advantages and disadvantages. The performance of the two control schemes is evaluated in terms of torque and current ripple, and transient response to step variations of the torque command. The analysis has been carried out on the basis of the results obtained by numerical simulations, where secondary effects introduced by hardware implementation are not present.
1,030 citations
TL;DR: In this article, a detailed model for the stationary and synchronous sine-triangle current regulators is presented, and the results demonstrate the limitations of the two most often used current regulators and the robustness of the synchronous current regulator.
Abstract: Detailed models are presented for the stationary and synchronous sine-triangle current regulators. Analytical and test results are compared for purposes of model verification and regulator evaluation. The results demonstrate the limitations of the two most often used current regulators and the robustness of the synchronous current regulator. The stationary sine-triangle and hysteretic current regulators are shown to have steady-state characteristics that depend on slip, operating frequency, and motor impedance. In contrast the synchronous regulator, because it lacks these dependencies, exhibits ideal steady-state current regulator characteristics without sacrificing bandwidth. Moreover, the complexities traditionally associated with the synchronous regulator are overcome with a simple equivalent implementation.
472 citations
TL;DR: In this paper, the authors compare the performance of the permanent magnet synchronous motor (PMSM) and the brushless DC motor (BDCM) on the basis of known engineering criteria such as power density, torque per unit current, speed range, feedback devices, inverter rating, cogging torque, ripple torque and parameter sensitivity.
Abstract: The permanent magnet synchronous motor (PMSM) and the brushless DC motor (BDCM) have many similarities; they both have permanent magnets on the rotor and require alternating stator currents to produce constant torque. For application considerations, these two motor drives have to be differentiated on the basis of known engineering criteria. Some of the criteria used to assess these two machines include power density, torque per unit current, speed range, feedback devices, inverter rating, cogging torque, ripple torque, and parameter sensitivity. Guidelines for the appropriate machine to be used for a given application are given based on the results of the criteria. >
416 citations
TL;DR: This paper aims at providing a review of the major techniques used for the induction motor parameter estimation, illustrated throughout with experimental and simulation examples related to various parameter estimation techniques.
Abstract: An induction motor is the most frequently used electric machine in high-performance drive applications. Control schemes of such drives require an exact knowledge of at least some of the induction motor parameters. Any mismatch between the parameter values used within the controller and actual parameter values in the motor leads to a deterioration in the drive performance. Numerous methods for induction machine on-line and off-line parameter estimation have been developed exclusively for application in high-performance drives. This paper aims at providing a review of the major techniques used for the induction motor parameter estimation. The paper is illustrated throughout with experimental and simulation examples related to various parameter estimation techniques.
376 citations
11 Jun 1990
TL;DR: In this article, the effects of parameter sensitivity on indirect vector control induction motor drives are reviewed and the importance of parameter adaptation is discussed and categorized based on the extent of use of the induction motor parameters.
Abstract: The effects of parameter sensitivity on indirect vector control induction motor drives are reviewed. The importance of parameter adaptation is discussed and categorized based on the extent of use of the induction motor parameters. The parameter sensitivity and compensation study is important from the point of view of optimum motor and power converter use. The scope for future research and some of the subsets of parameter compensation research are identified, and a detailed survey of the literature available in this topic is given. >
234 citations