Showing papers in "IEEE Transactions on Industrial Electronics in 1990"
TL;DR: In this paper, an adaptive hysteresis-band control method where the band is modulated with the system parameters to maintain the modulation frequency to be nearly constant is described, and an interior permanent magnet (IPM) synchronous machine load is considered.
Abstract: An adaptive hysteresis-band control method where the band is modulated with the system parameters to maintain the modulation frequency to be nearly constant is described. Although the technique is applicable to general AC motor drives and other types of load, an interior permanent magnet (IPM) synchronous machine load is considered. Systematic analytical expressions of the hysteresis band are derived as functions of system parameters. An IPM machine drive system with a voltage-fed current-controlled PWM (pulse width modulation) inverter has been computer simulated to study the performance of the proposed method. >
510 citations
TL;DR: An approach to intelligent PID (proportional integral derivative) control of industrial systems which is based on the application of fuzzy logic is presented, and it is possible to determine small changes on these values during the system operation, and these lead to improved performance of the transient and steady behavior of the closed-loop system.
Abstract: An approach to intelligent PID (proportional integral derivative) control of industrial systems which is based on the application of fuzzy logic is presented. This approach assumes that one has available nominal controller parameter settings through some classical tuning technique (Ziegler-Nichols, Kalman, etc.). By using an appropriate fuzzy matrix (similar to Macvicar-Whelan matrix), it is possible to determine small changes on these values during the system operation, and these lead to improved performance of the transient and steady behavior of the closed-loop system. This is achieved at the expense of some small extra computational effort, which can be very easily undertaken by a microprocessor. Several experimental results illustrate the improvements achieved. >
271 citations
TL;DR: A comprehensive review of the state of the art in the field of electric motor drives and control strategies is presented in this paper, where it is pointed out that drive technology has seen impressive growth during the last three decades.
Abstract: A comprehensive review of the state of the art in the field of electric motor drives and control strategies is presented. It is pointed out that drive technology has seen impressive growth during the last three decades. Recent advances in semiconductor power electronics and microelectronics have made is possible to use AC motors in many variable-speed drive applications. Implementation of new control techniques, such as field-oriented control and variable-structure control with sliding-mode features, has made AC motors a viable alternative to DC motors in high-performance drive applications. The advent of microprocessors/microcontrollers/microcomputers has made it possible to implement these complex control techniques. >
241 citations
TL;DR: In this paper, a new definition of instantaneous reactive power is presented, which includes both the conventional instantaneous reactive powers and the instantaneous power of a zero-phase component, and a simple control algorithm for the active filter derived from the new definition is described.
Abstract: A new definition of instantaneous reactive power is presented. This definition has a clear physical meaning that includes both the conventional instantaneous reactive power and the instantaneous power of a zero-phase component. A simple control algorithm for the active filter derived from the new definition is described. Simulations verified the control algorithm. >
231 citations
TL;DR: In this article, a sequence of progressively more complex state observers, each driven by measurements of phase voltages and currents, is developed for variable-reluctance motors, and the exponential stability of their error dynamics in a neighborhood of the origin is proved.
Abstract: A sequence of progressively more complex state observers, each driven by measurements of phase voltages and currents, is developed for variable-reluctance motors. For the simpler observers, the exponential stability of their error dynamics in a neighborhood of the origin is proved. For all observers, the results of numerical or physical experiments are provided to demonstrate the globally stable error dynamics. In several of the physical experiments, rotor position is estimated to better than one part in 50000 of a revolution. >
178 citations
TL;DR: Bounds on the position accuracy achievable in practical resolver-based position-sensing systems are determined from expressions for the position error reported by an R/D converter.
Abstract: Tracking resolver-to-digital (R/D) conversion has emerged as the most robust method for obtaining high-resolution position information from resolvers. When driven by ideal resolver signals, tracking R/D converters currently offer position resolutions up to 2/sup 16/ quantization intervals/period (16-b resolution), and accuracies to 2/sup 14/ intervals/period (14-b accuracy). The effects of nonideal resolver signal characteristics commonly encountered in practice are investigated. Expressions for the position error reported by an R/D converter due to amplitude imbalance, quadrature error, inductive harmonics, reference phase shift, excitation signal distortion, and disturbance signals are found. From these expressions, bounds on the position accuracy achievable in practical resolver-based position-sensing systems are determined. >
144 citations
TL;DR: In this article, the authors considered the control problem associated with brushless DC motors (BLDCMs) for direct-drive robotic applications and derived a feedback control law to compensate for the system nonlinearities.
Abstract: The control problem associated with brushless DC motors (BLDCMs) for direct-drive robotic applications is considered. In order to guarantee the high-performance operation of BLDCMs in such applications, the effects of reluctance variations and magnetic saturation are accounted for in the model. Such a BLDCM model constitutes a highly coupled and nonlinear dynamic system. Using the transformation theory of nonlinear systems, a feedback control law, which is shown to compensate for the system nonlinearities, is derived. Conditions under which such a control law is possible are presented. The need for the derivation of explicit commutation strategies is eliminated, resulting in reduction of the computations involved. To guarantee the high-performance operation of the system under substantial uncertainties, a robust control law is derived and appended to the overall control structure. The inclusion of the robust controller results in good tracking performance when there are modeling and measurement errors and payload uncertainties. The efficacy of the overall control law is investigated by considering a single-link direct-drive arm actuated by a BLDCM. >
140 citations
TL;DR: In this article, the acceleration tracing orientation method (ATOM) is applied to both controllers and the disturbance observer cancels out the total sum of these terms and enables each joint to trace the acceleration command.
Abstract: The authors propose a novel approach to force and compliance control of multi-degree-of-freedom (DOF) robot manipulators. The acceleration tracing orientation method (ATOM) is applied to both controllers. The control law is described in the Cartesian space; however, the final command is the acceleration in the joint space. The interactive terms in each joint disturb and deteriorate the joint motion. The disturbance observer cancels out the total sum of these terms and enables each joint to trace the acceleration command. As a result, a robust control is possible in the force task. The testing of the proposed system in a three-DOF robot manipulator is discussed. >
126 citations
TL;DR: In this article, an effective method for rotor resistance identification is presented for the purpose of improving the performance of vector control of induction motor drives, which is mathematically derived from proper selection of coordinate axes and utilization of the steady-state model of the induction motor.
Abstract: An effective method for rotor resistance identification is presented for the purpose of improving the performance of vector control of induction motor drives. The method is mathematically derived from proper selection of coordinate axes and utilization of the steady-state model of the induction motor. The major advantages of the method lie in its simplicity and accuracy. A series of computer simulations has been performed with very satisfactory results. >
120 citations
TL;DR: In this article, the concept of a redundant multi-inverter UPS (uninterruptible power supply) system which includes extended monitoring of the status and the operating conditions of all power electronic equipment is described.
Abstract: The concept of a redundant multi-inverter UPS (uninterruptible power supply) system which includes extended monitoring of the status and the operating conditions of all power electronic equipment is described. Each block of the UPS system is monitored by two independent microcomputers that process the same data. The microcomputers are part of a redundant distributed monitoring system that is separately interlinked by two serial data buses through which they communicate. They establish a hierarchy among the participating blocks by defining one of the healthy inverter blocks as the master. The actual master runs the central synchronizing unit for the entire system, whereas the slave units perform the control of equal active and reactive load sharing. Operation and fault detection are experimentally illustrated in a dual inverter system with a rating of 10 kVA of redundant power. >
119 citations
TL;DR: In this article, a passive wave-shaping method for single-phase diode rectifiers is presented, which maintains high-input power factor, lowers rectifier current stresses, and lowers the volt-ampere (VA) rating of the associated reactive components.
Abstract: A novel passive waveshaping method for single-phase diode rectifiers is presented. It is shown that application of the proposed method maintains high-input power factor, lowers rectifier current stresses, and lowers the volt-ampere (VA) rating of the associated reactive components as compared to the standard diode rectifier. Relevant input and output current waveforms, component ratings, and power factor values are derived. Different modes of operation are discussed as a means of obtaining high performance. Key predictions, such as input/output waveforms and associated harmonic spectra, have been verified experimentally on a 1 kVA laboratory prototype unit. >
TL;DR: In this article, a family of class-E/sup 2/DC/DC power converters is introduced and their analysis and design are presented and experimentally verified, which are composed of class E inverters and class E rectifiers.
Abstract: A family of class-E/sup 2/ DC/DC power converters is introduced. Their analysis and design are presented and experimentally verified. The converters are composed of class-E inverters and class-E rectifiers. Zero-voltage switching (with low dv/dt) of the transistor and zero-current switching (with low di/dt) of the rectifier diode reduce switching losses in both stages of the converters, making them especially suitable for high-frequency operation. Because of the high loaded quality factor of the resonant circuit, the range of frequency required for output-voltage regulation is as narrow as 5.46% for load resistances from a full load of 100 Omega to an open circuit. The full-load overall efficiency is 80.36% at 1 MHz. The converters can also operate at a fixed frequency if synchronous rectifiers are applied. The reduction of class-E/sup 2/ converters to lower order converters is presented. Many multiresonant converter topologies are created in this way. The class-E/sup 2/ converters can be utilized to build highly efficient high-power-density switching power supplies. >
TL;DR: In this article, the main considerations in the design of a single-switch-per-phase converter for a switched reluctance motor (SRM) drive are described, with particular attention given to the choice of converter topology, the type of switching devices, the normalized rating of the power devices, and input filter design.
Abstract: The main considerations in the design of a single-switch-per-phase converter for a switched reluctance motor (SRM) drive are described, with particular attention given to the choice of converter topology, the type of switching devices, the normalized rating of the power devices, and input filter design. The converter uses MOSFET switches. Experimental verification is included with a 6/4 pole personal-computer-controlled prototype SRM drive. >
TL;DR: In this paper, an analysis of the state-observer-based robust speed control of a self-controlled synchronous motor (SCSM) is presented, in which the speed and acceleration signals required for the implementation of the variable-structure speed control (VSSC) are dynamically estimated with state observers.
Abstract: An analysis of the state-observer-based robust speed control of a self-controlled synchronous motor (SCSM) is presented. A variable-structure control technique is utilized to achieve robust (parameter-insensitive) characteristics. The speed and acceleration signals required for the implementation of the variable-structure speed control (VSSC) are dynamically estimated with state observers. Two kinds of observers-the Luenberger full-order observer and an adaptive observer-are explored. The results obtained illustrate that Luenberger observers do not estimate the system states accurately when the system parameters vary. This inaccuracy in the state estimation results in a deterioration of the VSSC performance. Therefore, the possibility of using an adaptive state observer (ASO) is investigated. It is shown that the ASO estimates the system parameters and the system states simultaneously, thus making VSSC possible. The design methods and simulation results are presented to demonstrate the potential of the scheme. >
TL;DR: In this article, a novel control approach for a robust induction motor drive system with a voltage source inverter has been developed, where the induction motor and its corresponding inverter gating signal are controlled using the decoupling control theory.
Abstract: A novel control approach for a robust induction motor drive system with a voltage source inverter has been developed. In the scheme, the induction motor and its corresponding inverter gating signal are controlled using the decoupling control theory. In addition, an adaptive optimal speed regulator employing the model reference adaptive control (MRAC) is incorporated into the drive system to compensate for unfavorable errors. The principles and special features of the control scheme are discussed, and the configuration of the drive system is presented. Comparison is made between conventional proportional plus integral (PI) control and the MRAC. Test results show the robustness and superior dynamic performance of the proposed control system. >
TL;DR: In this article, the optimal control method of a drive position system with an electronically commutated brushless DC motor is discussed and verified through computer simulation using the data from real drive position systems.
Abstract: The optimal (according to the quadratic performance index) control method of a drive position system with an electronically commutated brushless DC motor is discussed. Initially developed for linear, unconstrained, and undistributed systems, this optimal control method is now applied to a system having constrained state and input variables (e.g. armature voltage, armature current, rotor speed) and unknown disturbances (e.g. load torque). The method uses an undisturbed and unconstrained model for a model-following adaptive control of the real system. The control method is verified through computer simulation using the data from a real drive position system. Results show that the controlled system operates effectively at the limiting state variables, which represent the real system. In addition, the final position is reached without overshoots. >
TL;DR: In this paper, the relationship between controller sampling rate and bearing performance is investigated, and it is shown that increased sampling rates and increased amounts of second-derivative feedback have similar effects on the bearing properties.
Abstract: Theoretical relationships are developed to relate the characteristics of a controller transfer function to the stiffness and damping properties of an active magnetic bearing for machine rotors. Both proportional and derivative feedback are shown to be necessary for closed-loop system stability, and, for the ideal case, bearing stiffness and damping properties are shown to be simple linear functions of the proportional and derivative feedback gain constants, respectively. The flexibility of a digitally controlled magnetic bearing is demonstrated by the implementation of algorithms which include second-derivative and integral feedback. Second-derivative feedback is shown to be effective at extending the usable bandwidth of the digital controller, and integral feedback rejects rotor position error in the presence of static loads. The relationship between controller sampling rate and bearing performance is investigated, and it is shown that increased sampling rate and increased amounts of second-derivative feedback have similar effects on the bearing properties. >
TL;DR: In this paper, an approach for constructing a field-oriented control system using the state-space method is proposed, which can be realized by coinciding the synchronously rotating reference frame with the axes of the secondary flux linkage reference frame and by simultaneously but independently adjusting the three control inputs.
Abstract: An approach for constructing a field-oriented control system using the state-space method is proposed. The field-oriented control system can be realized by coinciding the synchronously rotating reference frame with the axes of the secondary flux linkage reference frame and by simultaneously but independently adjusting the three control inputs. A control-system synthesis method that achieves speed control, field-oriented control, and constant flux control simultaneously is presented. The control system has a full-state feedback structure and is synthesized by applying a multi-input and multi-output optimal regulator theory. The excellent robustness of the constructed system results in zero steady-state errors for changes in parameters such as rotor resistance. The validity of the control scheme is verified by simulation studies. Results are presented for a field-oriented induction motor driven by a PWM (pulse-width modulation) inverter. >
TL;DR: In this article, a novel control method that suppresses oscillations generated when an induction motor is driven by PWM (pulse width modulated) inverters is described, where the suppression is done by keeping the power direction constant throughout the period of oscillation of the negative current component of the inverter input current.
Abstract: A novel control method that suppresses oscillations generated when an induction motor is driven by PWM (pulse width modulated) inverters is described. The suppression is done by keeping the power direction constant throughout the period of oscillation of the negative current component of the inverter input current. This period is determined only by the frequency of the PWM signals. Because it is not affected by motor parameters, such as the number of poles or motor capacity, the gains of the regulator in the control system do not have to be adjusted, even if this method is applied to various kinds of induction motor drive systems. Experiments have proven that oscillations can be suppressed regardless of the motor type or speed. This stabilizing control is suitable for general-purpose inverters that drive various types of motors. >
TL;DR: In this paper, a variable-speed, constant-frequency (VSCF) power-conversion scheme with a permanent magnet DC (PMDC) brushless generator is proposed.
Abstract: A variable-speed, constant-frequency (VSCF) power-conversion scheme with a permanent magnet DC (PMDC) brushless generator is proposed. The scheme is completely modeled for steady state by integrating the characteristic equations of the generator, the diode rectifier bridge and the inverter, and the harmonic characteristics for steady-state performance computation. Commutation overlap effects are also included. Key performance characteristics are experimentally verified with a laboratory prototype. The excellent correlation between the predicted and experimental results confirms the validity of the model. For the purpose of filter design, harmonics of the rectified generator voltages are analytically derived. A recommendation for overcoming the low power factor on the utility side at low speeds using the forced-commutated converters is given. >
TL;DR: In this article, the sliding-mode control concept is applied in the outer loop of a speed drive system utilizing a series-connected wound rotor induction machine (SCWRIM), and a design procedure is outlined for the slidingmode speed controller.
Abstract: The sliding-mode control concept is applied in the outer loop of a speed drive system utilizing a series-connected wound rotor induction machine (SCWRIM). A design procedure is outlined for the sliding-mode speed controller. The methods of decoupling and torque linearization for the SCWRIM are derived using the field-orientation as well as the torque angle control concepts. Sliding-mode control with cascaded integral operation is used to reduce torque chattering and steady-state error. Accelerator sliding lines are introduced to enable better utilization of the torque capability of the drive system. The parameter-insensitive response provided by this method of control is demonstrated. The effects on the dynamic and static performance with varying drive inertia and load disturbance are studied and compared with the conventional approach using PI control. The influences of sampling effects on sliding-mode control performance are also illustrated and discussed. Microcontroller-based implementation of the speed drive system is employed. Both simulation and experimental results are presented. >
TL;DR: In this paper, a class-E amplifier with an inductive impedance inverter is presented, which can operate under zero-voltage switching conditions for load resistances ranging from a short circuit to an open circuit.
Abstract: A design procedure and experimental results are presented for a class-E amplifier with an inductive impedance inverter. Experimental waveforms and characteristics measured at 1 MHz with an IRF620 MOSFET are given for the amplifier, which can operate under zero-voltage switching conditions for load resistances ranging from a short circuit to an open circuit. As the load resistance is increased at a fixed frequency, (1) the output power decreases, (2) a maximum efficiency of 96% occurs for optimum operation, (3) the peak values of the transistor voltage and the transistor current decrease, (4) the normalized peak values of the transistor voltage decrease, and (5) the normalized peak values of the transistor current increase. >
TL;DR: In this paper, a general analysis procedure for a static power converter using the transfer function approach is presented, which provides for closed-form expressions for all harmonics under balanced and unbalanced operating conditions.
Abstract: A general analysis procedure for a static power converter using the transfer function approach is presented. This method provides for closed-form expressions for all harmonics under balanced and unbalanced operating conditions. Unbalance in voltage magnitude and phase angle and errors in switching angles can be easily incorporated into the analysis. An example illustrating the effectiveness of this approach is given. >
TL;DR: In this article, an approach to speed control for AC motor drives that uses programmed PWM (pulse width modulation) switching patterns over the complete range of output speed is presented, which provides smooth operation during the required switching-pattern changes and guarantees high-quality output voltage and current in the AC motor load, making it most suitable for high performance, high efficiency applications.
Abstract: An approach to speed control for AC motor drives that uses programmed PWM (pulse width modulation) switching patterns over the complete range of output speed is presented. The scheme provides smooth operation during the required switching-pattern changes and guarantees high-quality output voltage and current in the AC motor load, making it most suitable for high-performance, high-efficiency applications. A detailed description of the scheme and its realization is provided. Results of an experimental investigation on a variable-speed induction motor and a permanent-magnet synchronous motor drive system illustrate the advantages of the scheme. >
TL;DR: In this paper, a high-frequency (HF)-link DC-DC parallel resonant converter (PRC) operating above resonance is analyzed using the state-space approach, including the effect of the leakage and magnetizing inductances of the highfrequency transformer.
Abstract: A high-frequency (HF)-link DC-DC parallel resonant converter (PRC) operating above resonance is analyzed using the state-space approach. The analysis includes the effect of the leakage and magnetizing inductances of the high-frequency transformer. Steady-state solutions are derived and used to obtain the design curves. A method of obtaining an optimum operating point under certain constraints is developed and used as the basis of a simple design procedure. The analysis shows that including an HF transformer introduces a new mode of operation in between the two general steady-state modes. Experimental results obtained with a MOSFET-based PRC for three different transformer turns ratios are presented to support the theory. Efficiencies of about 89% were obtained for 985 W, 115 V, and 230 V output converters, whereas an efficiency of about 86% was obtained for a 15 V, 63 A converter. It was observed that the introduction of the transformer considerably affected the performance, especially in the case of low output voltage and large load current converters. >
TL;DR: In this paper, the authors developed a dynamic simulator and analyzed the operating characteristics of duel cell power plants, focusing on the pressure difference between the cathode and anode of the fuel cell and the system base pressure.
Abstract: To estimate the operational characteristics of duel cell power plants, the authors developed a dynamic simulator and analyzed the operating characteristics. In the simulations, attention is given to the pressure difference between the cathode and anode of the fuel cell and the system base pressure. The former is important for safe operation of the fuel cell and the latter is important for safe operation of the reformer. For load following and shut-down modes of the 1 MW plant studied, calculation results were compared with actual test results and agree fairly well. >
TL;DR: In this paper, the authors describe a synchronization control scheme applicable to a robotic workcell, which consists of a conveyor system that transports industrial workpieces, a binary camera to recognize the geometric and other characteristics of the workpiece, and a robotic manipulator that is suitably controlled to direct its end effector to achieve a synchronized rendezvous with the work piece.
Abstract: The formulation and implementation of a synchronization control scheme applicable to a robotic workcell is described. Such a workcell typically consists of a conveyor system that transports industrial workpieces, a binary camera to recognize the geometric and other characteristics of the workpiece, and a robotic manipulator that is suitably controlled to direct its end effector to achieve a synchronized rendezvous with the workpiece. Subsequent to a successful rendezvous, the robot may pick up the piece (in pick-an-place operations) or perform such other online operations as assembly, processing, or quality inspection. A methodology to ensure rapid rendezvous with accurate tracking is emphasized. Simulation and implementation results are compared and discussed. >
TL;DR: In this article, a self-tuning regulator for the positioning of a direct-drive servomotor is described, where the estimator is based on a recursive least-squares equation, and the estimated parameters are the load inertia and viscous friction.
Abstract: The implementation of a self-tuning regulator for the positioning of a direct-drive servomotor is described. The servo motor is a permanent magnet DC motor in which no speed reducer is used. The auto-tuning regulator consists of two major loops. The inner loop contains a feedback (PD or PID) regulator with additional feedforward terms. The parameters of the feedforward compensation are adjusted by the outer loop, which contains an online parameter estimator. The estimator is based on a recursive least-squares equation, and the estimated parameters are the load inertia and viscous friction. This self-tuning regulator has been simulated with PC.MATLAB, and the results demonstrate the high performance of the scheme. Experimental results obtained with a small DC motor (Electrocraft E-576) are presented, and these results show good agreement with the digital simulation results. There are two innovative aspects to this work. First, parameter estimation is used to adapt the feedforward compensation terms instead of the gains of the feedback controller, as usually is the case in conventional indirect self-tuning regulators. Secondly, the complete adaptive controller has been implemented using a single-chip digital signal processor (DSP), which results in the reduction of system hardware and cost. >
TL;DR: In this article, a chattering alleviation control (CAC) algorithm is proposed for variable structure systems (VSSs) with both analog and digital controllers using the theory of CAC.
Abstract: A novel chattering alleviation control (CAC) algorithm is proposed for variable structure systems (VSSs). Both analog and digital controllers using the theory of CAC are applied to the position control problem of a DC servomotor system. Comparisons of the CAC with other VSS control algorithms indicate that the chattering can be alleviated. Since the input of the CAC method contains only low-frequency components, it will not excite unmodeled high-frequency plant dynamics. >
TL;DR: Two optimal codes (in the sense of the execution speed), straight-line code and general matrix-based code, have been developed for implementing the narrowband Kalman filter and two optimal codes are compared in terms of program memory size, data memory size and speed of execution.
Abstract: The author presents experimental results from two studies. First, a real-time narrowband Kalman filter is implemented with a floating-point digital processor DSP32. The real-time capability of this narrowband filter is investigated by varying parameters Q and R. The covariance matrices Q and R of the dynamic and measurement noise sequences are found to exhibit duality in the real-time tuning process and have a direct effect on system stability. If the value of Q used is smaller (with fixed R), the tracking time and the narrower tracking bandwidth of the filter will be longer. In addition, if the value of R used (with fixed Q) is smaller, the tracking time will be smaller, and the tracking bandwidth of the filter will be larger. The results are tabulated. Second, two optimal codes (in the sense of the execution speed), straight-line code and general matrix-based code, have been developed for implementing the narrowband Kalman filter. These two codes are compared in terms of program memory size, data memory size, and speed of execution. With the matrix-based code, the DSP32 performance is evaluated in terms of speed and memory size by varying the number of states of a Kalman filter. The results are also tabulated. >