Vector control methods for induction machines: an overview <s> I <s> New quick-response and high-efficiency control of an induction motor, which is quite different from that of the field-oriented control is proposed. The most obvious differences between the two are as follows. 1) The proposed scheme is based on limit cycle control of both flux and torque using optimum PWM output voltage; a switching table is employed for selecting the optimum inverter output voltage vectors so as to attain as fast a torque response, as low an inverter switching frequency, and as low harmonic losses as possible. 2) The efficiency optimization in the steady-state operation is also considered; it can be achieved by controlling the amplitude of the flux in accordance with the torque command. To verify the feasibility of this scheme, experimentation, simulation, and comparison with field-oriented control are carried out. The results prove the excellent characteristics for torque response and efficiency, which confirm the validity of this control scheme. <s> BIB001 </s> Vector control methods for induction machines: an overview <s> I <s> This paper synthesizes and develops a universal field oriented (UFO) controller for induction machines. The UFO controller decouples flux and torque in an arbitrary flux reference frame. Due to its high degree of generality the UFO controller lends itself to be fully compatible with all existing field oriented controllers, indirect as well as direct field orientation. As a consequence, the digital implementation of the UFO scheme is identical for all induction motor drives enabling the usage of identical hardware and software. Examples of UFO control block diagrams for different field oriented controllers are presented. The execution time of the UFO algorithm is compared with the classical rotor flux field orientation method when using a high speed digital signal processor. Further, this paper indicates that the flexibility of changing the flux reference frame can extend the stability region of the drive especially at high speed during flux weakening. Detuning problems in field orientation are handled in an optimal manner for each field oriented controller by proper selection of the model of the induction machine and its reference frame. > <s> BIB002 </s> Vector control methods for induction machines: an overview <s> I <s> 1. Elementary Principles of Mechanics.- 1.1 Newtons Law.- 1.2 Moment of Inertia.- 1.3 Effect of Gearing.- 1.4 Power and Energy.- 1.5 Experimental Determination of Inertia.- 2. Dynamics of a Mechanical Drive.- 2.1 Equations Describing the Motion of a Drive with Lumped Inertia.- 2.2 Two Axes Drive in Polar Coordinates.- 2.3 Steady State Characteristics of Motors and Loads.- 2.4 Stable and Unstable Operating Points.- 3. Integration of the Simplified Equation of Motion.- 3.1 Solution of the Linearised Equation.- 3.1.1 Start of a Motor with Shunt-type Characteristic at No-load.- 3.1.2 Starting the Motor with a Load Torque Proportional to Speed.- 3.1.3 Loading Transient of the Motor Initially Running at No-load Speed.- 3.1.4 Starting of a DC Motor by Sequentially Short-circuiting Starting Resistors.- 3.2 Analytical Solution of Nonlinear Differential Equation.- 3.3 Numerical and Graphical Integration.- 4. Thermal Effects in Electrical Machines.- 4.1 Power Losses and Temperature Restrictions.- 4.2 Heating of a Homogeneous Body.- 4.3 Different Modes of Operation.- 4.3.1 Continuous Duty.- 4.3.2 Short Time Intermittent Duty.- 4.3.3 Periodic intermittent duty.- 5. Separately Excited DC Machine.- 5.1 Introduction.- 5.2 Mathematical Model of the DC Machine.- 5.3 Steady State Characteristics with Armature and Field Control.- 5.3.1 Armature Control.- 5.3.2 Field Control.- 5.3.3 Combined Armature and Field Control.- 5.4 Dynamic Behaviour of DC Motor with Constant Flux.- 6. DC Motor with Series Field Winding.- 6.1 Block Diagram of a Series-wound Motor.- 6.2 Steady State Characteristics.- 7. Control of a Separately Excited DC Machine.- 7.1 Introduction.- 7.2 Cascade Control of DC Motor in the Armature Control Region.- 7.3 Cascade Control of DC Motor in the Field-weakening Region.- 7.4 Supplying a DC Motor from a Rotating Generator.- 8. Static Converter as a Power Actuator for DC Drives.- 8.1 Electronic Switching Devices.- 8.2 Line-commutated Converter in Single-phase Bridge Connection.- 8.3 Line-commutated Converter in Three-phase Bridge Connection.- 8.4 Line-commutated Converters with Reduced Reactive Power.- 8.5 Control Loop Containing an Electronic Power Converter.- 9. Control of Converter-supplied DC Drives.- 9.1 DC Drive with Line-commutated Converter.- 9.2 DC Drives with Force-commutated Converters.- 10. Symmetrical Three-Phase AC Machines.- 10.1 Mathematical Model of a General AC Machine.- 10.2 Induction Motor with Sinusoidal Symmetrical Voltages in Steady State.- 10.2.1 Stator Current, Current Locus.- 10.2.2 Steady State Torque, Efficiency.- 10.2.3 Comparison with Practical Motor Designs.- 10.2.4 Starting of the Induction Motor.- 10.3 Induction Motor with Impressed Voltages of Arbitrary Wave- forms.- 10.4 Induction Motor with Unsymmetrical Line Voltages in Steady State.- 10.4.1 Symmetrical Components.- 10.4.2 Single-phase Induction Motor.- 10.4.3 Single-phase Electric Brake for AC Crane-Drives.- 10.4.4 Unsymmetrical Starting Circuit for Induction Motor.- 11. Power Supplies for Adjustable Speed AC Drives.- 11.1 Pulse width modulated (PWM) Voltage Source Transistor Converter (IGBT).- 11.2 Voltage Source PWM Thyristor Converter.- 11.3 Current Source Thyristor Converters.- 11.4 Converter Without DC Link (Cycloconverter).- 12. Control of Induction Motor Drives.- 12.1 Control of Induction Motor Based on Steady State Machine Model.- 12.2 Rotor Flux Orientated Control of Current-fed Induction Motor.- 12.2.1 Principle of Field Orientation.- 12.2.2 Acquisition of Flux Signals.- 12.2.3 Effects of Residual Lag of the Current Control Loops.- 12.2.4 Digital Signal Processing.- 12.2.5 Experimental Results.- 12.2.6 Effects of a Detuned Flux Model.- 12.3 Control of Voltage-fed Induction Motor.- 12.4 Field Orientated Control of Induction Motor with a Current Source Converter.- 12.5 Control of an Induction Motor Without a Mechanical Sensor.- 12.5.1 Machine Model in Stator Flux Coordinates.- 12.5.2 Example of an "Encoderless Control".- 12.5.3 Simulation and Experimental Results.- 12.6 Control of an Induction Motor Using a Combined Flux Model.- 13. Induction Motor Drive with Reduced Speed Range.- 13.1 Doubly-fed Induction Machine with Constant Stator Frequency and Field-orientated Rotor Current.- 13.2 Control of a Line-side Voltage Source Converter as a Reactive Power Compensator.- 13.3 Wound-Rotor Induction with Slip-Power Recovery.- 14. Variable Frequency Synchronous Motor Drives.- 14.1 Control of Synchronous Motors with PM Excitation.- 14.2 Synchronous Motor with Field- and Damper-Windings.- 14.3 Synchronous Motor with Load-commutated Inverter (LCI- Drive).- 15. Some Applications of Controlled Electrical Drives.- 15.1 Speed Controlled Drives.- 15.2 Lineax Position Control.- 15.3 Lineax Position Control with Moving Reference Point.- 15.4 Time-optimal Position Control with Fixed Reference Point.- 15.5 Time-optimal Position Control with Moving Reference Point. <s> BIB003
N THE last three decades, the field oriented method (FOC) for control of AC drives has been analyzed and discussed in the literature, e.g.,  , BIB003 ,  -  . The current control loop and the determination of the reference frame, necessary in this control method, can be implemented in different ways. Moreover, the FOC method is sensitive to parameter variations, principally the rotor time constant. Therefore, different vector control strategies have been proposed trying to achieve the best performance and/or ease of implementation. Among these vector control methods, the following can be mentioned: field acceleration method (FAM)  , the proposal of Takahashi BIB001 , direct self control (DSC)  , and universal field orientation (UFO) BIB002 . As different mathematical notations have been used in these studies (e.g., spatial vectors, phase segregation, spiral vectors, matrices, …) it is difficult to introduce and evaluate the basic relationship among them. In this paper, one methodology of presentation is proposed in order to give clear concepts about the theme including an analytical comparison of the most important methods found in the literature.