This course focuses on analysis of electric power systems and motor drive systems and on their applications. It includes the p-q theory in three-phase circuits, and the instantaneous active and reactive power defined by the theory, as well as d-q transformation for ac motors. In addition, it presents the so-called vector control or filed-oriented control for induction and synchronous motors.
By the end of the course, students will be able to:
1) explain the similarity and difference on active and reactive power between single-phase and three-phase power systems.
2) apply the analysis method based on the "instantaneous reactive power theory" to fundamental analysis of electric machines and/or power systems.
3) apply the control method based on the "instantaneous reactive power theory" to basic control of electric machines and/or power systems.
4) derive the voltage and current equations for various electric machines and power devices.
5) understand the basis of instantaneous torque control methods for various ac motors and to implement the required controls.
Active power, reactive power, power flow, ac motors, torque control.
Intercultural skills | Communication skills | Specialist skills | Critical thinking skills | Practical and/or problem-solving skills |
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The instructor will first present some theories, analysis methods, and their applications. Students will have discussions and give presentations on
the assigned topics in the class.
Course schedule | Required learning | |
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Class 1 | Fundamentalｓ in the analysis of power converters and electric machines Introductions, phasor-based analysis, needs for analysis based on instantaneous variables. | Discussion on applications requiring instantaneous variable based analysis. |
Class 2 | Basic circuit theory and analysis methods Direct current and alternative current, ac circuit theory, phasor, complex power. | Discussions on the relation between ac circuit theory and transient analysis. |
Class 3 | Active and reactive power in single-phase ciruits Instantaneous power, active, reactive and apparent powers, power due to harmonic current. | Realization of power in single-phase circuit. |
Class 4 | Active power in three-phase circuits Three-phase circuits, power in each phase and total power, reactive power in three-phase circuits. | Comparison of the power in single-phase and three-phase circuits. |
Class 5 | Instantaneous reactive power theory Definition of instantaneous reactive power, its physical meaning | Realization of instantaneous reactive power. |
Class 6 | Applicationｓ of instantaneous reactive power theory to power converter control #1 Instantaneous reactive power in the power converters, reactive power compensators | Discussionｓ on the advantage of using instantaneous reactive power theory. |
Class 7 | Applicationｓ of instantaneous reactive power theory to power converter control #2 Harmonic current detection and active power filters, dc capacitor voltage control method | Comparison and consideration of the control performance with/without the instantaneous reactive power theorｙ. |
Class 8 | Rotating reference frame and equivalent circuits Stationary and rotating reference frame, their equivalent circuits. | Comparison and identification of the equivalent circuits. |
Class 9 | Various ｃoordinate transformations Three-to-two phase transform, rotating coordinate transform, symmetric coordinate transform | Confirmation of the applicability of the transformations. |
Class 10 | Structure and modeling of ac motors Internal magnetic flux and electromotive force, torque, induced electromotive force. | Confirmation of the relation between each element in the equivalent circuit and the corresonading part of the motor |
Class 11 | Voltage and current equations in ac motors Derivation of the fundamental equation, its physical meaning, transformations. | Discussion of the applicability of the derived equation. |
Class 12 | Modeling of ac motors Basic modeling, transfer function, applications to various motors. | Discussion on the modifications in the equation required for its application to various motors. |
Class 13 | Field oriented torque control of three-phase induction motors Transient response of induction motors, instantaneous torque, control schemes. | Discussion of the estimated performance of the torque response. |
Class 14 | Field oriented torque control of three-phase synchronous motors Transient response of synchronous machines, instantaneous torque, control schemes. | Confirmation of the stability of the torque control. |
Class 15 | Interior permanent magnet (IPM) synchronous motors Saliency and reluctance torque, maximum torque control, implementation of the control. | Confirmation of the maximum torque control. |
The lecture documents will be distributed through OCW/i.
The related documents, e.g. technical papers, will be introduced during the lecture.
Grading will be made only by the final examination (100%).
This course requires the knowledge taught in the undergraduate couses Electric Circuits I and II, Electricity and Magnetism I and II, and Electric Machinery.