ECET 211 Electric Machines & Controls Lecture 9-1 Adjustable-Speed Drives (1 of 2) Text Book: Electric Motors and Control Systems, by Frank D. Petruzella, published by McGraw Hill, 2015. Paul I-Hai Lin, Professor of Electrical and Computer Engineering Technology P.E. States of Indiana & California Dept. of Computer, Electrical and Information Technology Purdue University Fort Wayne Campus Prof. Paul Lin 1 Lecture 9-1 Adjustable-Speed Drives and PLC Installations (1 of 2) A Quick Overview of Motor Control Electronics (Chapter 9) Diodes, Transistors, Thyristors and ICs Part 1. AC Motor Drive Fundamentals Variable-Frequency Drives (VFD) Volts per Hertz Drive Flux Vector Drive Part 2. VFD Installation and Programming Parameters Selecting the Drive Lines and Load Reactors Location Enclosures Mounting Techniques Operator Interface Electromagnetic Interference Grounding Bypass Contactor Disconnecting Means Motor Protection Braking Ramping Control Inputs and Outputs Motor Nameplate Data Derating Types of Variable-Frequency Drives PID control Parameter Programming Diagnostics and Troubleshooting Prof. Paul Lin 2 1
Lecture 9-1 Adjustable-Speed Drives and PLC Installations Part 3. DC Motor Drive Fundamentals (SKIP) Applications DC Drives Principles of Operation Single-Phase Input DC Drive Three-Phase Input DC Drive Field Voltage Control Non-regenerative and Regenerative DC Drives Parameter Programming Part 4. Programmable Logic Controllers (PLCs) PLC Sections and Configurations Ladder Logic Programming Programming Timers Programming Counters Prof. Paul Lin 3 Lecture 9-1 Adjustable-Speed Drives and PLC Installations A Quick Overview of Motor Control Electronics (Chapter 9) Semiconductor Didoes Rectifier Diode Zener Diode Light-Emitting Diode Photodiodes Transistors Thyristors ICs Prof. Paul Lin 4 2
Lecture 9-1 Adjustable-Speed Drives and PLC Installations A Quick Overview of Motor Control Electronics (Chapter 9) Semiconductor Didoes: Rectifier Diode, Zener Diode, Light-Emitting Diode Photodiodes Figure 9-1 PN-Junction Diode Figure 9-2 Diode forward and reverse biasing Prof. Paul Lin 5 A Quick Overview of Motor Control Electronics (Chapter 9) Figure 9-3 Single-phase, half-wave rectifier circuit Prof. Paul Lin 6 3
A Quick Overview of Motor Control Electronics (Chapter 9) Figure 9-5 Single-phase, full-wave Figure 9-7 Three-phase, full-bridge rectifier circuit rectifier Prof. Paul Lin 7 A Quick Overview of Motor Control Electronics (Chapter 9) Figure 9-6 Capacitor filter Prof. Paul Lin 8 4
A Quick Overview of Motor Control Electronics (Chapter 9) Transistors Bipolar Junction Transistor (BJT) Figure 9-14 Bipolar junction transistor Figure 9-16 BJT switching of an AC load Prof. Paul Lin 9 A Quick Overview of Motor Control Electronics (Chapter 9) Transistors Figure 9-18 Phototransistor employed as part of an optical isolator found in a programmable logic controller (PLC) AC input module circuit Prof. Paul Lin 10 5
A Quick Overview of Motor Control Electronics (Chapter 9) Insulated-Gate Bipolar Transistor (IGBT) Figure 9-27 IGBT power module Figure 9-26 Insulated-gate BJT N type Prof. Paul Lin 11 A Quick Overview of Motor Control Electronics (Chapter 9) Figure 9-28 IGBT used in an electronic motor drive Prof. Paul Lin 12 6
A Quick Overview of Motor Control Electronics (Chapter 9) TRIAC Figure 9-35 Triac Figure 9-36 Triac switching circuit Prof. Paul Lin 13 A Quick Overview of Motor Control Electronics (Chapter 9) TRIAC Figure 9-37 Triac switching of PLC output module Prof. Paul Lin 14 7
Lecture 9-1 Adjustable-Speed Drives and PLC Installations The two most important technologies associated with motor control are Adjustable speed drives Programmable logic controller Part 1. AC Motor Drive Fundamentals Primary function of any electronic Adjustable-Speed Drive is to control Speed Torque Acceleration Deceleration, and Direction of rotation Prof. Paul Lin 15 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-1 Variable-speed AC motor drive used for lowerpower applications Prof. Paul Lin 16 8
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-2 Block diagram of a typical three-phase VFD Prof. Paul Lin 17 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-3 Three-phase and single-phase converter input connections Prof. Paul Lin 18 9
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-4 Inductor and capacitor connections within the DC bus Prof. Paul Lin 19 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-5 Typical VFD voltage measurement Prof. Paul Lin 20 10
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-6 The three sections of a variable-speed drive Prof. Paul Lin 21 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-7 Simplified circuit of a PWM inverter Prof. Paul Lin 22 11
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-7 Simplified circuit of a PWM inverter Figure 10-8 IGBT switch element Prof. Paul Lin 23 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Figure 10-9 Sine-wave line voltage superimposed on the PWM inverter output Figure 10-10 Inverter motor and control Prof. Paul Lin 24 12
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Open Loop vs Closed Loop Control Figure 10-11 Closed-loop control system Prof. Paul Lin 25 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Volts per Hertz Drive (for AC IM) V/Hz = Voltage/Frequency An Example: V = 460 volts, F = 60 Hz V/Hz = 7.67 apply to any frequency between 0 and 60 Hz Control principle: To maintain constant magnetic flux in the motor, the terminal voltage magnitude must increase roughly to the applied voltage Horsepower = Torque x Speed x k With other refinements: Low-frequency voltage boost Steady-state slip compensation Stability compensation Prof. Paul Lin 26 13
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Flux Vector Hertz Drive (for AC IM) A vector quantity has both magnitude and direction A Flux vector drive controls both the magnitude and direction of the magnetic flux in an AC induction motor. Figure 10-13 Vector Drives control both magnitude and direction of the magnetic flux Prof. Paul Lin 27 Lecture 9-1 (Ch 10) Adjustable-Speed Drives Flux Vector Hertz Drive (for AC IM) Figure 10-14 Sensorless vector control drive block diagram Prof. Paul Lin 28 14
Lecture 9-1 (Ch 10) Adjustable-Speed Drives Flux Vector Hertz Drive (for AC IM) Figure 10-15 Flux vector drive and encoder Prof. Paul Lin 29 Summary & Conclusion Questions? Prof. Paul Lin 30 15