1. VECTOR DRIVES EASA June 2005 “REACHING NEW HEIGHTS” Dave Ruehle and Bill Colton

2. Outline Define a Drive What is an Inverter Drive Why the Vector was Invented How Does a Vector Work What Types of Vectors Exist Typical Applications for Vector Drives

3. What is a Drive Parts and Pieces  Prime Mover  Mechanical Reduction(s) Control Circuits Ancillary devices Couplings Feedback

4. What is an Inverter Drive Terminology  Scalar Drive  VFD  ASD  VVVF  VFI

5. What is an Inverter Drive Speed Control Device  Controls STATOR frequency  Rotor changes speed with load Speed Changes dependant on motor slip NOT a current controller  Only a current limiter

6. Why the Vector was Invented Increase Application Efficiency  Better Speed Control  Better Torque and/or Force Control  More Efficient Use of Power

7. Why the Vector was Invented Performance Benefits  Rotor Speed Regulation  Lower Rotor Inertia Requirements  Much Wider Speed Ranges  Torque (or Force) Control  Zero Speed Full Torque

8. How Inverter Control Is Achieved Convert AC Input to DC Filter the DC Power Create a digital output pulse train varying the frequency and voltage to Stator

9. How Vector Control is Achieved Establish the motor/system Model  Stator Resistance  Stator Inductance  Rotor Resistance  Rotor Inductance  Air gap Losses  Machine Losses and Inertia

10. How Vector Control is Achieved This is achieved in several fashions  Manual – Programming Each Item  Auto Tuning Program Basics Run Tests for Additional Items  Adaptive Tuning Continuously Adjusting for Changing Conditions Now The System Model is Established

11. How Vector Control is Achieved Hardware Comparison ComponentsInverter Vector Converter X X Filter X X Output X X Feedback X

12. How Vector Control is Achieved Monitoring the feedback  Speed  Current  Back EMF Comparing to Established Model Adjust accordingly  Amount of Deviation  Motor/System Model

13. How Vector Control is Achieved Speed Changes

14. What Types of Vectors Exist Open Loop (Encoderless) Vector  Establishes the Shaft Position from the current (amp) measurement  Advantages Lower Initial Cost Reduced Wiring  Disadvantages Not as responsive Limited Speed Range Difficulty with Impact Loads Temperature Changes can be Problematic

15. What Types of Vectors Exist Closed Loop Vector  Monitors Shaft Position via Feedback Encoder Resolver  Advantages Excellent Speed Regulation Full Torque at Zero Speed Systems Capabilities Very Responsive Higher Safety Easier to Tune

16. What Types of Vectors Exist Closed Loop Vectors (Cont.)  Disadvantages Additional Initial Cost More Wiring Motor Length Requires Better Wiring Practice

17. What Types of Vectors Exist Space Vector  A method of firing transistor to control a specific element Current Feedback Voltage Feedback Hysteresis Sine Triggered (Coded) Vector  A method of firing transistors to control the sine wave

18. Applications for Vector Drives Extruders  Closed Loop for Clamped Dies  Open Loop for Continuous Feed Lifts  Closed Loop for Safety  Has been done with Open Loop and Mechanical Load Brakes – consult manufacturers

19. Applications for Vector Drives Bridge Drives – Typically Scalar Trolley Drives – Typically Scalar Conveyors – Typically Scalar Centrifugal Loads – Typically Scalar  Potential Energy Savings with Encoderless Spindle Drives – Typically Closed Loop  Rapid Response Times  Accurate Speed for Tapping  Controlled Grind Speed

20. Applications for Vector Drives Winders  Typically Closed Loop for Tension Control Mooring Winch – Encoderless Mixers – Typically Scalar Line Shaft Replacements – Closed Loop with “electronic line shaft” capability Cut to Length – Closed Loop with Motion Control

21. Applications for Vector Drives Flying Shear – Closed Loop with Motion Controller Stacker Cranes  Horizontal (X) – Scaler or Closed Loop  Elevation (Y) – Closed Loop for Safety  Bins or Forks (Z) – Scaler or Closed Loop Crushers  Oversized Scaler

22. Applications for Vector Drives Types of Braking  D.C. Injection  Shunt Braking – Most Common  Bus Sharing  Line Regenerative

23. Line Regenerative Applications Elevators Hoists Presses Centrifuges Unwind Stands Windmills Pumping Jack Drives Application where Heated Resistors are a problem Test Stands (dynamometers)