ECET 211 Electric Machines & Controls Lecture 9-2 ...lin/ECET211/sumii-2016/Lectures/ECET...1 1Prof....

1

1

ECET 211 Electric Machines & Controls

Lecture 9-2

Adjustable-Speed Drives and PLC Installations (2 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

Lecture 9-2 Adjustable-Speed Drives and PLC

Installations (2 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

Prof. Paul Lin 2

• 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

2


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

Prof. Paul Lin 3

Part 4. Programmable Logic

Controllers (PLCs)

• PLC Sections and

Configurations

• Ladder Logic Programming

• Programming Timers

• Programming Counters


Installations VFD Installation and Programming Parameters

Selecting the Drive - Based on load categories of the driven

machinery

• Constant Torque – friction loads such as “Traction drive”

and Conveyors

• Variable-Torque – loads require much lower torque at low

speed, such as “Centrifugal fan, Pumps, and Blowers”

• Shock (impact) – loads pattern: normal load conditions

followed by a sudden, large load, such as engaging a

clutch that applies a large load

Prof. Paul Lin 4

3


Installations VFD Installation and

Programming Parameters

Line and Load Reactors

• Line Reactor – connect

between the Line and the

VFD controller

• Load Reactor – connect

between the VFD and the

motor

• Functions

Stabilize the current

waveform on the input

side of a VFD

Reduce harmonic

distortion and the burden

on the upstream electrical

equipment.

Prof. Paul Lin 5

Figure 10-16 VFD reactor



Location

• Mount the VFD drive near the motor.

• Enclosure surrounding the drive should be well ventilated

or in a climate-controlled environment.

• Avoid dusty, wet, corrosive environment, constant

vibration, direct sunlight

• Adequate lighting and sufficient working space: NEC

Article 110 lists requirements for working space and

illumination

Prof. Paul Lin 6

4


Installations VFD Installation and Programming

Parameters

Enclosures

• Select proper NEMA-type enclosure

• Figure 10-17 VFD mounted within an

enclosure

Mounting Techniques

• Din-rail mounting

• Through-hole mounting

• Air-flow, cooling fan

• Figure 10-18 VFD mounting technique

Prof. Paul Lin 7



Parameters

Operator Interfaces

• Figure 10-19 Typical VFD operator

interface

• VFD data accessible in real-time

Frequency output

Voltage output

Current output

Motor RPM

Motor kilowatts

DC bus volts

Parameter settings

Faults

Prof. Paul Lin 8

5



Parameters

Electromagnetic Interferences (EMI)

• Noise suppression procedure

Use a shielded power cable

EMI filter

Twisted control wiring leads

Maintain at least 8-inch

separation between control and

power wires

Prof. Paul Lin 9



Grounding

• All electric motor drives, motors, and related equipment must meet

the grounding and bonding requirements of NEC Article 250

• Figure 10-21 General grounding requirements for a VFD

Prof. Paul Lin 10

6



Bypass Contactor

• Intended for use in case of a drive failure for-time emergency service

• In HVAC application, this allows heating or cooling to be maintained at

all times

• Figure 10-22 Power circuit connection of a VFD bypass contactor

Prof. Paul Lin 11




Disconnecting Means

• OSHA regulations

• NEC Article 430.102

Motor Protection

• VFD – short circuit

protection (fuses)

• VFD incorporated

protective functions

Stall prevention

Current limitation and

overcurrent protection

Short-circuit protection Prof. Paul Lin 12

Motor Protection (continue)

• VFD incorporated protective

functions

Undervoltage and

overvoltage protection

Ground fault protection

Power supply phase failure

protection

Motor thermal protection

through sensing of the motor

winding temperature

7




Figure 10-23 Typical VFD

package

Prof. Paul Lin 13



Parameters

Braking

• Dynamic braking

• Regenerative braking

• DC-injection braking

Figure 10-24 Dynamic braking

applied to a VFD

Prof. Paul Lin 14

8



Parameters

Ramping

• The ability of a VFD to

increase or decrease the

voltage and frequency to an

AC motor gradually.

• Figure 10-25 Variable-

frequency ramping functions

Prof. Paul Lin 15



Programming

Parameters

Control Inputs and

Outputs

Figure 10-26 Typical

VFD control inputs and

outputs

Prof. Paul Lin 16

9




Control Inputs and Outputs

Figure 10-27 Input digital

connections for two-wire or

three-wire control with stop,

forward, reverse, and jogging

functions

Digital/relay outputs

Analog inputs – 0 to 10V DC or 4

to 20 mA signal

Analog outputs

Prof. Paul Lin 17



Motor Nameplate Data

Motor specifications are programmed into the VFD to ensure

optimum device performance as well as adequate fault and overload

protection

Figure 10-28 Entering motor nameplate data

Prof. Paul Lin 18

10



Parameters

Two earlier types of Variable-Frequency

Drives

Figure 10-29 Simplified circuit of a

voltage source inverter (VSI)

• Also called “variable voltage

inverter”

Figure 10-30 Simplified circuit of a

current-source inverter (CSI)

• For large drives (about 200 hp)

Prof. Paul Lin 19



Parameters

PID Control (Built-in)

Figure 10-31 PID loop

Prof. Paul Lin 20

11




Parameter Programming

Parameter – a variable

associated with the operation

of the drive that can be

programmed or adjusted

Common adjustable

parameters

• Preset speeds

• Min and max speeds

• Acceleration and

deceleration rates

• Two- and three-wire remote

control modes

Prof. Paul Lin 21

Common adjustable parameters

• Stop modes: ramp, coast, DC

injection

• Automatic torque boost

• Current limit

• Configurable input jog

• V/Hz settings

• Carrier frequency

• Programmed password


Installations

Prof. Paul Lin 22

Part 4. Programmable Logic Controllers (PLCs)

• PLC Sections and Configurations

Figure 10-50 The major sections of a PLC system

12


Installations

Prof. Paul Lin 23


PLC Sections and Configurations

• Figure 10-51 Fixed programmable controller (Micro PLC)


Installations

Prof. Paul Lin 24


PLC Sections and Configurations

• Figure 10-52 Modular programmable controller

13


Installations

Prof. Paul Lin 25


Controllers (PLCs)

Ladder Logic Programming

• Figure 10-53 PLC relay ladder

logic program

• Figure 10-54 Hard-wired

start/stop circuit


Installations

Prof. Paul Lin 26



• Figure 10-55 Basic PLC instructions

14


Installations

Prof. Paul Lin 27



• Figure 10-56 Programmed start/stop circuit


Installations

Prof. Paul Lin 28


Controllers (PLCs)


• Figure 10-57 PLC wiring

designed to implement the

motor start/stop control

15


Installations

Prof. Paul Lin 29



• Figure 10-58 Programmed start/stop circuit with remote

standby and run pilot lights


Installations

Prof. Paul Lin 30


Controllers (PLCs)


• Figure 10-59 Wiring changes

for remote pilot lights

16


Installations

Prof. Paul Lin 31


Controllers (PLCs)

Programming Timers

Figure 10-60 On-delay timer

instruction

• On-delay timer (TON)

• Off-delay timer (TOF)

• Retentive timer (RTO)


Installations

Prof. Paul Lin 32

Part 4. Programmable

Logic Controllers (PLCs)

Programming Timers

Figure 10-61 On-delay

programmed timer

• Type of timer: TON

• Timer number:

Address T4:0

• Time base: 1.0 sec

• Present time: 15; ( 1

sec x 15 = 15 sec)

• (EN): Enable bit

• (DN): Done bit

17


Installations

Prof. Paul Lin 33


Programming Counters

• Figure 10-62 Wiring for the on-delay timer using the Allen-

Bradley SLC 500 modular controller

• Address I: 1/2 – Input: slot 1/terminal 2

• Address O:2/3

• Address O:2/8


Installations

Prof. Paul Lin 34


Controllers (PLCs)


• Figure 10-63 Up-counter

(CTU) instruction

• Type of counter: Up-counter

(CTU)

• Counter number: Address

C5: 1

• Preset value: 7

• Accumulated value: Initially

set at 0

• (CU): enable bit

• (OV): Overflow bit

• (RES): Reset

18


Installations

Prof. Paul Lin 35



• Figure 10-64 Programmed up-counter


Installations

Prof. Paul Lin 36



• Figure 10-65 Wiring for the up-counter implemented using the

Allen-Bradley SLC 500 controller

19


Installations

Prof. Paul Lin 37



• Figure 10-66 Parking garage counter

Summary & Conclusion

Questions? Contact Prof. Lin through:

Email: [email protected]

LINE Group Discussion Forum

Prof. Paul Lin 38

mailto:[email protected]

Date post:	18-Mar-2018
Category:	Documents
Upload:	dophuc
View:	218 times
Download:	2 times

ECET 211 Electric Machines & Controls Lecture 9-2 ...lin/ECET211/sumii-2016/Lectures/ECET...1 1Prof....

Documents