application of motors to adjustable …€¦ · ppt file · web viewapplication of motors to...
TRANSCRIPT
APPLICATION OF MOTORS TO ADJUSTABLE
FREQUENCY DRIVESPART 1
Alan Lowe, Senior Electrical Consultant
2
RISE TIMESREFLECTED WAVESBEARING CURRENTSCABLE SELECTIONIGBT
NON-AGENDA
3
AGENDA
INTRODUCTIONNOMENCLATUREWHY USE AFDHORSEPOWER, SPEED, TORQUEMOTOR CAPABILITIES & LIMITATIONSTYPES OF LOADS
4
PRE-TEST
5
A “SPECIAL” MOTOR WILL BE REQUIRED FOR DRIVE APPLICATIONS:
A. ALWAYS
B. MOST OF THE TIME
C. RARELY
D. NEVER
6
A MOTOR APPLIED TO AN AFD MUST MEET WHICH OF THE FOLLOWING:
A. NEMA M-G 1 PART 30
B. NEMA M-G 1 PART 31
C. IEEE 841
D. NEMA PREMIUM EFFICIENCY
7
OPERATING ON AN AFD A 100 HP, 1200 RPM MOTOR CAN DELIVER 100 HP
A. BETWEEN 1200 AND 1500 RPM
B. BETWEEN 600 AND 1200 RPM
C. ALL OF THE ABOVE
D. NONE OF THE ABOVE
E. DON’T ASK ME—I JUST CAME FOR LUNCH
8
DRIVE NOMENCLATURE
IS IT---
VSD, ASD, VFD, OR AFD
?
9
DRIVE NOMENCLATURE
VARIABLE VS. ADJUSTABLE
THE WEATHER OUTSIDE IS VARIABLE
THE TEMPERATURE IN YOUR HOME IS ADJUSTABLE
10
DRIVE NOMENCLATURE
“SPEED” VS. “FREQUENCY”THERE ARE MANY KINDS OF ADJUSTABLE SPEED DRIVES:• DC MOTORS• CONE PULLEYS• STEAM TURBINE• MECH. DIFFERENTIALS• EDDY CURRENT CLUTCHES• ADJUSTABLE VOLTAGE DRIVES• ADJUSTABLE FREQUENCY DRIVES
11
DRIVE NOMENCLATURE
BE CAREFUL--
“DRIVE”
CAN MEAN ALMOST ANYTHING
12
DRIVE NOMENCLATURE
DRIVE: THE EQUIPMENT USED FOR CONVERTING AVAILABLE ELECTRICAL POWER INTO MECHANICAL POWER SUITABLE FOR THE OPERATION OF A MACHINE. A DRIVE IS A COMBINATION OF A POWER CONVERTER (CONTROL), MOTOR, AND ANY MOTOR MOUNTED AUXILIARY DEVICES.
13
WHY USE AN AFD?
A. THE PROCESS REQUIRES IT
B. THE PROCESS CAN BE IMPROVED BY IT
C. ENERGY SAVINGS
D. EASIER ON DRIVEN EQUIPMENT
14
WHY USE AN AFD?
E. ACCELERATION OF HIGH INERTIA LOAD
F. TO AVOID FREQUENT MOTOR STARTING
G. AS A REPLACEMENT FOR GEARING
15
WHY WORRY ABOUT THE MOTOR? WHAT’S DIFFERENT?
A. CAN THE MOTOR PRODUCE THE REQUIRED TORQUE THROUGHOUT THE OPERATING SPEED RANGE?
B. WILL THE MOTOR HAVE ADEQUATE COOLING AT LOW SPEEDS?
C. WILL HARMONICS FROM THE DRIVE CAUSE THE MOTOR TO OVERHEAT?
16
WHY WORRY ABOUT THE MOTOR? WHAT’S DIFFERENT
D. WILL THE MOTOR FLY APART AT OVERSPEED?
E. WILL THE DRIVE VOLTAGE WAVEFORM DAMAGE THE MOTOR WINDINGS?
F. WILL THE DRIVE VOLTAGE WAVEFORM DAMAGE THE MOTOR BEARINGS?
17
IT’S A DRIVE SYSTEM !
18
THE MOTOR
WHAT DO WE MEAN BY A 100 HP, 1800 RPM
MOTOR?
19
HORSEPOWER
20
MOTOR HORSEPOWER
1 HP MOTOR33,000 FT-LBS/MIN
550 FT-LBS/SEC
746 WATTS / MOTOR EFFICIENCY
21
MOTOR HORSEPOWER
5252RPMTHP
RPMHPT 5252
22
60 75 904530150
25
50
75
100
125
% R
ATE
D H
P%
RA
TED
TO
RQ
UE
0
APPLIED FREQUENCY (HERTZ)
CONSTANT TORQUE CONSTANT HP
MOTOR HORSEPOWER
23
MOTOR HORSEPOWER
Generally a motor can deliver:
Rated TORQUE at and below base rated speed.
Rated HORSEPOWER at and above base rated speed.
But there are some LIMITATIONS!
24
NEMA MG-1
Part 30.2 GENERAL PURPOSE MOTORS USED WITH ADJUSTABLE-VOLTAGE OR ADJUSTABLE-FREQUENCY CONTROL OR BOTH
Part 31 DEFINITE PURPOSE INVERTER FED POLYPHASE MOTORS
25
LIMITATIONS: REDUCED COOLING
NEMA MG-1 FIGURE 30-2
1.0 S.F.MOTOR
1.15 S.F.
26
LIMITATIONS: HARMONIC HEATING
NEMA MG-1 FIGURE 30-3
IT DEPENDS ON THE MOTOR.
IT DEPENDS ONTHE DRIVE.
THERE’S NO ESTABLISHEDMETHOD OFCALCULATION.
27
MOTOR TORQUE vs. SPEED
RATED TORQUE = HP x 5252 / RPM
28
MOTOR TORQUE vs. SPEEDLRT per NEMA MG-112.38.1TABLE 12-2
29
MOTOR LOCKED ROTORTORQUE
30
MOTOR TORQUE vs. SPEED
P.U. TORQUE perNEMA MG1, 12.40.1
31
MOTOR PULL UP TORQUENEMA MG-1 12.40.1 PULL UP TORQUE FOR DESIGN A AND B MOTORS
32
MOTOR TORQUE vs. SPEED
BD TORQUE perNEMA MG1, 12.39.1
33
MINIMUM BREAKDOWN TORQUE
PER NEMA MG-1 12.39.1 FOR DESIGN A & B MOTORS
34
BREAKDOWN TORQUE
BREAKDOWN TORQUE
IS PROPORTIONAL TO (V/HZ)2
ABOVE BASE SPEED BREAKDOWN TORQUE
IS PROPORTIONAL TO (1/HZ)2
STARTING WITH 175% AT 60 HZ YIELDS 77.7% RATED TORQUE AT 90 HZ.
35
LIMITATIONS: TORQUE
NEMA MG-1 FIGURE 30-4
B.D. TORQUE= 77.7% TR
2/3TR x 3/2SR =HPR
36
TORQUE vs. SPEED
37
TORQUE vs. SPEED ON AFD
38
TORQUE vs. SPEED ON AFD
39
TORQUE vs. SPEED ON AFD
40
MOTOR TORQUE vs. SPEED
41
MAXIMUM SAFE SPEED
42
LIMITATIONS: MAX SAFE SPEED
POLES / RPM 200% / 120Hz 150% / 90Hz 125% / 75Hz
2 / 3600 Up to 5 HP Up to 30 HP Up to 50 HP
4 / 1800 Up to 20 HP Up to150 HP Up to 300 HP
6 /1200 Up to 75 HP Up to 350 HP N/A
ALLOWABLE OVERSPEED OPERATION
BASED ON NEMA MG 1 TABLE 30-1
43
LOAD CHARACTERISTICS
VARIABLE TORQUE
CONSTANT TORQUE
CONSTANT HORSEPOWER
44
VARIABLE TORQUE LOAD
CENTRIFUGAL PUMPS
FANS
45
VARIABLE TORQUE LOAD
22
21
2
1
RPMRPM
HH
2
1
2
1
RPMRPM
32
31
2
1
RPMRPM
HPHP
AFFINITY LAWS FOR CENTRIFUGAL PUMPS
46
VARIABLE TORQUE LOAD
47
VARIABLE TORQUE LOAD
48
VARIABLE TORQUE LOAD
102% LOAD @ 65 HZ
49
SELECT MOTOR FOR VARIABLE TORQUE LOADS
1.MAKE SURE THE MOTOR CAN OPERATE SAFELY AT THE TOP SPEED REQUIRED BY THE LOAD.
2.MAKE SURE THE MOTOR CAN DELIVER THE REQUIRED HORSEPOWER AT THE TOP SPEED.
3.LOW END OPERATION IS NOT A PROBLEM.
50
CONSTANT TORQUE LOADS
CONVEYORS
POSITIVE DISPLACEMENT PUMPS
CRANES
PAPER MACHINE SECTIONS
51
CONSTANT TORQUE LOAD
52
SELECT MOTOR FOR CONSTANT TORQUE LOADS
1.MAKE SURE THE MOTOR CAN OPERATE SAFELY AT THE TOP SPEED REQUIRED BY THE LOAD.
2.MAKE SURE THE MOTOR CAN DELIVER THE REQUIRED TORQUE AT THE TOP SPEED.
3.BELOW 30 HZ GIVE YOURSELF SOME MARGIN, LIMIT LOADING TO 80% OF RATING.
4.BELOW 15 HZ CONSULT THE MOTOR MANUFACTURER.
53
CONSTANT HORSEPOWER
UNWIND STAND OF A WINDER
A CENTER WIND REEL
PUNCH PRESS
54
CONSTANT HORSEPOWER
MOTOR MUST PROVIDE 165 FT-LBS AND 127.3 RPMOR
HP = 165 x 127.3 /5252 = 4
55
CONSTANT HORSEPOWER
56
CONSTANT HORSEPOWER
57
CONSTANT HORSEPOWER
58
SELECT MOTOR FOR CONSTANT HORSEPOWER LOADS1.MOTOR MUST BE ABLE TO DELIVER THE
SPEED AND TORQUE REQUIRED AT THE FASTEST AND SLOWEST OPERATING SPEEDS.
2.THE MOTOR WILL BE OF SPECIAL DESIGN OR VERY MUCH “OVERSIZED”.
59
SELECT MOTOR FOR CONSTANT HORSEPOWER LOADS
3.ALL PARTIES MUST BE INVOLVED:a) DRIVE VENDORb) MOTOR VENDORc) DRIVEN EQUIPMENT VENDORd) END USER
60
REMEMBER!
IN OUR SOCIETY: IAS
THE
APPLICATION MATTERS
61
APPLICATION OF MOTORS TO ADJUSTABLE FREQUENCY DRIVES
END PART 1
62
APPLICATION OF MOTORS TO ADJUSTABLE FREQUENCY DRIVES
QUESTIONS?
770-688-2575
63
PPIC 2013 ANNUAL CONFERENCE
PULP AND PAPER INDUSTRY COMMITTEE2014 ANNUAL CONFERENCE
ATLANTA, GEORGIAJUNE 23, 24 & 25