GR-83- 1

VARIABLE SPEED A-C MOTOR CONTROLLER FOR CANAL GATE HOISTS

March 1983 Engineering and Research Center

U.S. Department of the Interior, Bureau of Reclamation

Division of Research Hydraulics Branch

7-,2090 (4-81) Bureau of R e c l a m a t i o n

1. REPORT NO.

GR-83-1 4. T I T L E AND S U B T I T L E

TECHNICAL REPORT STANDARD TITLE PAGE 3. R E C I P I E N T ' S C A T A L O G NO.

Variable Speed A-C Motor Controller For Canal Gate Hoists

7. AUTHOR(S)

D. G. Ehler

9. P E R F O R M I N G O R G A N I Z A T I O N N A M E AND A D D R E S S

Bureau of Reclamation Engineering and Research Center Denver, Colorado 80225

12. SPONSORING AGENCY NAME AND ADDRESS

Same

5. REPORT DATE

March 1983 6. PERFORMING ORGANIZATION CODE

S. PERFORMING O R G A N I Z A T I O N REPORT NO.

GR-83.1 10. WORK UNIT NO.

11. C O N T R A C T OR GRANT NO.

13. TYPE OF REPORT AND PERIOD COVERED

14. SPONSORING AGENCY CODE

15. S U P P L E M E N T A R Y NOTES

Microfiche and/or hard copy available at the E&R Center, Denver, Colorado Ed:RNW

16. A B S T R A C T

A variable speed-motor controller for application to control large radial gate operation was tested in the laboratory. It will provide satisfactory variable-speed operation on large gate hoists in hydraulic structures. Application pro and con are discussed. Other desirable features are noted.

17. KEY WORDS AND DOCUMENT ANALYSIS

a. D E S C R I P T O R S - - / induction motors/ electric motors/ automatic control / control equipment /radia l gates/*variable-speed controller/

b. IDENTIF IERS- -

c. COSATI Field~Group 09

/ variable-speed dr ives /contro l systems

18. DISTRIBUT ION S T A T E M E N T

COWRR: 0900 SRIM:

19, S E C U R I T Y CLASS 21. NO. OF PAGES (T H 1~3 REPORT)

UNCLASSIFIED 2 4 20. SECURITY CLASS 22. PRICE

(THIS PAGE) UNCLASSIFIED

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GR-83 .1

VARIABLE S P E E D A - C MOTOR C O N T R O L L E R FOR CANAL GATE HOISTS

r.

, t

by Dave Eh le r

M

Hydraulics Branch Division of Research

Engineering and Research Center Denver, Colorado

March 1983

UNITED STATES D E P A R T M E N T OF T H E I N T E R I O R "k BUREAU OF RECLAMATION

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ACKNOWLEDGMENTS

The study described in this report was conducted by the author under the

supervision of E. J. Carlson, Head of the Hydraulic Research Section, Hydraulics

Branch. S. Gray assisted in setting up and performing the numerous test runs.

The work was performed for and funded by

the Bureau of Reclamation, Lower Colorado

Region, Arizona Projects Office, Phoenix,

Arizona.

As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserv- ing the environmental and cultural values of our national parks and historical places, and providing for the enjoyment Of life through out- door recreation.. The Department assesses our energy and mineral

resources and works to assure that their development is in the best interests of all our people. The Department also has a major respon- sibil ity for American Indian reservation communities and for people who live in Island Territories under U.S. Administration.

The information contained in this report regarding commercial products or firms

may not be used for advertising or promotional purposes and is not to be construed

as an endorsement of any product or firm by the Bureau of Reclamation.

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F r o n t i s p i e c e ~-- C h e c k s t r u c t u r e o n B e a c h 9 of t h e G r a n i t e B e e f A q u e d u c t , A r i z o n a . T y p i c a l r a d i a l ga t e s t r u c t u r e in w h i c h a m o t o r c o n t r o l l e r can b e u sed - - O c t o b e r 1981. P801-D-80199

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I I I I I I I I i I I, I I I I I I I

C O N T E N T S

P a g e

P u r p o s e . . . . . . . . . . . . ................................... 1

I n t r o d u c t i o n ............................................. 1

C o n c l u s i o n s ............................................ 2

A p p l i c a t i o n ............................................. 3

A o C v e r s u s d - c v a r i a b l e s p e e d d r i v e s . . . . . . . . . . . . . . . . . . . . . . . . . . 3

T e s t p r o c e d u r e s .......................................... 4

N o i s e t e s t s .......................................... 6

L o w v o l t a g e t e s t s ..................................... 7

T e m p e r a t u r e t e s t s ..................................... 7

R e s u l t s . . . ............................................. 8

T A B L E S

B-1

D - 1

E - 1

S u m m a r y o f n o i s e t e s t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

S u m m a r y o f c o n t r o l l e r l o w v o l t a g e t e s t s . . . . . . . . . . . . . . . . . . 2 0

S u m m a r y o f t e m p e r a t u r e t e s t s . . . . . . . . . . . . . . . . . . . . . . . . . 2 3

F I G U R E S

4

C - 1

E . 1

A

B

C

D

E

V a r i a b l e . l o a d a p p a r a t u s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

M o t o r c o n t r o l l e r t e s t e q u i p m e n t . . . . . . . . . . . . . . . . . . . . . . . . 6

C o n t r o l l e r o u t p u t v o l t s v e r s u s o u t p u t f r e q u e n c y f o r

v a r i o u s l o a d s .................................... 10

C o n t r o l l e r o u t p u t a m p e r e s v e r s u s o u t p u t f r e q u e n c y f o r

v a r i o u s s p e e d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

C o r c o m f i l t e r d e t a i l s . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . 18

T e m p e r a t u r e d e r a t i n g c u r v e f o r s i l i c o n p o w e r t r a n s i s t o r . . . . . . . . 2 4

. .

A P P E N D I C E S '

M a n u f a c t u r e r s / s u p p l i e r s o f a - c v a r i a b l e - s p e e d m o t o r

c o n t r o l l e r s . . . ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

N o i s e t e s t r e s u l t s . ................................. 15

C o r c o m s e r i e s K f i l t e r ............................... 18

L o w v o l t a g e t e s t s . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . 19

H e a t t e s t s ....................................... 21

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' . . . . . . . . i ~ _ .. PURPOSE- : '

The purpose of this s tudy was to de te rmine the opera t ion and feasibi l i ty of using a

var iable-speed-motor cont ro l le r i n a canal gate opera t ion system. The Bureau 's

s tandard radial gate design for spillway use is adapted to canal check structures. The

Grani te Reef Aqueduct conveys Colorado River water fro m the Buckskin Mounta ins

to the Phoen ix area for which there are many radia l gates that requi re precise

automat ic and manual controls.

• ' . . . . . . INTRODUCTION

In recent years, var iable a-c motor drive control lers have• been developed for

opera t ion in conjunct ion with 3-phase induc t ion a n d synchronous motors . A

Variable-speed Controllei" wi th an a-c motor provides a Useful variable-speed

drive which is safe, rel iable, and convenient . In canal au tomat ion , a Variable-speed

drive has many applicat ions. I t provides a wide speed range for precise ad jus tmen t

of canal gates and valves(it also provides variable speeds tha t can be p rogrammed by

computer for "gate s t roking;" type of opera t ion being devel0ped at the Bureau 's

E&R Center laboratories. Cer ta in fea tu resof variable-speed controllers make t hem

desi rable even if the var iable speed is not requi red . T o r q u e l im i t ands low start are

features tha t extend motor and equ ipmen t life. Also, it allows numerous starts

wi thout damaging the motor and equipment . These features are desirable in

a lgor i thms suchas "EL,FLO," z The, i n t ended appl ica t ion i s f o r the s tandard USBR

gate ho i s t having a 3-hp motor . A s tudy was done in the appl ica t ion of a:variable-

speed control ler to a gate hoist using a 3-hp motor. Hoist specifications follow.

~ ~ " B u r e a u o f Re'clamation s tandard radial gate sys tem

A motor ra ted 3-hp' 1,750-r/min with 240-r/min gear head

Gear box ratios 50:5:4:1 = 1000:1 for cable hois t

Cable speed at 1.65 f t / m i n

Radial gate, 2"5,000 ib : ' ~

2.08 hp calculated, 3 hp namepla te (60 percent over m i n i m u m design)

1 Falve)~, H.T., and P.C. Luning, Gate Stroking, REC-ERC-79-7, Bureau of Reclamation, Denver, Colo., 86 p., July 1979.- . . . . . 2 Buyalski, Clark P., and Edward A. Serfozo, Electronic Filter Level Offset (EL.FLO)

Plus Reset Equipment for Automatic Control of Canals, REC-ERC-79-3, BUreau of Reclamation, Denver, Colo., 145 p., June 1979.

!

It is anticipated that theGran i te Reef Aqueduct will have a standard radial

gate. The variable-speed drive is contemplated for the Granite Reef radia l

gate hoist system.

A number of variable-speed drives are available commercially; essentially,

all rectify the a-c power available and - - b y us!ng control semiconductors

(transistors, silicon controlletl rectifier, or T/'iacs) - - provide a Variable

voltage and a variable frequency output. A nf imber of manufacturers of

variable-speed motor controllers are shown iniappendix A.

AH the controllers are similar in that they produce an output that increases

in frequency and voltage beginning from zero ~ volts and zero hertz to the

desired ~ output voltage (230 V) and frequency (60 or 66 Hz) as set by

controls. All provide a torque limit feature m in reality, a current limit

a d j u s t a b l e to a maximum of 150 percent of rated current. The speed at

which the output increases or decreases also is adjustable. The controls

(reverse, speed, acceleration, and start/stop-reset) can be interfaced

readily to a computer.

CONCLUSIONS

1. The 3-hp variable-speed motor controller tested, is adequate to provide variable-

speed operation on the hate hoists to be installed On the Granite Reef Aqueduct .

2. Noise interference produced by the controller is low enough to be used in the

field without causing~interference to microprocessor I, electronic, and communication

circuits.

3. The motor controller must be matched to the motor being controlled for

horsepower rating and in revolutions per minute.

4. The Parajust (app. A) controller is temperatui-e rated conservatively. It will

provide cyclic duty at elevated temperatures.

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~ - , APPLICATION ,-

In this study the specific appl icat ion was to provide a va r i ab l e speed to a radial gate

hoist at an i r r igat ion canal. The cont ro l ler has a wide appl icat ion in the area of

hydraulics. Motor control ler applications include:

• Other types o fga tes such a s s l i de gates

• Motor ized valves

• 'Circulating pumps

• Motors used in a laboratory for mode l studies to control headgates, tailgates,

probe positions, etc.

A-C V e r s u s D - C V a r i a b l e - s p e e d D r i v e s

Conversion of a-c voltage to va r iab le d-c voltage is r equ i r ed for both types of

controllers; therefore , a control ler is r equ i red in e i ther case, '

Advantages of &c motors with controllers

+ Bet te r low speed control (with closed loop control) ~

+ More eff icient and economical for large horsepower rat ing (greater than 15 hp)

Disadvantages of d-c motors having controllers

- Greater d-c motor cost

- Gr'eater ma in tenance for d-c motor brush rep lacement and cleaning

- Spark'ing commuta to r is an explos ion/ f i re hazard for d-c motor

- Speed depends on load unless on a closed loop control

Advantages of a-c motors having controllers

+ Lower cost - - part icularly for induct ion m6tors

+ No brusiaes or slip rings on induc t ion motors

Disadvantages of a-c motorshaving controllers

-~Lower start ing torque; however, this has advan tages

- Ineff ic ient use of electrical power with poor phase angle.

- Ineffec t ive cooling at low speeds, generally not a p rob lem in i n t e r m i t t e n t

opera t ion

3

A 3-hp controller was tested in the laboratory. Testing was planned to investigate

operation of the controller at:

• Varying voltages ~

• • Short duration power losses

• Noise impressed on the line (resulting from Controller operation)

• Effect of a high ambient temperature on the controller. ~

The Central Arizona Projects Office provided the E&R Center laboratory the

Parametrics-Parajust motor controller (app. A).

TEST PROCEDURES

• Tests were devised to provide controller operating characteristics and to introduce

noise into the power circuits. The most difficult part of the test series was installing

equipment that provided a variable load on the motor. Various pump and motor

combinations were tried. A hydraulic pump having a 3-hp, 3.phase, 230-v, 1750.

r /min , motor was selected to provide a load for testing the controller. Several

variable-load arrangements provided considerable"insight into how the controller

• operated. Several other 3-hp motors rated at different speeds were tried. Results of

preliminary tests are covered later in this report.

The test apparatus consisted of (fig. 1):A 1,750-r/min motor, a positive displacement

hydraulic pump, pressure regulator, three-way valve, and pipe loop with a valve.

The motor and pump used are as described below:

Motor

Dyna Line (The Brown Brockmeyer Company, Dayton, Ohio)

MS M580, ES 7774, FR 213, CY 50/60, 3 ph, 3 hp, 2108/220/440 volt, type PM,

1450/1750 r /min, 9/4.5 ampere, serial No. C3463077, t empera tu re rise

40°C, SF 1.15

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Figure 1 . - - Variable-load apparatus. P801-D-80200

Pump

Weather Head Company (Cleveland, Ohio)

PN 408-05045, MOD WO730A-01H45-15, serial No. 5524

.~ ~'~

Pump hydraulic pressure and output amperes to the motor were used to determine

load. The following test equipment was used to obtain d a t a :

1. Data Technology Corp.

2. Tektronics Inc.

3. Hewlett-Packard Co.

4. General Electric Co.

5. John Fluke Mfg. Co.

6. John FlukeMfg. Co.

7. Superior Electric Co.

8. Hewlett-Packard Co.

model 30A digital voltmeter

model 434 storage oscilloscope

model 3582A spectrum analyzer

clamp-on ammeter

model 8020-A mult imeters (2)

model 80T-150 temperature probes (2)

Powers ta t" 20 A variable t ransformer

model 7414 four-channel oscillograph

Bourdon tube pressure gauge

A 16-ft-long wire (taped to the input power cable) was used for noise pickup to the

spectrum analyzer and oscilloscope. The test setup is shown in figure 2.

Figure 2. - - Moto r con t ro l l e r test e q u i p m e n t . PB01-D-80293

T h e f o l l o w i n g t e s t s w e r e r u n :

1. Electrical noise measurements made under varying load and speed

2. Outside influence - - fluorescent lights and a large d-c motor with controller

3. Noise tests with Corcom 30K6 filter installed in powerline

4. Load limit (electronic shear pin) at varying speed

5. Low voltage input for various speed and load conditions

6. Temperature tests at 40, 50, 60, and 67 °C (104, 122, 140, and 153 °F)

The controller input current, output current, output volts, and noise (measured

with spectrum analyzer and oscilloscope) were used to monitor the tests in all cases

except the tempera ture tests. Additional data such as hydraulic pressure (load) and

controller input volts were included as required.

Noise Tests

Noise measurements were made at a part icular pressure (load) and increasing the

speed control in 20 percent increments. Four load settings were established: no

load, one-third load, two-thirds load, and full load.

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The noise genera ted was observed using bo th a n osci l loscope-and a spec t rum

analyzer .A wire taped along the powerl ine feed for about 16 ft picked up the noise

signal. S tandards or documenta t ion are unavai lable on motor control ler noise, so

compar ison with o ther sources (d-c motor and f luorescent lights) was qui te

meaningful . Noise test results are in appendix B.

I t was diff icul t to s imulate noise in situ but, by comparison with common noise

sources, apparen t ly noise will be a minor problem. The noise tests were done

wi thou t an isolat ion t ransformer , and the cont ro l ler manufac tu re r r ecommends

using a t ransformer to provide addi t iona l isolat ion and noise reduct ion. Th i swi l l be

provided in the field by the station-service t ransformer .

A Corcom 30K6 EMI 30-A f i l ter was instal led in the last series of noise tests;

approximate ly 20 percent reduct ion in noise was .noted. Appendix C shows a

diagram of the Corcom fil ter. A f i l ter can be inc luded in the system but, it is not

necessary, according to lab tests . . . .

Low Voltage Test : ~.

The low voltage test was devised to moni to r control opera t ion and cont ro l le r

output . A variable t rans former was used to r e d u c e i n p u t voltage by increments un t i l

the control ler stopped. Various load settings and speed increments were used.

Appendix D shows lowvol tage tests.

Tempera tu re Test s

T e m p e r a t u r e tests were run with the cont ro l le r instal led in, an insula ted box hea ted

with various combina t ions of incandescent lamps. Tests were run at 40, 50, 60, and 67

°C (104,'122,140, and I53 °F) ambien t tempera tures . T e m p e r a t u r e probes were used

to moni to r the control led rect i f ier module and 'the control led ou tpu t module: The

cont ro l le r m a n u f a c t u r e r r 'ecommends 40 °C max imum a m b i e n t t empera ture .

However, vent i la t ing the enclosure, o r doub l i ng its or iginal volume, or using a

larger control ler will be sui table for 50 °C.

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Appendix E shows results of temperature tests. A Hewlett-Packard four-channel

recorder provided a continuous record of temperature changes during the tests.

RESULTS

A motor control ler devise installed, with the variable-speed feature, on radial gate

hoists will improve gate operation. It offers numerous advantages:

• Better precision in setting the gates,

• Improved motor life,

• Stall protection,

• Protection for exceeding limits (by setting electronic shear pin),

• Additional automation capability in supervisory control, and

• Improved automatic control operations.

The controller tested has a design current based on a 3-phase, 3-hp, 230-V, 1,750-

r /min motor. Nameplate data states 9.0-A running current. A review of various

motor nameplate data show 10.0 A for a 1,150 r /min motor (the controller would not

start this motor) and 7.7 A for a 3,500-r/min motor. Th e shear pin, set at 150 percent F

or approximately 14 A, did not trip the 3,500-r/min motor when starting under any

starting condition. It appears that the tested 3-hp controller is designed for use with

a 1,750-r/min motor. The electronic shear pin control could be lowered for use with

the higher r /min 3-hp motors, but cannot be used with the 1,150-r/min motor.

The controller cannot exceed 150 percent design current; however, the electronic

shear pin can be set to a lower current value. Current, which is a func t ion of output

voltage and frequency, is far less than the starting current when 230 V, 60 Hz are

applied to the motor. A lower starting current extends life of the bearings, the

motor windings: and the gear reduction assembly.

Variable speed allows the operator to select lower:speeds for small gate position

changes, particularly useful at low canal flow rates. Variable speed can be used for

supervisory control and automatic control dictated by new control algorithms, such

~isGate S t rok ing ~ and for init iat ing a slow gate movement to prevent abrupt changes

in canal water surfaces.

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The cont~eoller p r o v i d e s p r o t e c t i o n from low l ine voltage in two Wiiys. First , i t

operates normal ly at reduced speeds where ou tpu t •voltage is less than the reduced

"input voltage and, second, it provides overcur ren t • p ro tec t ion (electronic shear pin)

at hilgher speeds. When a motor is opera ted direct ly on the aoc l ine with reduced

voltage at 60 Hz, overheat ing and high current result.

Noise in t roduced into the powerl ine is a major concern for the proposed cont ro l le r

use. Most test ing of the control ler included de te rmin ing noise (app. • B).~ A

p r o m i n e n t result was the in te r fe rence level con t r ibu ted by f luorescent l ights in the

room adjacent to the cont ro l le r test area. Electr ical noise caused by l ights was as

high as that con t r ibu ted by the controller . Also, dur ing testing, several s tudies were

in progress using Digital E q u i p m e n t Company Minc LSI 11-23 computers and the

Hewlet t -Packard 9825 p rogrammable calculator. Wi th those computers opera t ing ,

dur ing the dura t ion of the cont ro l le r tests, observable noise re la ted prob lems were

not detected.

Motor l i te ra ture indicates that , with ou tpu t voltage p ropor t iona l to f requency (0 to

100%, 0 to 230V), the motor operates at constant torque. A check of recorded data

verifies tha t the voltage-speed re la t ion provides a constant to rque output . The

maximum speed, max imum voltage holds t rue for 100 percent speed set at 60 or 66

Hz and 1,750 or 1,925 r / m i n , respectively. F igure 3 shows results from two d i f fe ren t

tests and i l lustrates the voltage-frequency re la t ion for various loads; however, note

tha t the cur ren t changes with voltage (fig.•4). The 1,000-1b/inZ run is an overload

condi t ion that causes an electronic shear pin to function.

Tests show tha t all factors.-- ambien t t empera tu re , run t ime, speed, and r u n / r e s t

t ime - - inf luence tempera ture . The main advantage of this type of control ler is tha t

the cont ro l ler starts the motor at a constant torque. Therefore , the motor can be • . t

started repeatedly wi thout damage.

Tests showed tha t t empe ra tu r e constra ints are conservatively stated by the

manufac tu re r of the controller . Rat ing selection must include analyses of speed,

dura t ion of run, and dura t ion of rest. An off-the-shelf control ler will provide

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F i g u r e 3. - - C o n t r o l l e r o u t p u t volts versus o u t p u t f r e q u e n c y for va r ious loads - - m o t o r c o n t r o l l e r tests.

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FREQUENC Y,

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I 50 1 8 0 90

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F i g u r e 4. - - Cof i t ro l l e r o u t p u t a m p e r e s versus O u t p u t f r e q u e n c y for va r ious speeds - - m o t o r c o n t r o l l e r tests.

I I

11

cont inuous service at 40 o C (104 ° F). The manufactui-er states this can be raised to 50

° C (122 ° F) by dr i l l ing holes in the enclosure for vent i la t ion, doubl ing the enclosure

volume, or instal l ing the next larger controller . In the s tandard enclosure, test

results indicate that a cont inuous run at 50 °C did not cause any damage.

The most p robab le damage to the cont ro l le r at high t e m p e r a t u r e would be ithe

shor tened life of the fi l ter capacitors. Relocat ing these capacitors f rom the top to

the bo t tom of the enclosure at the factory will decrease exposure to heat.

The Parajust control ler funct ions well for automat ion. The s tar t -s top/reset can b e

replaced with a single contact for run-stop. Reverse is accomplished also with a

single contact (open-forward/closed-reverse) . The cont ro l ler speed is p rov ided by a

0- to 10-V signal. A control modu le also is ayailable tlo provide isolation as well as to

accommodate a variety of o ther input Signals. An addi t ional set of contacts is

available for control l ing the electric brakes if motor braking is required.

S t a n d b y power cannot be switched in while the Parajust is r unn ing as this would

cause the shear pin to funct ion and requ i re a resetl The t ransfer ~hould be made

while the control ler is off, or restart the control ler after power is reappl ied if the

control ler was runn ing when failure occurred.

Parajust or o ther type control lers meet field ins ta l la t ion r equ i r emen t s on Bureau

of Reclamat ion canal facilities. Concrete block or f ab r i ca t edbu i ld ing can be used at

e a c h installation. A bui ld ing provides more constant ambien t t empera tu re as

o p p o s e d to an open installat ion. As no ted earlier, t empe ra tu r e is the main

constraint for a 3-hp cont ro l ler with the 3-hp motor radial gate hoist system and can

be •designed for cooling. Tests show Parajust t empe ra tu r e ratings to be qu i te

conservative for the cont inuous run a t 50 °C (122 °F) wi thout modif icat ion.

I n t e r m i t t e n t duty - - typical of canal instal lat ion - - allows even higher ambien t

t empera tu re s for the same semiconductor case tempera tures . Case t empe ra tu r e of

the control ler semiconductors is a funct ion of:

• Ambien t t empera tu re ,

• Dura t ion of run t ime,

• Percent run to rest t ime, and

• To a lesser degree, percent speed.

12

I I I I i i I I i I i I I I I i I 1 i

I I I I I I I I I I I I I I I I I I I

By providing a softstart'(controlled current), the controller, can be cycled many•

times without-causing overheating or mechanical stress. A soft start has constant

starting torque or l imited current start. During the tests, the starting current

generally was equal to the normal running current. The low starting current

virtually eliminates resistance heating associated with normal motor starting

current of 6 to 10 times rated current. The associated constant s tar t ing, torque

eliminates damaging mechanical forces normally present in starting motors.

However, low speeds inhibi t cooling of most a-c motors. For extended periods of low

speed operat ion it may be required to design fo r high temperature windings and /or

forced cooling.

13

APPENDIX A

Manufacturers/Suppliers of A-C Variable-speed Motor Controllers

Allen Bradley -- PTI Controls Allen Bradley (414) 671-2000 1201 South Second Street Milwaukee, WI 53204

General Electric Company Electronic Comp. Sales (315) 456-2196 Building 23, Room 218 One River Road Schenectady, NY 12345

Incom-Fincor Controls Fincor Controls (717) 757-4641 3750 East Market Street York, PA 17402

Lovejoy Electronics -- MPR-IV Lovejoy Electronics, Inc. (312) 968-7089 2655 Wisconsin Avenue Downers Grove, IL 60515

Parametrics -- Parajust Parametrics (203) 795-0811 284 Racebrook Road Orange, CT 06477

Note: Th i s is a par t ia l list of m a n y m a n u f a c t u r e r s and suppl ie rs and is no t i n t e n d e d to be a summary .

14

I I i I i I I I I I I I i i I I

I I I

I I I I I I I I I I I I I I I I I I I

= A P P E N D I X B

Noise Tests Results

Electrical noise data were taken under a variety of condit ions in the laboratory at

various loads and percent speed. Noise runs appeared to be inconsistent uhti l the

background noise in tile laboratory was investigated. External sources, such as

f luorescent lights, and the d-c motor on the low ambient test f.acility, were checked.

Lights contributed significantly to noise, whereas the d-c motor attenuated the

noise - - perhaps by lowering the source impedance s e e n by the controller. Runs

were made both with fluorescent lights on and off.

In these tests, noise noted was in the audible spectrum with most of the energy in the

range of the olatput freq/iency to 300 Hz and then the energy level decreased to levels : .

below the background noise at 10,000 Hz and above.

Noise level is greatest at 20 to 60 percent speed. Noise level caused by fluorescent

lights is about the same level as that produced by the controller. The level is highest

at a load of about 2 hp. The design rating for the gate hoist motor is 2.08 hp. Results

are shown in table B-1.

Addit ion of the Corcom series K filter provides some improvement by reducing the

noise level to approximately 66 pet;cent of the noise level without the filter. This

addit ion could be added easily at a later t ime if noise is found to be a problem.

From test results, it is bel ieved that electrical noise introduced by the controller

will not be a problem for the considered application.

15

T a b l e B-1. ~ N o i s e t e s t r e s u l t s ~ m o t o r c o n t r o l l e r t e s t s

I I

Run No.

Fre- quency

set Load, Speed, Total Secondary

Lights lb/in 2 % WA ampere volt

2Noise millivolt peak-to-

peak

I I

66 O n F r i c t i o n (no load)

Controller

off 0 0 0 16 0 1.7 0.1 10 40

20 272.8 4.5 35 44 40 763.8 5.75 78.7 40 60 1229.7 6.25 113.6 40 80 1915.6 7.0 158 36

100 2598.1 7.50 200 40

I I I

2 60 O n 5OO ( 2 h p )

20 235.1 40 ~ 987.2 60 1629.0 80 2311.4

100 2559.1

4.0 34 100 7.0 74 80 8.25 114 80 8.5 157 60 7.5 197 40

I I

3 60 O n 750 (3 h p )

20 265 40 897.2 60 1543.3 80 2451.3

100 3325.5

4.5 3 4 28 7 74 24 8.25 108 26 9.25 153 26

10 192 28

I I

4 60 O n 1000 ( 4 h p )

30 1104.2 40 1553.7 6 0 2341.7 80 3400.0

100 3886.7

12.5 51 100 13 6 9 90 13 104 80

1 3 151 70 12 187 40

I I

5 60 O n 250 20 40 3 60 3 80

100

4.75 6.25 7.75 8.5 8.5

32.0 72.8

117 156 203

18 20 20 22 26

6 60 O n 500 20 3 40 3 60 3 80 3

100 3

16

5.75 6.75 8.50 9.25 9.00

359 77

115.6 160 200

20 18 18 18 22

I I I I

T a b l e B-1. - - N o i s e t e s t r e s u l t s - - . m o t o r : c o n t r o U e r t e s t s - - C o n t i n u e d

F r e o

Run quency Load, Speed, Total No. set Lights lb/in 2 % IVA

Secondary

ampere volt

aNoise millivoh peak-to-

peak

7 60 O f f 250 20 3 4 . 5 34.6

40 3 6.0 77.8

60 3 7.25 116.7

80 3 7.75 160

100 3 7.75 203

12

14

18

10

8

8 6 0 O f f ~ 5 0 0 • 20 3 ..... 5 . 379 -

w/filter 40 3 7.75 77.0

60 3 8 .75 116

80 3 9.25 157

~ ... 100 s 9 .... 201

-10

12

12

10

10

9 60 O n 250 20 3 4.75 40

w/filter 40 3 6 . 7 5 79

60 3 . . . . 8.00 120

80 a 8.50 159

100 3 7.5 202

18 18 18 18 18

1 Total volt-amperes =V~- (Line volt.amperes) = Frequency was related to the output and the 60 Hz input. The predominant frequency was the

3d harmonic and decreased in strength as the frequency increased above 400 Hz. s Data not recorded, initial tests.

. ' . .

17

A i

• A P P E N D I X C Corcom Series K f i l t e r

Par t -No. 30K6 30A

i m

i v

D

. u

F r e q u e n c y , M H z A t t e n u a t i o n , d b

. . . . . . . . . . . 0.15 0.2

. . . . . . . . . . . 15 20 0.5

30 10

55

L e a k a g e a t 250 V a.c . . . . . . . .

T e s t v o l t a g e . . . . . . . . . . . . . . .

l i n e to g r o u n d 0.5 m i l l i a m p e r e s

l i ne to g r o u n d 2250 vo l t s d.c. l i ne to l i n e 1450 vo l t s d.c.

O p e r a t i n g vo l t age . . . . . . . . . . 115 to 250 vo l t s a.c.

O p e r a t i n g f r e q u e n c y . . . : . . . 50 to 400 Hz

F i g u r e C-1. - - Corcom f i l t e r de ta i l s - - m o t o r c o n t r o l l e r tests.

18

O

20

55

I I I I I I I I I I I I I I I I I I I

I I I I I

I I I I I I I I I I I

APPENDIX D

Low Voltage Tests

The low voltage test provided answers to two questions:

1. Operation of the control logic, and

2. Operation of the motor.

The control logic functioned properly throughout the test. When the controller

could not provide the output voltage appropriate for the percent speed as noted in

tableD-l , the motor would draw excessive current and cause the electronic shear pin

to trip. This current becomes a function of both speed and, to a lesser degree, motor

speed and motor load. If low voltage is a common problem in parts of the field

installation, an upper limit on motor speed could be set by the canal microprocessor

controller or by a manual setting to match line voltage.

The shear pin and motor speed control provide two beneficial characteristics:

1. They prevent the motor from overheating from low voltage, and

2. They allow operation at lower speeds when a low vol tagecondi t ion exists.

From figure 2, speed percent appropriate for low line voltage can be determined.

Table D-1 shows test results. Note that, at 50 percent speed, the input voltage to the

controller can be reduced to 150 volts (65% rated ¢oltage input) and still operate the

canal gate.

19

T a b l e D - 1 . - - Summary of controller low voltage tests

Controller Controller Controller input, input, output, volts current volts

Controller Motor Motor ou tpu t , load, speed, current lb/ in 2 %

212 9 .5 - -

2 0 0 9 .2 - -

190 9 .0 - -

180 8 .3 - -

170 7 .6 5 1 . 4

160 7 .1 4 7 . 5

155 6 . 8 4 5 . 6

150 6 .1 43~7

170 - - 1 6 0 .

150 - - 160

- - 5 0 0 50

- - 5 0 0 50

- - 5 0 0 . .,~ 50 - - 5 0 0 50

6 .7 5 0 0 50

6 .3 5 0 0 50

6 .2 5 0 0 50

6 .1 5 0 0 150

14 ~ ~ 2100

14 - - 275

Motor and controller continued to operate with little degradation to 150 volts.

2 Controller electronic shear pin tr ipped because of overeurrent.

20

I I I I I I I I I I I I I I I I I I I

I I ,I

I I I I I I I I I I I I I I I I

• A P P E N D I X E • :

Heat Tests

A series of heat test rung were made with the var iable speed/i-c motor cont ro l le r

s tandard enclosure. ~ . , . . _

1. Cont inuous run a t ra ted hp , 80 percent speed, 40 °C (104 ° F ) a m b i e n t

t empera tu re

2 . Cont inuous run at ra ted hp, 50 percent speed, 50 °C (122 °F) ambien t

t empera tu re

3. Twenty percent run (2-min run and 8-min rest) at ra ted hp, 80 percent speed, 60 - ?

°C (140 °F) ambien t t e m p e r a t u r e

4. ' Twenty percent run (l-rain run and 4-min rest) at ra ted hp, 80 percent speed, 60

°C (140 °F) ambien t t empera tu re :

5. Twenty percent run (1-min run and 4-min rest) at ra ted hp, 40 percent speed, 60

°C (140 °F) ambien t t empera tu re

6. Thirty-th/-ee percent run (0.5 and 1-min) at ra ted hp, 80 percent speed, 50 °C

(122 °F) ambien t t e m p e r a t u r e

7. Twenty percent run (1-min run and 4-min rest) at ra ted hp, 40 percent speed, 66

° C (152 °F) ambien t t empera tu re

An i n s u l a t e d box hea ted by incandescent lamps was used to obta in the ambien t

t empera tu res required. The ambien t t empera tu re was m e a s u r e d at the middle of

the box and outside of the control ler enclosure.

F igure E-1 is a dera t ing curve for a typical high-power silicon transistor . For use in

the cont ro l ler at 93 °C (200 °F) - - the t empera tu re selected as the max imum device

t e m p e r a t u r e to be al lowed dur ing the tests - - the curve shows 63 percent of

max imum power dissipation.

A cont inuous run was made at 49 o C (120 ° F) ambien t tempera ture . The run resul ted

in about 93 °C on the power t ransis tors and the cont ro l led rectif ier . The

21

t empe ra tu r e i'ise results in a 47 percent dera t ing for the silicon power devices. F rom

this test, it seems tha t the cont ro l le r is ra ted conservatively for the 40 ° C ambient .

After the 49 °C test, a n u m b e r of runs were made using 93 °C as a m a x i m u m

condit ion. Table E-1 shows the test r e su l t s and indicates tha t a n u m b e r of

approaches may be used to accommoda te higher ambien t condi t ions and to a l l o w

safe cont ro l ler operat ion. The manufac ture r ' s l i t e ra tu re states tha t 49 °C ambien t

can be accommodated by using a larger enclosure or by providing the enclosure with

vent i la t ion. This change also could be used to accommodate the h igher ambien t

field conditions.

Tests revealed several o ther aspects of the motor ,cont ro l le r system. The motor

tends to overheat on long low-speed runs. Overhea t ing is due to loss of cooling air at

low speeds. Motors are available having h igh- tempera ture windings a n d / o r external

cooling.

The increase in sl ippage at low speeds (20 to 40%) was not iced also. Repet i t ive starts

at 80 percent speed did not cause the motor to overheat.

For long runs at slow speeds, jogging (on-off) could be considered as the motor does

not rotate below 10 or 15 percent.

22

I I I I I I I I I I I I I I I I I I I

I I I I

Test No.

T a b l e E-1. S u m m a r y o f temperature tests : - motor controller

-~ Control . . . . . . . . . . . . . . Rectifier module

Ambient Duty time temper- temper-

temperature, Per- Run Rest Speed, Load, ature, ature, °F °C cent min. min. % hp °F °C °F °C

104 40 100 Contin. - - 80 3 1 6 3 . 4 7 3 161.6 72 2 3 4 5 6 7

122 50 100 Contin. - - 50 3 140 60 20 2 8 80 3 203.0 95 199.4 93 140 60 20 1 4 80 3 195.0 91 188.0 87 140 ' 60 20 1 4 40 3 186 .8 86 182.2 83 122 50 33 0.5 1 80 3 138.2 59 138.2 59 152 67 20 1 4 40 3 2 0 3 . 0 : 9 5 197.6 92

I I I I I I I I I I I. I I 23

32 0

77 25

122 50

167 75 ¢ )

~ 200 g 9~ <1 : - "~ (:Z: 4- 212 I00 laJ EL ~

/ 2 3 4 - - 112 , : w o t.)

LL

257 125

D I S S I P A T I O N , p e r c e n t POWER

6 3 %

I I

I /

I t I I I I I

I /

50% I

I

• I

,oo~

o

302 150

347 175

392 200

'Temperature deroting curve for silicone power t r a n s i s , o r - m o t o r contro l ler , e s t

F i g u r e E-1. - - T e m p e r a t u r e d e r a t i n g c u r v e f o r s i l i c o n p o w e r t r a n s i s t o r - - m o t o r c o n t r o l l e r t e s t s .

24

I I I I I I I I I I I I I I I I I I I

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I I I I I I I I I I I I I I I I I I I