the controller –features. - '+domain name+' board layout. ac-input j1 j21 j4 jp3 +15 ,...

The controller – Features.

� 400 KW Power system configuration� Can power AC – DC – AC resonant series high power inverters up to 450 KW.

� An AC – DC conversion in the front end is suggested to be designed with a AC 6

pulse static thyristorized switch with 6 thyristors and free wheeling diode adequately

cooled.

� For thyristor based front end units use high speed sub-cycle interrupting MCCBS

( Merlin Gerin type ) of KA rating above 40 KA when semi-fuses are not feasible.

� Controller Card features

� Basic resonant inverter control circuitry.

�Build around an ASIC chip to vary resonant inverter frequency from 200 Hz to

1250 Hz.( Change Inverter control crystal U17 to 44 Mhz to get 2500 Hz )

�Basic power electronic system protection interface with LCD display module.

� AC-Static switch – controls the six front end thyristors

� For these power units , control card comes with an additional ASIC chip one

controlling the AC thyristorized static switch with 6 pulse firing with ramp up from

maximum phase angle to minimum angle near 6 degree ( margin )

� Maximum DC bus voltage adjustable to a fixed value and needs to be positioned so

that system power factor is greater than 0.90 – 0.92.

450 KW Power circuit configuration – overall view

STATIC 6 PL

RECTIFIER

MCCB

Choose Sub-cycle

instantaneous trip

Choose Sub-cycle

instantaneous trip

Semi – fuse

Semi-fuses

adequately rated

Semi-fuses

adequately rated

AC – DC rectifier

Choose 6 pulse

Thyristorized stack All

rated 1600 V , 750 A and ITSM > 20KA

Choose 6 pulse

Thyristorized stack All

rated 1600 V , 750 A and ITSM > 20KA

Free wheel diode

1600 V PIV

freewheeling

rectifier

1600 V PIV

freewheeling

rectifier

1600 uF DC

rated for 1200 V

1600 uF DC

rated for 1200 V

DCCT

rated 600A

Filter reactor

Iron cored 2 – 4 mHIron cored 2 – 4 mH

DC filter Cap

130 uF- 200 uF

rated 3000V

and 700 Hz per

leg

130 uF- 200 uF

rated 3000V

and 700 Hz per

leg

Resonant Cap

Inverter

Stack

MFCT

2 Thyristor + 2

Diodes for with

PIV rating

3000V and ITRMScurrent 4000 A

for thyristors

and 2000 A for

Diode

2 Thyristor + 2

Diodes for with

PIV rating

3000V and ITRMScurrent 4000 A

for thyristors

and 2000 A for

Diode

Inv stack

V- line

525 - 575 V AC 50

Hz - 3 phase

525 - 575 V AC 50

Hz - 3 phase

Load Coil Load Coil

Recommended design approach – 1

� AC static switch section :

� Use 0.22 uF capacitors and 25 Ohm 100 W non-inductive resistors as sunubber

circuits.

� Use MCCB with one Normally open aux contacts to sense MCCB on which will auto

turn on the AC switch and soft start the DC bus to the allowed maximum voltage.

� DC reactor to be water cooled .

� Inverter section

� 0.47 uF capacitor with 10 Ohm 750 W water cooled resistor as snubber components

on each thyristor( Can alternatively choose the diode based snubber )

� MF CT to be rated as 5000 A / 1 A for inverter current sensing.

� Locate DI / DT coils adequately far away from MS metal components of the panel.

� DI / DT coil section to be water cooled and capable of carrying the full rated 4000 A of

the inverter current.

Series capacitor per leg : 130-150 uF rated 3000 V rated 700 Hz.

Cap 4250 KVAR / 700 Hz / 3000 V YEsha or

5450 KVAR / 700 Hz / 3000 V GE.

DC bus capacitor : 1600 uF rated 1200 V

Incoming AC voltage : 415 - 525 V ac three phase with Converter 6 pulse

soft start with free wheeling diode .

Furnace coil : 27 turns , Diameter 650 mm , Height 785 mm

Coil measure inductance ( 320 uH ) D2/L = 0.0.538

Expected operating freq at peak power 550 Hz.

Actual measured oper. Char : 3000 V on inverter. (600) A on lines = 450 KW.

Operating frequency at peak power 600 Hz.

Jumbo C770 inverter SCR and matching diode

DI/DT coil : 12 uH per leg

Recommended design approach – contd

� Inverter Design philosophy

The controller wiring scheme

AC INPUT JACK

415 V

AC - 1

Ph 10 lines

18 V AC

8 lines

2 lines

Power Supply

Transformer

Power Supply

Transformer

Panel

lamps

10 lines

+15 V com

GLD-SW

RW-PR-SW

DMW-PR-SW

DMW-TP-SW

Push button /

switch

inputs

Push button /

switch

inputs

Power Supply

for pulse

Trigger boards

Power Supply

for pulse

Trigger boards

JACK J11

3 lines

7 lines

JACK JP2

+15

GND -15 MFCT GND

GND PT

JACK JP4

GND -SCR +SCR

Pulse amplifier

signal drive for

inverter

Pulse amplifier

signal drive for

inverter

JACK JP7 JACK JP3

Panel meters

JACK

J12

DC Bus

Feedback

After choke

CONTROL BOARDCONTROL BOARD

Controller Box

2 lines

2 lines

LCD CON JP 11

LCD

DCCT

GND Gnd CT

P1

2 lines

To AC static

switch pulse

trigger board

To AC static

switch pulse

trigger board

+ -

JACK JP1

Remote /

Local

switch

Remote /

Local

switch

Remote oper

R

B

JACK

J13

CONV DC

Feedback

before choke+ -

Control board layout.

J1AC-INPUT

J21 J4 JP3

+15 , -15 , +5 , +15

regulator sections

OPTO ISOLATED INPUT

SECTION

ASIC_INV22 Mhz Xtal

10 Mhz Xtal

uC

rst

uC

JTAG

DC BUS

MONITOR

ANALOG ELECTRONICS

Calb F-mtr

Calb WIN

Calb C-flt

Calb MFCT

Calb I-flt

Calb I-hold

Calb PT-gain

Calb V-lmt

Calb Pwr_mtr

Calb G- mtr

Calb Span

J12

1

DC flt LED

1

P1

J7

LCD COM JP11

JP 20

JP 21

ASIC_INV

JTAG

1

JP10

JP15

Calb C-FB

Calb C-PW

Calb Max-V

Calb ACCR

CONV_ASICDC BUS CONTROL

SYSTEM

FOR 450 KW power

units

AC switch

trigger

uC

11.0592 Mhz

Inverter

Freq

control

Calb C_MT

ASIC_CON

JTAG

1JP16

St.switch

control clock

Sync on LED

Freq down LED

Freq up LED

J13

D46

D31

D30

D1 D3 D5 D7+5v LED +15v LED -15v LED E +15v LED

D33

D33

3.3v LED

Jack AC-INPUT for ac voltages input for regulator.

18 V input

from control

trafo - one

sec . winding

18 V input

from control

trafo - one

sec . winding

18 V input

from control

trafo - one

sec . winding

18 V input

from control

trafo - one

sec . winding

+ 15 V regulation Circuit

-15 V regulation Circuit

7.5 V input

from control

trafo - one

sec . winding

7.5 V input

from control

trafo - one

sec . winding


18 V input

from control

trafo - one

sec . winding

18 V input

from control

trafo - one

sec . winding


Used for Opto primary circuit

drive from external switches.

Used for Opto primary circuit

drive from external switches.

AC INPUT JACK

JP 1

18 V input

from control

trafo - one

sec . winding

18 V input

from control

trafo - one

sec . winding

Line synchronizingLine synchronizing

Using R – B phase

voltage waveform

reference for

synchronizing AC

static switch

Gnd

Jack JP2 for CT inputs and control connections.

JACK JP2

+ 15 V

-15 V

GND

DCCT

External DCCT

GND

MFCT

Inverter Coil current

S1

S2

Burden to suit

max inverter RMS

MF current is

equal to 5 V .

Burden to suit

max inverter RMS

MF current is

equal to 5 V .

Locate burden near CT with

1 MF non-polar capacitor as

filter

Locate burden near CT with

1 MF non-polar capacitor as

filter

LEM H600AS

I to V transducer

Red

Black

White

DC Current

Current direction to ensure +ve

voltage on DCCT pin

Rb

Rb = 10 K for minimal load on DCCT

Voltage output

proportional to current

and 4.5 V at 600 A DC

Jack JP4 , JP2 , JP7 , JP12 & JP3 connections.

From MF bus

through fuse

1500 V / 5V

MF trafo

Jack JP4 Jack JP7

SCR-pos

GND

SCR-neg

Firing Amplifier board

+p -p gnd

G +scr

K +scr

G -scr

K -scr

18 V ac

GND

F-mtr

G-mtr

P-mtr

Freq-Mtr

GLD meter

P-mtr

Jack JP3

No

connections

Jack JP12

From DC bus through

Attenuation resistor divider

+ -

GND

PT

GND

G-CT

No

Connections

GND CT

Suitable burden

Jack JP2 - D25 pin_outs for Lamp drives & inputs

Pin : 13 ………… + 5 V ( ASIC supply) .

Pin : 12 ………… OC- FLT lamp. ………….

Pin : 11 ………… INV_ON lamp. ………….

Pin : 10 ………… RDY lamp. ………….

Pin : 09 ………… DMW-PR lamp. …………

Pin : 08 ………… Pot Wiper ………… .Internal point PW (sht 4 of 4).

Pin : 07, 06 & 05 No connection.

Pin : 04 ………… OFF push button ………….Drives OFF-PB opto ( sht 4 of 4).

Pin : 03 ………… GDL-trip input …………. Drives GLD opto ( sht 4 of 4).

Pin : 02 ………… DMW-temp input ………… Drives DM-TMP opto ( sht 4 of 4).

Pin : 01 ………… Gnd ( Electronics inputs +15 V gnd ) (opto primary circuit).

Pin : 25 ………… DMW-TEMP lamp. ……….

Pin : 24 ………… DC_FLT lamp. ………….

Pin : 23 ………… HOLD lamp …………….

Pin : 22 ………… RW-PR lamp …………….

Pin : 21 ………… POT HI-END ……………. Internal point PH (sht 4 of 4).

Pin : 20 ………… POT LO-END ……………... Internal point PL (sht 4 of 4).

Pin : 19 & 18 No connection.

Pin : 17 ………… ON push button ……………. Drives ON-PB opto ( sht 4 of 4).

Pin : 16 ………… RW-PR input …………….. Drives RAWPRIP opto(sht 4 of 4).

Pin : 15 ………… DMW_PR input ……………. Drives DMPRIP opto (sht 4 of 4).

Pin : 14 ………… +15 - Electronics input -OPTO primary side use & PWR_ON lamp.

Jack JP2 Male

View

Pin 13Pin 1

Pin 25

From ASIC

Through

Buffers

From ASIC

Through

Buffers

View of wired control card on typical 100 KW unit

� Illustration for card with AC static switch control

Inverter

control

ASIC

Inverter

control

ASICASIC for

Static

switch

control

ASIC for

Static

switch

control

Opto

isolated

Interface

Opto

isolated

Interface Onboard

Power

Supply

Onboard

Power

Supply

Power circuit response to the control system.

1000 Kg

LOAD

COIL

Ld

Ld

LVdc

pos_pls

neg_pls

I inv

Cs

Cs

Inverter power circuit

For 450 KW power

+ SCR & + Diode

-SCR & -Diode

130 uf

3000 V

700 Hz

130 uf

3000 V

700 Hz

10uh

2 layer

4 T /lyr

200 ID

10uh

2 layer

4 T /lyr

200 ID

750 V DC

LOW FREQ operation without overlap

HIGHFREQ operation with overlap

pos_pls

neg_pls

pos_pls pos_pls

neg_pls neg_pls

+SCR

Current

+ Diode

Current

-SCR

Current

-Diode Current

+ SCR

Current + Diode Current

- SCR

Current

-Diode Current

+ SCR

Current

- Diode

Current

MF CT

DC bus feed back for Inverter protection

2 - 4 mH reactor

1600 uF DC

filter Cap.

DCCT

400 Ohms 5 W

13.6 K 150 W

13.6 K 150 W

DC bus

feedback

From Front

end Rectifier

From Front

end Rectifier

To Resonant

inverter

stack

To Resonant

inverter

stack

Choose 2 x 6.8 K for

DC bus voltages near

750 V for 450 KW power

+

-

Choose to get about 17

– 28 V across when DC

bus at nominal 750 V DC

Connection scheme – rear of controller

Connect

DCCT and

MFCT here

Warning :

Burden MF

CT to make

current into

voltage.

Else

damage can

occur

Connect

DCCT and

MFCT here

Warning :

Burden MF

CT to make

current into

voltage.

Else

damage can

occur

415 control power415 control power

CONV

output

feedback

before DC

choke

Connect GND CT with

burden to convert to

voltage.

Warning : Usage without

burden will damage unit

Connect GND CT with

burden to convert to

voltage.

Warning : Usage without

burden will damage unit

External interlock

& protection . Use NC

contacts

Connect MF

feedback

transformer

here

Use shielded cable to connect

Inverter thyristor firing board here

18 V AC Power supply for Inverter

firing board unit comes from here .

Note : This

scheme does not

show the wiring

for the AC static

switch firing and

remote on / off

unit

18 V AC

Power

supply for

conv

firing

board

DC bus

feedback

after choke

NO

contact

from

incomer

MCCB to

auto

start DC

bus

Remote

on/off

pendant

STATIC

SWITCH

trigger

Front facia of controller

Blinking light when

system ready.

During fault

condition shuts off

Blinking light when

system ready.

During fault

condition shuts off

Turns on when

inverter turned on

Turns on when

inverter turned on

Max Voltage or

power lamp

Max Voltage or

power lamp

Illuminates when

DC bus collapses.

Illuminates when

DC bus collapses.

External power

applied lamp

External power

applied lamp

Inverter Over

current or ground

fault

Inverter Over

current or ground

fault

Raw water pressure

interlock ( use NC )

Raw water pressure


DM water pressure


DM water pressure


DM water

temperature


DM water

temperature


Inverter ON PBInverter ON PBInverter OFF PBInverter OFF PB

Ground leakage

meter

Operating Inverter

Frequency

Operating power

Power set

potentiometer

LCD digital display and settings – 1

� Displays running parameters in percentage from 0 to 100 %

� Fault indications & display controlled from micro controller. Use uC rst switch for

resetting micro controller is case of corrupted display. Resetting micro controllr has no

effect on inverter / static switch control systems.

� Card adjustment potentiometer settings using JP20 and JP21

� Normal operation : JP20 is in place.

� Calibration of card setting : JP21 - Page 1 of setting .

JP21 & JP 20 - Page 2 setting .

� LCD display conditions

SYSTEM READY

System ready for switch on Fault in system

PSF COI GNF RPF

DPF DTF IOC DCF

PSF : Phase sequence Fail – ( units with AC switch control )

COI : Converter over current - ( units with AC switch control )

GNF : Ground fault. Sensing from external Ground leakage detector.

RPF : Raw water Pressure Fault from external NC interlock.

DPF : DM water pressure –ext interlock

DTF : DW water temp – ext interlock.

IOC : Inverter over current

RPF : DC bus fault

Fault reset is by pressing the OFF PB.


� Displays calibration settings of potentiometers on card.

� All settings as nominal 100 % maximum.

� Display organized as two pages .

� Page 1 display when JP21 is shorted.

� Page 2 display when JP21 and JP 20 are shorted .

� Normal running condition is when JP 20 is shorted.

Page 1

IFLT_S : XX PWS_S : XX

CPW_S : XX

IFLT_S : R15 IFLT ( TP 10 ) CW increase ( refer DWG sheet 2 of 9)

CPW_S : R170 MAX V CW increase ( refer DWG sheet 9 of 9)

PWS_S : R59 SPAN CW increase ( refer DWG sheet 3 of 9)

Page 2

IH_S : XX VL_S : XX

CIFLT_S : XX

IH_S : R22 IHLD ( TP 11 ) CW increase ( refer DWG sheet 2 of 9)

VL_S : R41 VLMT ( TP13 ) CW increase ( refer DWG sheet 2 of 9)

CIFLT_S : R123 CFLT CW increase ( refer DWG sheet 3 of 9)

WIN_S : XX

WIN_S : R63 WIND CW increase ( refer DWG sheet 3 of 9)


� Display when system in operation

Fault in operation

CV : XXX GL : XXX PW : XXX

IV : XXX IC : XXX F : XXX

CV : Converter voltage in 0 to 100 %

GL : Ground leakage current in 0 to 100 %

PW : Power level 0 to 100 %

IV : Inverter voltage 0 to 100 %

IC : Inverter current 0 to 100 %

F : Frequency 0 to 100 %

Trigger signals STATIC SWITCH CONNECTION

� The firing signals for Static switch SCRs from Trigger board

R-P SCR

GK

Y-P SCR

GK

B-P SCR

GK

R-N SCR

GK

Y-N SCR

GK

B-N SCR

GK

R-P SCR : R phase positive SCR

Y-P SCR : Y phase positive SCR

B-P SCR : B phase positive SCR

R-N SCR : R phase negativeSCR

Y-N SCR : Y phase negative SCR

B-N SCR : B phase negative SCR

G : gate

K : Kathode

Synchronizing the STATIC SWITCH

� The procedure

� Uses the AC 18 V synchronizing waveform in JP1 jack ( refer page 8 )

� This synchronizing voltage should be VRB ( R phase to B phase 415 volts )

� Illustration for the R + SCR ( similar for the other five SCRs )

RB Y B

Range of useful firing angle movement for

the R + SCR

Range of useful firing angle movement for

the R + SCR

Max voltage position

adjust with R170

Max voltage position

adjust with R170

System uses one line to

line reference between VR

and VB and internally

digitally locks to the line

frequency and generates

the other references

needed for all the other five

SCRs.

Circuit design notes – 1

� Synchronizing input from transformer RC smoothening , filtering & clamping

� RC time constant of 2 ms

� Zeners clamp to + / - 10 V

� RC time constant of 2 ms

� Zeners clamp to + / - 10 V

� Second level active RC filter

� Square waved to 5 V peak

and ground reference

� Second level active RC filter

� Square waved to 5 V peak

and ground reference

From

trafo

To converter phase control

ASIC chip as synchronizing

reference buffered . Monitor

test point TP25

To converter phase control

ASIC chip as synchronizing

reference buffered . Monitor

test point TP25

� AC5-18 �� SYNCP �� SYNRY �� RYSYNC


� Converter Thyristor Gate trigger outputs - six signals generated by ASIC

� RP , BN , YP , RN , BP , YN is the sequence when RYP is the line sequence

� All six pulses buffered.

� CONV_ON signal from Inverter ASIC

which senses Breaker_on signal .

� All six pulses buffered.

� CONV_ON signal from Inverter ASIC

which senses Breaker_on signal .

� All six pulses brought

out to connector

� All six pulses brought

out to connector

� Test point TP 24 for RP pulse

� Test point TP26 for 60 deg

pulse train

� Test point TP 24 for RP pulse

� Test point TP26 for 60 deg

pulse train

� Six firing pulse signals from

the ASIC – Pins 81 � 87

� Six firing pulse signals from

the ASIC – Pins 81 � 87

� Sync signal at pin 117

� ASIC produces sync capture

signal at pin 124 tied to LED 46

indicator

� Pulse signals enabled by

CONV_EN signal

� Sync signal at pin 117

� ASIC produces sync capture

signal at pin 124 tied to LED 46

indicator

� Pulse signals enabled by

CONV_EN signal TP26

60deg

Notes on synchronizing

� Reversal of the VRB in synchronizing will prevent the DC bus from turning on.� This can be identified that the DC bus will not soft start to the maximum DC voltage

adjusted with R 170 potentiometer.

� Best way to check synchronization is to use two 100 W lamp loads in series across the

DC bus and see soft start. If VRB is not correct soft start wont happen and the lamps

will momentarily blink and disappear. If no lamp load is available this can be identified

that the DC voltmeter in the panel will not rise slowly but momentarily the DC cap bank

will charge up and hold max voltage.

� DC bus soft starting and under control of R170 potentiometer is conclusive in showing

that synchronizing is perfect.

� Ensure that there is a small bleed in the DC bus ( The DC bus monitor resistances of

6.8 K used normally will be sufficient - page 14 )

� Unit has over-current trip on the AC static switch. Hence any very high starting surge

current during start up ( or failed DC bus capacitor ) will cause Converter Over Current

fault in controller and indicated by bthe OC-FLT fault lamp coming on and COI fault in

display

� Static switch will auto start when Line breaker is closed and detected by the auxiliary

NO connection at “BRK ON“ connected to +15 V ( see page 15 )

� The Phase fail connection ( page 15 ) can be used for interlock if external Phase

reversal / fail detector circuit / instrument is used externally . This controller has no

facility to detect phase fail or reversal.


� Notes on Converter Thyristor Gate trigger ASIC .

� Power supply +5 v and GND through jumpers JP18 & JP19.

� ASIC control program connector JP18 for program download .

� U16 Converter control Crystal ( 10 Mhz ) controls all internal control processes .

� ADC chip U34 provides analog interface for converter phase angle control analog

signal conversion to digital reference ( 12 bit ) . ADC control is through converter ASIC

( pin 17 : ADCTR signal )

� ADC converts max 10 V-in CONV_POWER

analog signal to 12 bit digital signal A0��A11

� ADC converts max 10 V-in CONV_POWER

analog signal to 12 bit digital signal A0��A11

� Converter ASIC

enabled by CONV_EN

signal fro Inverter

ASIC and ADCTR

signal controls ADC

chip

� Converter ASIC

enabled by CONV_EN

signal fro Inverter

ASIC and ADCTR

signal controls ADC

chip

� JP16 for program

download

� JP16 for program

download

� JP18 & JP 19 for ASIC +5 V and GND � JP18 & JP 19 for ASIC +5 V and GND


� Notes on Converter min and max phase angle setting and metering and ASIC

program downloading

� Downloading connector JP16.

� Maximum Converter Voltage controlled by pot set R170

� U21D OpAmp circuit controls Converter phase angle ramp up speed and drop out .

Ramp up adjustable ( soft start ) with R196 ( ACCR pot )

� R170 – Max Conv Volt � R170 – Max Conv Volt

� To Pin 13 of ADC chip for converter phase angle control

analog voltage for Digital conversion

� To Pin 13 of ADC chip for converter phase angle control

analog voltage for Digital conversion


� Converter over-current fault circuit and Converter volt metering circuit

� Feed back of converter DC bus . Use 200 K 5 W drop resistor on each leg

� DC meter calibration ( 1 mA fsd) with pot R195 ( C_MTR ) and or R157 ( C_FB)

� DC current DCCT sense compared for setting converter fault ( R123 – CFLT pot )

� Connect to DC bus through 200 K ,

5 W resistor


5 W resistor

� U18A comparator for CFLT – Converter over current

trip setting .

� Trip output CONV_IFLT 5 V clamped signal goes to

Inverter Control ASIC for pull out of CONV_ON signal

that comes back through a buffer as CONV_EN signal

to Converter control ASIC

� U18A comparator for CFLT – Converter over current

trip setting .

� Trip output CONV_IFLT 5 V clamped signal goes to

Inverter Control ASIC for pull out of CONV_ON signal

that comes back through a buffer as CONV_EN signal

to Converter control ASIC


� Inverter On signal and Power Control Pot supply

� Feed back of actual power level from DC current through DCCT .

� Inverter On signal allows Power pot reference – PH pin of Power set Pot .

� PH ( Pot HI pin ) setting maximum adjusted with SPAN pot (R59) to adjust

maximum power level depending on DCCT calibration .

SPAN


5 W resistor for Pos and Neg


5 W resistor for Pos and Neg

� Min Power setting

fixed by R58 resistor

� Min Power setting

fixed by R58 resistor


� Inverter Power Control using Frequency

UP and DWN SIGNAL .

� Feed back of actual power

level IREF.

� Power set voltage PW from

Power pot wiper .

� WIND setting ( R63) sets a

small window above IREF (

IREF plus delta )

� PW within Window locks

frequency

PW set

IREF

IREF+ delta

WINDOW

DWM signal ( LED 31 ) goes

high and Inverter reduces

frequency (DWM)

DWM signal ( LED 30 ) goes

high and Inverter increases

frequency (UP)

� PW is the Power pot set wiper.

� IREF is the gain adjusted

DCCT signal proportional to

power

� PW is the Power pot set wiper.

� IREF is the gain adjusted

DCCT signal proportional to

power


� Inverter Trip setting ( IFLT )

� Feed back of Inverter current from medium Frequency CT – ACCT.

� TP9 is full wave precession full wave rectified MF current waveform .

� Compared at Comparator U6A for IFLT setting ( R15 ) . Unit trips on Inverter Overcurrent

when this IFLT is sensed.


� Inverter Limit setting ( VLMT )

� Actuated by Volt limit ( VLMT ) pot R41.

� PT feedback for Inverter Volt sensing . Precession rectifier for full wave rectification .

� PT gain adjustment ( PT_G ) R38.

� Inverter frequency control overrides Power pot setting and goes to HOLD state .


� External Power hold facility ( HOLD )

� Used when Dual track configuration is used . Two Inverters working on common DC bus and

each inverter power under hold limit when other inverter is in high power ( Needs auxiliary

Current summation card linked to DCCTs in both inverter DC use bus bar )

� Signal C1 compared with HOLD pot ( R22 ) and IHOLD signal is produced.

� C1 attenuated signal ( 10 % attenuation ) is compared with HOLD set IHLD and IDEC

actuated . This is a feature when the second unit in dual track can be auto reduced in power ..


� Frequency meter calibration

� Inverter ASIC provides a pulse train of double the inverter frequency with fixed on time and

variable off time . As frequency goes up , off time drops and so duty cycle effectively

increases. This is Buffered and a adjustment pot ( R75 ) FMTR is provided to directly link to a 1

mA fsd frequency meter .


� External interlocks for water system and control

� Breaker on sense - To allow converter to be turned on sensing MCCB on . (LED D42)

� Phase sequence sense – IF activated , unit will not start ( wrong phase sequence ) . Need to

use external Phase sequence relay . By pass if not used. (LED D47)

� ON sense - connected to Power ON push button to start inverter . (LED D29)

� OFF sense – Connected to Power OFF push button which is also fault reset . (LED D28)

� RAWPR sense – Raw water pressure low sensing . High when Pressure is normal (LED D27)

� GLD sense - Ground detector – High when Ground detector senses earth fault from an

external ground detector. (LED D28)

� DMPR – DM water pressure low sensing . High when Pressure is normal . (LED D25)

� DMTMP – DM water temperature sensing . High when temperature is normal. (LED D24)

� All external interlocks and

actuations through Opto

couplers

To Inverter ASIC

input

Power up sequence .

� Power up sequence

� Breaker on - ( when Units have Thyristors front end converters ) .

� Checks if phase sequence is alright and no water fault ( Interlock lamps

D42,47,227,26,25,24 will glow ).

� DC fault may light up . Press RESET ( OFF PB ) to reset DC fault .

� Ready lamp blink will indicate that inverter is ready for start up.

� Press Power ON ( ON PB )

� Inverter should start up at lowest frequency ( approx 300 Hz )

� At lowest pot setting , Inverter would continue running at lowest power setting . ( D31 LED in

control card would glow if DCCT calibration is correct . Else Unit will go up gradually in

frequency and power till actual power sensed through DCCT is near Pot setting .

� Increase POWER POT to raise frequency and power . When Power raises LED D30 in

control board will light up momentarily as the frequency rises.

� When Power reaches pot setting , frequency will lock .

�Power OFF will stop the Unit.

�In case of any fault , the appropriate fault lamp will go on and inverter stop.

� During a fault indication the REDY lamp on front facia will glow permanently . Will go back to

normal blink state when fault is reset .

� Note that in case of GLD ( Ground fault ) I-over current indication and DCFLT indicator could

also turn on depending on nature of GND fault.

the controller –features. - '+domain name+' board layout. ac-input j1 j21 j4 jp3 +15 ,...

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