shyamsunder

STUDY OF STATIC CONVERTER IN AC LOCOMOTIVE

ABSTRACT:

Our project is a study the conversion of the DC / AC voltage into 3phase 415volts for running auxiliary machines by using the static converters in AC locomotive

This Project Report On Static Converter For Railway starts with by explaining the details about Electric Loco Shed. Electric Loco Shed maintains locomotive for utilization in freight and passenger train. All the miner and major inspection are carried out in the shed on a regular schedule specified by RDSO (Research Design Standard Organization).

The Static Converter provides an artificial means by which a three-phase motor can be operated from a single-phase supply thereby offering a cost-effective solution to this dilemma. In most instances, no modification to the machine is necessary.

This is the technique for converting the single phase to three phase AC supply in electric locomotives.Static converters are roles very important role in electric locomotives .This is the new technic used in electric locomotives in india.

ACKNOWLEDGEMENT

We take the opportunity to thank one and all who have helped in making this project possible. We are thankful to SR ENGINEERING college ananthasagar, warangal for giving us this opportunity to work on a project as a part of our curriculum.

We would like to express our sincere thanks to” Divisional Electrical engineers office Electrical Loco Shed Kazipet” for giving us the opportunity to work within their environment. The interest they showed in our mini project was admirable and their constant encouragement motivated us to give our best.

We are also like to express our sincere thanks to our internal guide P.Soumya of Electrical and Electronics department for his precious guidance and kind co-operation at every stage of project work.

We would like to express our sincere thanks and deep sense of gratitude towards our H.O.D Mr.Dr.C .venkatesh, faculty and staff of E.E.E.’s for their kind co-operation in this regard and making our project a successful one.

PROJECT ASSOCIATES

EEE-[B Sec] STUDENTS

2012-2015

INDEX

CHAPTER I:

180 KVA STATIC CONVERTER

1.1 Intraduction

1.2 Working principle

1.3 Brief Technical specification

CHAPTER II:

DEVELOPMENT STAGES OF 180 KVA STATIC CONVERTER

2.1 Kit-2

2.2 Kit-3

CHAPTER III:

DISCRIPTION OF STATIC CONVERTER

3.1Main control Unit(MCU)

3.2. Thyristor Gate Drive Card (TGDU)

3.3 .Chopper Gate Drive Card (CGDU)

3.4. Inverter Gate Drive Card (IGDU)

3.5. Display card (DCU)

3.6. Power Supply Card (PS1)

3.7.Power & Control Schematic Diagrams (KIT – 2,KIT-3)

3.8,Protection & Settings

CHAPTER IV:

PHOTOGRAPHY OF 180 KVA CONVERTER

Photograph4-1: Front View of Cubicle-1

Photograph4-2: Inside View of Cubicle-1

Photograph4-3: Side View of Cubicle-1

CHAPTER V:

PHOTOGRAPHY OF 180 KVA SIV KIT 3

Photograph-5.1: Power Input Connections of Cubicle-1

Photograph-5.2: Filter Choke Sec

Photograph-5.3: Rectifier, Invert circuit

CHAPTER VI:

DESCRIPTION OF SIV WITH SMPS CHARGER

6.1 The major sections of Generic converter are listed below

6.2 Protections:

6.3 Sequence LEDs:

6.4 Fault LEDs:

6.5 Communication LEDs:

6.6 Display Operation:

6.7 Fault Abbreviations:

6.8 Start-up Procedure after Long Duration Maintenance Shut Down

CHAPTER VII:

Working of Power and Auxiliary Control logic in loco motive

7.1 Load of Static Converter:

7.2 Load Duty Cycle:

7.3 QCON Relay:

7.4 QSIT Relay:

* BIBILIOGRAPHY

CHAPTER-1

180 KVA STATIC CONVERTER

1.1INTRODUCTION:

The first Static converter was used in WCAM – 3 locomotives jointly developed by RDSO and BHEL in 1997. The Static Converter converters the DC / AC voltage into 3phase 415volts for running auxilary machines. This converter was supplied by ACEC . In late ninteesSIEMENS provided 8 nos 180 KVA Static Converter in conventional Locomotive at ELS /NCR / CNB. Presently CLW manufactures only Static Converter fitted locomotive and tilldate, the total population of Static Converters fitted loco are more than 750.

The electric locomotive basically works at 25 KV, 50Hz supply. The 25KV AC supply is drawn from overhead catenaries wires. The supply from overhead wires are drawn through a pantograph inside the loco transformer. This transformer is an autotransformer from which regulated voltage is taken to a rectifier block for conversion from AC to DC .It may be worth mentioning that the final tractive effort is through DC traction motor hence AC is required to be converted to DC.

The DC current from rectifier block is then filtered to pure DC and then fed to traction motor.There are 6 traction motors which works parallel to provide the attractive effort for hauling the train.All the operations are controlled through control circuit which works at 110 volt DC. Various power equipments during operation gets heated up and hence to cool the same, it is done by various blowers.Electric Loco Shed maintains locomotive for utilization in freight and passenger train.

All the miner and major inspection are carried out in the shed on a regular schedule specified by RDSO (Research Design Standard Organization). Monthly schedule are done at an interval of 45 days and major schedule are carried out after 18 months.

1.2.WORKING PRINCIPLE:

The converter generates 415V, 3 phase, 50Hz output from 760V / 830V, 1 phase, 50Hzinput which is available from the main locomotive transformer. The static converter is made using a half controlled single phase bridge rectifier at the input, a DClink filter and a three phase IGBT based PWM inverter. All functions of the converter are controlledthrough 32 bits Digital signal processor (DSP) together with an EPLD & host of digital gates andanalog amplifiers.

Fig 1.1 front view of converter

Advantages of Static Converter:

 Very steady output voltage with maximum regulation of ± 5%.

 All the 3-phase output voltages are balanced resulting in balanced supply to the loads.

 Very high system efficiency.

 Soft starting of loads possible resulting in reduced system over loading.

 In-built fault management system with storage of faults and traces.

 Various problems of auxiliary machines are reduced due to regulated andbalanced supply voltage.

The converter consists of following sub-modules:

1.2.1. Input Section:

The input section consists of input fuse (MF), Metal oxide varistors and input bus bar. Input fuse issued to protect the converter and for ensuring safe operation of the converter under worst input conditions. Metal oxide varistors (MOV) are used to protect the converter from surges.

1.2.2. Rectifier Section:

FIG 1.1.Rectifier section

The rectifier section is made using a half controlled single phase bridge rectifier. This consists of ahalf controlled bridge rectifier, made up of 2 thyristors and 2 diodes. When the input AC voltage ispositive, one of the thyristors is fired with a predetermined delay. It starts conducting and thevoltage of the DC link rises. The current continues to flow due to the DC link reactor, until the inputvoltage changes polarity and the other thyristor is fired. Now, the other thyristor with thecorresponding diode takes over the current. The rectifier circuit converts single-phase AC inputvoltage into DC voltage of desired level (760 volts).

Fig1.2 Wave forms of rectifier section

The main controller maintains the DC link voltage at a preset value by controlling the firing angle of the thyristors. A PI controller is used to determine the firing angle. If the DC link voltage is lower thandesired voltage, the firing angle will be small and if the DC link voltage is higher than thedesiredvoltage, the firing angle will be increased. RC snubber circuit are provided across eachthyristors and Diode’s to protect against high dv / dt experience by devices.

1.2.3. DC Link Filter & Over Voltage Chopper:

The DC link filter consist of DC link Choke (FL) and DC link Capacitors (FC). DC link Choke and Capacitors provided at the output of the rectifier to reduce the ripples in the DC link voltage that isfed to the inverter.The over voltage chopper is made-up of an IGBT switch with a resistor and an anti-parallel diode.The IGBT switches the resistor on and off in the DC circuit if the DC voltage exceeds a presetvalue.The chopper dissipates the extra energy and protects the system from over voltage,especially during transients at start-up.

1.2.4. Inverter Circuit:

The Inverter consists of six IGBT modules. IGBT modules are configured as a 3-phase bridge circuits. The bridge is made up of three identical phase branches and each branch consists of twoIGBTs.The DC link voltage is converted into PWM sinusoidal waves by switching IGBTs at a highfrequency. The width of the individual pulses in the PWM wave determines the amplitude of theoutput voltage and thewidth of the pulse block determines the output frequency.

As the system is a constant voltage, constant frequency system, the output frequency is maintained at 50Hz and the PI controller receives an output voltage feedback in order to keep thevoltage constant, too. The final stage is responsible for generation of switching signals utilizingSpace Vector Pulse Width Modulation (SVPWM) technology.State-of-the-art space vector PWM techniquehas been adopted in the design of inverter softwareas this technology is more flexible & adapts to wider variations in the input DC link voltages. Forbetter regulation of the output voltage, proportional integrated control has been used.

1.2.5. Output LC Filter:

The Inverter output voltage is PWM, which is converter into sine wave by using output filter. Itconsists of 3 phases AC Choke (ACL) and 3 phases Capacitor (ACC).

1.3.Brief Technical Specification:

Input

Nominal voltage : AC single phase, 760V or 830V (corresponding tocatenary voltage of 22.5KV)

Min. voltage continuous : 642V ac

Max. Voltage continuous : 1014V ac

Min. voltage at which convertertrips on under voltage: < 591V ac

Max. Voltage beyond whichconverter trips on over voltage: 1150V ac

Input voltage range for whichguaranteed converter performanceis available: 642V to

1014V ac

Input voltage range for whichguaranteed converter performanceis not available but converter willnot trip oneitherunder voltage orover voltage: 591V to 642V on lower side1014V to 1150V on higher side

Power factor : 0.8 (At rated conditions)

Input frequency : 50±3Hz

Output

Output power : 180kVA, 0.8pf (at nominal operation)

Overload : 200% for 5sec. (360KVA & current limit of 600A)

Voltage 1 : AC 415V±5%, 3 phase system(fundamental at nominal continuous rated input voltagebetween 642 - 1014V)

Frequency : 50Hz±1%

Waveform : Sine wave

THD in voltage :  10% (up to 20th harmonic)

Efficiency :  92% (At nominal input voltage & rated load)

Voltage 2 : DC 110V±5%,[±5% ripple (rms) at full load and at nominal continuousrated input voltage of 642 - 1014V]

Mechanical

Size (approx.) : Cubicle 1 - 670mm(L)×1805mm(W)×1650mm(H)

Weight : Approx. 1440 kg (1320 kg + 120 kg)

Cooling : Forced air cooling for Cubicle-1

General

Ambient temperature : 0ºC to 70ºC (max. 55ºC inside loco)

Humidity : 100% in rainy season (90% at 55ºC)

Altitude : 160m above mean sea level

Dust : 1.6mg/cub m, max. Ph 8.5

Audible noise : 80dB (A) at 1meter distance from cubicle as per IEC1287-1.

Display & communication : Vacuum fluorescent display and RS-232 port for datalogging.

Control voltage : DC 110

CHAPTER-2

DEVELOPMENT STAGE OF 180 KVA STATIC CONVETER

The first 180kVA static converter of AAL make was commissioned in loco no. 23640 / WAG-5 on 16.02.2001 at Electric Loco Shed, Tughalakabad. This model of SIV was having two distinct parts Cubicle-1 (Main converter) and Cubicle-2 (uncontrolled battery charger). The maincubicle had space at the bottom to accommodate the MVMT duct as clear flat space was not available in nonmodular type of locomotives. The width of the converter was kept at 550mmdue to shortage of space in WAG7 non-modular locomotive. In this model these two cubicles had to be fitted separately even though clear flat space was available in modular WAG7 locomotives under manufacture at CLW. This was done for achieving standardization and producing common equipment for all types of locomotives.Initially all loads were started on DOL. Later RDSO proposed soft starting of load in SIV. In soft starting feature, all loads (MVMT 1 & 2, MVRH, MVSL 1 & 2, MVSI 1 & 2, MPH, batterycharger)ramp up gradually except compressors by using Variable Voltage Constant Frequency technique .The software was modified during field trial itself to cater for soft start. TheVariable Voltage Constant Frequency technique is used in both KIT-2 and KIT-3 version.In these version the converter can store 63 faults and 3 to 4 trace data’s. The SIV had sinewave output and has prompted Railways to use smaller frame size industrial motors.

2.1:KIT- 2

During initial design the input devices available were of 2600V. These were sufficient to meet the specifications requirement. Subsequently higher voltage (3600V) devices (Thyristors,diodes) were made available. These higher voltage-rating devices give additional margin during peak temperature conditions at max OHE voltage. So rectifier section device rating was increased and implemented in all supplied units on FOC basis. This was termed as KIT2 modification.

The Kit-2 modification emphasize on two activities:

1. Strengthening the input circuit to take care of high input voltage.

2. Improve the thermal engineering

Following are the activities done in Kit-2 modification:

(a) Voltage rating of thyristor & diode increased in rectifier section from 2600V to 3600V.

(b) Snubber components voltage & wattage ratings increased.

(d) Current rating of chopper IGBT increased from 150A to 200A.

(e) Churning fans and heat exchanger provided in power section for reduced internalambient temperature. Force cooling for output AC choke

(f) Self -ventilation provided in 3 phase AC filter capacitor.

Fig 2.1 kit 2 diagram

2.2:KIT – 3

Single cubicle design of 180kVA SIV proposed. In this the battery charger dimension changedto 850mmx670mmx390mm and make compatible to place at the bottom of main cubicle\(Cubicle-1).Our existing 180kVA SIV can be installed in all locomotives (WAG-5, 7, WAP-1, 4, 6 WAM-4).But the latest modification in WAP-4 locomotive in which the cab area has been increased,result in reducingthespace for SIV. Thus CLW / RDSO proposed to installed the SIV parallel to corridor. Placing the SIV in parallel to corridor was only possible if its height is less than1700mm. So as per requirement, we reduced the height to 1650mm and can be installed in alltype of locomotives. The additional features of this single cubicle 180kVA SIV are as follows:

(a) Kit-2 already implemented.

(b) Inverter IGBT rating increased from 800A to 1200A.

(c) Fiber optical cable used in control system (signal from Main Control Unit (MCU) to GateDriver unit (GDU) and vice-versa) to eliminate EMI effect.

(d) Reduced height to 1650mm from 1700mm to make compatible for WAP-4 locomotives.It’s dimensions are 1650 mm x 1805 mm x 670 mm

(e) The display was made removable and can be fitted either on front (for perpendicular toRail) and side (for parallel to Rail i.e. in WAP4)

2. Force cooling provided in 3 phase AC filter choke to reduce heat in AC choke core, inwhich coolingis provided by using exhaust air of cooling fan used for heat sink cooling.

3. Changed the female portion of Wago type connector of Main Control Unit (MCU) andPower Supply card (PS1) in all supplied units with D-type connector with multiple entry points in MCU & PS1 in newly supplied units (New design single cubicle 180kVA staticconverter). This was done to take care of intermittent false sensing of low control supplyi.e. P5_LVD.

4. Internal and External earth leakage detection were provided.

CHAPTER-3

Description of Static Converter

(KIT – 2 & KIT – 3)

Description of Static Converter

(KIT – 2 & KIT – 3)

The converter generates 415V, 3 phase, 50Hz output from 760V / 830V, 1 phase, 50Hz input which is available from the main locomotive transformer. General schematic of the converter is shown in Figure

Fig 3.1.Scaematic diagram of generic converter

The static converter is made using a half controlled single-phase bridge rectifier at the input , a DC link filter and a three phase IGBT based PWM inverter. All functions of the converter are controlled through 32 bits Digital signal processor (DSP) together with an EPLD & host of digitalgates and analog amplifiers.

3.1.1. Input Section

3.1.2. Rectifier Section

3.1.3. DC Link Filter & Over Voltage Chopper

3.1.4. Inverter Section

3.1.5. Output Section

3.1.6. Cards

The converter consist of following cards:

3.1. Main Controller Unit (MCU):

The main controller card consists of 32 bits digital signal processor (DSP) together with an EPLD,host of digital gates and analog amplifiers controlled the function of the converter. It generates switching pulses to drive the IGBTs and thyristors. It also monitors sensor signals to detect faults and abnormal operation of the static converter. Status of various parameters are monitored and compared with the reference levels. Desired preventive and corrective actions are initiated through the respective controllers in the event of abnormal conditions. Faults, if any are identified, stored in the fault memory and also can be displayed through display panel.A communication port with RS-232 interface is provided on the front panel for control gain setting,fault information and real time monitoring through a Notebook PC. A keyboard and Vacuum Fluorescent Display (VFD) is provided on the front panel for selection of operation mode & text display of monitoring status, voltage, current & fault messages.

FIG.3.1:CONTROL BLOCK DIAGRAM

The various input and output signals of MCU card are as follows:

3.2 Thyristor Gate Drive Card (TGDU):

3.3 Chopper Gate Drive Card (CGDU):

3.4. Inverter Gate Drive Card (IGDU):

The gate driver circuit receives switching pulses from the MCU card. The opto-coupler in the gate driver provides the perfect isolation between the power circuit and the control circuit for these pulses. After further amplification, these switching pulses are sent to the Inverter IGBTs. In case of over-current of the inverter, the gate driver blocks the gate pulses to protect the IGBTs and feeds the information back to the main control card.

3.5. Display card (DCU):

A Vacuum Fluorescent Display (VFD) is provided for display parameters and fault data along with its associated keys / push buttons. Display is provided on the front panel for selection of operation mode & text display of monitoring status, voltage, current level & fault messages. The display card also provides LED indications of various faults.A communication port with RS-232 interface is provided on the front panel for fault informationand real time monitoring through a Notebook PC.

3.6. Power Supply Card (PS1):

The power Supply card (PS1) generates +/- 15 volts and 5 volts from 110 volts DC supply. Thecontrol supply generated by PS1 card is then supply to MCU, Inverter GDU, Thyristor GDU,Chopper GDU, DCU cards and DCPT, DCCT and CHCT.

3.7. Sensors

1. Input Current Transformer (ACCT)

The Input Current Transformer (ACCT) is use tomeasure the input current. It is locatenear input section / Fuse. Its ration is 800 / 1 Amp.

2. Input Potential Transformer (ACPT 1) : The Input Potential Transformer (ACPT 1) is use tomeasure the input voltage. It is located at RFU sectionarea. Its ration is 1300/7.22 volts.

3. DC Link Current Transducer (DCCT)

The DC Link Current Transducer (DCCT) is use tomeasure the DC link current.

4. DC Link Voltage Transducer (DCPT)

The DC Link Voltage Transducer (DCPT) is use tomeasure the DC link voltage. It is located at RFUsection area.

5. Chopper Current Transducer (CHCT)

The Chopper Current Transducer (CHCT) is use to measure the Chopper current.

3.7.Power & Control Schematic Diagrams (KIT – 2,KIT-3):

FIG 3.11 POWER CONTROL OF KIT2 FIG3.12 POWER CONTROL OF KIT3

3.8,Protection & Settings:

The Static converter is equipped with circuits to protect itself and its load from all disturbances. Its operation is stopped by all fault conditions.

1. Open Circuit in Auxiliary Winding

This circuit detects that input voltage is too low or completely absent. It is practically the protection frominput under voltage.

2. Fuse Failure in Converter

This circuit monitors the signals from the fuse contacts and if a fuse blows the converter is tripped.

3. Thermal Overloading

Temperature sensors are mounted on the heat sinks of the rectifier unit and the inverter unit. If the temperature of the heat sink exceeds a predetermined level, a fault signal is sent to the main controller.The operation of inverter is stopped. The circuit resumes operation automatically when the temperaturereturns to normal.

4. High/Low Voltage in DC Link

A voltage sensor monitors the DC link voltage. If DC link voltage is too high or too low, the main controllershuts down the converter.

5. Failure of Power Supply to Control Electronics

The main controller monitors the power supply. If a failure is detected, the main controller blocks the gatesignals of IGBTs and thyristors.

6. Transient & Surge Protection

Voltage surge suppressor is provided at the input

off the inverter.

7. Output Over Current

The output of the inverter is protected against overload. Whenever the output current exceeds the predetermined value, a fault signal is sent to the main controller to initiate required protection.

8. Short Circuit at Output

The output of the inverter is protected against short circuit. Whenever the output current exceeds the predetermined value, the main controller initiate required protection. Under short circuit conditions, a fast current limit protects the power semi-conductors in the 3-phase Inverter Bridge.

9. Earth Leakage

In case the earth leakage detector has detected an earth leakage current, an earth fault is initiated and the inverter trips.

10. Single Phasing

The single phasing protection is automatically available in the inverter through the over current protection.If the output current of the inverter exceeds the predetermined limit due to single phasing, then the inverter will trip.

CHAPTER-4

PHOTOGRAPHY OF 180 KVA CONVERTER

Photograph4-1: Front View of Cubicle-1 Photograph4-2: Inside View of Cubicle-1

Photograph4-3: Side View of Cubicle-1

CHAPTER-5

PHOTOGRAPHY OF 180 KVA SIV KIT 3

Photograph-5.1: Power Input Connections of Cubicle-1

Photograph-5.2: Filter Choke Sec Photograph-5.3: Rectifier, Invert circuit

FIG 5.4 Display Panel

5.1 Operating Instructions:

Preface:

This write-up gives guidelines for the operating the 180kVA static converter system, powerup, shut down procedures, system monitoring & control facilities on the display unit.

Display Panel:

System monitoring & controlling facility on the display panel.Figure6.8 shows the display panel general arrangement and system monitoring and control facilities provided on the display panel. An analog voltmeter, for monitoring the input supply voltage is provided at the top of display panel. An analog ammeter for monitoring the battery charging / discharging current is provided at the top of the display panel. Operating status (sequence) / fault status (detection) indication LEDs are provided for following parameters.

(a) RxD (Amber) and TxD (Green) : Blinking – Indicates MCU healthiness.

(b) AC input ON (Amber) : Indicates AC power input is available.

(d) Inverter ON (Amber) : Indicates that inverter at the output section is healthy and is turned ON.

(e) Input over voltage (Red) : Indicates that input voltage is more than specified limits.

(f) DC link over voltage (Red) : Indicates that the voltage in DC section i.e. after rectifier is more than the set limit indicating a fault in rectifier section.

(g) Input over current (Red) : Indicates that input current is more than the specified limit indicating a fault ineither inputrectifier or at load side.

(h) Output over current (Red) : Indicates that output load current is more than the specified limits, indicating problem in the inverter section or load section.

(i) Fuse trip (Red) : Indicates that the input fuse is blown indicating a problem in the rectifier section.

(j) Fan fault (Red) : Indicates that the cooling fan in the static converter is faulty.

(k) Earth fault (Red) : Indicates that earth leakage is more than thespecified level.

(l) Rectifier fault (Red) : Indicates that the input side rectifier is faulty.

(m) Inverter fault (Red) : Indicates that the output side inverter isfaulty.

Vacuum Fluorescent Display (VFD) is provided for display of operating and fault data along with its associated keys / push buttons (Up, Down, Menu, and set).Buzzer is provided for audio annunciation of fan fault. Following keys are for future use and are non functional presently: EDIT, RESET, BUZZER RESET RS-232 communication port is provided on the display panel. Presently connector CN2 is being used & connector RS-232 is redundant and not used.

5.2 VFD Operation:

􀀀 Press 'DOWN' key, to enter the main menu.

'Data Monitor', 'Fault Data', and 'Time Set' options are available on the main menu.

􀀀 Scroll up or down and select the desired menu option by using 'UP' or 'DOWN' key.

􀀀 Press 'SET' key to enter the selected menu option.

􀀀 Press 'MENU' key to exit the sub menu and return to the main menu.

􀀀 Selection of 'Data Monitor' option provides display of parameters Virms (Input voltage), Iirms (Input current), Vorms (Output voltage), Iorms (Output current) on the first display page / screen, Vdc (DC link voltage), Vurms (U Phase voltage), Vvrms (V Phase voltage), Vwrms (W Phase voltage) on the second display page / screen andIurms (U Phase current), Ivrms (V Phase current), Iwrms (W Phase current), angf(Firing angle of rectifier) on the third display page / screen.

􀀀 Once the 'Data Monitor is selected, press 'DOWN' key to toggle between the above three display pages / screens.

􀀀 Selection of 'Fault Data' option provides display of the list of faults with details offault i.e. brief description of the fault, date and time of fault occurrence. Maximum63 faults can be stored & displayed.

S.No. Event Observed Description of Event

1. VIN_OVD........................... Input Over Voltage

2. VIN_LVD............................ Input Low Voltage

3. DC_OVD............................ DC Link Over Voltage

4. DC_LVD ............................ DC Link Low Voltage

5. VLD_OVD.......................... Output Over Voltage

6. VLD_LVD........................... Output Low Voltage

7. IN_OC1.............................. Input Over Current (Instantaneous)

8. IN_OC2.............................. Input Over Load

9. AC_OC1 ............................ Output Over Current (Instantaneous)

10. AC_OC2 ............................ Output Over Load

11. DC_OC.............................. DC Link Over Current

12. CH_OC.............................. Chopper Over Current

13. P5_LVD ............................. 5 Volt Control Power Supply Low Voltage

14. P15_LVD ........................... 15 Volt Control Power Supply Low Voltage

15. M15_LVD........................... –15 Volt Control Power Supply Low Voltage

16. CHO_GDUF....................... Chopper GDU Card Fault

17. GDUF_U............................ Inverter U Phase GDU Card Fault

18. GDUF_V............................ Inverter V Phase GDU Card Fault

19. GDUF_W........................... Inverter W Phase GDU Card Fault

20. ELD_FT ............................. Earth Leakage Detection Fault

􀀀 Selection of 'Time Set' option allows the user to set / change the time / clock setting of the unit.

􀀀 Press 'SET' key to move between the digits and select the digit, whose value is to be changed / set

􀀀 Use 'UP' or 'DOWN' key to set the desired value for the digit.

􀀀 Once the time setting / changing is done by moving the cursor to the last digit by using 'SET' key.

􀀀 Press the 'SET' key to save the new time setting, or

􀀀 Press 'MENU' to return to the main menu, without saving the time changes

CHAPTER-6

DESCRIPTION OF SIV WITH SMPS CHARGER

This converter generates 415V, 3 phase, 50Hz output from 760V / 830V, 1 phase, 50Hz inputwhich is available from the main locomotive transformer. General schematic of the converter is shown in below Figure

Figure-6.1: Converter Schematic Diagram

The static converter is made using a half controlled single-phase bridge rectifier at the input, a DC link filter and a three phase IGBT based PWM inverter. All functions of the converter are controlled through 32 bits Digital signal processor (DSP) together with a host of digital gates and analog amplifiers.

6.1 The major sections of Generic converter are listed below: -

A. Input section

B. Rectifier section

C. Dc link filter & chopper

D. Inverter section

E. Output section

F. Modular Control Rack

Here, we discuss the Modular control Rack of SIV which comprises of main control cards. (Plrefer previous chapter for description of items no A to E)

F) Modular Control Rack: -

Modular Control rack is a separate covered chamber in SIV front end for housing of main control cards. It is dust protected and is forced cooled by churning fan.

In Modular control Rack, following cards are mounted: -

1) Main controller Unit ( MCU) :

It includes the sequential digital inputs, ADC part andcontrol of rectifier, inverter, chopper and battery charger .The main controller generatesswitching pulses to drive the IGBTs and thyristors. It also monitors sensor signals todetect faults and abnormal operation of the static converter. The status of the staticconverter and input / output parameters are monitored and recorded by controller. This data is also stored in the memory. An RS-232 PORT is provided for control gain setting, fault information and real time monitoring through a Notebook PC. The maincontroller is based on the Digital Signal Processor, for higher reliability, performance and flexibility.

6.2 Protections:

The static converter is equipped with circuits to protect itself and its load from all disturbances, which are listed below:

 Open Circuit in Auxiliary Winding

 Ground Fault in AC Input Circuit

 Ground Fault in 3ø Load

 Auxiliary Converter Phase Fault

 Line to Line Short Circuit

 Thermal Overloading

 Fuse Failure in Converter

 High/Low Voltage in DC Link

 Failure of Power Supply to Control Electronics

 Transient & Surge Protection

 DC Link Short Circuit

 Input Over/Under Voltage

 Input Over current

 Dropping Out of EM Contactors of Auxiliary Motors

This protection is provided by the locomotive control circuit and this protection is not in the scope of the converter.

6.3 Sequence LEDs:

(a) SIV ON (Green) : Indicates "SIV ON" switch is ON

(b) Input low voltage (Green) : Indicates AC power input is low

(d) Rectifier ON (Amber) : Indicates rectifier at the input section ishealthy and turned ON

(e) Inverter ON (Amber) : Indicates that inverter at the output section ishealthy and is turned ON

(f) Charger ON (Amber) : Indicates that charger is healthy and isturned ON

(g) Inverter OK (Green) : Indicates that inverter is working fine

(h) Charger OK (Green) : Indicates that charger is working fine

6.4 Fault LEDs:

(a) Input over voltage (Red) : Indicates that input voltage is more thanspecified limits

(b) Input over current (Red) : Indicates that input current is more than the specified limit indicating a fault in either inputrectifier or at load side

(c) DC link over voltage (Red) : Indicates that the voltage in DC section i.e.after rectifier is more than the set limit indicating a fault in rectifier section

(d) DC link over current (Red) : Indicates that the current in DC section i.e.after rectifier is more than the set limit indicating a fault in rectifier section

(e) AC output over voltage (Red) : Indicates that output 3ø load voltage is more than the specified limits, indicating problem in the inverter section or load section

(f) AC output over current (Red) : Indicates that output 3ø load current is more than the specified limits, indicating problem in the inverter section or load section

(g) DC output over voltage (Red) : Indicates that output voltage of charger ismore than the specified limits, indicatingproblem in the inverter section or loadsection

(h) DC output over current (Red) : Indicates that output current of charger ismore than the specified limits, indicatingproblem in the inverter section or load section

(i) Fuse fault (Red) : Indicates that the input fuse is blown indicating a problem in the rectifier section

(j) Fan fault (Red) : Indicates that the cooling fan in the static converter is faulty

(k) Earth fault (Red) : Indicates that earth leakage is more than the specified level

(l) Rectifier fault (Red) : Indicates that the input side rectifier is faulty

6.5 Communication LEDs:

(a) RS232 Tx (Amber) : Indicates communication between PC anddisplay card

(b) RS232 Rx (Green) : Indicates communication between PC anddisplay card

(d) RS485 Rx (Green) : Indicates communication between display card and logger card

(e) USB (Amber) : For future use

(f) UIC run (Green) : Indicates healthy condition of display card

6.6 Display Operation:

(a) View parameterVin Vdc Vu Iu Vbat Vout I/P Freq Vv Iv Ibat Iout Fang Vw Iw Itot Iin Idc O/P Freq O/P Freq Vbin.

(b) Event data view Upto 128 events can be viewed using up / down key with fault no., date and time of occurrence of the fault.

(c) Set date and time Selection of 'set date and time' option allows the user to set / change the time /clock setting of the unit.

􀀀 Press '>' & '<' keys to move between the digits and select the digit, whose value is to be changed.

 Use 'UP' or 'DOWN' key to set the desired value for the digit.

 Once the time setting / changing is done, press the 'SET' key to save the new time setting.

􀀀 Press 'MENU' to return to the main menu, without saving the time changes (i.e., maintaining the previous time settings).

(d) Clear Fault Clears all faults

(e) View date & time In this mode, date and time will be displayed.

6.7 Fault Abbreviations:

Following is the list of fault abbreviations that can be recorded and their description:

S.No. Fault Observed Description of Fault

1. VIN_OV ............................. Input Over Voltage

2. VIN_LV .............................. Input Low Voltage

3. DC_OV .............................. DC Link Over Voltage

4. DC_LV................................ DC Link Low Voltage

5. VLD_OV ............................ Output Over Voltage

6. VLD_LV ............................. Output Low Voltage

7. IN_OC1.............................. ..Input Over Current (Instantaneous)

8. IN_OC2.............................. ..Input Over Load

9. INV_OC1 ............................Output Over Current (Instantaneous)

10. INV_OC2 ......................... Output Over Load

11. DC_OC.............................. DC Link Over Current

12. CHO_OC ...........................Chopper Over Current

13. P15_LV.............................. 15 Volt Control Power Supply Low Voltage

14. M15_LV ........................... –15 Volt Control Power Supply Low Voltage

15. CHO_GDUF....................... Chopper GDU Card Fault

16. INVGDU_UF .................... Inverter U Phase GDU Card Fault

17. INVGDU_VF .................... Inverter V Phase GDU Card Fault

18. INVGDU_WF .................... Inverter W Phase GDU Card Fault

19. ELD_FT ............................. Earth Leakage Detection Fault

20. SPhase_FT........................ …Output side Single Phasing Fault

6.8 Start-up Procedure after Long Duration Maintenance Shut Down

Follow the same procedure as prescribed in the start-up procedure during commissioning.

Short Duration Shut Down & Start-up Procedure

Switch ON the control power ON by turning ON the loco battery switch (HBA).

-- Check that the RxD / TxD LEDs are blinking normally.

-- Turn ON the panto.

-- Put OFF the BLCP, BLVMT switches.

-- Turn ON BLDJ and then BLRDJ for 1 sec.

-- Check that all the loads are turned ON normally.

CHAPTER-7

Working of Power and Auxiliary Control logic in loco motive

Working of Power and Auxiliary Control logic in loco motive

7.1 Load of Static Converter:

Converter is designed to feed following loads as given in the following table. The data has been taken from Annexure-A of the RDSO Specifications.

1. MVSI 1 & 2 Motor for silicon rectifiercooling 1 & 2\2×2.2 2×4.7 2×32.4

2. MVSL 1 & 2 Motor for smoothing rectifier cooling blowers 1 & 2 2×2.2 2×4.7 2×32.4

3. MPH Motor for transformer oil pump 3.2 7.0 36.5 MCP 1 & 2 Motor for main compressors (2000 lpm) 2×20.5 2×43.13 2×328.7OR

4.MCP 1, 2 & 3 Motor for main compressors (1000 lpm) 3×10.5 3×23.1 3×154.85

5. MVRH Motor for main transformer cooling blower 22.0 41.33 278.5

6. MVMT 1 & 2 Motor for traction motor cooling blower 1 & 2 2×26 2×47.43 2×309

7. CHBA Battery charger and other load 2.5 7.0 7.0

8. MVRF DBR blower 33.0 63.0 380.0

7.2 Load Duty Cycle:

The converter is designed to feed the loads mentioned above as per following duty cycle:

(a) All the motors MVRH, MVSI1 & 2, MVSL1 & 2, MPH, MVMT1 & 2 and batterycharger are turned ON along with the static converter. This starting of the motors is with Variable Voltage Variable Frequency (VVVF) / VVCF starting resulting into less stress on the motors, associated switchgear, input transformer and the converter itself.

(b) After 5 sec. of stage (a) additional load of one compressor motor (of 20.5kW) or two compressors (of 10.5kW each) is added direct on line at the output of converter.

(c) After 5 sec. of stage (b) additional load of 2nd compressor (of 20.5kW) or third compressor (of 10.5kW) is added at the output of the converter.

(d) MVRF will be switched ON during rheostatic breaking operation. MVRH will OFF and MVRF will start as DOL.

Note: Sequencing of the loads as described above has to be built in the control circuitryof the locomotive. All timing devices, commutating devices required for ensuring this sequencing is not the part of converter and locomotive builder will be responsible for designing, procurement & implementation of such sequencing circuit of the auxiliary load.

7.3 QCON Relay:

This relay is used to give the indication, that converter output voltage is a fully developed i.e.415 volt. The battery negative is directly connected to the relay and positive ( 700 ) is routed through potential free contact of converter. When the converter is in OFF condition, the potential free contact is also open means QCON relay not in energized condition. But when converter is in ON condition and fully developed voltage the potential free contact become close means positive path to QCON relay completed and relay energized

7.4 QSIT Relay:

This relay is used to give the indication, that there are some fault (internal / external) due to which converter is tripped. This relay also opens the DJ. The battery negative is directly connected to the relay and positive ( 700 ) is routed through potential free contact of converter.

When the converter is in OFF condition, the potential free contact is also open means QSIT relay not in energized condition. But if the converter tripped three consecutive times due to any reason internal / external (except Fuse fault) then on fourth time this potential free contact will closed and complete the positive path and QSIT relay energized. Two NC contact of QSIT is used in control logic of DJ circuit branch, which open the DJ, and make impossible to closed till we reset the converter.

10.BIBILIOGRAPHY

1.AUTOMETERS ALIANCE LIMITED(AAL) MANUAL.

2.RDSO MANUAL.

3.LIBRARY OF INDIAN RAILWAYS.

4. WEB SITE OF INDIAN RAILWAYS.

5.POWER ELECTRONICS BY P.S.BIMBRHA.

6.ELECTRIC TRACTION BY GUPTHA.

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