• Author / Uploaded
• Usman Saeed

Citation preview

ALFANAR TRANNING CENTER

DC / UPS Training Course O October b 2010

10/14/2010

1

ALFANAR TRANNING CENTER SHAROURAH POWER PLANT EXTENSION PROJECT

NAME: Mohamed Ibrahim

10/14/2010

2

Presentation of DC System Introduction • A guaranteed and reliable power supply is absolutely essential for electronic equipments, automation systems and telecommunication and data systems existing in modern power plants. • Equipment involved in data and communication technology requires supply voltages that have to be generated from the mains as well as from a battery-assisted d.c voltage. Battery/Rectifier • These Equipments q p could be supplied pp from AC or DC sources. Accordingly, means should be developed to generate AC voltages from battery backed d.c. voltages to ensure continues supply to these loads in case of AC power failure from the mains. Inverter • To ensure quality of AC voltage supplied to the loads, automatic voltage regulator is used. Constant Voltage Transformer (CVT)

10/14/2010

3

Presentation of DC System Principle of Operation • The main target is to provide an uninterruptible power supply to critical AC and d DC lloads. d • AC voltage from unit auxiliary supply is rectified to DC voltage. This rectified AC is provided with a back-up battery system to supply the DC loads. loads • DC voltage from the main DC bus bar is converted to AC voltage through Inverter to provide AC loads.

10/14/2010

4

Main AC Supply

Rectifiers

CVT

Battery

Main DC Panel Inverter AC UPS Panel

10/14/2010

DC Dist. Panel

5

Modes of Operation Normal Mode of Operation • The AC main supply is healthy. • The two rectifiers are sharing the total DC load. • Battery is in floating status (rectifiers are supplying the battery internal resistance losses) . • AC loads are supplied from DC main bus bar through inverter .

10/14/2010

6

Modes of Operation Failure/Maintenance of The Inverter • The AC main supply is healthy. • The two rectifiers are sharing the total DC load. • Battery is in floating status (the healthy rectifier is supplying the battery internal resistance losses) losses). • AC loads are supplied from AC main supply through CVT.

10/14/2010

7

Modes of Operation Failure/Maintenance of One Rectifier • The AC main supply is healthy. • Only one rectifier is supplying the whole DC loads. • Battery is in floating status (the healthy rectifier is supplying the battery internal resistance losses) . • AC loads are supplied from DC main busbar through inverter .

10/14/2010

8

Modes of Operation Failure of Both Rectifiers • The AC main supply is healthy. • Both rectifiers are out of service. • The battery is supplying the whole DC loads. • AC loads are supplied from AC main supply through CVT.

OFF

10/14/2010

9

Modes of Operation Failure of AC Main Supply • The AC main supply is out of service. • Both rectifiers are out of service. • The battery is supplying the whole DC load. • AC loads are supplied from DC main bus bar through inverter.

10/14/2010

10

Modes of Operation Restoration of AC Main Supply • The AC main supply is Healthy. • Both rectifiers are sharing the DC loads and charging the battery. • The battery is in the charging status. • AC loads are supplied from DC bus bar through inverter.

10/14/2010

11

Presentation of DC/AC Inverter Inverter Principle of Operation • In one simple inverter circuit, DC power is connected to a load through a circuit i it with ith ttransistor i t switches it h and d anti-parallel ti ll l di diodes. d Th The ttransistor i t switches is rapidly switched back and forth to allow current to flow back to the DC source following two alternate paths through one end of the load and then the other. The square q wave form obtained can be filtered to obtain pure sine wave form.

10/14/2010

12

Inverter Operation Modes Continuous Mode • The AC loads are supplied from the DC source through the inverter. • Change over to AC mains without interruption within 2.5 ms if the inverter output voltage deviates from the nominal by more than 10%. • The loads will be switched back from the AC mains to the inverter output after 30 sec when the inverter output voltage is again within limits

AC Mains

AC Output DC Source

10/14/2010

13

Inverter Operation Modes Standby Mode • The AC loads are supplied from the AC mains during normal operation. • The inverter remains switched on and kept synchronized to the AC mains and operates with no load. • When the AC mains voltage goes out of limits the load is transferred to the inverter output within 12 ms. • The loads are switched back to the AC mains automatically when the voltage is within limits again. AC Mains

AC Output DC Source

10/14/2010

14

Inverter Panels

Manual Bypass

• The Inverter is provided with manual bypass switch so that the inverter and the electronic AC mains changeover switch can be isolated for maintenance purposes. • The manual changeover without interruption can take place only when the AC mains and the inverter outputs are synchronized h i d and d within ithi limits. li it 10/14/2010

15

Inverter Panels

Measuring Devices

10/14/2010

16

Inverter Panels Indication Leds H8 H1

H6

H9 H2

10/14/2010

H5

H7

H1

Umains>Unom-10%

H2

DC voltage within limits

H5

Uinv > Unom-10%

H6

« AC mains i » switch it h

H7

« Inverter » switch

H8

« Bypass » switch

H9

« Automatic » switch 17

Inverter Maintenance

• The inverter equipment requires very little maintenance. • Prevent dust from accumulating in the inverter equipment. • Clean the inverter equipment with nothing more than an insulated brush and a vacuum cleaner if that should become necessary. • If fuses blow, replace them only with fuses of the same type and value. • Check Ch k th the nominal i l values l off voltage lt and d ffrequency very occasionally. i ll • The fan in the power semiconductor cooling system should be replaced every 4 years.

10/14/2010

18

Presentation of Charger Rectifier Principle of Operation • The Three phases input voltage 400Vac supply the “Full Bridge” constituted of 6 thyristors y ((V1 to V6)) through g the input p transformer T1. • The AC incoming lines can be interrupted with the internal CB Q001. • The DC voltage coming from the bridge is filtered by the cells L1-C10 to obtain a ripple less than 3% RMS on the DC output output. • The pulses to order the thyristor blocks are provided by electronic card A1 (Thyristor Regulator Card).

10/14/2010

19

Charger Operation Modes Floating Charging • The Charger is keeping the battery in the floating status with a defined set voltage per cell. • The three phase 400Vac from the mains is rectified to 125Vdc supplying the DC loads connected to the DC panels.

10/14/2010

20

Charger Operation Modes Boost Charging • The boost mode starts automatically after a battery discharge (in case of ac power failure). • The boost voltage value is adjusted to 138 v. • The charger will switch over automatically to the floating mode (normal operation) after the set delay time. • The boost mode can be started also manually through the menu present in the front LCD display.

10/14/2010

21

Charger Operation Modes Equalizing Charging • U Used d only l ffor th the commissioning i i i charge h off th the vented t d sealed l d llead d acid id or NiCd battery types to form the battery cells. • Equalizing charge level consists of high DC voltage 144V with limited current to around 240 A. A • Equalizing charge must be used without load, only the battery bank is connected to the DC charger. q g charge g starts manually y from the menu p present in the LCD display. p y • Equalizing

10/14/2010

22

Charger Panels LCD Operating Panel

DC Output Voltage Indication Leds

10/14/2010

Navigation Buttons

23

Rectifier Maintenance

• The unit does not need to be maintained, however, check the following: ¾ The screws, if all the mechanical parts are rightly fixed. ¾ Check the floating voltage and adjust, if necessary, through the menus presents on the LCD display. Disconnect the battery before setting. ¾ Check the boost voltage and adjust, if necessary, through the menus presents on the LCD display. Disconnect the battery before setting. ¾ Dust the unit every year. ¾ Replace the thyristor bridge fan every 5 years. ¾ Replace the chemical capacitors C10 on the rectifier output every 10 years.

10/14/2010

24

Presentation of Battery Battery Concept • A battery is a device in which chemical energy is directly converted to electrical energy . p of two • It consists of one or more voltaic cells, each of which is composed half cells (electrode) connected in series by the conductive electrolyte. • The electrolyte is a conductor which connects the electrodes together and also contains ions which can react with chemicals of the electrodes. Half Cell

10/14/2010

25

Presentation of Battery Battery Concept • Chemical energy is converted into electrical energy by chemical reactions that transfer charge between the electrode and the electrolyte at their interface. • The chemical reaction occurs because potentials exist between two dissimilar materials (lead plate and lead-dioxide plate) placed in an electrolyte (sulfuric acid). • Si Since th the voltage lt off a b battery tt iis relatively l ti l constant, t t the th capacity it off a battery b tt to t store energy is often expressed in terms of the total amount of charge able to pass through the device Ampere Hours

10/14/2010

26

Presentation of Battery Lead Acid Battery • Th The llead-acid d id cellll consists i t off a metallic t lli llead d anode d and d a llead d di dioxide id (Pb02) cathode, which are immersed in a dilute sulfuric acid solution (H2SO4). • During discharge, the lead dioxide (positive plate) and lead (negative plate) react with the electrolyte of sulfuric acid to create lead sulfate, water and energy.

10/14/2010

27

Presentation of Battery

Lead Acid Battery • During charging, the cycle is reversed. The lead sulfate and water are electrochemically converted to lead, lead oxide and sulfuric acid by an external electrical charging source source.

10/14/2010

28

Presentation of Battery Lead Acid Cell Construction Pole Post Screw connection for easy and safe connection.

Vent Plug Release g gas in case of excess pressure and protect the cell from atmosphere

Separators Special micro porous material for electrical separation of the positive and negative plates

Positive Electrode Tubular T b lar plates made from special low antimony selenium alloy

Negative Electrode Grid flat plate made from selenium alloy 10/14/2010

Container

29

Presentation of Battery Battery Data Electrode Electrolyte Ampere Hour No. of Cells Internal Resistance Short Circuit Current Total Weight Fl ti Voltage Floating V lt

10/14/2010

Lead Selenium Alloy Sulphuric acid 3000 60 0.1 mΩ/cell 19200 A 13700 KG 2 25 V/cell 2.25 V/ ll

30

Presentation of CVT Principle of Operation • CVT stands for Constant Voltage Transformer. • CVT is a voltage regulator. The main purpose of using a CVT is to provide stabilized output voltage within certain limits. • The voltage regulator consists of a fully electronic control circuit circuit, a motor driven variable autotransformer and a series transformer (booster).

10/14/2010

31

Presentation of CVT Principle of Operation • The control circuit is connected on the output of the regulator. • When the output voltage varies from a preset value, an unbalance is detected by the control circuit. • This unbalance signal is amplified and used to operate the servo driven motor of the autotransformer. • This movement gives to the series transformer the additive or subtractive voltage necessary to have the correct output value.

10/14/2010

32

Presentation of CVT CVT Data Nominal Input Voltage Rated Power (kVA) Input Voltage Variation Rated Current Nominal Output Voltage

10/14/2010

400 V 50 +/- 10% 150 A 230 V

33

Presentation of CVT CVT Data Output Accuracy Output Frequency Load Power Factor Harmonic Distortion

10/14/2010

+/- 2% +/ 50/60 Hz +/- 2% Any Less Than 0.2

34

Presentation of CVT CVT Data Cooling Operating Temperature Degree of Protection g Weight Dimension

10/14/2010

Free Convection 0 to 40 oC IP20 430 kg g 1800*800*800 (H*W*D)

35

Presentation of AC/DC Panels

Si l Li Single Line Diagram Di (SLD)

Main DC Panel 8EDED01

AC UPS Panel 8EUEU01 10/14/2010

DC Dist Dist. Panel 8EDED02

36

Presentation of AC/DC Panels Main DC Panel (8EDED01) Incoming Feeders Rectifier # 1

10/14/2010

Rectifier # 2

Battery

37

Presentation of AC/DC Panels Main DC Panel (8EDED01) Outgoing Feeders Measuring and signaling

Inverter

Spare

10/14/2010

DC DIS. Panel

38

Presentation of AC/DC Panels DC Distribution Panel

Outgoing Feeders

Continue..

10/14/2010

39

Presentation of AC/DC Panels DC Distribution Panel

Outgoing Feeders

Continue..

10/14/2010

40

Presentation of AC/DC Panels DC Distribution Panel

Outgoing Feeders Incoming Feeder From Main DC Panel

Continue..

10/14/2010

41

Presentation of AC/DC Panels DC Distribution Panel

Outgoing Feeders

Continue..

10/14/2010

42

Presentation of AC/DC Panels DC Distribution Panel

Outgoing Feeders

Continue..

10/14/2010

43

Presentation of AC/DC Panels AC UPS Panel

Outgoing Feeders

Continue..

10/14/2010

44

Presentation of AC/DC Panels AC UPS Panel

Outgoing Feeders

Continue..

10/14/2010

45

Presentation of AC/DC Panels AC UPS Panel

Outgoing Feeders Incoming Feeder From Inverter/CVT

Continue..

10/14/2010

46

Presentation of AC/DC Panels AC UPS Panel

10/14/2010

Outgoing Feeders

47