4.10.1 LV system
The auxiliary equipments for generator include 12 radiator cooling fan motors (8.6KWx8x14), 2 air compressor motors (18.5kWx2), 2 booster (22kWx1) and one DC power source panel (4kW).
The auxiliary equipments for power plant include 2 HFO pump motors (18.5KWx2), 2 DO pump motors (18.5KWx2), 4 HFO separator module (11kWx4), 12 boiler water feed pump motors (2.2kWx12) and two soft water pump motor (3kWx2).
The lighting and air conditioner system is about 30kW, all lighting equipments are considered during civil work.
The fire fighting system includes 2 fire-fighting pumps (22kWx2) and one water feed pump (7.5kW). All fire-fighting equipments are considered during civil work.
The maintenance system includes one 10T double girder bridge crane (10kW) and maintenance electrical boxes (total 50kW).
4.10.1.1 L.V. power source for power plant
One station transformer (1250KVA/11kV/0.4kV) is installed for supplying LV power source for the power plant.
4.10.1.2 DC panel
The power supply of control plant, protection, signal, automatic device and trouble lighting adopts 100AH direct current electrical source system.
220/24V DC battery charger of suitable capacity along with Lead acid automotivetype rechargeable batteries (12 V DC) is used. Charger is fully automatic, with trickle and boost charging facility.
Major Components
1) Transformer
2) Electronic controllers
3) AC/DC ammeter, voltmeter
Metering Devices
4) Voltmeter (with selector switch) for AC input voltage
5) Voltmeter for DC output voltage
6) Ammeter for load and battery current
Indications
7) Mains supply ON
8) Float mode / Boost mode
9) Charger Tripped
Controls possible from Charger
10) Mains supply ON / OFF
11) Initial / Normal charging mode selection
12) Fault reset
Protections provided for Charger
13) Over load / short circuit / earth fault
14) Over voltage
Battery reverse
4.10.3 Control system
4.10.3.1 DG
For each one generator, one control and operation panel and one local control desk are supplied. On the control and operation panel, the following functions can be carried out on remote mode:
- Starting engine
- Speedup
- Speed-down
- Generator switch ON/OFF
- Voltage adjustment
- Reactive power share
- Synchronization
- Voltage measuring changeover
- Lube oil pressure
- Water pressure
- Voltage
- Current
- Frequency
- Power
- Excitation current
- Speed
- Alarm
On the local control desk, the following functions can be carried out on site:
- Starting engine
- Speedup
- Speed-down
- Stop
- Emergency shutdown
- Measuring and display such as alarm, lube oil temperatures (inlet and outlet), cooling water temperatures (inlet and outlet), exhaust gas temperatures, lube oil pressure, cooling water pressure, lube oil pressure for cylinder head, speed and others.
All generators can work in parallel; load can be equally shared among all generators automatically. Auto synchronization system is adopted between generators and network and among generators. Manual synchronization system is supplied for standby.
4.10.3.2 Central control panel
A central control panel is installed in the control room, which is used for displaying signals for auxiliary equipments including oil storage level alarm, water level alarm, oil temperatures, steam pressure and others.
4.10.4 Protection system
4.10.4.1 Diesel engine
The diesel engine will stop automatically in case of the following failures:
- Very low lube oil pressure
- Very high lube oil temperature
- Very high water engine outlet temperature
- Engine over speed
The diesel engine will alarm automatically in case of the following failures:
- Low lube oil pressure
- Low water pressure
- Low fuel pressure
- High lube oil temperature
- High water temperature engine inlet
- Alternator bearing temperature high
4.10.4.2 DG electricity system
The generator adopts digital integrated relay protection system for monitoring and protection.
A DMR362 digital integrated relay is installed on each generator switchgear, which is used for alternator protection, switch control, monitoring, measuring and display.
The following functions can be carried out on the relay:
- Differential
- Reverse power
- Over current
- Earth failure
- Over voltage
- Low frequency
- Over frequency
- Over load
- Accurate measuring of all operation parameters such as power, voltage, current, frequency, power factor and others
- Display the conditions of all switches
- Running record and failure store.
4.10.4.3 11kV electrical system
One DMR341 digital integrated relay is installed on each11kV outgoing panel, the following functions can be carried out on the relay:
- Over current
- Earthing failure
- Running record and failure store
- Controlling switch on site or on remote mode
4.10.5 Lighting and fire fighting system
The buyer takes responsibility for the lighting and fire fighting system during civil work.
Lighting (inside of main building)
The power plant adopts the lighting system as follows:
l Normal AC lighting system
l The direct current trouble lighting system
l The safety lighting
l The guard lighting
Normal AC lighting system
The normal AC lighting system provides whole the lighting of power plant. The normal AC voltage is 220 V.
The direct current emergency lighting system
One set of switch panel is installed in the control room. Usually the AC electrical system work for illuminate system. When the system breaks down, it will automatically switch to direct current emergency lighting system. At the important place & exit/entrance of main building and subsidiary workshop far away from the main building, the lighting system adopts emergency lighting with the storage battery, with power supply time no less than 30 minutes. The AC electrical source of the emergency lighting connects to the normal lighting network.
The fire extinguishing water & the industrial water and the living water are united and independently to be supplied;
In the power plant, annularity main water supply pipe for fire extinguishing (living) and hydrants whether in the plant or out of the plant shall be installed.
Enough fire extinguishers in the main plant building and other buildings will be installed.
The drain will be collected to a main pipe line through branch pipes. Then it will be discharged by the buried channel.
4.10.6 Earthing and lighting strike protection
The buyer should consider all earthing system arrangement during civil work.
Earthing system of the project includes lighting proof earthing for construction building earthing, PEN protecting earthing for station LV power supply system, ect.
For the reason of generating set and H.V. equipments, probability of lighting strike on the power station is increased. The earthing system connecting to the ground with nature fully by earthing bars, and the resistance should be less than 1Ohm. Except that, the earthing system should be connected to the vertical man-made object to complete a close-circularity network. It avoids the grounding, contacting and stepping over-passing the permission range. The earthing material must be satisfied to the request for conducting, antisepsis and short-circuit heat stabilize. The horizontal earthing object adopts 40x4 flat steel of hot galvanized steel, and the vertical earthing bars adopt L50X5 hot galvanized angle bar or Φ50 hot galvanized steel pipe. For thunder-stroke wave overload voltage endangering, the generating system has set zinc lightning arrester on the H.V. bus-bar. For the direct thunder-stroke protection, an lighting acceptor should be set on the main building.
All metal shell of electrical equipments should be connected to the PE line reliably to avoid electrical shock when the insulation of the equipment is failure.
4.11 Transmission line:
The buyer takes responsibility to transmit power from main outgoing panel to used position.
