The scope of electrical system consists of the electrical equipments inside of main building. The Buyer takes responsibility to transmit power from the feed-out panel to user position.

The generator switchgear is used to deliver electricity from alternator to busbar.

1)            3 pole electrically operated Air Circuit Breaker (ACB)

2)            Metering / Protection CT and PT

3)            Meters, indicators

4)            Ammeter for every phase

5)            Voltmeter with selector switch

6)            ACB ON

7)            ACB OFF

8)            ACB spring energized

9)            Manual ACB ON/OFF

DMR-301P digital common relay is adopted for gen-set protection, which is used for alternator protection, switch control, monitoring, measuring, display and electrical failure record.

The following functions and protection can be carried out on the relay:

-          Voltage locked over current

-          Reverse power

-          Over current

-          Over voltage

-          Low 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 storage

10)         Control and operation functions

The generator switchgear provides necessary Monitoring, Control and Protection functions for the DG set.

Main functions for control and operation:

-          Starting engine

-          Speed control

-          Voltage adjustment

-          Load sharing mode select

-          Voltage measuring changeover

-          Current measuring

-          Frequency indication

-          Power indication

-          Excitation current indication

-          Speed indication

-          Alarm

 

A LV auxiliary panel is supplied for all auxiliary equipments including air compressors, cooling towers, fuel unloading stations (provided by customer), HFO treatment equipment and others.

The L.V. electrical systems consist of auxiliary electrical system for generator, auxiliary electrical system for power plant.

The auxiliary equipments for generator include 1 cooling tower motors (5KW), 1 air compressor motors (5.5kW) and 1 booster motor (11kWx1).

The auxiliary equipments for power plant include 1 HFO unloading pump station (11KWx2), 1 DO unloading pump station (11KWx2), 1 HFO separator module (7.5kW), 2 boiler water feed pump motors (2.2kWx2) and one soft water pump motor (3kW).

Notes: customer provides fuel unloading pump stations and all fuel storages.

 

For each one generator, one control and operation panel and one local control desk are supplied.

Gen-set control and operation panel

The control and operation panel in the control room provides necessary Monitoring, Control and Protection functions for the DG set. It controls the Gen-set running according to the program set in PLC. All Gen-set’s running parameters such as voltage, current, power, power factor, frequency, and speed can be displayed on it.

Major Component in console

1)    Control PLC

2)    Speed Governor controller

3)    Automatic Voltage Regulator

4)    Engine Frequency Monitoring Unit

5)    Meters

Ammeters (3 nos)

Voltmeter with selector switch

Power meter

Frequency meter

PF meter

Analog Excitation fundamental ammeter

Analog Excitation harmonics ammeter

Counter for running hours

6) Operation and indicators

Push buttons, change over switches

VCB engaged indication,

Engine start permission indication

Excitation change over switch

DG VCB ON/OFF

DG VCB Trip and alarm indication

Engine Idling/Rating

Engine start

Engine normal and emergency stop

7) AVR

The integral TWL-ND AVR is designed for the TFW generator specially. It configures with stability adjusting, voltage adjusting, and gen-set paralleling reactive power sharing adjusting.

Input capacity         AC 230V

Compare voltage      AC 100V from PT AC

Current signal         CT 5A from CT B

Max. Output           DC.100V, 10A

Trigger Type          Alternator exciter Remanence

Accuracy             ±1%

Am. Temp            -40~+60°C

Reactive sharing      Auto regulating

1)            T4500 auto synchronizer

SELCO T4500 auto synchronizer is designed for automatic synchronization between generator and bus-bar in a minimum of time by controlling the speed via the electric servomotor on the governor.

The T4500 measures the voltage across two phases on either side of the circuit breaker in order to obtain data on voltage, frequency and phase difference for closing the circuit breaker at exact phase accordance.

The synchronization function will become active when the difference between the bus voltage and the generator voltage is within limits. The voltage difference is selectable between 2% to 10%.

When the synchronization function is active, the T4500 will automatically adjust the speed of the generator through the governor in order to match the frequency to the bus-bar.

The T4500 will continuously adjust the generator speed until the frequency difference is within limits. When the voltage and frequency difference are within limits, the closing signal will be activated just before the next phase accordance, anticipating the circuit breaker make time. The T4500 compensates for this make time so that the circuit breaker will close exactly at zero phase.

Specifications for the T4500:

Circuit breaker operating time               20~200mS

Frequency difference                       0.1~1Hz

Voltage difference                         10%

Reference voltage                         110/100V with voltage matching

Operating Temp                           -20~+70°C

Contact rating                              AC: 380V, 2A, 250VA; DC: 110V, 2A, 100W

Auto synchronization system is adopted between generators and network and among generators. Manual synchronization system is supplied for standby.

Main functions on the control and operation panel:

-          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

 

Local Control Desk

Local Control Desk is provided for monitoring pressure and thermal parameters of the running engine. Also starting, stopping and speed control of engine is possible in local control operation mode. It is located near the engine.

Major Components in Local Control Desk

1)    Pressure gauges, switches

Lube oil filter inlet pressure

Lube oil filter outlet pressure

Lube oil in cylinder head inlet pressure

Cooling water pressure

2)    Temperature indication

Cylinders cooling water temperature scanner

   Cylinder cooling water outlet temperature measurement system with Cu50 thermo resistor for each cylinder and scanned by a multi-channel meter.

Engine exhaust temperatures scanner

   Pyrometric exhaust gas system with thermocouple for each cylinder and turbocharger, and scanned by a multi- channel meter.

Lube oil engine inlet /outlet temperature

Water engine inlet/outlet temperature

3)    Engine RPM indicator with cranking and over speed protection.

4)    Push buttons, indicating lamps, selector switches

- Common engine alarm

- Engine start permission

- Local / remote mode select

- Engine start / stop

- Flasher off

- Engine speed raise / low

- Emergency stop

 

The diesel engine will stop automatically in case of the following failures:

-          Very low lube oil pressure

-          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

-          High lube oil temperature

-          High water temperature engine inlet

-          Alternator bearing temperature high

 

The generator adopts digital integrated relay protection system for monitoring and protection.

A DMR362 digital integrated relay is installed on generator switchgear, which is used for alternator protection, switch control, monitoring, measuring, display and SOE record.

The following functions are configured on the relay:

-          Differential current

-          Reverse power

-          Instant trip current

-          Voltage locked over current:

-          Over current

-          Over load

-          Earth failure

-          Over voltage

-          Under voltage

-          Low frequency

-          Over frequency