HCMT Electrics Flashcards
Overview of train electrics
Where are the Pantos located?
Number one end of all motors
What type of process raises the Pantos electric pneumatic or mechanical?
Electric & pneumatic
What main reservoir pressure is required to raise the Pantos when the cab is activated
700 KPA
What level of power is available from the batteries to power and auxiliary compressor which raises the local Panto?
110V DC
At what main res pressure will the Pantos on the DMp cars raise automatically?
400 to 450 K PA
Where is the high-voltage box located and what is contained in it?
No. 1 end of all motors and it contains the high Speed circuit breaker and harmonic wave detection device
What is the purpose of the high Speed circuit breaker?
The HSCB protects the traction inverter from further damage if there was a fault by tripping.
- Extra info …If this happens, you might get an alert, which is a level one or level two on the HMI to let us know.
- The TCU/ACU reset push button can be used to reset the HSCB when prompted by the TMS it is located in the electrical cabinet on the A side of the cab.
What does the harmonic wave detection device HWDD do?
Protects against power quality problems
due to harmonic currents generated from either the traction system, or from the overhead contact wire
When does the harmonic wave detection device cut off power to both traction and the auxiliary inverters?
When a preset threshold limit of harmonic, frequency is exceeded by two seconds, or more
if it detects 3 consecutive breaches over a period of 1 minute, the traction and auxiliary contactor will remain open indefinitely
What does the electrical auxiliaries system do?
The overhead 1500 V DC provides power to the auxiliary inverters in the auxiliary power supply unit.
This convert 1500 V DC into 415 V AC that powers, the
battery charger,
main compressors
HVAC’s and the
traction cooling system
What does the battery charger do?
Convert 415V AC in 110V DC that charges the battery and provides power to auxiliary loads
What does the vehicle traction system do?
Traction power comes from the overhead via the high-voltage box, which supplies 1500V DC to the two traction inverter modules located in the variable voltage variable frequency cabinet.
This, then provides three phase power to the traction motors
What are the two main functions of the vehicle traction system?
Providing traction combined with electrical braking
Collecting electrical energy from the overhead and transforming to different voltage levels
How many Traction inverter modules are in the VVVF Cabinet?
2
What do the brake resistors do?
Release the energy generated from the ED braking
How are Traction faults reset in the traction inverter?
The reset, automatically through the inbuilt system fault protection
What will happen if the traction inverter has a repetition of faults within a certain timeframe?
It won’t be automatically reset. The traction inverter will be locked and a manual reset becomes required.
How are some faults such as overvoltage, overcurrent, and module failures dealt with?
They can be reset via the TCU APS reset push button the driver will be prompted via TMS
When is the driver able to use the TCUAPS button?
Only if prompted by the TMS and authorized by the train controller
What is the purpose of the auxiliary inverter?
Convert 1500 V DC into three phase 415 V AC to power all AC loads. 240 V AC to cabin saloon GPO’s
What does the medium voltage box do?
Maintains the 415 V AC train bus that runs the length of the train
How many cells in the battery box and how many volts?
80 cells provide 110 V DC
What if there is a fault or failure on one battery set?
The other battery sets can supply 110 V DC to the train line
