6
Medha Servo Drives Pvt Ltd.
MAS 696 Operator’s Manual
windings. Overview block diagram is given in Fig. 1.2.
The Diesel Engine drives the main Generator Assembly. The Main Generator
assembly has two Alternators which are MAIN ALTERNATOR and
COMPANION ALTERNATOR. The Traction Alternator converts the Diesel
Engine mechanical power into 3 phase AC electrical power. The Alternator’s
two windings’ (left bank and right bank) outputs are connected to two air
cooled Rectifier Assemblies consisting of high voltage, high current silicon
Diodes with Fuses in the 3 phase Full Wave Rectifier circuit. The two
Rectifiers output are connected in series across the DC LINK. The AC
3-phase power is converted into DC power by Rectifier Assembly. These are
the internal parts of TA-17-CA-6B Main Generator Assembly.
Rectified DC power supply is applied to DC LINK. When all DCL switch gears
are closed, DC voltage is applied to IGBT based Traction Inverters. Each
Traction Inverter has separate control module in the form of Traction
Computer. The Traction Computer receives Traction Motors’ speed,
temperature, Voltage and Current values for controlling the IGBTs to
maintain required torques according to Notch selection.
The Traction inverters have main role in controlling the 3 phase induction
motors. The Traction Inverters converts the DC power into 3 phase AC power
for variable frequency using IGBT based technology. Six DC LINK switch
gears passes the DC power to the six Traction Inverters through its closing
TM1
TM 3
TM 5
TM2
TM 4
TM 6
C A
Deisel
Engine
Alternator
Auxiliary
Generator
Starting
Motors
A.G.
Control
(ZCD/GD)
Excitation
Control
Propulsion
Control
Governor
Engine
Control
Air
Compressor
Locomotive
Battery Unit
TCC
Grid
Resistors
Rectifier
Traction
Computer
Traction
Inverter
Traction
Computer
Traction
Inverter
Traction
Computer
Traction
Inverter
Traction
Computer
Traction
Inverter
Traction
Computer
Traction
Inverter
Traction
Computer
Traction
Inverter
Fig. 1.2 Block Diagram of Locomotive Control System