DC and AC Traction Motors Overview

Transformer windings are categorized by their function in a system, like primary, secondary, traction, auxiliary, and filter windings.

The total power-handling capacity of all windings in a transformer, measured in kVA or kV.

Objectives for the indigenous development, integrated system design, high redundancy, and flexible system for electric locomotives.

A crucial part of a locomotive's control system to manage the entire operation, receiving signals and instructions for different components.

Dual VCU setup (VCU1 & VCU2) for redundancy, each fitted with a CPU card; the master VCU controls the overall system, and is a modular design.

Receives digital output channel data from the main and redundant CAN communication channels (MVCUCC, MACC).

Reads and transmits digital input channel data through main and redundant CAN channels (MVCUCC, M628ACC).

The central component in the locomotive's CAN communication network, controlling vital parts and managing main and redundant communications (and failure management).

The central processing unit (CPU) of the locomotive's Vehicle Control Unit (VCU), responsible for all control functions. It manages the entire computer system.

Components like microcontrollers, CAN, and RS485 interfaces, RAM, and other connections that are part of the VCU.

The VCU operates on ±15V and ±7.5V DC input voltages.

A system where if one Main CPU (VCU1) fails, the other (VCU2) takes over control.

The VCU constantly interacts with on-board systems like traction converters, auxiliary converters, etc. to maintain and control their functions.

The VCU regulates the pantograph, which collects electricity from overhead power lines.

VCU manages various control functions, including brake interactions, compressor controls, and ventilation level computations.

The VCU connects to the locomotive control stand (cab) to receive driver inputs and display information.

The VCU interacts with the existing braking system through digital and analog signals.

The VCU communicates and controls the traction converters, which convert energy to drive the locomotive.

DC traction motors have a commutator, brushes, bearings, and gears

Separate CAN communication channels on each VCU for fault tolerance and improved system reliability.

Vehicle Control Unit: a unit that controls and monitors various systems.

DC traction motors have commutators and brushes, requiring more maintenance. They are bulky and lack power regeneration. A separate converter is needed for regeneration

AC traction motors have no commutator or brushes. They need less maintenance, are smaller, and facilitate power regeneration, reducing the need for converters.

Command given to the motor system based on the throttle position, controlling the motor's torque to drive or brake.

Issues detected in the traction converter, part of the vehicle's drive system.

CLW manufactures 3-phase electric locomotives using technology acquired from ABB/ADTRANZ

User-adjustable parameters of the traction converter unit, configured by the Vehicle Control Unit (VCU).

3-phase IGBT-based locomotives use GTO (Gate Turn-Off Thyristors) technology in converters.

System to prevent the wheels from losing traction, enhancing stability in varying conditions.

The graphical representation of an Insulated Gate Bipolar Transistor (IGBT).

Process of precisely setting the wheel size parameter in the control system.

Graphical representation for Gate Turn-Off Thyristors (GTO) used in power electronics.

Units supporting other vehicle functions with CAN connections to VCU.

IGBTs are considered the most advanced power device among IGBTs, GTOs, and SCRs in power electronics.

The VCU manages switching over to a backup auxiliary converter in case of failure.

MEDHA SERVO DRIVES (P) Ltd. developed India's first IGBT-based 3-phase drive propulsion equipment (MEC628V2) for electric locomotives (WAG9/WAG9H/WAP7/WAP5).

Driver display unit communicating with VCU via RS485 for data display in graphical or text formats.

IGBT-based 3-phase drive propulsion equipment is commonly used in WAG9, WAG9H, WAP7, and WAP5 electric locomotives.

The WAG-9 locomotive uses a 6 FRA 6068 motor

Communication protocol used by LCD TFT Display to link with VCU.

The WAG-9 locomotive's 1-hour motor rating is 1156 HP, 2089 V, 290A, 1135 rpm

The WAP-5 locomotive's continuous motor rating is 1563 HP, 2180V, 370A, 1585rpm,160.3Hz

The components of an auxiliary converter are Line Rectifier, DC Link, and Inverter. Battery Charger is also a sub-assembly.

The battery charger is housed in the ACU2 cabinet and can be powered by either AC2 or AC3 converters.

The three-phase output of the auxiliary converters is normally 415V, while the battery charger output is 111V.

Line rectifiers use Thyristors as active switches to convert AC to DC.

Inverters use IGBTs to convert DC to AC.

The M304V2CC is a control card using a 16-bit microcontroller that communicates with power modules using CAN.

The M304V2CC receives inputs like I/P ELD CHANNEL, earth leak current, temperature, and loco battery voltage.

Digital inputs of M304V2DIO card include feedback signals from contactors and battery charger MCB.

Protects the power supply module from overcurrent.

Provides regulated DC power supplies needed by modules in an auxiliary computer.

Converts AC input from a transformer to regulated DC power.

Stores DC power from the Line Rectifier, using capacitors and an LC filter. Also regulates DC voltage.

Reduces overvoltages on the DC link in the Aux. Converter.

Converts DC power from the DC link to AC power for auxiliary loads. Utilizes 3 frequencies (37, 47, 50 Hz).

Devices using the AC power generated by the Aux.converter.

Converts 415V AC input to 111V DC for battery charging.

Guards the battery charger from faults by using different feed-forward and feedback signals.

Ensures operation is performed safely by identifying and reacting to any errors.