Modernisation kit for the 2300 HP and 2700 HP Asynchronous Diesel Electric Locomotives


The technical and functional solutions used in the implementation of the modernization concept

1. Traction-braking static converters block

The traction-braking static converters block is executed as an assembly  with fixed component parts, with locked access doors allowing easy access for service.

It consists of the following elements:

  • Three-phase rectifier for synchronous generator;
  • Inverters for traction and braking;
  • Electro-dynamic brake chopper;
  • Forced ventilation system for static converter block and traction motors 1,2,3.

The three-phase rectifier for the synchronous generator is a three-phase rectifier with diodes and single-sided air cooling.

Power : 600-1800 kVA;

Input voltages : 3 x (467-1400) Vac;

Frequency : 40-120Hz;

Output voltage: 600 - 1800 Vcc

Output current: 364-950 Acc.

The three-phase rectifier has high reliability and low power loss due to the use of state-of-the-art electronic components, reduced dimensions and optimal use of cooling surfaces.



Traction and braking inverters

Three phase static inverters equipped with IGBT technology.

Input voltages: 600-1800 Vcc;

Maximum Input Voltage (In Electrodynamic Braking): 1950 Vcc;

Maximum output voltage: 1400 Vac;

Maximum output current: 370 Aca;

Frequency: 0-120Hz.


Low power loss due to the use of IGBTs with high performance drivers;

Forced air cooling and small overall dimensions;


The modular construction facilitates easy intervention in the event of a malfunction;

Fiber optics controll ensuring optimum operation for the traction motors.


Electro-dynamic braking chopper (optional)

Transfers the electric energy produced by the traction motors to the braking resistors during the dynamic braking.

Suppress overvoltage in DC intermediate circuit, limiting DC link voltage..

Maximum input  voltage: 1950 Vdc;

Maximum resistors braking: 2x400 kW;

Cooling type: forced air cooling. 

Forced ventilation system for the traction – braking static converter block 


The ventilation system is also cooling the first three traction motors, using two ventilation groups supplied with power from a three-phase inverter.

The ventilation system allows two levels of ventilation with variable motors speed.


2. Control and auxiliary services block


It is used for the control of the locomotive and to supply power to the auxiliary services. This block is designed according to the IP 20 protection standard and should be placed in the engine compartment.


It has the following components:

  • Central computer unit;
  • Traction- braking computer unit;
  • synchronous generator voltage regulator (type RAT GSP);
  • battery charging and 24 Vdc switching  power supply (type SIBA LDE);
  • Static converter for supplying power to the auxiliary services with individual load protection, type CSASA 85 KVA;



  • The central computer unit it is based on microcontroller technology, it outputs to one color display in each driver cabin, it handles the locomotive controls, analog signals and traction motors control. Through the display in the driver`s cabin, it provides the locomotive`s status to the driver, using graphical, text and vocal output. The driver can reset any faults from his cabin. The display can record the locomotive`s status and can provide the driver with maintenance instructions. The central computer unit is made of seven types of modules:
    • Digital input modules – 5 pcs
    • Digital output modules – 2 pcs
    • Analog input modules – 5 pcs
    • Analog output module – 1 pc.
    • Central computer module – 1 pc.
    • Power supply – 1 pc
    • CAN communication module – 1 pc.


Input data types

  • 160.. 24V digital signals distributed on 5 PID modules, each handling 32 inputs.
  • The PED modules can handle 64 output lines using 24 V/2A signals. The output interface is distributed on two modules, each of them with 32 output lines.
  • It can convert 60 analog signals, using 5 modules with 12 analog inputs each.
  • From the 12 input channels, 8 are using 0-20 mA signals and the other 4 can be configured to use 0-20 mA, 0-500 mA or 0-10 V.
  • The system outputs 6 4-20 mA analog signals using the analog output module.
  • The communication module, is handling the communication with the diagnosis and monitoring systems from the driver`s cabins, using one CAN bus.
  • The computer module, implements the control algorithms and the data transfer inside the central computer and has two external CAN serial ports to communicate with the traction computer and with the Diesel engine`s computer.
  • The power supply is connected to the 24 V supply line of the locomotive and absorbing a maximum current of 1,5 A. 



  • The traction - braking computer controls the electric traction and braking with an optimal load on the  Diesel engine. Access the engine room and the front panel connectors allow easy and fast interventions for any module. The computer is using Double Eurocard modules, mounted in a 19 inches Rack. For the control of the motors, the computer is using high performance PWM modulation algorithms. The computer is using three types of modules:
    • Inverter control module - 6 pcs.
    • Computer control module – 1 pc.
    • Power unit module – 3 pcs.


One inverter control module contains the following parts:

  • 3 analog inputs 0…200 mA
  • 4 analog inputs 4…20 mA
  • 2 selectable analog inputs 4…20 mA/0 - 10 V
  • 4 selectable analog outputs 0…20 mA/0 – 10 V
  • 4 dedicated rotary encoder inputs
  • 16 digital inputs with common ground and galvanic isolation
  • 4 digital inputs with individual ground and galvanic isolation
  • 8 digital outputs (24V/2A)
  • 8 fiber – optic inputs
  • 8 fiber – optic outputs
  • 1 RS232 serial communication port with galvanic isolation
  • 1 CAN serial communication bus




One TC_M module contains the following parts:

  • 3 analog inputs ( 0…300 mA )
  • 2 analog inputs ( 0…75 mA )
  • 1 analog input ( 0…60 mA )
  • 2 analog inputs ( 4…20 mA )
  • 2 selectable analog inputs 4…20 mA /0-10 V
  • 4 selectable analog outputs 0…20 mA / 0- 10 V
  • 16 digital inputs with common ground and galvanic isolation
  • 4 digital inputs with individual ground and galvanic isolation
  • 8 digital outputs ( 24V/2 A)
  • 4 fiber-optic outputs
  • 4 fiber-optic inputs
  • 1 RS232 serial communication port with galvanic isolation
  • 3 CAN communication buses



The power supplies output the following voltages:

  • TC_MS_A1 – 24V/ 4,5A ( supplying the electronics circuits )
  • TC_MS_A2 -/+ 24 V/4,2 A (supplying the transducers )
  • TC_MS_A3 -/+ 24V/4,2 A ( supplying the transducers )



The computer is connected to the 24 V supply line of the locomotive and absorbs a maximum current of 18 A. The modules are connected to the other equipments using front panel connectors (electric circuits and fiber optics).

  • Fixed point DSP (Digital Signal Processor) used for implementing core Vector Motor Control. Supervisory Processor for other functions and communications with Locomotive Computer
  • Vector Motor Control with Space Vector PWM modulation for complete Variable Voltage Variable Frequency (VVVF) inverter implementation.
  • High switching frequency PWM and six-step modulation used at highest speeds.
  • Parameter adaptation used with changing operating conditions of the traction motor.
  • Each of the  Traction Computer's inverter control module controls one inverter and is independent from the others.
  • Traction Motor currents, voltages, DC Link voltage, current, and temperature from all IGBTs are monitored.
  • All fault diagnostics are relayed to the central computer, to be displayed in the driver's cab.

Synchronous generator voltage regulator (type RAT-GSP)


RAT - GSP is an automatic voltage regulator for the synchronous generator and it is mounted in the apparatus block on one of the vertical walls.

RAT - GSP receives information from  the central computer prescribing voltage control as unified signal (4 ... 20 mA). RAT - GSP sends the measured voltage of  the synchronous generator  as a unified signal (4-20 mA) to the central computer.  Also, the voltage information is sent as a unified signal to the static converter for the auxiliary services.

RAT - GSP outputs an error signal to the central computer and can be reset by the central computer.


Main technical characteristics :


Control circuits input voltage:  24 VDC (+20% -30%);

Output current: max 10 Acc;

Output voltage three-phase rectifier range: 600 - 1800 VDC;

Overload and short circuit protection.


Battery charger and 24 Vdc power supply(type SIBA LDE)

The battery charging unit sends the measurements of battery voltage and current to the central computer, as 4-20 mA unified signals. It uses the latest IGBT technology. The unit is cooled using the forced air cooling of the apparatus block.

Technical characteristics :

  • Battery charging voltage: maximum 27 Vdc at 20 °C;
  • Temperature compensated charging voltage;
  • Battery charging current limited to 70 Adc;
  • Total output current: 250 Adc +/- 5%;
  • Supply voltage: 575 V dc +/- 5%.

 The battery charging unit handles the following:

  • overload protection
  • short-circuit protection (maximum 300 Adc)
  • over-voltage protection


Auxiliary services static converter  (CSASA 85 kVA)


CSASA 85 kVA is mounted on the external side wall of the apparatus block. The chopper inductor and AC voltage filter are mounted inside the apparatus block.

The system has the following advantages:

  • High reliability due to the IGBT technology;
  • Modular design, allowing easy maintenance;
  • The latest technology electronic components with low commutation losses allow the unit to be cooled using the air cooling system of the apparatus block;
  • Protection for overload (with an I2t characteristic), short-circuit, phase fault and over-voltage increases the electric motors operating time;
  • It ensures a soft start of the electric motors, with constant Volt/Hertz control, limiting the electric and mechanical shocks during start.
  • Allows full control of the speed of the electric motors, depending on the temperature of the traction motors, which extends the operating life of the ventilation motors and increases the fuel economy.
  • The power supply uses the voltage generated by the dynamic braking, increasing fuel economy


The static converter for supplying  the auxiliary services has the following structure:

  • chopper (CH_SA): 1 part
  • inverters (INV_1-4_SA) : 4 parts

The chopper (CH_SA) is powered from the DC Link with the voltage varying from 600 V to 1950 V, and is supplying power to the auxiliary services inverters.


The first inverter (INV_1_SA) supplies power to seven 5.5 kVA electric motors used to cool the traction-braking static converters and the traction motors. The technical chracteristic of this inverter are:

  • Output voltage: 3 x (0..380) Vac, 0-50 Hz
  • Maximum output power: 38.5 kVA

The second inverter (INV_2_SA) supplies power to the electric motors that cool the apparatus block and the 220 Vac filter  voltage, and has a maximum power of 11 kVA.

The third inverter (INV_3_SA) supplies power to the screw compressor and to the ventilatin fan of the compressor.

 The technical characteristics for this inverter are:

  • Output voltage: 3 x (0..380) V ac, 0-50 Hz
  • Maximum output power: 30 kVA

The fourth inverter (INV_4_SA) supplies power to the electric motor that cools the braking resistors. 

The technical characteristics for this inverter are:

  • Output voltage: 3 x (0..380) V ac, 0-50 Hz
  • Maximum output power: 5,5 kVA

All inverters are protected for overload, short-circuit, minimum supply voltage, maximum supply voltage, phase fault and report errors to the central computer.





To meet any requirements regarding size, access, mounting or electrical connections, the panel is made from fiber-reinforced polymer.

To increase the comfort during operation, the area behind the panel is closed with removable boards. Under the panel, behind the removable boards, are mounted the terminal boxes, used to link the panel to the electrical equipments, air lines, electro-pneumatic systems moving the windscreen wipers, air horn or windscreen cleaning system. On the vertical boards are mounted the traction motors disabling switch, the driver’s cabin heaters, 220 V ac electric sockets and the circuit breakers that protect the electric equipment from the driver’s cabin. On the panel are mounted the electrical and pneumatic equipment required by the driver’s operation. 

The dashboard has  the following equipments:

  • Vehicle monitoring unit (PRO-UMV) is an integrated embedded system that has a graphical display with high brightness that displays the current status of the locomotive to the driver and presents solutions to the problems that may occur. The measurements that are used by the central computer unit are displayed in different screens that can be accessed using the keyboard or the touch screen. Stored information can be downloaded to an USB external memory to interpret the data on the PC. The driver is able to reset some faults incurred by pressing the touch screen. Due to its flexibility, the system can communicate through various communication interfaces (CAN, Ethernet, RS-232, RS-485, Profibus, CANopen, etc.);
  • Panel activation key and driving direction switch;
  • Traction/braking controller;
  •  Electro-penumatic braking controller;
  •  Manometers for the braking cylinders, compressed air container, and train line;
  • Analogic indicators for the traction/braking tractive force, Diesel engine speed and DC Link voltage
  • Frequency synthesized transceiver;
  • Diesel engine status and fault indicators;
  •  Lighted switches to control the cabin lighting, the compressor or the ventilation;
  • INDUSI and DSV control block;
  • Shunting control block;
  •  Primary braking controller;
  •  Air horn controller;
  • Windshield washing control block;
  •  DSV command block.
  • Air conditioner unit  The driver’s cabins are fitted with Coleman air conditioners mounted on the roof of the cabins. Each unit has a cooling power of 12000 BTU and is powered from the 24 V supply line.
  • Heating system of the driver’s cabins are fitted with PTC heating elements with a maximum power of 2 kW. The heating elements have adjustable heating levels, are self-protected and have a high thermal efficiency.



Breaking resistors block (optional)


This block is fitted with its own cooling fan, driven by a tri-phased asynchronous motor, powered by a voltage and frequency inverter supplying 3 x 400 Vac / 50 Hz.

The cooling air is absorbed from the locomotive’s exterior, below the resistors block, and exhausted to the exterior, above the block.

The braking resistors block has its own ventilation piping.

The maximum braking power is 2 x 356kW;

The maximum input voltage for the dynamic braking is 1950 Vdc;

Rated resistor: 2x9,60 ohm;

Mass: 400 kg;

Fan motor power: 4,6 kW.



The compressed air production system (optional)

The compressed air production system is fully automated and it uses an encased screw compressor in one piece made by Gardner Denver, type Tamrotor TEMPEST 6+ . The compressor is driven by a asynchronous motor with squirel cage and powered by a static voltage and frequency converter. The converter assumes the soft start of the motor and the mechanical transmission is made using a wide multi-finned Poly V belt.


  • increased reliability and efficiency due to the screw compressor;
  •  noiseless operation;
  • reduced oil quantity in exhaust air and reduced total oil consumption, determining enhanced exhaust air quality;
  • the air flow is constant over large variations of the power-supply voltage;
  • the static converter prevents current shocks when the electromotor starts up.

Technical specifications:

Pn: 30kW;

Un: 380 V with a variable frequency of 50 Hz;

Rated output air flow at a pressure of 10 bar: 3,2 Nmc/min;

Oil consumption: 3 mg/mc compressed air.