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

 Technical and functional solution implemented for modernization. 

1.Traction-braking static converter block



The hardware parts are mounted on a all welded frame fitted with locked access doors that provide easy access whenever repairs are needed.

It has the following components:

  • Three-phased rectifier for synchronous generator;
  • Traction – braking  inverters;
  • Electrodynamic braking chopper (optional);
  • Electrodynamic forced ventilation system for the traction and braking static converter block. 


Three - phased rectifier  for the synchronous generator

Is realised with diodes and it has single side cooling.


Power: 600-1800 kVA;

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

Frequency: 40-120Hz;

Output current: 364-950 Acc.


Three phased rectifier has a high reliability and minimal power loss by the use of modern electronic components and the dimensions are reduced by using optimal cooling surfaces..




Traction-braking inverters

For supplying power, three phased static converters are used, built on IGBT technology.


Input voltage: 600-1800 Vcc;

Maximum electrodynamic braking input voltage: 1950 Vcc;

Maximum output voltage: 1400 Vac;

Maximum output current: 370 Aca;

Frequency: 0-120Hz.


The traction inverters have a low power loss due to the usage of last generation semiconductor technology IGBT;

The overall dimensions are reduced and  the cooling is done by forced air flow.

Every inverter has a modular design with a lockable revolving door, allowing easy interventions and asecured environment. The inverters are controlled with optical fibers



Electrodynamic braking chopper (optional)


It complete the transfer of the electric energy that is produced by the traction motors when they work in electrodynamic braking condition (like a generator) to the braking resistors block.

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 1,2 and 3 traction motors, using two ventilation groups that are supplied with power from a voltage and frequency inverter.

The ventilation system allows two levels of ventilation and the speed of the motors can be variable.



2.Command and auxiliary services apparatus block


It is used for the control, adjustment and signal of the locomotive and to supply power to the auxiliary services. The apparatus 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;
  • Voltage regulator for the synchronous generator (type RAT GSP);
  • 24 Vdc switching  power supply for the control circuits and battery charging (type SIBA LDE);
  • Static converter for supplying power to the auxiliary services with individual load protection, type CSASA 85 KVA;




  • Central computer unit it is based on microcontroller technology it has one colour display in each driver cabin, it manages, it manages the locomotive controls, the most important analog signals and motors protection. 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 PID modules – 5 pcs
    • Digital output PED modules – 2 pcs
    • Analogic input PIA modules – 5 pcs
    • Analogic output PEA module – 1 pc.
    • Central computer PCC module – 1 pc.
    • PSA power supply – 1 pc
    • CAN communication module PCD – 1 pc.


Input data types

  • 160 24V digital signals distributed on 5 PID modules, each handling 32 inputs.
  • The PED modules can control 64 consumers using 24 V/2A signals. The output interface is distributed on two PED modules, each of them with 32 command channels.
  • It can convert 60 analogical 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 PEA module.
  • The PCD module, is providing the communication with the diagnosis, monitoring and signalling systems from the driver`s cabins, using one CAN bus.
  • The PCC 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. 



  • Traction - braking computer controls the electric traction and braking and the optimum usage of the Diesel engine, synchronous generator and traction motors. Access from the passage to 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 algorithms, designed for traction. The computer is using three types of modules:
    • Inverter control module TC-S - 6 pcs.
    • Computer control module TC_M – 1 pc.
    • Power unit module TC_MS_A – 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, for the electric circuits and fibre 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 using Space Vector PWM for complete Variable Voltage Variable Frequency (VVVF) inverter implementation. Motoring and Dynamic Braking operations in full speed range of the motors.
  • High switching frequency used in asynchronous PWM mode and six-step mode used at higher speeds.
  • Parameter adaptation used with changing operating conditions of the Traction Motor.
  • Each Traction Computer controls functions related to one Traction Motor only and are independent from each other. One Power supply card, two analog signal processing cards, and one computer card (with DSP) make up one set of Traction computer.
  • Traction Motor currents, voltages, DC Link voltage, current, temperatures from all IGBTs and capacitors are sensed for monitoring, control and protections.
  • All fault diagnostics are available from Locomotive Computer directly
  • Redundant Optic Fiber communication with automatic changeover used for interfacing with Locomotive computer.

Voltage regulator for synchronous generator (type RAT-GSP)


RAT - GSP is an automatic voltage regulator for adjusting the voltage at the output of 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, protection, diagnostics as unified signal (4 ... 20 mA), information it introduces in the voltage regulator, comparing it to the voltage information read by a voltage transducer located on the synchronous generator. RAT - GSP sends the measure 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 sends the error  information to the central computer. In case of emergency it can be reset by the central computer under certain conditions.

Construction system allows access for adjustments, checks, fixes, measurements etc by loosening front mounting block and cover. Printed circuit board and connecting removable connectors allow easy replacement if necessary.


Main technical characteristics:


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

Output current: max 10 Acc;

Set the output voltage three-phase rectifier: 600 - 1800 VDC;

Protection against overload and short circuit output current.


24 Vdc switching power supply for the control circuits and battery charging (type SIBA LDE)


SIBA LDE is designed to power the control circuits of the battery charger. 


The battery charging unit sends the battery voltage and current to the central computer, as 4-20 mA unified signals. It use  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 is designed with the following protections:

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


Static converter for supplying the auxiliary services with individual fault protection (CSASA 85 kVA)


CSASA 85 kVA is designed with individual thermal and electromagnetic protection circuits, 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.