Poznań 3-08-2024r.

Hybrid Multiple Unit (HZT).

The Type 36WEh Hybrid Multiple Unit Impuls 2 is the first Polish train which, in addition to being electrically powered from a 3 kV DC overhead contact line, also has a diesel drive in the form of the MTU PowerPack system. This system allows the train to run on routes without electric traction.

The HZT Impuls 2 type 36WEh series train was built in Nowy Sącz in secret and was completely developed by Polish engineers and technicians. The vehicle is not only innovative, but above all practical and has fitted perfectly into the Polish railway network. As of 31 December 2018, the length of active railway lines in Poland was 19,200 km, of which 11,900 km are electrified. During the People’s Republic of Poland, it was planned to electrify the entire railway network. However, the inept communist-run national economy could not carry out this plan. The HZT Impuls 2 type 36WEh vehicle uses innovative technologies that have managed to combine into a functioning system.

In 2019, the vehicle was officially unveiled at the 13th TRAKO 2019 International Trade Fair in Gdansk. During this fair, NEWAG S.A. was awarded the main prize in the prestigious competition named after engineer Ernest Malinowski, for products and technical innovations used in railways. The winner of the competition was the Impuls 2 type 36WEh Hybrid Traction Unit.

HZT NEWAG IMPULS 2 type 36WEh is the newest and most modern multiple unit in the world, which in Poland is already being used by several regional railways. This vehicle has prevented the emergence of further white spots on the map of the Polish Railway Network, which have excluded a significant part of Polish society from access to this mode of transport. The first vehicles of this type were purchased by: Zachodniopomorskie Province, Dolnośląskie Province, Łódzkie Province and Wielkopolskie Province.

HZT NEWAG IMPULS 2 type 36WEh is a three-car train, which travels at a speed of 160 km/h under electric traction, and thanks to internal combustion engines, on routes without wires, it travels at a speed of 120 km/h. These are parameters that fit perfectly on Polish tracks. The train takes 330 passengers on board and, importantly, is adapted for people with reduced mobility. Passengers have at their disposal: WIFI, 230 V AC power sockets, USB ports, air-conditioning, space to carry a bicycle, a modern passenger information system, under-window tables, luggage racks, closed-system toilets.

It may be added that NEWAG also offers bimodal vehicles, i.e. with an additional diesel section. No carrier has yet ordered such a vehicle. Vehicles with hybrid or bimodal drive guarantee a running speed of up to 120 km/h.

New energy storage facilities.

NEWAG is not standing still. In February 2023, it developed Europe’s first hybrid multiple unit (HZT) with a supercapacitor energy storage system from Medcom. Medcom has developed a supercapacitor energy storage system for NEWAG S.A.’s Impuls 2 hybrid multiple unit. The new vehicle was presented in September 2023, at InnoTrans, and is the first of its kind in the world. Developed by Medcom, the vehicle’s dual-propulsion system is a traction inverter that not only controls the operation of the asynchronous traction motors, but also generates voltage to power the onboard systems when running in diesel mode. For the Impuls 2 hybrid trains, Medcom also supplies auxiliary inverters, buffer power supplies, TCMS and low-voltage switchgear.

Presented at InnoTrans, the new HZT 36WEh unit was additionally equipped with a supercapacitor storage. Through the effective use of electrodynamic braking, implemented by traction inverters during vehicle operation in combustion mode, the super-condenser reservoir is charged so that the stored energy can be used in the next cycle. The propulsion system recovers the kinetic energy of the accelerated vehicle and converts it into electrical energy, which is then stored in the on-board supercapacitor storage. The stored energy is then used while the train is stationary to power the vehicle and also to restart it up to a speed of around 50 km/h. As a result, the train is able to leave the station platform solely on clean and free energy.

Mr Pawel Chodun, Vice President of MEDCOM’s Board of Directors, explained; – “The expansion of the propulsion system we have used to date required the addition of two new components to the system – a super-condenser tray and an accompanying DC/DC converter. The energy recovered during braking is first transferred from the traction inverters to the DC/DC converter, which reduces the voltage. Only then does it go into the supercapacitor bank. As the vehicle accelerates, the inverters raise the voltage and then the energy is directed to the inverters. Precise system management ensures that the diesel generators only increase their output when the energy from the storage tank is exhausted.”

According to analyses carried out by NEWAG, on the Goleniów – Kołobrzeg section, fuel consumption was reduced by 17% – 22%. With diesel prices and the daily operation of the vehicle, this will translate into savings running into millions of PLN. An equally important advantage of the modernisation is the very quiet operation of the vehicle and the reduction in exhaust fumes during standstill at the railway station and during start-up. The control system increases the power of the diesel generators only after a distance of about 500 metres, which provides increased comfort for passengers waiting on platforms.

Medcom’s supercapacitor banks have so far been used on trams. They are used, among others, in PESA JAZZ trams for Warsaw and Gdańsk and in Hyundai Rotem trams for Warsaw.

Data T-T HZT NEWAG IMPULS 2 typu 36WEh:

The train consists of three carriages. Bo’2’2’Bo axle arrangement. Unladen weight 119,000 kg. Gross weight 120,500 kg. Maximum axle load per track 183.3 kN. Number of passengers up to 330. Length with couplings 59.30 m. Rated power 1 600 kW. 3 kV DC power supply. Entrance door clearance 1.30 m. Entrance threshold height from rail head 0.62 m. The train can be operated at ambient temperatures of -25 to +40 degrees Celsius. Maximum operating speed; 120 km/h – in diesel mode, 160 km/h – in electric mode. Starting acceleration; ≥0.4m/s² – in diesel mode, ≥1.1m/s² – in electric mode. Kinematic gauge PN-EN 15273-2:2013. 1435 mm rail gauge. LED lighting technology.

PowerPack.

The PowerPack 1800 and 1600 series are designed as a compact and flat structure specifically for installation under the floor or on the roof of a traction vehicle. As a result, each PowerPack can be individually configured to the requirements of the respective rolling stock manufacturer.

MTU Diesel engines of the 4000 series, with an output of 390 kW, are used as the internal combustion drive. The 36WEh trains are equipped with two drive units called PowerPacks. Each consists of an MTU diesel engine, 6-cylinder, turbocharged in-line, with 390 kW. The engine can be combined with a ZF hydromechanical traction transmission or with a power generator. The latter solution is on Impuls 2 type 36WEh trains. The engine also has ancillary equipment such as an engine radiator, alternator, air conditioning compressor and air intake and exhaust systems, among others. These engines are characterised by; high reliability, ease of maintenance, long overhaul intervals and low specific fuel consumption. The transmission is optimised for speeds up to 120 km/h. The MTU 4000 series diesel engines are manufactured in 6H, 8V, 12V, 16V and 20V cylinder configurations and are good for installation in a wide range of locomotives, SZTs and HZTs. They use MTU common rail fuel injection. The diesel engines have a good power-to-weight ratio. On the HZT Impulse 2 train, the diesel engine drives a 360 kW power generator, which gives a voltage of 2,700 V to 3,050 V.

The MTU PowerPack uses motors; 6H1800 or 12V1600, which are centrally located. The speed of the motor shaft is transmitted either to the transmission or to the traction generator. On the opposite side of the PowerPack is the cooling system and optional other equipment: on-board generator, air compressors, air conditioning, CaPos. The exhaust system is on one side of the combustion engine and the air intake is on the other side of the engine. The whole unit rests on a single frame, which can be mounted under the floor of the wagon body or on its roof. The unit can use hydraulic, mechanical or electric transmissions. Thanks to its compact design, the PowerPack has a plug-and-play configuration, allowing quick assembly or disassembly and easy access to components. This solution also reduces the weight of the entire unit. MTU PowerPacks have electronic control of the most important parameters of the unit, which allows the technical condition of the power unit to be monitored in real time. The MTU PowerPack meets EPA Tier 3, 4i and EU Stage IIIB standards. MTU PowerPack have selective catalytic reduction (SCR) technology, and in Polish NOx reduction. Undoubtedly, the drive has low vibration and accepted noise levels.

The MTU PowerPack with 2 x 390 kW is fitted, for example, on SZT PESA Link and SZT NEWAG 222M Impuls trains. The same power unit is fitted on foreign SZT Bombardier Turbo Star trains. On the other hand, PowerPack 390 kW power units ranging from 1 unit to 4 units are fitted to Alstom Lint 54 passenger trains; depending on the number of carriages. 

MTU also offers the Hybrid PowerPack. This is a system additionally equipped with batteries, ranging from 30.6 kWh to 122.4 kWh. This solution has a mechanical transmission and an electric motor or just an electric motor.

Description of HZT NEWAG IMPULS 2 type 36WEh.

HZT NEWAG IMPULS 2 type 36WEh is a train composed of three carriages, and their designations are as follows; first car ‘A’, second middle carriage ‘C’, third end carriage ‘B’. The train has all the features of the EZT Impuls 2 type 36WE. These features include an economical driver’s cab with the possibility of adding a seat for a helper. The cab has individual air conditioning and a heating system. A fridge, kettle, microwave, washbasin and additional cabinets can be fitted. A separate door leading to the mechanic’s cabin has been fitted from the outside, both on one side and on the other. The previous EMU Impuls 1 did not have such a door. There is only one door from the passenger section to the cab. There is no door between the cab and the engine area, which increases the noise level in the cab.

Switching from catenary to diesel traction is simple. The direction of travel is given to Zero. On the systems screen, under the equipment tab, we give the mode window. We lower the pantograph. After a few seconds on the screen, we switch to diesel mode. When the electronics switch over, we return to the main screen and use the same lever from the pantograph to activate the PowerPack. You have to remember to activate the fast switch. Everything takes a few seconds. We do the same in reverse. The pantographs are placed on the middle section of the train.

The floor in the Impulse 2 vehicle is 0.62 m high and 0.76 m above the bogies. However, in the first and last car where there are PowerPacks under the floor is higher. Individual wagons can be equipped with a different number of passenger doors. Type 36WEh has one pair of passenger doors in each wagon. This increases the passenger changeover time, but increases the number of seats. The door gauge is 1.30 m. An additional plus is the reduction in the number of door automation systems. The interior of the train was designed in consultation with Wielkopolska Railways. The entire train is Class 2. The middle carriage is suitable for disabled travel and the carriage of bicycles and prams.

The middle section has one large toilet in a closed system. The doors to the toilet are opened manually, as the automation failed on Impuls 1 trains. The toilet is suitable for disabled passengers and is equipped with a baby changing station.

The electric traction motors have an output of 400 or 500 kW. The 36WEh vehicle uses 4 x 400 kW traction electric motors. These are three-phase asynchronous motors, and are electronically controlled via an inverter. There is one inverter per bogie. The mechanical transmissions are two-stage.

The vehicle is equipped with automatic Scharfenberg-type couplings. The novelty is the guards, which are easy to unlock and move upwards because they are permanently connected to the coupling. There is no possibility of losing them.

Written by Karol Placha Hetman