ICE-4 trains have been running on DB’s rail network since 2015. With speeds of up to 275 kilometers per hour (km/h), they are predominantly used on high-speed lines (HSL). In these trains, IGBT semiconductor elements control the high-performance electrical drives whose activation is effected for the required galvanic isolation via plastic optical fibres (POF). Unfortunately, previous solutions were space-intensive and sensitive. A new miniaturised solution now facilitates handling enormously.
A new innovation of ICE trains is so-called powercars. These cars each contain complete car traction systems that are independent of other cars and feature transformer, power converters, traction motors and drive wheelsets. As a result, the train formation features fewer constraint points than in multiple-unit trains in which the traction components are distributed over several cars. Each of these powercars has a traction power of 1.65 MW and delivers a starting traction of 75 kN. IGBT semiconductor modules are installed in the traction power converter. HARTING now offers a new, miniaturised solution in IGBT control which enormously simplifies handling. HARTING’s solution features an electrical plug-in connection and optical transmission, thereby combining the advantages of two transmission technologies.
Doubling of optical fibres
In order to galvanically separate the high voltage differences between the drive and drive control of locomotives, optical fibres are used to transmit signals. For safety reasons, these transmission links in locomotives often feature redundancy. This leads to a doubling of the necessary optical fibres. For example, a three-phase motor alone requires 6 controller boards (2 IGBTs per phase).
Previously, each optical fibre had its own transceiver connection on the controller and driver board. However, in the event of servicing this is unfavourable since optical interfaces are sensitive and numerous individual interfaces must be carefully connected. In addition, in the event of damage the entire controller board must be replaced. This involves a considerable amount of time and money.
Together with established rail vehicle manufacturers, HARTING has developed a solution featuring a transmission principle that includes the relocation of the transceiver of the controller board to a pluggable module, thus integrating the optical interface in line with the principle of "connect electrically and transmit optically". HARTING uses solutions from the DIN 41612 series for the electrical mating and as a system housing. These solutions meet the stringent requirements of the railway market in terms of robustness, EMC and shock and vibration (IEC 61373).
The Multifibre module (provide HARTING link) enables the customer to simultaneously contact up to 16 optical channels in the smallest possible space. As a result, both installation and service can be simplified and shortened. The integration of the optical interfaces into a connector that can be quickly swapped out makes it faster, easier and less expensive to service the controller boards that are used.
Rugged and good flow behaviour
IGBTs are a further development of the vertical power MOSFET. An insulated gate bipolar transistor (IGBT) is a semiconductor device used in power electronics since it unites the advantages of the bipolar transistor (good flow behaviour, high blocking voltage, ruggedness) and advantages of a field effect transistor (almost powerless drive).
There are four different basic types of IGBTs. Depending on the doping of the base material, n- and p-channel IGBTs can be produced. These are subdivided into a self-conducting and a self-locking type. This property is selectable as part of the manufacturing process. In the circuit symbols for self-conducting IGBTs, which are also referred to as depletion types, a solid line is drawn between the collector (C) and emitter (E) terminals. This line is depicted in broken form in the self-locking types, also called an enhancement type. The gate terminal (G) serves as a control terminal for all types.
DIN standard DIN 41612
The DIN standard DIN 41612, colloquially referred to as the VG strip, defined the types of connectors which are primarily used for multi-pin electrical connection of printed circuit boards in the low-voltage area. The standard consisted of several parts and was replaced in February 1999 by European Standard EN 60603-2, also known as IEC 60603-2.
The class of these connectors consists of a total of 13 different basic designs and numerous derived versions, most of which are manufacturer-specific. All these connectors are used in the area of 19" racks per DIN 41494 to establish the connection between the plug-in cards, which are usually designed in the format of Eurocards, and the bus circuit board installed behind it in the frame. The pin number of the plug ranges from 20 to 160 pins.