Green mobility has become an important topic in both transport and environmental policy, as governments promote the use of zero-emission vehicles to reduce air pollution in metropolitan areas and meet their climate goals. As a result, electric buses are considered an effective means of moving away from the internal combustion engine to a zero-emissions drive. For a decade now, HARTING has been supporting the charging infrastructure by supplying electromobility connectors. Today, the product range extends far beyond efficient interfaces for electric vehicle charging infrastructure.
HARTING recognised the trend towards electric mobility early on. Since 2010, the manufacturer has been providing interfaces that meet IEC 62196 for charging infrastructure for battery-powered vehicles. Initially, the main challenge was to enforce standards. Infrastructure manufacturers, electricity providers and vehicle manufacturers had to agree on uniform specifications, data formats and mating faces. For Europe, a uniform system for charging stations (Type 2) has been in place since 2016. Since then, anything new that has been created for charging stations must use the connector faces Type 2 and CCS Type 2 (‘Combo’), especially if the stations are open to the public.
HARTING has continuously expanded its e-mobility portfolio; it includes different types of AC charging plugs for Europe, the US and China. HARTING also offers solutions for combined AC/DC charging (Combo). In addition, HARTING has designed particular interfaces for use with so-called In-Cable Control and Protection Devices (IC-CPD).
Charging process for electric buses
In principle, there are three charging methods for electric buses. In practice, transmission occurs predominantly by means of a pantograph or plug-in connector, and to a negligible extent by induction. Consequently, in addition to its plug-in connectors, HARTING also offers interfaces for charging via pantograph. This is a scissor-like extendable frame with charging contacts which dock onto a charging rail and transmit the power for the batteries. Depending on the customer’s requirements, HARTING can offer a whole range of interface solutions for all aspects of the pantograph:
- Robust interfaces are required for the switching device of the pantograph, which is located on the roof of the e-bus. Depending on the required degree of protection, Han® A, Han B®, Han® HPR, Han® M or Han-Eco® are used.
- The ‘inner workings’ are formed by monoblock inserts or modules for data, signals and power.
- Power is routed to the battery storage via Han® HC contacts (up to 650 A and 4000 V).
- The new Han® S series connectors are recommended for wiring the battery storage modules.
- The entire range of HARTING PCB connectors are available for data and power transmission for devices and control units within the battery management system (e.g. har-flex®, har-flexicon® and various PCB adapters with a round connector face).
HARTING also provides interfaces for the wiring of e-buses and their subsystems. HARTING connectors supply passenger information systems, cameras, lighting, sensors, displays and devices in the cockpit, ticket machines, stop request sensors and USB chargers with data, signals and/or power.
Adequate EMC shielding is also important in many e-bus applications. The closer a connection is to the pantograph, the higher the requirements for EMC. Here, HARTING can transfer significant know-how from the rail sector. Combinations that meet the high demands of the rail industry also work in the e-bus.
The goal: Boost power density
The trend in battery storage is towards higher power density, with the primary goal being to increase the range of vehicles. To do so, more electrical energy must be available in the same battery volume. For the interfaces, it follows that they must become more powerful without taking up more space. With the Han® S, HARTING has already presented a particularly flexible and space-saving solution up to 200 A. In the future, the goal will be to further increase maximum transferable power.
This has consequences for the EMC properties of the interfaces. The higher the transmitted power, the higher the risk of interference in data lines. Solutions must be found that support the processing and assembly of storage systems in large quantities. In this regard, HARTING has already presented promising device connection technology, most recently the Han® 1A series that offers contact inserts with a shielding option. The series’ housings are made of plastic and can be easily assembled and equipped with shielding elements. Such solutions promote both the flexible production of interfaces and the ability to rapidly assemble large quantities of connectors.