capacitors on the DC side (output side) is particularly important. The maximum capacitor size is set to 1 uF at the DC output, i.e., with a filter in the system, the filter can be provided with 500 nF capacitance on positive and negative conductor If several filters are used in parallel, the size must be reduced accordingly. In addition, the discharge resistors must be at least 1 MOhm to enable insulation measurement in the system. The design of Schaffner standard filters provide the opportunity to modify the components used to meet customer specifications within the scope of the existing safety certificates. DC filters about to be launched to the market are the models FN2220 or FN2230, which can be adapted as required and identified with a unique suffix. Customer specific modifications are also possible

for standard AC filters, but there are different requirements for the design of these filters (>1 MOhm leakage resistors remain). The great advantage of modification of a standard filter is that it has already been certified. This means that even after modification, all certifications remain in place, which considerably reduces the time to-market. If the mechanics remain the same, samples ready for series production can be rapidly made available and initial delivery can take place quickly. Schaffner works on the premise of “first time right“ saving valuable waiting time for our customers before series production can take place. Example product descriptions based on standard DC filters: FN2200Q1*-250-99-R66* - FN2200 Standard filter for 250 A with 220 nF (Q1) capacitors with increased discharge resistances (R66 - 1.5 MOhm in parallel to X and Y capacitors); FN2211-400-99-C23*-R99*- FN2211 Standard filter for 400 A with 500 nF (C23) capacitors with increased discharge resistances (R99 - 10 MOhm in parallel to X and Y capacitors) *further variations possible


A part of the IEC61851-21-2 standard defines the limit values and the corresponding measurement setups. It is important to ensure that the correct network simulations and limits are used. On the input side (main power grid side) it must also be defined in which environment the charging point will be used, i.e., whether it is an industrial (Class A) or residential environment (Class B). The “CPT” port (conductive power transfer) must be terminated according to CISPR 25:2008 and the

AC/DC input port terminated according to CISPR 16-1-2:2014. The limit lines for the AC/DC input port follow the specifications of IEC 61000-6-3, for the CPT port the limit values shown in the following diagram for conducted emission (between 150 kHz and 30 MHz) apply. Since not only the functionality but also the

design of the charging stations is important, the size of the filters is often also decisive. Furthermore, the cost factor is playing an increasingly important role. The life cycle of products is similar to that of the start of photovoltaic industry, all manufacturers initially grow very fast and have few resources available to deal with the EMC filter topic. This often results in oversized filters. The first major wave of industrialization is typically followed by a consolidation of manufacturers, and thus also by an increase in production capacity. At this time, cost factors also play an important role. At the time of consolidation an application-specific solution must be available so customers can continue to be satisfactorily served in the future. This application-specific solution must also be optimized in terms of cost and size. FN2220 and FN2230 will be application specific filters designed for EV charging purposes.


To ensure the safe operation of EV charging stations, a galvanic separation between the input and output side is required in addition to compliance with EMC requirements and standards. The use of medium-frequency transformers is particularly beneficial for DC fast charging stations, where inverter technology is anyway required for rectifying the AC mains voltage. Compared to conventional main grid transformers, they can be designed much more compact with the same performance. This means that they can also be placed in constricted charging stations. Schaffner offers a broad portfolio that can meet almost all customer needs. Depending on requirements cooling can be natural or forced convection or even water cooling can be applied. Power in the two to three-digit kVA range can be generated. Within the framework of a research project in operation with RWTH Aachen University, even a 5,000 kVA medium-frequency transformer for coupling DC networks was successfully delivered and tested.


The “Cluster Electric Mobility South-West” in the State of Baden-Württemberg/Germany is one of the most important regional associations in the field of electric mobility. It brings together relevant players in the field of E-Mobility to research and work together on future-oriented approaches for vehicles, charging systems and forms of mobility. As an international leader in electromagnetic compatibility, Schaffner is now contributing to the electromobility technology field in the E-Mobility innovation cluster of the State of Baden-Württemberg. With the help of Schaffner’s experience in EMC

filter design, smooth and efficient operation of the charging station infrastructure can be made possible. In close cooperation with the other companies in the cluster, optimal solutions are thus created in a targeted manner. Electromobility is considered one of the main drivers in current global megatrends – “Electrification, Urbanization, Digitalization, Climatic Change“. For this reason, we see it as our task to provide cutting-edge technology.


Based on many years of experience with charging technology, Schaffner is able to provide complex customer specific solutions. In charging stations, for example, high power consumption via the capacitors can occur during no-load operation. With the help of additional logic switches, this problem can be completely eliminated and entirely integrated into the filter. The Schaffner Group works hard to offer its customers the perfect solution - at every stage of industrialization and with maximum delivery reliability. Our company blog, SCHAFFNER IMPULSE, provides many interesting articles on the subject of EMC in EMobility. For example, by developing compact, current compensated chokes, Schaffner has succeeded in reducing interference signals in the car between 80 and 400 amperes with only one magnetic core. An interesting overview of the standards landscape of electric vehicle charging infrastructures and our products which have been implemented in this area can be found in the article EMC and E- Mobility and in another article on EMC in the charging cycle.

Figure 2



Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52