Since TOYOTA’s first Prius in 1997, the public relates electro-mobility to the automobile mega-market. Even though it may be the most important market, it is not the first in its evolution. Much earlier, the material-handling industry started to build its future on electrified vehicles. In 2018, more than 1 million electrified vehicles went into the global industry – almost exclusively operating from low battery voltages between 24V and 96V.

Figure 1: SKAI3 design-platform with user-controller (blue)

The material handling industry serves as an example of demand driven electrification. Besides the smaller pallet movers, where warehouse-use demanded electrification from the start of their mass-usage already in the 1950’s, the larger counterbalanced forklifts as well as the tow-trucks started their tour against their gas or diesel powered brothers in the late 1980’s. The success rate differs greatly across the regions. While in 2015 Europe already bought more electric than combustion engine large trucks, the global percentage for the electrification of large trucks today is just touching one third. 

The material handling vehicles are not the only success story. Starting from bicycles, through e-rickshaws, Tuk Tuks and golf-carts all the way to small passenger cars, the silent low-voltage revolution is on the move. The latest group of vehicles coming in the focus of electrification are recently small tractors and diggers. Low-voltage powered vehicles are often exempt from subsidies but still these vehicles are gaining constantly. The simple reasons: they are cheap, they are safe, electricity and maintenance cost are very low and they are silent and do not pollute the cities. 

SEMIKRON, a leading supplier of power electronics equipment, has been providing products for vehicle electrification for more than 25 years. Starting with material handling applications  (such as forklifts) in the early 1990s, SEMIKRON has since equipped more than 1.5 million vehicles  for material handling, beyond 200,000 passenger cars with power electronic products, plus more than 50,000 traction inverters into electrified buses in China.

The overall accumulated field operating hours exceed several billion in total by now. The resulting field data underline the fundamental advantages of solder free assemblies of power semiconductors, which is the standard in all SKAI inverters. The lack of solder joints in the power semiconductor assembly enables the product to fulfil the challenging requirements for load power cycling, which is a direct consequence of the continuously ongoing accelerations, decelerations and lifting actions of the manoeuvring forklift.

The growing number of low-voltage applications demands a wide range of solutions to match the requirements in performance, size and function. The upcoming SKAI3 LV, the 3rd generation of MOSFET based inverter, offers a power electronic platform that can easily be equipped by the drivetrain designer with the controller and software combination needed to meet the application requirements. A power density of more than 25 kVA/liter and a total volume of less than 1.8 liters allows the design to fit into many applications with its standard case already. For designs with special requirements regarding space, cooling or power connectors, the design is a perfect starting point for a customer specific design.

SEMIKRON contributes to the global efforts for decarbonisation with a wide range of products for electrified vehicles. For all low voltage applications, SEMIKRON offers the SKAI3 LV inverter-platform to make it easy for vehicle manufacturers, drive-train suppliers or inverter specialists to develop the optimum design.