SKAI systems have been developed in line with the latest automotive standards and system qualification standards, allowing short time-to-market and lower development costs. The systems are supplied as standard modules with low-voltage MOSFETS or high-voltage IGBTs and in single-, dual- or multiple-inverter topologies. SKAI systems have been developed to meet individual customer specifications. SEMIKRON is a single-source supplier that covers everything from feasibility and proof-of-principle studies, to the development of optimum system architecture, to electrical and mechanical simulations, end qualification and complete-system series production. All SKAI 2 modules are fully qualified using analysis such as highly-accelerated life testing (HALT) and end of component-life testing, with full failure-mode effect analysis studies conducted at all critical points of the design cycle, to ensure that they meet relevant automotive standards.
The high-voltage SKAI 2 is available as a water-cooled 600/1200V IGBT inverter system, and has been optimised for use in applications such as full-electric cars, plug-in hybrid cars and electric buses. This system is based on the established sintered, 100% solder-free SEMIKRON SKiM93 IGBT modules, features a polypropylene film DC-link capacitor, driver electronics, a latest-generation DSP controller, EMC filters, and current, voltage and temperature sensors, and comes in an IP67 module case. Communication with the vehicle master controller is via a CAN bus. These systems are designed for outputs of up to 250kVA.
The low-voltage SKAI 2 is available as an air-cooled or water-cooled 50/100/150/200V MOSFET single and dual inverter system that is used mainly in forklift trucks and other materials-handling applications. These systems are suitable for a motor output of up to 55 kVA. They incorporate many of the same features as the IGBT-based systems and therefore offer the benefits to customers that they behave in the same way, use the same core control system and I/O connections, and the same system structure.
The third type of SKAI 2 platform is a multi-converter box. These systems are also housed in water-cooled, IP67-protected cases and communicate with the vehicle master controller via a CAN bus. The signal interface features analogue and digital I/Os to allow for the connection of a wide variety of sensors, such as temperature sensors and resolver inputs. A typical multi-converter system would include a three-phase 40kVA active front-end converter, a three-phase 20kVA drive inverter, a three-phase 10kVA drive inverter, and a 14V/300A or 28V/165A DC/DC converter.
“20 years of experience in the development of hybrid and electric power systems for use in forklift trucks, buses and agricultural equipment and machinery have gone into the development of our SKAI modules,” said Harald Jäger, Head of SEMIKRON’s System Group. “The System Group has now launched the second generation of SKAI modules, a series of robust systems for use in a wide variety of applications. We offer support at a local level to high-volume customers around the world, by providing an interface to the company’s design, specification and production functions.”
SKAI systems are based on SEMIKRON’s established SKiiP pressure contact technology, which boasts extended service life and high load cycling capability. SEMIKRON’s systems and semiconductor components are manufactured in high-tech production processes that include end-of-line function tests and, if required, 100% burn-in tests, ensuring a high degree of quality.