HybridKI based on HybridPACK 2 IGBT module

Infineon has launched a complete three-phase inverter system solution (HybridKIT based on HybridPACK 2 IGBT module), which can reduce the workload of designers in the structural design stage of (H) EV inverters and help them Ling's HybridPACK2 IGBT power module performance is evaluated, this IGBT module is suitable for inverter applications up to 80KW.

Inverter system development steps

The complete structure diagram of HybridKIT for HybridPACK2 is shown in Figure 1. HybridPACK2 is a typical 6-tube IGBT product that supports three-phase inverters. The main issues and challenges to be considered in the design are as follows:

The DC bus supporting capacitor used in the inverter system provides the decoupling of the power module and the battery. Film capacitors are best for this application. The main parameters include the working voltage of the capacitor, the allowable ripple voltage and the rms current. In order to reduce the stray inductance of the entire system, the modules and capacitors should be mechanically matched to each other.

In order to avoid overheating of the module temperature and exceeding the maximum allowable temperature specified in the module manufacturer's product manual, a heat dissipation channel must be designed for the power loss in the module. Therefore, the design of the cooling system is of great significance for achieving the best performance of the product and ensuring the service life of the product.

In order to fully realize the control, monitoring, evaluation, safety and protection functions on the motor control board and IGBT drive circuit board inside the inverter, it is necessary to do a comprehensive planning and design at the beginning of the system design stage, including component selection Design and determine the PCB circuit board + inverter high voltage circuit wiring, etc. A good layout can ensure good electromagnetic compatibility, and reserve enough electrical clearance and creepage distance. In addition, software development, testing, and debugging are also required.

All in all, the inverter system is an important core component of (H) EV, and efforts must be made to build the system.

Parts and functions of HybridKIT and HybridPACK2

HybridKIT (Figure 2) fully considers the above design challenges and is a system solution elaborately designed by Infineon for customers. It enables customers to easily and quickly complete inverter development and structural design and integration of the entire (H) EV Into HEV. Because HybridKIT enables customers to quickly evaluate various key parameters, it can help customers shorten the product development cycle. HybridKIT is not only a reference design, but also supports early system testing (for example, when HybridKIT is included in a hardware-in-the-loop (HiL) system) or initial prototype testing system testing.

Infineon's IGBT power module HybridPACK2 (Figure 3) and module-based HybridKIT can meet the application requirements of automotive under special working conditions, including thermal cycle stability and power cycle stability. In the development of the HybridPACK module series, we have made major improvements in the following two aspects: the connection of the bonding wire on the chip surface (bonding wire) and the solder joint between the substrate and the substrate (IGBT copper base plate). Therefore, most water cooling systems can meet Hybridpack's heat dissipation requirements. HybridPACK2 is designed to meet the 80kW drive requirements. HybridPACK2 contains all the power semiconductor devices required by the inverter and three NTC (negative temperature coefficient) resistors for temperature measurement. The module is designed for a maximum operating junction temperature of 150 ° C and contains a six-cell structure consisting of a third-generation trench field-stop IGBT (insulated gate bipolar transistor) and a freewheeling diode matched to it. The maximum rated current and voltage of HybridPACK2 are 800A and 650V, respectively, and conduction loss and switching loss are the lowest among similar products.

HybridKIT's second module includes a DC bus support capacitor B25655J4507K (manufactured by Epcos), which is electrically and mechanically matched to achieve a compact design and low stray inductance. After adjustment and testing, ensure that the capacitor fully meets the requirements of HybridPACK2.

For applications requiring higher power or higher operating temperature, we provide water-cooled components. The water-cooled component can be directly fixed to the IGBT module with screws, and an integrated rubber pad is added in the middle to play an appropriate sealing role. All design parameters are optimized to ensure a compact form factor, the best cooling effect and a longer service life.

The module uses two independent PCBs in order to design the circuit board according to the most advanced design rules, specifications and standards. The two PCBs include: IGBT drive circuit board and MCU control circuit board. The six-channel IGBT driver board is optimized in electrical and mechanical aspects to meet the requirements of HybridPACK2. The driver board has the following main functions: an isolated DC-DC power supply for the IGBT drive to ensure electrical isolation between six different IGBT drivers (1ED020I12-FA, Infineon's driver based on air core non-magnetic transformer technology) ; DC bus voltage detection with electrical isolation (as input for protection / monitoring function); temperature measurement via NTC element; active clamp diode for short-circuit protection; each IGBT driver is individually equipped with independent push-pull output power Amplify the circuit to improve the current driving capability.

The logic circuit board includes all the components needed to control the driver board. In addition, it provides the interface between all other components necessary to form a complete inverter system, including: motor interface (encoder and resolver), current sensor interface, communication (CAN and RS232) and additional analog and Digital input / output interface. With Infineon ’s on-board microcontroller (TC1767), various protection and monitoring functions, driver control, and evaluation of HybridPACK2 performance can be easily implemented through software. Sample software for these functions is under development.

HybridKIT for HybridPACK2 is both a reference design and an excellent tool for developing three-phase inverter systems. It not only supports hardware test and measurement (ie short circuit, temperature, etc.), but also supports software development. It contains all the components necessary to form a complete system, and provides interfaces (motor interface, current measurement and communication interface) to connect with other external components. A complete set of documents are also provided, including parts list, circuit design and layout data, etc., so that customers can start the development of (H) EV system as soon as possible.