From Discrete IGBT Modules to Power Stacks

Transcription

1 From Discrete IGBT Modules to Power Stacks APEC 2015 March 19 th 2015 Charlotte, NC SEMIKRON Inc. G. Genet P. Drexhage K. Haddad Slide - 1 -

2 What is a power stack? 1. Heatsink 2. Thermal Interface Material (TIM) 3. Power semiconductor module 4. DC link (busbars and capacitors) 5. Snubber capacitor 6. Driver electronics (isolation, protection circuitry) 7. Busbar As of 2012, IHS (global research group) tracks Power Stacks as a separate product in its world market study for power semiconductors Slide - 2 -

3 How are power stacks utilized? Power stacks are a sub-assembly within a power converter POWER CONVERTER ENCLOSURE Disconnect Controller Typical Applications Drives Traction Renewables Wind Solar UPS, Energy storage Battery Flywheel Fuses Contactor Power Stack(s) Magnetics/Filter Slide - 3 -

4 How are power stacks utilized? New/Start-Up Business (Market-Entry Phase) Limited engineering + production resources Desire to focus on core competency (e.g. flywheel, battery, proprietary technology) Mid-Sized Business (Growth Phase) More developed engineering + production resources Desire for system level cost reduction Mature Business (Commodity Phase) Strong design capabilities Concerned with large scale costs (production time, logistics) Standard Stacks Custom Stacks Modules and Value- Add Services Slide - 4 -

5 How are power stacks utilized? Real-world examples Motor Drive Development Project 3-phase inverter with standard IPMs and standard DC link configuration No customization (off the shelf product) <10 pieces/year Elevator Motor Drive Rectifier, brake, inverter, DC link Optimized for up/down load profile Joint design project with customer 100s of pieces/year Hybrid-Electric Vehicle Drive Baseplate-less module, heatsink (liquid-cooled insert) Thermal grease application Customer specification 1000s of pieces/year Slide - 5 -

6 The power stack as a commodity item For most inverters (motor drives, grid tie inverters) the circuit topology is not unique, only the operating parameters Ideal mechanical design restricted by power module design A 2-level IGBT inverter = 3 half-bridge modules with DC link A B C B C Limited number of potential configurations! Slide - 6 -

7 The power stack as a commodity item One inverter stack can be configured for a variety of applications Reduction in cost and lead-time for the stack supplier Inverter phase leg Buck converter Boost converter Brake chopper Stack supplier handles paralleling (driver jitter, symmetrical bus design, etc.) Switching frequency Sharing inductance magnetics 3-phase interleaved buck/boost converter Slide - 7 -

8 The power stack as a commodity item Buy a stack Build a stack Commodity power stacks are desirable from a supply chain standpoint: Specification B Specification Design & Engineering Pre-qualified and tested item One part number to handle C Qualification Short time-to-market when standard stacks are used A Stack Procurement D Material Procurement However, careful specification still required! E Manufacturing Not a one-size fits all when it comes to operating parameters: Voltage Current System Integration F Testing System Integration Switching frequency Cooling method Buying a stack makes sense if $A < $(B+C+D+E+F) Slide - 8 -

9 Advanced modules require advanced integration Unique modules with high performance packaging..but difficult to implement effective busbars! modular design with multiple DC terminals to reduce stray inductance between DC link and IGBTs Manufacturer can eke out the best module performance through careful stack design Module - 3-phase IPM Multiple DC terminals Stack - DC link - AC busbars - Current sensors Less design risk for the end user Slide - 9 -

10 Power stacks as a vehicle for evaluating new technology Provide a safe and quick method of experimenting with a new topology User Controller Example: Three-level inverter Reduced number of gate signals to allow easier adaptation of existing two-level controllers Prevention of prohibited switching states (NPC) Conditioned analog signals ready for integration with controls Allows a user to develop control software prior to scaling up to a higher power level Fault logic, user interface, power supplies Voltage, Current, Temp., Feedback Drivers + Isolation t t t Slide

11 Power stacks as a vehicle for evaluating new technology Allow a user to weigh the benefits of a new technology Silicon Silicon carbide (hybrid) Example: Silicon Carbide (SiC) Stacks built with SiC using the same module package as traditional silicon User can easily make a cost vs. performance comparison in their system Evaluate effect of increased switching frequency on reduced filter/magnetics SAME FOOTPRINT Silicon Silicon carbide (full) SAME FOOTPRINT Slide

12 Summary A power stack is a discrete block within a power converter. Power stacks: make sense to outsource for certain, but not all, business types can be transitioned from standard custom component as a business grows can be an off-the-shelf/commodity item for certain topologies allow for rapid prototyping and development with: new circuit topologies new technologies Slide

13 Thank you for your attention! Slide