Report

Modeling and Simulation of HEV and EV Power Electronics Dr. Sam Dao Applications Engineer Paul Goossens Vice President, Applications Engineering © 2011 Maplesoft, a division of Waterloo Maple Inc. The HEV/EV Modeling Problem HEV and EV modeling presents new problems • Complex, multi-domain models • Difficult to run in realtime for HiL applications • Coupling between domains can cause unexpected responses • Batteries and power electronics are very complex • Costly prototypes must be built to reveal system-level problems © 2011 Maplesoft, a division of Waterloo Maple Inc. The Need for Fast and Accurate Models Accurate system-level models require accurate battery and power electronics models • Electro-chemical battery models are very complicated physical systems with complicated mathematical descriptions • Interaction of battery with power electronics and vehicle dynamics reveals higherorder effects can be mitigated • Access to system-level equations provides further insight © 2011 Maplesoft, a division of Waterloo Maple Inc. HEV Components HEV Powertrain IC Engine Simple: controlled torque driver (ideal or lookup map) Mean Value: physical equations for overall power output and fuel consumption Cycle-by-cycle: detailed four-stroke model Engine/transmission coupling Controllable Friction Clutch (built into MapleSim library) Torque Converter (lookup tables for torque ratio and load capacity) Transmissions Basic components Decomposed planetary (planet-planet, planet-ring) Dual ratio planetary: co-rotating/counter-rotating planets Manual 5-speed Automatic 4-Speed (ZF 4HP22: 3 planetary gears, 12 clutches) 6-speed Dual-clutch Ravigneaux 4-speed Lepelletier 4-Speed CR-CR 4-speed Continuously Variable Transmission (CVT) Ideal or Lossy (Lookup tables for meshing friction, torque friction, slip) Differentials Passive/Active Ideal/Lossy Energy Storage/Conversion •Batteries/Fuel Cells •Motors •Generation/Regeneration •Power Conversion •State-of-charge control Vehicle Dynamics •Multibody components for 3D Chassis Modeling •Chassis/Suspension/Steering •Stability Analysis and Control Example: Hybrid-Electric Vehicle FTP Drive Cycle: Simulation Results Power Split: Torque/Speed Video © 2011 Maplesoft, a division of Waterloo Maple Inc. Battery Modeling in MapleSim Sam Dao, PhD, Maplesoft Batteries Details Physics and Equivalent Circuit: • Lead-Acid • Ni-MH • Li-Ion for the following chemistries: LiNiO2, LiCoO2, LiV2O5, LiFePO4 (Lithiumiron/iron phosphate), LiMn2O4, LiMn2O4 low plateau, LiTiS2, LiWO3, NaCoO2. © 2011 Maplesoft, a division of Waterloo Maple Inc. Approaches to Battery Modeling Circuit-based models: • represents battery behaviour as electrical circuit • conceptually simple • hides the battery physics Chemistry-based models • more accurate modeling of all battery characteristics • many configuration parameters • complicated model © 2011 Maplesoft, a division of Waterloo Maple Inc. Circuitry Battery Model Relate SOC to component values based on experimental data Battery capacity Short and long time response, charge depletion and recovery Pros: Simple and easy to understand Accurate model and fast to simulate Cons: Does not include temperature effects New model has to be developed when battery parameters are changed Open-circuit voltage © 2011 Maplesoft, a division of Waterloo Maple Inc. Circuitry Battery Model • Comparison with actual battery discharge: © 2011 Maplesoft, a division of Waterloo Maple Inc. Physics-Based Battery Models • Lithium-Ion battery modeling using porous electrode theory: Cathode: Li1 y CoO2 yLi ye LiCoO2 Anode: LiyC6 C6 yLi ye Porous negative electrode contains graphite Porous separator Porous positive electrode contains metal oxides © 2011 Maplesoft, a division of Waterloo Maple Inc. Physics-Based Battery Models Distribution of liquid-phase concentration over x: © 2011 Maplesoft, a division of Waterloo Maple Inc. Physics-Based Battery Models Discharge voltage with pulse current (30 A) Battery voltage with different cathode chemistries © 2011 Maplesoft, a division of Waterloo Maple Inc. Power Electrical Components and Circuits in MapleSim Paul Goossens, Maplesoft Basic Components Semiconductors BJT (NPN, PNP) MOSFET (N, P) Diodes Triggered components Thyristor, GTO Multi-phase components Motors/Generators DC Permanent Magnet, Excited Armatures Equivalent Circuit AC Synchronous and Asynchronous Multi-phase Stepper Brushless DC Power electrical subsystems IGBT © 2011 Maplesoft, a division of Waterloo Maple Inc. IGBT Single-stage Driver © 2011 Maplesoft, a division of Waterloo Maple Inc. Three-phase IGBT Drive Asynchronous Induction Motor Speed © 2011 Maplesoft, a division of Waterloo Maple Inc. What is MapleSim? MapleSim is a truly unique physical modeling tool: • Built on a foundation of symbolic computation technology • Handles all of the complex mathematics involved in the development of engineering models • Multi-domain systems, plant modeling, control design • Leverages the power of Maple to take advantage of extensive analytical tools • Reduces model development time from months to days while producing highfidelity, high-performance models © 2011 Maplesoft, a division of Waterloo Maple Inc. Summary Complex physical modeling is becoming increasingly important – and increasingly complex – particularly in EV and HEV systems design, testing and integration MapleSim is the ideal tool for rapid development of complex multi-domain physical models of EV and HEV systems for fullpowertrain simulation and testing Extensive range of battery and power-electronic models is available to give you the fidelity you need Thank You Questions? w w w. m a p l e s i m . c o m ww w. m a p l e s o f t . c o m / s u b s c r i b e