1. Virtual lab on power systems management: the Hybrid Electric Vehicle A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 1 Institut d’Organització i Control de Sistemes Industrials Universitat Politècnica de Catalunya

2. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 2 Outline Introduction HEV model The DC bus Electric machines Power converters Storage elements Electrical loads ICE model and fuel consumption Mechanical transmission and vehicle modelling Power management Standard speed profiles HEV virtual lab description Conclusions

3. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 3 Introduction The increase in industrial activity, and the improvement of population living standards makes that the European Union (EU) increases year by year its energy consumption. Different strategies are developed to search for alternative energies and to rationalize and optimize the energy consumption. Temporary energy storage elements can be applied to manage the energy consumption of several systems, such as an Hybrid Electric Vehicle.

4. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 4 Introduction In order to disseminate the existing problems in key generation, processing and energy management virtual laboratories (VL) can serve as platforms for testing and learning different systems and concepts related with them. Virtual laboratories: allow students to construct their own mental model are cheaper than the hands-on laboratories allow to compare different scenarios and configurations

5. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 5 HEV model HEV can be classified in two large families, depending on the topology: Series: mechanical decoupling between ICE and the wheels, which allows to regulate the ICE speed independently of the velocity of the vehicle. Parellel: only one electrical machine is required.

6. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 6 HEV model To simplify the model implementation, a generic system able to describe the behaviour of both HEV configurations and conventional vehicle, has been developed.

7. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 7 HEV model: The DC bus All electrical components are connected through a DC bus. All elements connected in the DC bus share the same voltage, Vbat, which in the model is fixed by the batteries in order to assure causality. This connection is modelled using the Kirchhoff law:

8. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 8 HEV model: Electric machines Permanent magnet motors, induction motors, and recently switched reluctance machines, are considered the most likely candidates for the propulsion system for an HEV. Since the dynamics of the electrical machines are faster that the vehicle ones, they are reduced to a simple static relationships:

9. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 9 HEV model: Power converters Power converters are switched electronic devices which allow to regulate the electrical power flow in the system. In the proposed scheme the power converter allows to control the energy flow to the electrical machines and the ultra-capacitors by means of the n control signal. The simplified static model for the power converter (neglecting the losses) is:

10. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 10 HEV model: Storage elements Batteries and ultra-capacitors are included in the HEV as energy storage elements. Only the energy in the ultra-capacitor is managed, while the energy stored in the batteries comes from the power balance of the system. Battery: Ultracapacitor:

11. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 11 HEV model: Electrical loads Current vehicles contain a number of comfort components such as air conditioning system, illumination, or music. In the proposed model the effect of these components is modeled as resistive load with a certain power consumption:

12. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 12 HEV model: ICE model and fuel consumption The ICE has been considered as an ideal torque source. The fuel consumption of the ICE, is also obtained as a function of the mechanical speed and power. Depending on the HEV topology, the ICE speed corresponds to the mechanical transmission or the electrical generator.

13. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 13 HEV model: Mechanical transmission and vehicle modelling The vehicle is modelled as a mass under the action of some external forces. Considering a gear box, g, and the wheel radius, r: Damping force, Fa: Fb is the break force.

14. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 14 Power management The power management is based on to determine Kp, the ratio of the delivered power by the ICE in front of the required by the vehicle. The power management of this IVL takes into account: Regenerative breaking policy. State of charge of the battery. Vehicle speed and acceleration.

15. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 15 Standard speed profiles In order to compare different energy management algorithms and HEV topologies a set of standard speed profiles have been designed. These profiles take into account urban, road or highway driving, or a mixed case. The default driving cycle included in the interactive virtual lab is the mixed cycle so-called New European Driving Cycle (NEDC).

16. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 16 HEV virtual lab description Presented Interactive Virtual Lab has been entirely developed using Easy Java Simulations, EJS. EJS is a free and open-source interactive tool developed to build Interactive Virtual Lab in a very simple and straightforward manner. The laboratory is decomposed in three almost independent parts: 1.Model: Variables and relations between these variables. This includes the differential and algebraic equations. 2.View: The view corresponds to the virtual laboratory outputs. These outputs are constituted by different windows which contain generic graphics and representations of the systems. 3.Control: This part contains the actions that a user can perform on the simulation.

17. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 17 HEV virtual lab description The main window of the virtual lab contains: Start, Stop and Reset buttons. Configuration menu, which allows to choose the configuration of the HEV (series, parallel or conventional). Speed profile, with a pointer with the position in the profile. Dynamic bars with the battery and ultracapacitor levels. Load selector.

18. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 18 HEV virtual lab description Additional windows have been introduced in order to tune and analyze the energy management algorithms (for example the braking police). The evolution of most relevant parameters can be observed in several graphical windows. Simulations obtained with different configurations or parameters, can be compared.

19. 19 Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya HEV virtual lab description 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009

20. Virtual lab on power systems management: A. Escolà, A. Dòria-Cerezo, R. Costa-Castelló the Hybrid Electric Vehicle IOC- Universitat Politècnica de Catalunya 8th IFAC Symposium on Advances in Control Education Kumamoto, October 21-23,2009 20 Conclusions This tool has been developed using the EJS software, which lets you create dynamic models with a graphical interface. Future developments includes: a pollution model, a power management tool,… and the use of EJS with other kind of energy systems such as wind turbines, flywheel energy storage system,... An interactive virtual laboratory which allows to simulate an energy management system (an hybrid electric vehicle) is presented. This IVL has been developed as a pedagogical tool to introduce engineering students in concepts and main ideas behind HEV. The use and evaluation of the IVL in courses will give a necessary feedback to improve the presented tool.