1. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 MODELLING ELECTRIC VEHICLES AT RESIDENTIAL LOW VOLTAGE GRID BY MONTE CARLO SIMULATION W.Du TU Delft The Netherlands

2. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225  Problem, Objective and Methodology  Base Model (By Monte-Carlo Simulation)  An Example of Simulated Low Voltage Grid  EV Appliance and EV Scenarios  DNOs’ Pricing Strategies  Model Results, Validation and Conclusion W.Du – the Netherlands – Session 5 – 1225 Structure

3. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Problem and Objective  Problem: Uncertain EVs’ impacts on low voltage electricity grid  Objectives: Supporting DNOs in grid asset capacity planning Finding out more accurately probabilities of possible overloads caused by EVs Analyzing DNOs’ pricing strategy in influencing EV charging behaviors

4. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Method

5. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Base Model (Monte-Carlo Simulation)  Model represents regular household behaviors of using electrical appliances  Stochastically generate load profiles more realistic then using aggreated and deterministic simulatainty factor especially true for low voltage grid  Aiming at finding more accurate the impacts of having EVs at households

6. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Base Model (Monte-Carlo Simulation)-Cont.  Household Types (HTs) Eight HTs by size, age and working status Percentages for HTs are based on Dutch statistic data  Electrical appliances Commonly used 25 types in Dutch households are stored Information including highest power, duration of use time Penetration degrees based on available statistics, market data and related researches  Usage of appliances Three types distinguished in relation to use time: constant use; instant use and semi-constant use Probability distributions are pre-defined in power usage, frequency to be used and duration time of each use.

7. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 An Example of Simulated Residential Grid

8. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 EV Appliances  Treated as household appliances Type: instant use  Only full battery-engined EV is considered  Attributes: Power usage:in triangular distribution (unit :watt) Duration of charging:in triangular distribution (time unit : minute) penetration degree: in percentage frequency of being charged in different charging periods:in triangular distribution (unit : integer)

9. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 EVs Scenarios  Starting Time: Start charging immediately after arriving at home Charging after 11:00pm  Charging Rate: low rate of 3kW and high rate of 10kW.  Charging Time EV efficiency of 5km/kWh is assumed EVs are assumed to be charged at households until full Distance driven pre-defined based on Dutch statistics  Penetration Degrees 0.1 to 1 in step of 0.1

10. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 DNOs’ Pricing Strategy  Shifting Charging Time Shifted to after 11:00pm from 10% of households onward up to 100% in step of 10%  Reducing Charging Time Reduced in 10% to 50% of previous settings

11. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Simulation Results Highlighted EVs’ charging load in a single household load profile

12. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Simulation Results – Cont. Aggregation of transformer loads

13. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Simulation Results – Cont. Aggregated peak load and probabilities of overloads

14. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Validation  Two Steps: Validation of the base model Validation of EVs’ charging profiles  Data Comparition Aggregations of household loads will be compared with empirical transformer loads provided by Enexis B.V., NL The EVs’ charging results will be validated with real sampled data at individual households

15. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Conclusion  Modelling EVs as household appliances by a Monte-Carlo simulation  Aiming at analysing EVs’ charging impacts on residential low voltage grid capacity  Charging scenarios are generated stochastically with different penetration degrees and charging patterns  DNOs’ pricing strategies also are estimated in their influences on EVs’ charging patterns

16. Frankfurt (Germany), 6-9 June 2011 W.Du – the Netherlands – Session 5 – 1225 Thank you for your attentions!