Christian Lederer
CISC Semiconductor GmbH, Austria
Integration of Electric Vehicle Charging Infrastructure into Building Automation
Systems
“ecoCity eMotion” 24-25th September 2014, Erlangen, Germany
European Conference on Nanoelectronics and Embedded Systems for Electric Mobility
Presentation Outline
Motivation
Integration of EVSEs into the BEM
Extension of OCPP 1.5
Software Architecture
Hardware Platform
Motivation
Reduce power peaks at PCC
Shift energy consumption into lower tariff zones
EVs are high loads
EVSEs must be integrated into the Building Energy
Management (BEM)
Source: Siemens AG
Building Energy Management
PV and Storage are connected to the BEM via BACnet/IP
EVSEs use OCPP
Gateway is needed to translate between OCPP and BACnet
EVSE is converted into a BACnet device
Source: Siemens AG
OCPP EVSE as BACnet Device
EVSE is represented as BACnet device to the BEM
OCPP messages are mapped to BACnet objects
Translation between an event-based into a state-based protocol
Integration of EVSEs into the BEM
BACnet
GW reads/writes properties (objects) of the BACnet device
GW reacts on Change-of-Value services from the BEM
OCPP
Webservices based on OCPP 1.5+
GW implements Central Service of OCPP
Handles requests from the Charge Point
GW contains Charge Point client
Triggers actions on the Charge Point
Extension of OCPP 1.5
C. Lewandowski, S. Haendeler, C. Wietfeld: „Performance Evaluation of Large-Scale Charge Point Networks for Electric Mobility Services“, ICSNC 2011.
For energy management purposes, additional data need to be communicated, e.g. “max. charging current” and “assigned charging current”
Extension of OCPP 1.5
Data Transfer Request used to transmit additional
information
Capacity of the EV‘s battery
SOC of the EV‘s battery
Target SOC
Departure time
Max. power which can be consumed by the EV
Max. power which can be delivered by the building
Software Architecture
Based on OSGi [1]
Hardware independent
Highly scalable
Addition of bundles at runtime
Software Components
HTTP server
Apache Axis 2 [2]
Web services engine
Simple Object Access Protocol (SOAP)
Web Services Description Language (WSDL)
BACnet/IP stack [3]
BACnetOCPPGateway
Additional instances can be added dynamically
Hardware Platform
Smart Gateway
Microprocessor without Interlocked Pipeline Stages (MIPS)
34Kc, 32 bit, 500 MHz
128 MB RAM
25 MB flash
20 MB used by Axis 2
4 Gigabit Ethernet ports
Summary
Seamless integration of OCPP EVSEs into BEMs using
BACnet
Extension of OCPP 1.5
Scalable software architecture
Multi-purpose hardware platform
References
[1] OSGi Alliance: http://www.osgi.org/Main/HomePage
[2] The Apache Software Foundation: Apache Axis 2,
http://axis.apache.org/axis2/java/core/
[3] BACnet4J: https://github.com/empeeoh/BACnet4J