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