Communication for Plug-in Vehicles as a Distributed Energy Resource
|Publication Date:||1 December 2013|
This document applies to a Plug-in Electric Vehicle (PEV) which is equipped with an onboard inverter and communicates using the Smart Energy Profile 2.0 Application Protocol (SEP2). It is a supplement to the SEP2 Standard, which supports the use cases defined by J2836/3TM. It provides guidance for the use of the SEP2 Distributed Energy Resource Function Set with a PEV. It also provides guidance for the use of the SEP2 Flow Reservation Function Set, when used for discharging. It is not intended to be a comprehensive guide to the use of SEP2 in a PEV.
SAE Information Report J2836/3TM defines two system architectures in which a Plug-in Electric Vehicle (PEV) and the connected Electric Vehicle Supply Equipment (EVSE) together serve as a Distributed Energy Resource (DER). The inverter could be located in the PEV in which case AC power would flow from the PEV through the EVSE to the electric power system. Alternatively, the inverter could be located in the EVSE in which case DC power would flow between the PEV battery and the EVSE as needed by the inverter to perform the selected DER function.
The entity that contains the inverter should be the focus of any communication with the system that is controlling the DER devices for the DER application. This communication should be with the PEV in the case of an onboard inverter or with the EVSE in the case of an external inverter. While this recommended practice only applies to a PEV with an onboard inverter, it could optionally be followed by an EVSE manufacturer to guide SEP2 implementation for the case where the inverter is located in the EVSE. J2836/3TM provides guidance for updates required to J2847/2 to provide a DER DC mode that will allow the inverter in an EVSE to use the PEV battery when operating together as a DER. This DER DC mode will be an inner loop control mode modeled on the internal PEV communication between the inverter and the battery management system for an onboard inverter.
This document has five specific objectives:
Provide guidance for WHAT information needs be exchanged with the PEV using SEP2.
Provide guidance for HOW to manage the actual exchange of information with the PEV using SEP2.
Define RULES of engagement for the creation and use of information, the timing of information exchanges, and the resolution of conflicts by the PEV. The behavior of the PEV is governed by its own controls, displays, and embedded software. The purpose of SEP2 is only to move information to and from the PEV in support of the PEV functions. While SEP2 provides some recommended behavioral guidance, this document should be followed for the implementation of PEV functionality if there is a conflict.
Identify CHANGES for the next version of SEP2 and IEC 61850 to better support the requirements of SAE J2836/3TM. In some cases SEP2 supports SAE J2836/3TM requirements, but IEC 61850 does not. In other cases, the reverse is true.
Provide EXAMPLES of the use of SEP2 to perform selected V2G applications. There are too many possible V2G applications to create an exhaustive set of examples. However, a few examples can help guide the development of the embedded PEV software required to implement the protocol for the inverter functions.