Efficient Energy Management Architecture of Distributed Energy Resource Microgrid Site with Electrical Vehicle Supply Equipment

In recent advancements of distribution grid automation, there is a trend to separate monitoring

& control from front-of-the-meter (FTM, sometimes referred to as FOM) and behind-the-meter

(BTM) resources. This categorization and separation of monitoring & control typically enables an advanced distribution management system (ADMS) to communicate with FTM DER resources through a deterministic protocol and route, such as DNP3 on synchronous digital hierarchy (SDH). On the other hand, BTM DER resources can be managed by the layered architecture of a distributed energy resource management system (DERMS) and aggregators utilizing an industrial internet of things (IIoT) protocol, such as the IEEE 2030.5—Smart

Energy Profile Application Protocol (also known as SEP 2.0).

As deployments of distributed solar, storage, and electrical vehicle supply equipment (EVSE) increase exponentially, the energy ecosystem is getting more complex. These are often installed as part of an existing BTM electrical system, such as in commercial & industrial (C&I) applications, creating C&I microgrids with a complex energy system that requires management.

In this paper, we study the energy management in a C&I microgrid with local solar generation, battery energy storage system (BESS), and EVSE integration.

Under the proposed C&I microgrid architecture and subsystems, the operational technology

(OT) or IIoT protocols utilized may be required for: •

•

• Grid control of DER— IEEE 2030.5

Site energy management system (EMS) to control generation, storage and load—

Modbus

Management of EVSEs— Open charge point protocol (OCPP) OCPP has been widely adopted by EVSE vendors and charging station management systems

(CSMS) operated by charge point operators (CPOs). But the purpose of OCPP is to manage the user experience for EV owners rather than managing electric systems and charger load control at individual sites. Using OCPP for the latter may lead to less-than-ideal load situations in use cases such as the C&I microgrid applications, which are studied in this paper.

As EVSE integration and grid control capabilities increase system complexity, this paper proposes the following devices for coordination between protocols to achieve sufficient control and management for the C&I microgrid and distribution grid control and management:

•

• DER Gateway: IEEE 2030.5 client gateway proposed in this paper to support the grid control functionalities of the complex C&I energy system.

OCPP Gateway: Novel device that translates EVSE energy management related data to

Modbus for site EMS. With the integration of the two devices, a BTM C&I microgrid can communicate with DERMS and its corresponding electric utility while being able to control on-site EVSEs while they are communicating with their corresponding CPOs.

The dual gateway microgrid (DGM) architecture proposed in this paper can help fulfil local energy system management, grid control functionalities such as demand response, flow reservation or active/reactive energy services, and EV charging commercial transactions, as well as overall the user experience.