The Open Smart Charging Protocol (OSCP) is an open communication protocol that enables the smart charging of electric vehicles (EVs). The primary function of the OSCP is to establish communication between the charge station operator (CSO) and the distribution system operator (DSO). Such communication helps forecast the available electricity grid capacity for 24 hours.
Figure 1 shows the role of the OSCP in the EV smart charging infrastructure. The electricity grid is connected to the CSO with the help of this protocol.
Figure 1. The role of OSCP in the overall smart charging of EV charging infrastructure.(Image: CIRED)
The OSCP was initiated by the Open Charge Alliance (OCA), which had earlier initiated its popular and widely adopted Open Charge Point Protocol (OCPP).
As per the technical document of the OSCP 2.0, four Actors are considered in the OSCP ecosystem as follows.
1. Flexibility Resource refers to devices that can produce or consume electrical energy flexibly. In the EV charging infrastructure, such devices can be EVs, battery storage systems, heat pumps, windmills, or solar PV panels. The use cases of Flexibility Resource can be attributed to smart charging of EVs and energy storage. The EVs can be charged during off-peak hours, and the energy storage, such as batteries, can be discharged during peak hours.
2. Flexibility Provider controls the Flexibility Resource(s) and can alter the energy pattern usage, especially during the peak hours when EV charging is not the top priority. The Actor can be used during demand response when requests can be made to shift the power usage. Depending on the need, ancillary services such as frequency and voltage control can also be initiated.
3. Capacity Provider manages and measures a certain network area and imposes limits on energy consumption. Examples of Capacity Providers include DSOs and Transmission System Operators (TSOs). It’s particularly useful for early management at the source, depending on the capacity and demand of the power usage. The Actor can also meet unexpected demand during an emergency period.
4. Capacity Optimizer is slightly different from a Capacity Provider. As the name suggests, Capacity Optimizers analyze and optimize the energy usage in the network. It includes a wider range of variables depending on which the energy usage is optimized.
Capacity Optimizers can help integrate renewable energy during an early weather forecast. Its scope can also be further expanded to optimize energy distribution.
Figure 2 shows the relationship between the different actors of the OSCP 2.0. The Capacity Provider and Optimizer drive the Flexibility Provider. In doing so, the OSCP has a well-documented process. However, the OSCP does not apply to the communication between Flexibility Provider and Resource.
Figure 2. An illustration showing the relationship between the four Actors of the OSCP 2.0. (Rakesh Kumar, Ph.D.)
Case study
A research study was conducted on 1,000 public chargers using the OSCP and OCPP by researchers from ElaadNL in 2020. The purpose was to examine the effect of smart charging on a large scale in the Netherlands. The distribution of the chargers across the country can be seen in Figure 3.
Figure 3. EV charger distribution across the Netherlands to study the effect of the OSCP and OCPP on the EV charging infrastructure. (Image: MDPI)
Two limitations were considered throughout the study. The first relates to the transformer handling capacity, and the second is the number of running sessions. Even with the limitation of running session count, 1.5 lakh sessions were handled to get a large sample size to study the effect of smart charging.
The study’s outcome is that the protocols adjusted the charging profiles of 52% of the total 1.5 lakh sessions. In doing so, the charging current was kept within the range of 13 to 20 A. With the remaining 48% of sessions, the EVs could be charged with a higher-than-usual power rating without any negative grid impact.
Summary
The OSCP and OCPP are promising combinations for the smart charging of EVs with respect to the efficient use of the electric grid. The OCA initiates both these protocols; therefore, they will be compatible with each other as the smart charging ecosystem evolves.
The four Actors in this protocol are an emerging concept of the OSCP 2.0, and understanding their relationship can offer EV charging operators an insight into the multiple variables that govern smart charging. The author feels that the number of Actors will rise in the revised version of this protocol, but only time will tell.
References
- Open Smart Charging Protocol 2.0, Open Charge Alliance
- Large Scale Smart Charging of Electric Vehicles in Practice, MDPI
- OSCP – An Open Protocol For Smart Charging of Electric Vehicles, CIRED
- About Open Smart Charging Protocol (OSCP), Solid Studio
Images
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