Comparateur de bornes de recharge et systèmes de gestion Modbus RTU - Comparateur de bornes de recharge et systèmes de gestion

Abbreviations

A = Ampere
AC = Alternative Current
API = Application Programming Interface
CB = Circuit Breaker
CHadeMo = CHArge de MOve
CPO = Charging Point Operator
CCS2 = Combined Charging System type 2
DC = Direct Current
EMS = Energy Management System
eMSP = eMobility Service Provider (providing e-mobility card to users in order to charge across Europe on public charging station)
GPRS = General Packet Radio Service
kW = kilowatt
kWh = kilowatt-hour
LM = Load Management
MID = Measuring Instruments Directive
OCPP = Open Charge Point Protocol
OCPI = Open Charge Point Interface
RCD = Residual Current Device
RCM = Residual Current Monitor
RFID = Radio-frequency Identification
VDC = Volt Direct Current

AC charging station

AC (alternative current) charging stations charge with alternating current. The power of an AC charging station can vary between 3.7kW and 22kW. The alternating current passing through the charging station must be transformed into direct current to charge the battery of an electric vehicle. It is transformed using an AC/DC converter located in the electric vehicle.

Access control

To protect access to charging stations, there are different types of access control, such as RFID badge readers, smartphone applications, QR-code scanners, etc. This prevents anyone from free charging.

Backend

A backend is a management platform on which the data from intelligent charging stations is hosted, with different functionalities depending on the service provider. For example, you can view your charging infrastructure, control the charging station in real time, manage access and users on the charging infrastructure, or bill the electricity costs associated with charging electric vehicles.

Battery storage

DC charging stations with battery storage are available on the market. These charging stations charge their batteries in alternating current at moderate power, and thanks to the accumulation of energy in the storage battery, they can deliver direct current electricity at high power directly to the battery of an electric vehicle.

Billing management

A billing management system collects and stores information (kWh, location, charge point, user identification, date, time, start of charge, end of charge) from a charging station via the OCPP (Open Charge Point Protocol) communication protocol. To transfer data to a platform, charging stations must have access to the Internet via LAN, WiFi or GPRS (SIM card). Management systems, also known as ‘management platforms’, can interpret load data according to the needs of system users. Generally speaking, a billing management system (backend or management platform) offers:

view the infrastructure in real time
view all the load sessions that have taken place
extract load session reports
programme badges for access to the infrastructure, or even badges that can be used at public charging stations (LU and EU) –
charge for charging sessions on a per-user basis –
reimburse charging sessions carried out at home by employees using company vehicles – make charging infrastructure publicly accessible (CPO as a service – Charging Point Operator – usually own and operate private or public charging infrastructure)
establish simple and/or complex tariffs for access to charging stations.

Charging management for AC and DC charging stations

This is a smart chargingor energymanagement system that can manage both AC and DC charging stations in the same electrical circuit.

Charging station nominal power

Private charging infrastructures (domestic connection for single-family homes) are in principle limited to 11 kW, which is recommended and sufficient for the home. A higher charging capacity (up to a maximum of 22 kW) requires an increase in the capacity of your domestic connection. You should also make sure that the power of the planned installation matches the technical specifications of your electric car. Note that the comparison tool includes charging stations whose power rating can be adapted (from 22 kW to 11 kW).

DC charging station

A DC (direct current) charging station charges with direct current. The power of a DC charging station can vary between 20kW and 400kW. Alternating current is transformed into direct current (AC/DC) in the DC charging station, delivering direct current directly in the electric vehicle’s battery.

Dynamic Load Management

Dynamic: this involves distributing a given amount of power fairly or unfairly (prioritisation) between several charging stations, taking into account the power currently available according to the building’s real-time consumption. For example, the building’s main circuit breaker is 100A, which is equivalent to around 69kW three-phase. With Dynamic Load Management, if the building consumes 60kW, there would only be 9kW available for the charging infrastructure, which would be distributed between the various charging stations in use. If the building now only consumes 29kW, there would still be 40kW available for the infrastructure. This system generally requires an additional smart meter as well as current transformers that can measure the current (A – Ampere) required by the building in real time, and this smart meter communicates the information to the charging infrastructure so that it can adapt according to the power available.

Energy management

Energy Management Systems make it possible to bring together different energy devices on the same platform / App for the purpose of energy optimisation. These include charging stations (AC and/or DC), storage batteries, photovoltaic panels and heat pumps.
Objectives :

manage energy devices
monitor energy consumption
allocate power, manage charging priorities, schedule deferred charging sessions.

Klimabonus subsidies

Charging stations eligible for Klimabonus subsidies are indicated with a green ‘Yes’; if charging stations are not eligible, they are indicated with a red ‘No’.
There are 3 levels of support.

Basic charging station
Intelligent charging station: this is a charging station equipped with the OCPP 1.6 communication protocol and capable of communicating data from the charging station to a management system platform.
Charging stations in collective buildings: these are charging stations equipped with an intelligent charge management system or compatible with an external charge management system.

Find out how much aid is available depending on the type of charging station: subsidies.klima-agence.lu

Load management

Charging management, better known as Load Management or Smart Charging, is an intelligent system that enables a defined amount of power to be shared between several charging stations via wired or wireless communication.

Wired communication: the charging stations communicate with each other via a network cable (Ethernet cable with RJ45 connectors). Each charging station is connected in a star configuration to a common (unmanaged) switch. In this configuration, the most common communication protocol is Modbus TCP/IP. There are also charging stations which communicate with each other in series (bridging from one charging station to another with a 2-wire RS485 cable); in this case, the most common communication protocol is Modbus RTU. In both cases, we are talking about locally managed Load Management.

Wireless communication (OCPP Smart Charging): the charging stations are all connected to the Internet, either via WiFi or GPRS (SIM card). The charging stations are then integrated into a load management platform, and load management is carried out remotely via this platform. The platform sends charging instructions directly to the charging stations via the OCPP Smart Charging communication protocol. This system requires stable Internet communication.

Load scheduling

Some load or energy management systems can activate deferred charging sessions. This makes it possible to optimise energy consumption according to the power available at specific times (off-peak hours vs. peak hours).

Load split

Function that allows the power available on a charging station to be split in two if the station has two charge points. For example, a charging station with two charge points produces a maximum of 22kW: if one car is charging, it can charge at 22kW, but if two cars are charging at the same time, they will each have only 11kW.

Modbus RTU

Modbus RTU (Remote Terminal Unit) is a Modbus serial communication protocol designed for industrial automation systems. In particular, it facilitates the exchange of data between various devices, such as sensors, actuators and controllers, connected to a shared communication channel

Modbus TCP/IP

Modbus is a simple and widely used industrial communications protocol for sending data between industrial devices. Modbus TCP/IP is an adaptation of the well-established Modbus protocol for use over TCP/IP networks and allows Modbus devices to communicate via Ethernet, making it easy to connect devices over long distances or to connect to devices over a network.

TCP/IP is a data link protocol used on the Internet to allow computers and other devices to send and receive data.

TCP/IP stands for Transmission Control Protocol/Internet Protocol. It enables devices connected to the Internet to communicate with each other via networks.

Source: www.avg.com/fr/signal/what-is-tcp-ip ; www.ipw-systemes.com/quest-ce-que-modbus-tcp

OCPP 1.6

The Open Charge Point Protocol (OCPP) provides a uniform solution for the method of communication between the charge point and the central system. Thanks to this protocol, it is possible to connect any central system to any charge point, regardless of the supplier. A uniform standard avoids all kinds of coordination problems and is therefore an advantage for the entire electric vehicle market. To ensure that all safety functions and features are present, version 1.6 is mandatory.

Payment system

A means of payment that is widely deployed in Europe, such as a bank card reader or a generated QR code. This has been introduced as part of the AFIR (Alternative Fuel Infrastructure Regulation) and the accessibility of public charging infrastructures.

Power reduction by the user

Functionality enabling the user to reduce the power of a charging station either via a smartphone App or via another means accessible from the charging station. For example, when it is not necessary to charge at 11kW, because the car is going to be parked in the same place for more than 8 hours, it is possible to reduce the power of the charging station to 5kW, for example, and charge more slowly. This avoids creating a peak in consumption on the network and reduces your electricity bill following the increase in low-voltage grid tariffs that came into force on 1 January 2025.

Prioritising charge points

This function allows you to prioritise one or more charge points. For example, I have a maximum power available for the charging infrastructure of 52kW and there are 7 charging stations. I want one charging station to remain at 22kW all the time – prioritising this station – and the rest of the power is distributed equally between the remaining 6 charging stations, i.e. 5kW each. Not all Load Management systems offer this functionality. However, it is available in both static and dynamic versions.

PV Surplus (solar electricity surplus)

Functionality for a charging station to charge an electric vehicle only when the solar production, in a self-consumption configuration, produces a surplus of electricity compared with the consumption required in the home. This feature allows you to charge your electric vehicle instead of feeding the surplus electricity back into the grid, ensuring that your vehicle is charged using local, sustainable electricity.

Standardised interface for external management system

These interfaces enable standardised communication between different energy devices (charging stations, smart meters, photovoltaic panel inverters, heat pumps, storage batteries, etc.). Here are a few standardised communication protocols:

Modbus TCP/IP
Modbus RTU (RS485)
OCPP Smart charging – EEBus.

Static Load Management

Static: this involves distributing a given amount of power equitably between each charging station in the same cluster. For example, I have 40kW of power and 4 charging stations. If two cars are charging simultaneously, the two charging stations can each deliver 20kW. If 4 cars are charging simultaneously, each charging station delivers 10kW. This type of system is often programmable on the charging stations themselves and requires no additional external controller. There is a MASTER charging station in which the maximum power available is programmed, and the other charging stations are SLAVES, which receive instructions from the MASTER charging station. In this case, we are talking about a system that is specific to the manufacturer and integrated into the charging station technology. However, some brands of charging station require an external controller (additional module) which will itself control a certain number of charging stations.

Modbus RTU

Modbus RTU

Discover the different models below :