Concepts of electric car charging

Charging power (kilowatts, kW)

The charging power tells how quickly the charging station can charge the electric vehicle's battery. It is expressed in kilowatts (kW), and higher charging power means faster charging.

For example:

• 3.7 kW (16 A, 1-phase). Charging at this power is slower, but it is usually sufficient for most people who charge their car overnight.
• 11 kW (16 A, 3-phase). The 11 kW charging power enables the car battery to be fully charged most of the time during the night, even if the battery is almost empty. This power requires a three-phase electrical connection
• 22 kW (32 A, 3-phase). This power level enables fast charging of the electric car, and it is especially suitable for situations where the charging time is critical, or there are several electric cars in the household.

Charging current (Amps, A)

The charging current means the strength of the current with which the electricity flows from the charging device
to the electric car battery. It is expressed in amperes (A). Put simply, what
the higher the amperage, the faster the electric car's battery can charge, as long as
other factors, such as the voltage (volts) and the car's reception capacity, are sufficient.

Features and meaning:

1. Determinant of charging speed: Charging current is one of the most important factors that affect charging speed. A higher charging current enables more electric power (kW) to be transferred to the car, which shortens the charging time.
2. Load on the electrical system: The size of the charging current also affects how much load the home's electrical system has to withstand.
   A larger current requires and may require a more robust electrical system
   for example, updating fuses, wires or sockets in order to maintain safety.
3. Adjustability: In some charging stations and portable charging devices, the charging current can be adjusted. This enables the charging to be adjusted according to the electrical capacity of the home, thus avoiding overloading the electrical network or tripping fuses.
4. Safety: A charging current that is too high in relation to the capacity of the home's electrical system can cause overheating and a fire hazard. It is therefore important to ensure that the charging current is matched to the capacity of the home's electrical network and that the charging device used is safe and approved for charging an electric car.

Examples of common charging currents:

• 10 A: This is often the maximum current of a standard household socket, which means a charging power of about 2.3 kW (10 A * 230 V = 2300 W = 2.3 kW). This is a slower and less efficient but safe current for smaller and temporary charging.
• 16 A: Common current used in most home charging stations and blue CEE sockets. This current, combined with a voltage of 230 V, gives a charging power of about 3.7 kW, which is common for home charging.
• 32 A: This charging current enables faster charging and is often used in more efficient home charging stations and three-phase sockets. 32 A current in a three-phase system (400 V) gives up to 22 kW of charging power, which enables significantly faster charging.

Summary:

The charging current is a key factor that affects how fast an electric car will charge
can be downloaded. Choosing a suitable charging current can ensure safe and
an efficient charging process adapted to the home electrical system and the car
according to the charging capacity.

Mains voltage (Volts, V)

Network voltage refers to the level of electrical voltage provided by the electrical network, which
used to transfer electrical energy to home sockets, appliances and
charging devices. The voltage is expressed in volts (V), and it is an essential factor in charging an electric car, as it directly affects the formation of the charging power together with the charging current.

Features and meaning:

1. Common voltage levels:
• 230 V (single-phase): This is the usual voltage in households, including in Finland. The single-phase 230 V network is used in standard home sockets and smaller home charging stations.
• 400 V (three-phase): The three-phase 400 V network offers more power, which allows for faster charging. This voltage is available when the house has a three-phase electrical system and is used in more powerful charging stations, such as 11 kW and 22 kW charging devices.
2. Generation of charging power:
• The generation of charging power (kW) is based on the combined effect of voltage and current (amperes). For example, a single-phase 230 V network combined with a 16 A current produces approximately 3.7 kW charging power. A three-phase 400 V network and 32 A current can produce up to 22 kW charging power: 3 phase * 32 A * 400 V * *
3. Effect on charging speed: Higher network voltage enables higher charging power and thus faster charging time. For example, a three-phase 400 V system is significantly faster than a single-phase 230 V system, so the battery of an electric car charges much faster.
4. Safety and compatibility: Chargers and electric cars are designed for a certain voltage level. It is important to make sure that the charging device and the car charger are compatible with the voltage used. This ensures safe charging and prevents damage to devices.
5. Advantages of a three-phase system: A three-phase 400 V system provides a more even and efficient power distribution, which reduces the load on individual phases. This makes it more efficient and better suited for higher power consumption needs, such as charging an electric car.

Summary:

The mains voltage is a key factor in charging an electric car, as it determines
together with the charging current, the charging power and thus the charging speed. The single-phase 230V network is the most common for home charging, but the three-phase 400V network enables significantly faster charging, which makes it an attractive option for more efficient charging solutions.

Charging method (Mode 2, Mode 3, Mode 4)

When charging electric cars, different charging methods are used, which determine
charging process and its security. Different charging methods offer different powers and
safety features. Here are explanations of the three main ones
about the download method:

Mode 2:

• Description: Mode 2 is the simplest and most often used charging method in households. It uses a standard household socket, and charging is done using a special portable charging cable that includes a built-in control and protection system.
• Features:
• Socket: A standard household socket is used (e.g. 230 V, 10 A or 16 A).
• Charger: The charging cable contains a control unit that monitors the charging process and provides basic protection such as overload and ground fault alarms.
• Power: Typically limited to 2.3 kW - 3.7 kW, depending on the current of the outlet.
• Suitability: Good for temporary or emergency charging, but not recommended for regular use due to long charging time and socket load.

Mode 3:

• Description: Mode 3 is the most common charging method at public charging points and most home charging stations. It uses a special charging station and a separate charging cable, which offers faster and safer charging compared to Mode 2
• Features:
• Socket: Special charging points or home charging stations are used, which can be either single-phase (230 V) or three-phase (400 V).
• Charging device: The charging cable is integrated into the charging station or point and contains an intelligent control unit that manages the charging process, protections and communicates with the car's charging system.
• Power: Mode 3 can provide power from 3.7 kW up to 22 kW, depending on the charging station and electrical system.
• Suitability: Well suited for home charging and public charging points where fast and efficient charging is needed. Offers better security and control compared to Mode 2

Mode 4:

• Description: Mode 4 is the fastest charging method and is used in high-power fast charging stations that offer very fast charging times. This charging method does not use standard sockets, but is designed especially for high-power charging solutions.
• Features:
• Socket: Does not use standard sockets, but special fast charging stations that can use either single-phase or three-phase voltage.
• Charger: The charging cable and station are designed to support high-power charging (DC fast charging) and include intelligent control and protection systems.
• Power: Mode 4 can provide power from 50 kW up to 350 kW, which enables very fast charging (e.g. 80% of the battery reserve in 10-20 minutes).
• Applicability: Mainly used in public fast charging stations, such as along highways or urban charging points, where there is a need to quickly charge the car to increase travel or driving capacity.

Summary:

• Mode 2: Uses a standard outlet and portable charging cable, basic charging, suitable for emergency or temporary charging.
• Mode 3: Uses special home charging stations or public charging points, offers faster and safer charging compared to Mode 2
• Mode 4: Used in fast charging stations, provides very fast charging and high power, usually in public charging stations.

Connection to the vehicle: Type 2

The Type 2 connector, also known as the Mennekes connector, is one of the most common charging connectors for electric cars, especially in Europe. The Type 2 connector is a versatile and safe connection standard that offers an efficient and reliable way to charge electric cars. Its support for single-phase and three-phase charging, wide compatibility and high safety standards make it a popular choice in Europe and other regions.

Possibility of load management

Load management (Dynamic Load Management) means the regulation and management of the load on the electrical network, so that electrical energy is used efficiently and safely. When charging electric cars, load management can help optimize the charging process, reduce the load on the electric grid and save energy. Here is a comprehensive explanation of the possibilities of load management:

Features and benefits:

1. Optimization of energy consumption:
• Time selection: Load management can adjust the charging time according to when electrical energy is cheaper or more environmentally preferable, such as at night or when the proportion of renewable energy in the electricity grid is high.
• System prioritization: The system can prioritize charging at times when the total load is lower or when other large electrical devices are not used in the house.
2. Network load management:
• Load balancing: Load management can evenly distribute the charging of electric cars to different phases of the network or at different times, preventing overloading of a single phase or problems with the electrical network.
• Limiting electricity consumption: If the household's electricity consumption approaches the network's maximum capacity, load management can limit or adjust the charging power so that the network's load remains under control.
3. Consumption monitoring and management:
• Intelligent monitoring: Load management systems can monitor the energy consumed during charging of an electric car and provide reports that help optimize energy use and save on electricity costs.
• Usage statistics: The systems can provide information on charging history, consumption and energy savings, which can be especially useful for large energy consumers or companies.
4. Future development directions:
• V2G (Vehicle-to-Grid) technology: This technology allows electric car batteries to be used to support the electric grid. Load management can coordinate how and when the energy stored by cars is returned to the grid, improving grid stability and efficiency.
• Dynamic pricing: Systems can use dynamic pricing and real-time electricity price information to optimize charging time and power, based on electricity market price fluctuations.
5. Applications and integrations:
• Smart home system: Load management can be integrated into smart home systems that control household electricity consumption, lighting, heating and other consumption. This integration can provide a comprehensive view and control of the home's energy use.
• Management of charging stations: Many modern charging station management systems offer built-in load management that optimizes charging power and time without the need for separate control.

Summary:

The possibility of load management offers many advantages when charging electric cars, including more efficient use of energy, network load management and optimization of consumption.

Utilization of the electricity exchange price

Utilizing the electricity exchange price means optimizing electricity pricing, taking into account electricity market prices, which vary in real time and daily.

The stock exchange price of electricity varies during the day and night depending on demand, supply and other market factors. By taking advantage of these price fluctuations, you can choose the charging time when the price of electricity is the lowest.

Smart charging devices and home energy management systems can integrate electricity exchange price data. They can adjust the charging power and schedule automatically, taking into account electricity market prices. By taking advantage of lower electricity exchange prices, you can significantly reduce energy costs.

Utilization of solar electricity

Using solar electricity means converting the sun's radiation into electrical energy with the help of solar panels and using it in households.

With the help of solar panels, you can produce the electricity needed by your own home or company. This can reduce electricity bills and reduce dependence on the grid.

Producing solar electricity yourself can significantly reduce electricity bills, especially if a sufficient number of panels are installed to cover most of the household's energy needs.

Photovoltaic systems can be integrated into home energy management systems that can adjust heating, cooling, and other electrical appliances based on the production of solar electricity.

Charging stations: Solar electricity can also be used to charge electric cars, which can improve energy efficiency and reduce electricity bills even further.

OCPP

OCPP (Open Charge Point Protocol) is an open communication protocol that enables data exchange between electric car charging stations (charging points) and background systems.

OCPP 1.6: Uses SOAP (Simple Object Access Protocol) communication protocol.

OCPP 2.0: Moves entirely to WebSocket-based communication, which provides more efficient and real-time data transfer.

Several different types of information related to the management, monitoring and billing of charging stations are transferred via the protocol. With the help of this information, OCPP enables efficient and safe management of charging stations and flexible operation between different operators and service providers.

RCD

An RCD (Residual Current Device), also known as a residual current device or a residual current device , is an electrical safety device that cuts off the power supply if it detects a current leak, which can be caused by, for example, a faulty device or an electric shock.

An RCD monitors that the current going into an electrical circuit matches the current returning from it. If there is a difference between the two currents (i.e. current leakage to ground), this indicates a potential hazard such as broken wire insulation or a dangerous current path through a person.

When an RCD detects such a current leakage, it automatically breaks the circuit, usually very quickly (within milliseconds), preventing possible electric shocks and other hazards.

RCD sensitivity is defined in milliamperes (mA). The most commonly used RCD has a sensitivity of 30 mA, which is sensitive enough to protect the human ear from electric shock.