Inside the EV Charging Station: Power Electronics and Energy Management Systems
Electric vehicles are taking the world by storm. Electric vehicles are the key technology to decarbonise road transport, a sector that accounts for around one-sixth of global emissions.
EV charging stations are complex systems that use a variety of power electronics and energy management systems to safely and efficiently deliver electricity to electric vehicles.This article will focus on the power electronics and energy management system inside EV charging stations.
What is power electronics
A study that utilises electronic power devices from converting one form of electric power into another form of electric power with proper control is known as Power Electronics.Power Electronics is regarded as an important subfield of electrical and electronics engineering.
Power electronics for electric vehicles
In EV charging stations, power electronics are used to convert the alternating current (AC) power from the grid into direct current (DC) power, which is the type of power that electric vehicles use.For electric vehicles, it comprises of three key devices: the onboard charger, an AC - DC rectifier to charge the battery; the inverter, a high-power DC to AC converter for the battery to power the traction motor; and a DC-DC converter for the high-voltage traction battery to power a low-voltage battery .The most common type of power electronics used in EV charging stations is a DC-DC converter. DC-DC converters can be used to step up or step down the voltage of DC power. This is important for EV charging stations because electric vehicles need to be charged at different voltages depending on their battery capacity. Other type of power electronics used in electric vehicles are :
AC-DC converters: These converters are used to convert AC power from the grid into DC power.
Inverters: These converters are used to convert DC power into AC power. This is necessary for some types of EV charging stations, such as Level 2 chargers.
Power factor correction (PFC) devices: These devices are used to improve the efficiency of AC-DC converters.
EV charging stations may also include other power electronics components, such as
Isolation transformer: This transformer separates the EV battery from the grid, which helps to protect the EV from electrical hazards.
Cooling system: This system cools the power electronics components to prevent them from overheating.
Control board: This board monitors and controls the operation of the power electronics components.
Above image shows different power electronics converters used in electric vehicles.Power electronics converters in EV. Typical traction motors in use are: permanent magnet synchronous motor, induction motor, classical synchronous machine or some hybrid motor variant which typically combines permanent magnet excitation with reluctance-effects.
Energy management system and their implementation in electric vehicle industry
Energy Management Systems are computer-aided systems that collect energy data from submetering devices in the field, and make it available through charts with graphics and energy analyzers for the purpose of simplifying, accelerating understanding and effective management of energy resources. In the EV industry , energy management systems are used to control the flow of power from the grid to the electric vehicle.They basically use a variety of sensors to monitor the state of the grid and the EV charging station. The EMS then uses this information to determine how much power to deliver to the EV.
Energy management system is also used to
Optimise the charging process and minimise the cost of electricity.
Prevent overloading of the grid.
Balance the load between multiple EV charging stations.
Integrate EV charging stations with renewable energy sources, such as solar and wind power.
The EMS can also be used to integrate the EV charging station with renewable energy sources, such as solar and wind power.
Detects leaks, equipment failures, outlier consumption, and other undetected faults.
Understand energy consumption in real-time
Set conservation targets through monitoring and controlling
Summing UP
Power electronics and energy management systems are playing a vital role in making EV charging more efficient, affordable, and sustainable.Power electronics components are essential for the operation of EV charging stations. They allow the stations to safely and efficiently convert AC grid power to DC power to charge EV batteries.
