How to Deal with The Challenges of AC Charging Stations
Electric vehicles (EVs) have reshaped the transportation sector, drastically cutting carbon emissions and clearing the way for significant climate progress.
Electric vehicles can be charged through either alternating current or direct current power. AC charging relies on a converter that is built inside the car and is usually called an “onboard charger”. This converter is used to convert power from AC to DC and then feed it into the car's battery.
AC chargers are common in the EV ecosystem as they are comparatively less expensive to produce, install, and operate. Due to these lower costs, charging at AC charging stations is usually much cheaper, making them more popular for general day-to-day charging.
However, AC Charging Stations have some hurdles and limited power (less than 22 kW), requiring a more extended time to charge the car fully. The charging time of an AC charging station can take about 12 hours, depending on the charger's power level and the characteristics of the battery. Nevertheless, the solutions to deal with these challenges are explored below in this article.
Classification of AC Charging
EV chargers are classified by levels, and the levels describe how quickly a charger will recharge an EV's battery. The higher the charger output, the faster the EV battery will recharge. Let's look at the difference between level 1 and level 2 and their main applications.
● Level 1
L1 is the slowest level of charging. They are plugged directly into a standard 120 volt (V) AC outlet that supplies 1.3 kW to 2.4 kW average power output-equivalent to 3-5 miles of EV range per hour - and conforms to the provisions and requirements of the SAE J1772 Standard.
However, charging overnight will add 30-50 miles of range, and it takes 24 hours to charge an empty EV battery. L1 charging occurs mainly in residential settings, and only a few L1 chargers are built for public use. Sometimes, L1 chargers are included with the purchase of an EV. The cost of charging at L1 stations depends on the size of the EV battery and the electricity cost at the charging location.
● Level 2
L2 chargers operate at 208-240 Volt and output about 3 kW to 19 kW of AC power, as defined by the SAE J1772 Standard. This power output means 18-28 miles of range per hour. However, an average EV can be fully charged within 8 hours or less. The most common types of chargers are L2. These chargers have been deployed to various countries and can be found in many public locations, including grocery stores, hotels, malls, and parking garages.
L2 chargers are also popular in workspaces, and employees can leave their EVs charging for long durations. The price for charging at L2 stations varies greatly; however, some providers offer free charging. Many EV drivers choose to buy an L2 charger for home use as it allows them to charge their EV overnight. Charging an EV at home requires the infrastructure for residential L2 ports.
1. Outdoor Environmental Issues
Most outdoors charging stations are located in unfavorable environments and are subject to the effects of adverse weather conditions. Adequate moisture and corrosion protection practices should be carried out in coastal and humid areas. Also, it's essential to use power converters that meet high safety standards to resist these external factors and harsh environmental conditions.
2. Grid reliability
Outdoor charging stations can be subject to a series of power quality issues, including significant voltage fluctuation, voltage unbalance, harmonic current distortion, harmonic voltage distortion, and more. If left unnoticed, these issues can result in damage or even failure at the expense of the equipment's preservation and people's safety. For this reason, power supplies for this application need to provide a high tolerance range to resist this wide power fluctuation in an EV charging station.
3. Large Temperature Changes
Just like any equipment placed outdoors, EV charging stations are affected by the weather and climate conditions of their surrounding environment. One of the elements to consider when designing the electric circuit of an EV charging station is the large temperature changes it might be affected by.
Power modules for this type of equipment need to be able to resist even the greatest temperature changes both during the day and across all seasons. The MORNSUN's power supply solutions for EV charging stations are designed to withstand and provide reliable power under all weather and seasonal conditions.
MORNSUN is a leading manufacturer of efficient, reliable, and compact power solutions, including AC/DC converter, DC/DC converter, AC/DC enclosed switching power supply, EV power supplies, transceiver module, signal conditioning module, power module, and more.
MORNSUN's AC/DC converters have a wide input voltage range of 85~305VAC that helps meet the key power design requirements for the EV charging stations in different countries.
With wide operating temperatures, MORNSUN's products can resist extreme outdoor environmental conditions and have good EMC performance when encountered with high-voltage surges such as lightning strikes. MORNSUN's line of products complies with universal standards to ensure your safety.