Electric vehicle charging station circuit diagram

Electric vehicle charging stations supply power for recharging electric vehicles.EV charging station circuit is a complex system.The purpose is to safely and efficiently deliver electricity from grid to battery of electric vehicle.This article will focus on circuit diagram of electric vehicle charging station and function of each section of circuit.

Basic components of charging station circuit and their functions

Typical EV charging station is made up of at least one smart controller board and one power socket board.The smart controller manages security,services and connectivity to remote servers.Power socket distributes and measures energy.

AC mains -Most EV charging stations connect to the AC mains power supply

Protection and filtering-It consists of circuit breaker which protects circuit from overload and short circuits , Ground fault circuit interrupter which detects and interrupts current leakage to prevent electric shock ,surge protector which guards against voltage spikes EMI filter that reduces electromagnetic interference that disrupt other electronic devices.

Power conversion circuits- It consists of a rectifier which AC mains power into DC power. DC to DC converter which Steps up the DC voltage to the level required for battery charging

Safety and monitoring - It consists of temperature sensors which monitors temperature of the charger and battery to prevent overheating,ground fault detection to ensure proper grounding and prevent electric shock,isolation transformer to provide additional isolation for safety.

Battery management system-A Battery Management System (BMS), which manages the electronics of a rechargeable battery, It safeguards both the user and the battery by ensuring that the cell operates within its safe operating parameters. BMS monitors the State Of Health (SOH) of the battery, collects data, controls environmental factors that affect the cell, and balances them to ensure the same voltage across cells.

Electric vehicle (EV) charging station circuit diagrams

Electric vehicle (EV) charging station circuit diagrams can vary greatly depending on the level of charging it supports.

Level1 charging

120V AC - up to3.3kW

Main components of level1 charging are Input power ,ground fault circuit interrupter,charging cable and control unit

Function of these components are

Input power: Connects to a standard 120V AC outlet.

Ground Fault Circuit Interrupter (GFCI): Protects against electrical shock.

Charging cable: Connects the charger to the EV's charging port.

Control unit: Monitors and manages the charging process, including communication with the EV.

For most users, Level 1 charging (120 VAC at 15A-20A) will be the most available power supply that all on-board chargers should be capable of handling as it will be easily accessible to all users.

Level 2 charging

240VAC , up to 10.2 kW

Main components of level 2 charging are Input power,circuit breaker ,rectifier,inverter,PWM controller

Function of these components are

Input power: Connects to a dedicated 240V AC circuit.

Circuit breaker: Protects the circuit from overload.

Rectifier: Converts AC input to DC power.

Inverter: Converts DC power to AC power at the correct voltage and frequency for the EV battery.

Pulse Width Modulation (PWM) controller: Regulates the charging current.

Additional features may include communication ports, displays, and user authentication.

EV owners would prefer to take advantage of the faster charging Level 2 (240 VAC at 40A) that will allow for faster charging times compared to the Level 1, but will require a larger power source to supply the appropriate current and voltage. By having the capacity to utilize both types of charging, you provide the user with more flexibility in their charging options

Level 3 charging/DC charging

These are known as fast chargers, as DC chargers bypasses the need of onboard chargers inside the vehicle, thus the EVs can be charged faster. The power rating of the charger varies between 10kW to 400kW globally. A typical level 3 charger takes distribution voltage from the electric utility transformer. This is 480-volt three phase power. This power comes into a switchboard where it is then directed to various transformers and an inverter.