Protocols & Standards

Ocpp(Open Charge Point Protocol)

OCPP, standing for Open Charge Point Protocol, is akin to a unifying language for electric vehicle (EV) charging stations. It's a foundational aspect of modern charging infrastructure, allowing charging stations to interact with centralized management systems.

Essentially, OCPP is an open specification that enables EV charging stations to communicate with a centralized management system. It acts as a universal interface that ensures seamless interactions between different components.

Analogous to a Smart Home: The concept of OCPP can be likened to a smart home system. Just as various smart devices like light switches, air conditioners, and garage doors exchange messages with a central control system (e.g., a smartphone), OCPP allows EV charging stations to interact with a main hub. Everything can be controlled and monitored from one place, providing a cohesive and intelligent network.

PWM(Pulse Width Modulation)

Pulse Width Modulation (PWM) is a critical technology used in Electric Vehicle Supply Equipment (EVSE) to communicate the maximum charging current to the Electric Vehicle (EV).

How It Works: PWM works by varying the width of the 'on' and 'off' pulses in a periodic signal, controlling the amount of power sent to the load. In the context of EV charging, the PWM signal is applied to the control pilot circuit.

Duty Cycle: The 'duty cycle' refers to the percentage of time the signal is 'on' in one complete cycle. This determines the charging current that the EVSE specifies for the EV. The standard IEC 61851-1 defines the meaning of the applicable duty cycle values.

Charging Rules: Different duty cycle values correspond to different charging conditions. For example, if the duty cycle is less than 3%, no charging is allowed. Other values will define various charging speeds, ensuring the charger and vehicle are in agreement about the rate of charge.

Importance in EV Charging: PWM's precise control enables the charger and vehicle to communicate effectively, optimizing the charging process. By defining specific duty cycles for different charging states, it ensures safety and efficiency in the charging process, accommodating various charging needs and constraints.

In essence, PWM in EV charging acts as a sophisticated communication protocol between the vehicle and charging equipment, defining the rules for how the vehicle should be charged. Its precise control of the charging current according to the defined standard ensures a smooth, safe, and efficient charging experience, adapting to the specific requirements of each EV.

BMS(Battery Management System )

A BMS is a complex electronic system that manages a rechargeable battery, whether a single cell or an entire battery pack.

Monitors: Keeps track of various parameters such as voltage, current, temperature, and state of charge (SOC).

Controls: Regulates the charging and discharging processes, ensuring the battery operates within safe limits.

Balances: Ensures that the cells within a battery pack charge and discharge evenly, maximizing efficiency and lifespan.

Protects: Implements safety measures to prevent overcharging, overheating, short circuits, and other potentially harmful conditions.

Communicates: Interfaces with other vehicle systems, providing data and diagnostics that inform the driver and other electronic controls.