With the rapid increase in the market share of new energy vehicles, the number and frequency of use of car charging piles have exploded. How to charge cars conveniently and quickly is the ultimate goal of all industry personnel. Public charging piles for society and some household charging piles require backend management system support. There are many charging pile management platforms on the market, and the connection methods between car charging piles and management systems are also diverse. In this field, ordinary connection protocols based on OCPP (Open Charging Point Protocol) and TCP have become the two more common forms.
1. Charging connection based on OCPP protocol
OCPP is a global open communication protocol. Its goal is to achieve interoperability between charging piles from different manufacturers and different management systems. As long as this agreement is followed, charging piles produced by any manufacturer can be connected to any management system that follows this agreement. The main reason for this is his openness. OCPP defines a series of specifications, including message format, communication process, etc., so that efficient data exchange can be achieved between charging piles and management systems, and WebSocket connection mode is adopted. The data format uses JSON and XML formats, which are clear and clear. Convenient development.
Advantages based on OCPP:
Openness: OCPP is a global open standard. Any company can obtain the protocol from public channels and use and develop related equipment and software. Promote industry cooperation and development.
Compatibility: Due to the openness of OCPP, charging piles and management systems have higher compatibility under the OCPP-based connection method,
and equipment from different manufacturers can work together in the same system.
Ease of use: Since OCPP adopts the WebSocket connection method, and the data content adopts the conventional web interface content formats JSON and XML,
it is more friendly to the development of management systems and promotes the development of the software ecosystem in the industry.
Real-time: OCPP protocol uses WebSocket to connect. It is a connection that supports two-way transmission and can monitor the status of charging piles in real-time,
including charging power, current, etc., and providing timely operating data for the management system.
Disadvantages of being based on OCPP:
Data volume: Since the data adopts JSON and XML formats that are easier to understand and use, repetitive data and data field names in the content will increase the size of the data. When using mobile networks, the data traffic used will increase and a certain amount of bandwidth will be required.
2. Common protocol based on TCP
TCP (Transmission Control Protocol) is a reliable, byte stream-based transmission communication protocol. OCPP’s WebSocket is also implemented on the basis of TCP. TCP connection method usually uses long connections to maintain the connection between charging piles and management systems. Real-time communication.
Advantages of ordinary TCP-based:
Stability: Based on TCP, it is a persistent and reliable connection method that can maintain stable communication between the charging pile and the management system and ensure the accuracy and integrity of the data.
Real-time: TCP connection supports real-time two-way communication, allowing the management system to obtain the latest status of the charging pile at any time and realize real-time monitoring of the charging process.
Flexibility: The TCP-based connection method is relatively flexible, suitable for different scenarios and needs, and can be configured according to specific application scenarios. Each manufacturer can design the optimal transmission protocol according to its own needs to achieve better performance and lower consumption.
Efficiency: The TCP protocol uses a data flow method, which is more low-level and can simplify the data content,
thereby greatly reducing the amount of data and using the minimum amount of data to complete data transmission.
Making it more efficient in performance. Uses less data traffic and can transmit stably under lower network bandwidth.
Disadvantages of ordinary TCP-based:
Closedness: Because most common protocols are customized by equipment manufacturers and software companies. He is not an open protocol.
This will lead to incompatibility between different manufacturers and different software companies. If a software company needs to access charging piles from multiple manufacturers,
it will need to develop multiple sets of protocols. If the charging pile manufacturer needs to supply to multiple software companies,
it may also need to develop another set of protocols upon request, increasing development costs.
Not easy to use: For more efficient transmission, use a more streamlined data format. The format of the data flow is difficult to interpret and not intuitive enough,
making interpretation and development more difficult. It will increase the project development cycle and development workload.
Whether it is based on the OCPP protocol or the ordinary connection method based on TCP, their purpose is to provide users with a more intelligent, convenient, and reliable charging experience. As an open protocol, OCPP promotes the interconnection and interoperability between charging equipment and realizes the intelligence and diversity of equipment. The TCP-based connection method ensures efficient communication between charging piles and management systems through stable data transmission, providing users with more stable and reliable charging services.