What communication methods are used for real-time monitoring in home solar PV systems?
Classification and Introduction of Common Communication
Wired Communication:
- RS485:This is a balanced transmission differential interface, similar to a telephone line, used to connect devices like inverters and batteries. It offers strong anti-interference capabilities, long transmission distances, and multi-point access, making it suitable for industrial control and instrumentation environments.
- CAN bus:CAN (Controller Area Network) is a fieldbus standard that provides a reliable and efficient communication method for multiple electronic control units. Widely used in automotive electronics and industrial automation. Some energy storage batteries also use this communication method.
Wireless Communication:
- Wi-Fi:Home wireless networks allow you to remotely monitor the operation of your solar system using devices like smartphones and computers.
- Bluetooth:With a shorter transmission range, Bluetooth is primarily used for connections between small devices. In balcony pv storage systems, it's used for immediate monitoring and control but doesn't allow for remote viewing over the internet.
- Zigbee:Low-power consumption, suitable for communication between sensors and controllers. Generally used for communication between two devices, and less common in home photovoltaic storage systems.
- LoRa:Used for information exchange between devices. With a long range and strong wall penetration ability, it's suitable for large-scale IoT applications. It can also be used in photovoltaic storage systems.
Common Communication Methods in Home Solar Storage Systems
The real-time monitoring function of a solar PV storage system includes two types: wired and wireless, enabling both local and remote monitoring.
Local monitoring——RS485 wire/CAN wire connection
1.For communication between the inverter and battery
- The inverter and the battery are required to be compatible with the same Energy Storage System Communication Protocol
- Transmits data such as battery charge/discharge current, battery voltage, SOC, battery temperature, and alerts.
2.For communication between the inverter and a computer host
Using RS485 or CAN wiring, real-time monitoring of a solar PV storage system’s power generation and storage status can be done directly on a local computer. This setup also allows for configuring system output power and other settings.
- RS485 allows monitoring of various real-time parameters like PV input voltage and current, battery voltage, charge/discharge current
Remote monitor——Wi-Fi/Bluetooth:
- The inverter transmits all data of the balcony solar storage system to the user via Wi-Fi or Bluetooth.
- Each inverter typically has a corresponding app that can be downloaded and bound to the inverter's device information via Wi-Fi or Bluetooth.
- Real-time monitoring and display of various parameters of the photovoltaic storage system on a mobile phone.
- Data can be stored on the internet for calculating total generation and revenue.
- Allows control of AC output power, battery charging and discharging power, and charging and discharging time through the app.
LoRa:
- Generally used for information exchange between devices.
- Newer smart meters and inverter controllers interact through LoRa. The smart meter monitors the output AC current, performs internal calculations, and sends the information to the inverter via LoRa to control its operation.
Communication Security and Privacy
- Data security:While wireless signals like Wi-Fi and Bluetooth can be intercepted or tampered with, the risk is relatively low for home solar systems due to their short communication range and mature security technologies.
- Personal information:Personal information is not involved in the registration process for photovoltaic storage systems, so there's no risk of personal privacy leaks.
