The solar street light controller is applied in the solar lighting system and is responsible for coordinating the work of solar panels, batteries, and loads. It is one of the most critical components in the solar street lighting system, and provides guarantee for the efficient and safe operation of the entire solar lighting system.
The solar street light controller is mainly used for solar lighting and power supply systems such as solar garden lights, streets in commercial areas, roads in factory parks, traffic lights, landscape lights, pastoral areas, and unattended communication base stations.
As a solar street light controller, it should have the following basic functions: to charge the battery in the optimal state of late charging, to automatically turn on and off the street light or load, and to have overload protection, short circuit protection, reverse discharge protection, reverse polarity protection, Lightning protection, undervoltage protection, overcharge protection, load boot recovery settings.
The choice of solar controller should pay attention:
A: The controller with low power consumption should be selected. The controller operates 24 hours a day. If the power consumption of the controller is high, it will consume some power. It is better to choose a controller with power consumption below 3 mA.
Two: To select a controller with high charging efficiency, a controller with a three-stage charging control mode of strong charging, balanced charging, and float charging adopts MCU intelligent control and can always charge the battery with maximum power through internal calculations. In the winter or when the light is insufficient, the charging mode using the MCU intelligent control is about 20% more efficient than the non-MCU intelligent controller.
Three: With high-precision control, high-precision is a comprehensive expression of product design, but also a good manifestation of the selection of materials, but also reflects the production process. Non-high-precision solar street light controllers often result in high repair rates, poor reliability, and low market prices due to irrational product design and poor material selection.
Four: Only select the controller with two separate control, this is convenient for power adjustment of the whole lamp. In the rare pedestrians at night, one or two lights can be turned off automatically to save electricity, and power can be adjusted for LED lights. In addition to selecting the above power saving function, when setting the controller undervoltage protection value, try to adjust the undervoltage protection value to ≥10.8V to prevent the battery from overdischarging.
Design principle
Solar street lights are based on the sun's light as their main source of energy, and they can be charged independently at night and used at night. No need to lay any complicated and expensive circuit pipelines, etc. At the same time, the layout of the lamps can also be arbitrarily adjusted. It is safe, efficient, and energy-saving without any other pollution. The process of charging and using the switch adopts light-controlled + time-controlled automatic control without manual operation and stable operation. Reliable, saving electricity and power resources, maintenance-free, the practicality of solar street lamps has been fully recognized by people. This article describes the design of solar street lamp controllers based on MCU smart microcontroller, which can realize automatic identification of 12V and 24V batteries. Can realize the scientific management of the battery, can indicate the battery over voltage, undervoltage and other operating states, responsible for controlling the output of the load, by detecting the voltage value of the solar panel to identify whether it is day or night, and you can set the voltage value arbitrarily At the same time on the load over-current, short circuit protection and other functions.
The hardware circuit composition and working principle are based on the hardware structure of the system. The intelligent controller of the solar street lamp is based on the PIC microcontroller. The peripheral circuit is mainly composed of a voltage acquisition circuit, which is mainly responsible for the output control and detection circuit, the LED display circuit, and the keyboard circuit. The voltage acquisition circuit includes: the solar panel and the battery voltage acquisition for the identification of the intensity of the sun light And battery voltage acquisition. The two bits of the P3 port of the microcontroller are used as keyboard input ports for the setting of the operating mode and other parameters. The design and implementation of PIC microcontroller, voltage acquisition and battery management, load output control and detection circuits in the system. PIC microcontroller using RISC-type CPU core, compatible with the common 8051 instruction set, but also new features: on-chip Flash program memory 10k, DataFlash data memory 2k, RAM data memory 512 bytes, while there is a watchdog (WDT On-chip integrated MAX810 dedicated reset circuit, integrated 8-channel 10-bit resolution ADC and 4-channel PWM; programmable eight-level interrupt source four priority levels, with system programmable (ISP) and application programmable (IAP) and other features, on-chip resources, high integration, easy to use. The PIC microcontroller implements the scheduling of the system's work, the setting of external input parameters, the management of the battery and the load, and the indication of the working status. All kinds of parameter settings can be completed by the key circuit and the fourth pin of the PIC microcontroller. Voltage Acquisition and Battery Management Solar panel voltage acquisition is used to determine the intensity of the sun's rays and can therefore be used as a daylight and dusk identification signal. At the same time, the system supports solar panel reverse connection and reverse charging protection. Accumulator battery voltage is used for battery voltage identification. Using the microcontroller's PWM function, the battery charge management. Open-battery protection: If the battery is open, the controller will shut off the load if the solar battery is normally charged to ensure that the load is not damaged. If the controller is not charging at night or when the solar battery is not charging, the controller will not receive power. There will be no action. Overcharge protection: When the charging voltage is higher than the protection voltage (15V), the battery is automatically shut off; after that, when the voltage drops to the maintenance voltage (13.2V), the battery enters the floating state, when it is lower than the maintenance voltage (13.2V) ) After the float charge is turned off, it enters the equal charge state. When the battery voltage is lower than the protection voltage (11V), the controller automatically turns off the load switch to protect the battery from damage. Through the PWM charging circuit (intelligent three-phase charging), the solar panel can maximize its effectiveness and improve system charging efficiency. This system supports reverse battery, overcharge, over discharge. Load Output Control and Detection Circuit The system has designed two load outputs, each of which has independent control and detection, and has perfect over-current and short-circuit protection measures.
connection method
The general solar controller should connect the battery line first, then connect the lamp line, then cover the battery board with black cloth, and then connect the solar panel cable.
