First of all, we need to understand that the system composition of LED solar street lights is composed of LED light sources (including drivers), solar panels, batteries (including battery insulation boxes), street lamp poles (including basic) grade auxiliary wire, and the solar street lamp control that we focus on today. The device is composed of several parts. Although the cost ratio of the controller in the entire solar street light system is very low, generally only about 120 yuan -200 yuan, but the responsibility is very large. If the choice is not good, it will greatly reduce the stability and stability of the entire system. Long service life. A relatively mature and stable controller can usually reduce the cost of the entire system through its functions to achieve cost savings. Next, we will let professional LED street lamp manufacturers introduce how to buy LED solar street lamp controller.
1: Exit protection voltage
Some customers often find that after the solar street light has been on for a period of time, especially after a continuous rainy day, the street light will be off for a few days or even many days, the battery voltage is normal, and the controller and the lamp are not faulty.
This problem has puzzled many engineering companies. In fact, this is the problem of the voltage value of "exit undervoltage protection". The higher the value is set, the longer the recovery time after undervoltage is, which causes many days to be unlit. light.
On this issue, the industrial version controller allows each customer to set the voltage value of exit protection according to the configuration. But it is worth noting that the configuration of the battery board must be reasonable. If the daily charge of the battery board cannot meet the discharge capacity of the night, in the long run, the battery is often in deep discharge, and the life is greatly shortened, so the configuration of the battery board must be enlarged. The larger the configuration of the battery board, the lower the voltage that can be set out of the protection, so that it will not affect the battery.
2: LED lamp constant current output
Due to its own characteristics, LED must be constant or limited by technical means, otherwise it cannot be used normally. Common LED lamps are used to achieve a constant current to the LED lamp by adding a driving power supply, but this driver accounts for about 10% -20% of the total power of the entire lamp. For example, an LED lamp with a theoretical value of 42W, plus After driving, the actual power may be around 46-50W. When calculating the solar panel power and battery capacity, 10% -20% more must be added to meet the power consumption caused by the drive. In addition to this, if you add an additional drive, there is one more link that causes a malfunction. The industrial version controller performs constant current without power consumption through software, with high stability and reduced overall power consumption.
Three: output period
Ordinary controllers can only be set to turn off for 4 hours or 8 hours after the lights are turned on, which can no longer meet the needs of many customers. The industrial version controller can be divided into 3 periods, the time of each period can be set arbitrarily, according to the different use environment, each period can be set to off state. For example, in some factories or scenic areas where there is no one at night, you can close the second period (late night), or both the second and third periods to reduce the cost of use.
Four: LED lamp output power adjustment
Among the luminaires for solar applications, LED lamps are the most suitable for outputting different power through pulse width adjustment. While limiting the pulse width or current, the duty cycle of the entire output of the LED lamp can be adjusted. For example, a single 1W LED 7 string 5 and a total of 35W LED lamps can be discharged at night. Power adjustment, such as adjusting to 15W in the middle of the night and 25W in the early morning, and locking the current, so as to meet the lighting throughout the night, and save the configuration cost of the battery board and battery. It has been proved by long-term experiments that the LED lamp with pulse width adjustment method has much less heat generated by the whole lamp, which can prolong the service life of the LED.
In order to achieve the purpose of saving electricity at night, some lamp factories make the interior of the LED lamp into a 2-way power supply, and turn off the power supply at night to halve the output power, but practice has proved that this method will only cause half of the light source Decay, inconsistent brightness or premature damage to the light source.
Five: line loss compensation
Line loss compensation function is currently difficult to achieve conventional controllers, because it requires software settings, according to different line diameter and line length to give automatic compensation. Line loss compensation is actually very important in low-voltage systems, because the voltage is low and the line loss is relatively large. If there is no corresponding line loss voltage compensation, the output voltage may be much lower than the input, which will cause the battery to advance Under-voltage protection, the actual application rate of battery capacity is discounted. It is worth noting that when we use low-voltage systems, in order to reduce the line loss and voltage drop, try not to use too thin cables, and the cables should not be too long.
Six: heat dissipation
In order to reduce costs, many controllers do not consider the problem of heat dissipation, so when the load current is large or the charging current is large, the heat increases, the internal resistance of the field tube of the controller is increased, resulting in a significant decrease in charging efficiency, and the service life of the field tube after overheating Greatly reduced or even burned, especially the outdoor environment temperature in summer is very high, so a good heat dissipation device should be essential for the controller.
Seven: MCT charging mode
The charging mode of the conventional solar controller is a three-stage charging method that imitates the commercial power charger, that is, three stages of constant current, constant voltage, and floating charge. Because the energy of the mains grid is infinite, if the constant current charging is not carried out, it will directly cause the battery to explode and be damaged, but the solar street lamp system has a limited panel power. Scientifically, if the current generated by the battery board is greater than the current limited by the first section of the controller, then the charging efficiency will be reduced. The MCT charging method is to track the maximum current of the battery board without causing waste. By detecting the battery voltage and calculating the temperature compensation value, when the battery voltage is close to the peak value, then the pulse trickle charging method is adopted to make the battery full It also prevents overcharging of the battery.
Through the above, we understand that the main function of the solar LED street lamp controller is to protect the battery, which must have overcharge protection, overdischarge protection, light control, time control, anti-reverse connection, charging trickle protection, undervoltage protection, waterproof Protection, etc. Because when we choose enough solar LED street lights, we must consider the controller from the protection voltage, LED constant current output, output period, LED lamp output power adjustment, line loss compensation, heat dissipation, and MCT charging mode. It is also crucial to choose a well-known and reputable solar street lamp manufacturer.