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Selection of solar controller
- Jun 05, 2018 -

1: Exit protection voltage

Some customers often find that the solar street lights after a period of time, especially after continuous rainy days, road lamps will not be bright for several days or even many days, testing battery voltage is normal, the controller, lights are also no fault.

This problem has been puzzled by many engineers, in fact, this is the problem of "withdrawal from under voltage protection" voltage value, the higher the value setting, the longer the recovery time after the undervoltage, it also causes many days to be unable to light the light.

In this case, the industrial version controller enables each customer to set the voltage value of the exit protection according to the configuration. But it is worth noting that the configuration of the battery board must be reasonable. If the battery board is not charged every day, the battery is often in a deep discharge and the battery life is greatly shortened, so the configuration of the battery board must be magnified, the larger the configuration of the battery board, the protection voltage will be exited. The lower the setting, this will not affect the battery.

2: Constant current output of LED lamp

Because of its own characteristics, LED must carry out constant current or current limiting by means of technology, otherwise it can not be used normally. The common LED lamp is by adding a driving power to realize the constant current of the LED lamp, but this drive takes up to about 10%-20% of the total power of the whole lamp, such as a LED lamp with a theoretical value of 42W, and the actual power may be around 46-50W. When calculating the power of solar panels and battery capacity, 10%-20% must be added to meet the power consumption caused by driving. In addition, with more drivers, there is more than one failure. The industrial version controller has no power consumption and constant current through software, and has high stability and reduced overall power consumption.

3: Output period

Ordinary controller can only set up 4 hours or 8 hours after turning on the lights for several hours. It has been unable to meet the needs of many customers. The industrial controller can be divided into 3 periods, each time period can be set at any time, according to the different environment, each time period can be set to close state. For example, in some factories or scenic spots, no one at night, the second period (late night) can be closed, or second or third periods are closed to reduce the cost of use.

4: Output power regulation of LED lamp

Among the lamps and lanterns used in solar energy, the LED lamp is the most suitable to achieve different output power through pulse width adjustment. While limiting the pulse width or limiting the current, the duty ratio of the whole output of the LED lamp is adjusted, such as the LED7 string 5 of a single 1W and the LED lamp of the total 35W. At night, the power adjustment can be carried out respectively at night and in the early hours of the morning, such as the late night adjustment to 15W, the early morning adjustment into 25W, and the locking of the current, so that the current can be full. The lighting of the whole night saves the cost of battery and battery configuration. It has been proved by long-term experiments that the LED lamp with pulse width adjustment mode has much less heat generated by the whole lamp and can extend the service life of LED.

In order to save electricity at night, some light factories make the interior of the LED lamp into 2 power sources and turn off a power source at night to halve the output power, but it has proved that this method will only lead to half light source first light failure, disagreement of brightness, or early damage of a light source.

5: Compensation for line loss

The line loss compensation function is very difficult at present, because the software needs to be set up, and automatic compensation is made according to different diameter and length. The line loss compensation is very important in the low voltage system, because the voltage is low, the line loss is relatively large. If there is no corresponding line loss voltage compensation, the output voltage may be lower than the input end, which will cause the storage battery in advance under voltage protection, the actual application rate of battery capacity is discounted. It is worth noting that when we are using the low voltage system, we should try not to use too thin cables and cable lines to reduce the line loss.

6: Heat dissipation

In order to reduce the cost, many controllers do not consider the heat dissipation. When the load current is larger or the charging current is larger, the heat increase, the controller's field tube resistance is increased, the charging efficiency is greatly reduced, the service life of the field tube is greatly reduced and even burned after the overheated field tube, especially in the summer outdoor environment temperature. Very high, so a good heat sink should be a controller.

7: MCT charging mode

The conventional solar controller's charging mode is to copy the three stage charging method of the city's chargers, that is, three stages of constant current, constant voltage and floating charge. Because the energy of the electric power grid is infinitely large, if no constant current charge is not carried out, the battery will be damaged directly, but the battery board power of the solar street lamp system is limited. So it is not scientific to continue the use of the constant current of the city electric controller. If the current of the battery board is larger than the first limit of the controller. The current will cause a decrease in charging efficiency. MCT charging mode is to track the maximum current of the battery board, not waste. By detecting the voltage of the battery and calculating the temperature compensation value, when the voltage of the battery is close to the peak, the pulse trickle charge method is adopted, which can make the battery fill and prevent the overcharge of the battery.