Calculation method of solar photovoltaic system
With the shortage of traditional energy sources, solar energy applications will become more and more widespread, especially in the field of solar power generation in a few years has developed industries.
1: one of the most important link of the restriction of solar power applications is the price, with a pair of solar street road as an example, two loads such as 6 in the lower reaches of the effective light 4.5h/ days, every night on 7 hours, increase the battery in 20% reservation amount) the panels would need about 160W, according to the panels the cost will be 4800 yuan, plus the battery cost about 180AH is around 1800, the whole street is one-time large investment costs caused by the main bottleneck of application of solar street lamp.
2: the service life of the battery should be considered in the application of the lamp system, the battery warranty for three years or five years, but in general. Half a year later there will be charging dissatisfaction with the situation, some of the actual charging rate could fall to around 50%, which will affect the continuous rainy days during the night is very important to choose a good battery.
3: some engineering companies often use the LED lamp as solar street lighting, LED lamp layer but the quality is uneven, serious attenuation of LED semi illumination 50%. The best choice for light and long service life, high light efficiency, light slow LVD electrodeless lamp, or use low pressure sodium lamp.
4: a problem for the selection of the controller is often ignored by the project, the quality controller is uneven, the 12V/10A controller market price range, although is the smallest part of the value of the entire lighting system, but it is a very important link. The controller has a direct impact on the cost of procurement, Sun Life and the whole system: one should choose the controller with low power consumption controller, 24 hours of uninterrupted work, such as power energy, the best choice of power consumption at 1 Ma (MA) following controller. Two: to choose a high charge controller, with MCT charging module tracking the maximum battery board current, especially in winter or insufficient illumination period, MCT charging mode is about 20% higher than other efficiency. Three: adjust the power of the controller, with power adjustment of the controller has been widely promoted, in the night, pedestrians scarce hours can automatically close all the way or two way lighting, LVD lights can be adjusted for power. In addition to the choice of more power saving function, should also pay attention to the protection of the function of the battery controller and other components, like the controller can protect the battery and increase battery life, also set the controller undervoltage protection value, as far as possible to prevent vqn battery discharge.
5: the farther away from the city where also should pay attention to security work, many contractors for construction of negligence, lack of effective security, resulting in storage components stolen, not only affect the normal lighting, can also cause unnecessary loss of property. At present, most of the cases in the project are stolen batteries, and the storage battery is an effective anti-theft measure. It is better to install the battery box on the lamp pole for welding and strengthening.
6: controller waterproof, controller is generally installed in the shade, battery box, and generally will not enter the water, but in actual engineering cases, the controller terminal for rainwater along the connection line into the controller, resulting in short-circuit. So in the construction should pay attention to the internal connection wire bent into a "U" type and solid type, external connection type "U", so that the rain can not pour into the controller also can be caused by short circuit, interface outside daub waterproof glue.
7: in the practical application of many solar lights, solar lights can not meet the normal lighting needs in many places, especially poor spur related components in rainy days, another major reason is that a lower component cost, not according to the needs of design configuration, reducing battery lead to unable to provide in the rainy day road lamp lighting the solar panel and battery configuration formula:
A: first calculate the current: such as: 12V battery system; 40W lights 2, a total of 80 watts. Current = 80W / 12V = 6.7 A
Two: calculate the battery capacity requirements: such as: street lamp lighting time every night accumulated the need for full load for 7 hours (H) (such as 8:00 night night 11:30 open, closed 1, opened 2 at 4:30 Road, 5:30 am closed) lighting needs to meet 5 days of consecutive rainy days. (5 days plus rainy days ago night lighting, 6 days) battery = 6.7A * 7h * (5 + 1) days = 6.7A * 42h = 280 AH in order to prevent the battery from overcharge and overdischarge of battery charging, generally up to 90%; the remaining 20% or so discharge. So 280AH is only about 70% of the real standard in the application. Three: calculate the peak demand panels (WP): the street lamp every night for 7 hours to accumulated lighting time (H); *: the average panel received daily effective light for 4.5 hours (H); the least amount of relaxation of reserved panels 20%. WP / 17.4V = (6.7A * 7h * 120%) / 4.5hWP / 17.4V = 12.5, WP = 217 (W) * 4.5H: daily illumination time was near the middle and lower reaches of Yangtze River sunshine coefficient. In addition to the solar street lamp controller components, line loss, loss, and ballast or constant current source power is different, may be around 5%-25% so 162W also is the theoretical value in the practical application, according to the actual needs of the increase
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