Principle of solar energy conversion

- May 23, 2019-

The solar energy

The main function of solar charge and discharge controller is to protect battery. The basic functions must have overcharge protection, overdischarge protection, light control, time control and anti-reverse connection.

The general parameters of battery protection voltage against overcharge and overdischarge are shown in the table

1) change the state of the circuit when the battery voltage reaches the set value.

In the selection of devices, the current use of single-chip microcomputer, also use comparator, the scheme is more, each has characteristics and advantages, should be based on the needs of the customer base characteristics of the selection of the corresponding scheme.

2) surface treatment

The product USES the static electricity coating new technology, with FP specialized building materials coating primarily, may satisfy to the product surface color and the environment coordinated consistent request, simultaneously the product self-cleanness is high, the corrosion resistance is strong, the aging resistance, is suitable for any climate environment. The processing technology is designed to be coated on the basis of hot dip zinc, which greatly improves the product performance and meets the most stringent requirements of AAMA2605.2005. Other indicators have met or exceeded the relevant requirements of GB.

Conversion principle

The solar controller adopts high speed CPU microprocessor and high precision A/D AD converter. It is A microcomputer data acquisition and monitoring control system. It can not only collect the current working status of PV system quickly and in real time, and obtain the working information of PV station at any time, but also accumulate the historical data of PV station in detail, providing an accurate and sufficient basis for evaluating the rationality of PV system design and testing the reliability of system component quality. In addition, the solar controller also has the function of serial communication data transmission, which can centralized management and remote control of multiple photovoltaic system substations

Solar panels are the core part of solar street lamps and the most valuable part of solar street lamps. Its function is to convert the solar radiation capacity into electric energy, or send it to the storage battery for storage. Monocrystalline silicon solar cell, polycrystalline silicon solar cell and amorphous silicon solar cell are common and practical among numerous solar cells. In the eastern and western regions with good sunshine, polysilicon solar cells are better, because the production process of polysilicon solar cells is relatively simple and the price is lower than that of single crystal. In the south where there are more overcast and rainy days and less sunshine, it is better to adopt monocrystalline silicon solar cells, because the performance parameters of monocrystalline silicon solar cells are relatively stable. Amorphous silicon solar cells are better when there is insufficient sunlight outside, because amorphous silicon solar cells have lower requirements for solar lighting conditions.

The controller

Regardless of the size of solar lamps, a good performance of the charge and discharge controller is essential. In order to prolong the service life of the battery, its charging and discharging conditions must be limited to prevent the battery from overcharging and deep charging. Where the temperature difference is large, the qualified controller should also have the temperature compensation function. At the same time, the solar controller should be combined with the street lamp control function, with light control, time control function, and should have the function of automatic cutting control load at night, so as to extend the working time of the street lamp in rainy days.

battery

Because the input energy of solar photovoltaic power generation system is very unstable, it is generally necessary to configure the battery system to work. Generally, there are lead-acid batteries, ni-cd batteries, ni-h batteries. The choice of battery capacity should generally follow the following principles: first of all, under the premise of meeting the requirements of night lighting, the energy of solar cell components during the day should be stored as far as possible, and at the same time, the energy should be stored to meet the requirements of continuous cloudy and rainy night lighting. Battery capacity is too small to meet the needs of night lighting, the battery is too large, on the one hand, the battery is always in the state of power loss, affect the battery life, at the same time cause waste. The accumulator should be matched with the solar cell and the power load (street lamp). There is a simple way to determine the relationship between them. The power of the solar cell must be more than 4 times higher than the load power for the system to work properly. The voltage of the solar cell to exceed the working voltage of the battery 20~30%, in order to ensure the normal negative charge to the battery. The battery capacity must be 6 times higher than the daily load consumption.

The light source

Solar street lamps use what kind of light source is an important index of solar lamps and lanterns can normal use, solar lamps and lanterns commonly use low pressure, low pressure sodium lamp, energy-saving lamps energy-saving lamps, DLED light source.

(1) low-voltage energy-saving lamp: low power, high light efficiency, but 2000 hours of service life, low voltage lamp black, generally suitable for solar lawn lamp, garden lamp.

(2) low pressure sodium lamp: low pressure sodium lamp light efficiency is high (up to 200Lm/w), but the inverter, low pressure sodium lamp price is expensive, the whole system build high, less use.

(3) non-pole lamp: low power, high light efficiency. The light in the 220 v (pure sine wave, frequency 50 hz) under the condition of normal mains, life can reach 50000 hours, on the solar lamps and lanterns is greatly reduced and the service life than common energy-saving lamps (because solar lamps and lanterns is a square wave inverter, solar power 220 v output frequency, a bit, is cannot be compared with the ordinary mains voltage).