The main technical parameters of the photovoltaic controller are as follows:
1. System voltage The system voltage is also called the rated working voltage. It refers to the DC operating voltage of the photovoltaic power generation system. The voltage is generally 12V and 24V. The medium and high power controllers also have 48V, 110V, 220V, etc.
2. Maximum charging current
The maximum charging current refers to the maximum current output by a solar cell module or a square array, and is divided into 5A 6A 8A 10A 12A 15A 20A 30A 40A 50A 70A 100A 150A 200A 250A 300A and other specifications according to the power size. Some manufacturers use the maximum power of solar modules to express this content, which indirectly reflects the maximum charging current of the technical parameters.
3 solar cell array input channels
Low-power photovoltaic controllers are generally single-channel input, and high-power photovoltaic controllers are input by solar cell arrays. Generally, high-power photovoltaic controllers can input 6 channels, and the maximum number of accessible photovoltaic controllers is 12 and 18 channels.
4 circuit itself loss
The loss of the controller's circuit itself is also one of its main technical parameters. It is also called the no-load loss (quiescent current) or the maximum self-consumption current. In order to reduce the loss of the controller and improve the conversion efficiency of the photovoltaic power supply, the loss of the controller circuit itself should be as low as possible. The maximum self-loss of the controller must not exceed 1% or 0.4W of its rated charging current. According to the circuit itself, the loss is generally 5~20MA.
5. Battery Overcharge Protection Voltage (HVD)
The overcharge protection voltage of the battery is also called the fully-disconnected or over-voltage shutdown voltage, which can be set at 14.1 to 14.5V (12V system), 28.2 to 29V (24V system), and 56.4 to 58V depending on the needs and the type of battery. Between the (48V systems), the typical values ​​are 14.4V, 28.8V, and 57.6V, respectively. The shutdown recovery voltage (HVR) of the battery charge protection is generally set to be between 13.1~13.4V (12V system), 26.2~26.8V (24V system), and 52.4~53.6V (48V system), and the typical value is 13.2. V, 26.4V, and 52.8V
6. Over discharge protection voltage (LVD) of the battery
The over-discharge protection voltage of the battery is also called under-voltage disconnection or under-voltage shutdown voltage, and can be set at 10.8 to 11.4V (12V system), 21.6 to 22.8V (24V system), and generally depending on the needs and the type of battery. Between 43.2. to 45.6V (48V systems), the typical values ​​are 11.1V, 22.2V, and 44.4V, respectively. The shutdown recovery voltage (LVR) of the battery over-discharge protection is generally set to be between 12.1 to 12.6V (12V system), 24.2 to 25.2V (24V system), and 48.4 to 50.4V (48V system), and the typical values ​​are 12.4V, 24.8V, and 49.6V.
7. Battery charging float voltage
The charging float charge voltage of the battery is generally 13.7V (12V system), 27.4V (24V system), and 54.8 (48V system).
8. Temperature compensation
The controller generally has a temperature compensation function to adapt to different ambient operating temperatures and set a more reasonable charging voltage for the battery. The temperature compensation coefficient of the controller should meet the technical development requirements of the battery, and the temperature compensation value is generally -20~ -40mV/oC.
9. Working environment temperature
The controller's use or working environment temperature range varies from -20 to +50 oC depending on the manufacturer
10. Other protection features
(1) Controller input and output short-circuit protection. The controller's input and output circuits must have a short-circuit protection circuit to provide wave protection. (2) Anti-recharge protection. The controller must have a protection function to prevent the battery from being charged to the solar cell in the reverse direction.
(3) Reverse polarity protection function. The solar cell module or the battery access controller, when the polarity is reversed, the controller must have the function of protecting the circuit.
(4) Lightning protection. The input of the controller is protected against lightning strikes. The type and rating of the arrester should ensure that the expected impact energy is absorbed.
(5) Impact voltage and surge current protection. Apply 1.25 times the nominal voltage to the solar cell input of the controller for one hour and the controller should not be damaged. The controller charging loop current is 1.25 times the nominal current for one hour and the controller should not be damaged.