- Main technical parameters of photovoltaic controller
GB / T 19064-2003 has specific requirements for the main technical indicators of the controller: the loss of the controller shall be small, and the maximum power consumption of the controller shall not exceed 1% of its rated charging current; It is specified that the voltage drop of charging or discharging of the controller shall not exceed 5% of the rated voltage of the system. The main technical parameters of the photovoltaic controller are as follows.
1.1. Rated voltage
System voltage, also known as rated working voltage, refers to the DC working voltage of photovoltaic system, which is generally 12V 24v. 48V. 110V. 220V, etc
1.2. Maximum charging current
The maximum charging current refers to the maximum current of solar cell module or simulation output, which can be divided into 5A and 6A according to the power 8A，10A. 12A. 15A，20A，30A，40A. 250A, 300A various specifications. It is expressed by the maximum power of the factory, which indirectly indicates the technical parameter of maximum charging current.
1.3. Battery overcharge protection voltage
The battery overcharge protection voltage, also known as full off voltage or overvoltage off voltage, is generally set according to different needs and battery types. 14.1 ~ 14 5V (12V system), 28.2 ~ 29V (24V system) and 56.4 ~ 58V (48V system). Typical values are 14.4v 28.8V，57.6v.
1.4. Battery charging protection recovery charging voltage
The recovery charging voltage of battery charging protection is generally set to 13.1 ~ 13.4v (12V system), 26.2 ~ 26.8v (24V system) and 52.4 ~ 53.6v (48V system), and the typical values are 13.2v respectively 26.4V and 52.8v
1.5. Battery over discharge protection voltage
Battery over discharge protection voltage, also known as undervoltage shutdown voltage, is generally set according to different needs and battery types. 10.8-11.4v (12V system), 21.6-22.8v (24V system) and 43.2-45.6v (48V system).
Typical values are 11.1v 22.2V. 44.V.
1.6. Recovery of discharge voltage from battery over discharge
The recovery discharge voltage of battery over discharge is generally set as 12.1-12.6v (12V system), 24.2-25.2v (24V system) and 48.4-50.4v (48V system). Typical values are 12.4V respectively 24.8v and 49.6v
1.7 Battery charging float voltage
The floating charge voltage of battery charging is generally 13.7v (12V system), 27.4v (24V system) and 54.8v (48V system).
1.8. Circuit loss
The loss of the controller circuit itself is also called no-load loss or maximum self consumption current. In order to reduce the loss of the controller and improve the use efficiency of photovoltaic power supply, the loss of the controller circuit itself should be as low as possible. The maximum self consumption of the controller shall not exceed 1% of its rated charging current. According to different circuits, the self consumption is generally 5-20ma
1.9. Number of input channels of solar cell array
Low power photovoltaic controllers are generally single-channel input, while high-power photovoltaic controllers are multi-channel input by solar cells. Generally, 6 channels can be input, and 12 channels and 18 channels can be connected at most.
1.10. Working ambient temperature
The use or working environment temperature of the controller is generally – 20 – + 50 ℃
1.11. temperature compensation
Controllers generally have temperature compensation function to adapt to different working environment temperatures. The temperature compensation coefficient of the controller shall meet the technical requirements of the battery, and its temperature compensation value is generally – 2-4mv / ℃
1.12. Other protection functions
Generally, the controller also has anti reverse charging protection function, polarity reverse connection protection function, short-circuit protection function, anti lightning protection and impulse voltage and impulse current protection function.
- Main performance characteristics of photovoltaic controller
2.1 low power photovoltaic controller
Low power photovoltaic controller has the following characteristics.
(1) At present, most low-power photovoltaic controllers use low loss, long-life MOSFET and other electronic switching components as the main switching devices of the controller.
(2) PWM control technology is used to quickly charge and float charge the battery, so that the energy of solar power generation can be fully utilized.
(3) It has single and double load output and multiple working modes. Its main working modes include: ordinary on / off working mode (i.e. working mode not subject to light control and time control), light control on / time control off working mode. The closing time of dual load controller can be set separately
(4) It has a variety of protection functions, including reverse connection of battery and solar cell, open circuit of battery, overcharge and over discharge of battery, over voltage of load, anti reverse charging at night, over temperature of controller and other protection functions.
(5) Use the LED indicator to display the working status, charging status and battery power, and display the changes of system working status and battery remaining power through the change of LED indicator color.
(6) It has the function of temperature compensation. Its function is to set a more reasonable charging voltage for the battery under different working environment temperatures, so as to prevent the premature decline or even scrapping of the battery charge and discharge capacity caused by overcharge and undercharge.
2.2. Power light supply controller
Generally, the controller with rated load current greater than 15A is divided into medium power controller. Its main performance features are as follows.
(1) LCD screen is used to display various important information such as working status, charge and discharge, such as battery voltage, charging current and discharge current, working mode, system parameters, system status, etc
(2) It has automatic / manual / night function, and can be programmed to set the control mode of load as automatic or manual mode. In manual mode, the load can be opened or closed manually. When the night function is selected, the controller turns off the load during the day; When night is detected, the load will be automatically turned on after a delay for a period of time. When the timing time is up, the load will be automatically turned off. The delay time and timing time can be programmed.
(3) It has many protection functions such as battery overcharge, over discharge, output overload, overvoltage, over temperature and so on.
(4) It has the function of floating charge voltage and temperature compensation.
(5) It has the function of fast charging. When the battery voltage reaches the ideal value, the fast charging function starts automatically, and the controller will increase the charging voltage of the battery. When the battery voltage reaches the ideal value, start the fast charging countdown program, and enter the fast charging state after the timing time, so as to make full use of solar energy
(6) The medium power photovoltaic controller also has ordinary charge and discharge working mode (i.e. working mode not subject to light control and time control), light control on / off working mode, light control on close working mode, etc.
2.3 high power photovoltaic controller
The high-power photovoltaic controller adopts microcomputer chip control system, which has the following performance characteristics.
(1) The high-power photovoltaic controller has LCD dot matrix module display, which can arbitrarily set and adjust the charge and discharge parameters and temperature compensation system through programming according to different occasions. It has Chinese operation menu to facilitate user adjustment.
(2) The high-power photovoltaic controller can meet the special requirements of different occasions and avoid the oscillation caused by the simultaneous opening and judgment of all charging switches.
(3) The high-power photovoltaic controller can display the photovoltaic charging status and load thanks status of each circuit through the LED indicator.
(4) The high-power photovoltaic controller has 1 ~ 18 solar cell input control circuits, which are completely isolated from the main circuit and have high anti-interference ability.
(5) The high-power photovoltaic controller has the power accumulation function, which can display the parameters such as battery voltage, load current, charging current, photovoltaic current, battery temperature, cumulative photovoltaic power generation (a · h or W · h), cumulative load power consumption (w · h) and so on in real time.
(6) The high-power photovoltaic controller has the function of statistical display of historical data, such as overcharge times, over discharge times, short circuit times, etc.
(7) The user can set the charging state and discharging state of the battery respectively.
(8) The charging voltage detection of each circuit of high-power photovoltaic controller has the “return difference” control function, which can prevent the switching device from entering the oscillation state.
(9) The high-power photovoltaic controller has a series of alarm and protection functions, such as battery overcharge, over discharge, output overload, short circuit, surge, solar cell reverse connection or short circuit, battery reverse connection, night anti reverse charging and so on.
(10) High power photovoltaic controller can provide passive dry nodes required by generator or standby power starting circuit according to system requirements
(11) High power photovoltaic controller is equipped with RS232 / 485 interface for remote control The PC monitoring software can measure real-time data, display alarm information, modify control parameters, and read historical data such as the maximum voltage of the battery, the minimum voltage of the battery, the accumulated photovoltaic power generation and the accumulated load power consumption every day for 30 days.
(12) The parameter setting of high-power photovoltaic controller has the function of password protection, and the user can modify the password.
(13) The working mode of high-power photovoltaic controller can be divided into ordinary charge discharge working mode (step-by-step current limiting mode) and one-point charge discharge mode (PWM working mode). The one point charging and discharging mode is divided into four charging stages, which can control more accurately, better protect the battery from overcharge and make full use of solar energy.
(14) The high-power photovoltaic controller has the function of real-time clock without power failure, and can display and set the clock.
(15) High power photovoltaic controller has lightning protection function and temperature compensation function.
2.4 configuration and selection of photovoltaic controller
The configuration and selection of photovoltaic controller shall be determined according to various technical indexes of the whole system and with reference to the product sample manual provided by the manufacturer. Generally, the following technical indexes shall be considered.off grid photovoltaic power generation controller
- System working voltage
The system working voltage refers to the working voltage of the battery pack in the solar power generation system. This voltage shall be determined according to the working voltage of DC load or the configuration and selection of AC inverter, generally 12V and 24V 48V. 110V and 220V, etc
3.Rated input current and number of input channels of photovoltaic controller
The rated input current of photovoltaic controller depends on the input current of solar cell module or square array. The rated input current of photovoltaic controller shall be equal to or greater than the input current of solar cell. The number of input channels of photovoltaic controller shall be greater than or equal to the design number of input channels of solar cell square array. Generally, the low-power controller has only one input of solar cell array, and the high-power photovoltaic controller usually adopts multiple inputs. The maximum current of each input is equal to the rated input current / number of input channels. Therefore, the output current of each battery array should be less than or equal to the maximum current allowed to be input by each channel of photovoltaic controller.
4.Rated load current of photovoltaic controller
The rated load current is the DC output current from the photovoltaic controller to the DC load or inverter. The data shall meet the input requirements of the load or inverter.
In addition to the above main technical data to meet the design requirements, the parameters such as ambient temperature, altitude, protection grade and overall dimension, as well as the manufacturer and brand are also factors to be considered in the configuration and selection of the controller.