The full name of the solar controller is the solar charge and discharge controller. It is an automatic control device used in the solar power generation system to control the multi-channel solar cell array to charge the battery and the battery to supply power to the solar inverter load. It regulates and controls the charging and discharging conditions of the battery, and controls the power output of the solar cell components and the battery to the load according to the power demand of the load. It is the core control part of the entire photovoltaic power supply system.
Introduction:
The solar control system consists of solar panels, batteries, controllers and loads.
The solar controller is a device used to control the photovoltaic panel to charge the battery and provide the load control voltage for the voltage sensitive equipment. It regulates and controls the charging and discharging conditions of the battery, and controls the power output of the solar cell components and the battery to the load in accordance with the power demand of the load. It is the core control part of the entire photovoltaic power supply system. It is specially designed for the power supply system of communication or monitoring equipment in remote areas. The controller's charge control and load control voltages are fully adjustable, and can display battery voltage, load voltage, solar array voltage, charging current and load current. Almost all solar power generation systems powered by batteries require a solar charge and discharge controller. The role of the solar charge and discharge controller is to adjust the power, the power delivered from the
Solar Panel to the battery. The overcharge of the battery can at least significantly reduce the battery life, from the worst to damage the battery until it cannot be used normally.
The solar controller uses a high-speed CPU microprocessor and a high-precision A/D analog-to-digital converter. It is a microcomputer data acquisition and monitoring control system. It not only can quickly collect the current working status of the photovoltaic system in real time, obtain the working information of the PV station at any time, but also accumulate the historical data of the PV station in detail, which provides an accurate and accurate method for evaluating the rationality of the PV system design and the reliability of the quality of the inspection system components. Sufficient basis. In addition, the solar controller also has a serial communication data transmission function, which can centrally manage and remotely control multiple photovoltaic system sub-stations.
Solar controllers usually have 6 nominal voltage levels: 12V, 24V, 48V, 110V, 220V, 600V.
At present, the controller is developing towards multi-function, and there is a trend to integrate the traditional control part, inverter and monitoring system.
effect:
The most basic function of the solar charge and discharge controller is to control the battery voltage and open the circuit, and that is, when the battery voltage rises to a certain level, it stops the battery charging. The old version of the controller mechanically completes the opening or closing of the control circuit, stopping or starting the power delivered to the battery by the power supply.
In most photovoltaic systems, a controller is used to protect the battery from overcharging or over-discharging. Overcharging may vaporize the electrolyte in the battery and cause malfunctions, while overdischarging the battery may cause premature battery failure. Both overcharge and overdischarge may damage the load. Therefore, the controller is one of the core components of the photovoltaic power generation system and the main part of the BOS (Balance of System).
Simply put, the functions of the solar controller can be divided into:
1. Power adjustment function;
2. Communication function: 1 simple indication function 2 protocol communication function such as RS485 Ethernet, wireless and other forms of background management;
3. Perfect protection function: electrical protection reverse connection, short circuit, over current, etc.
principle:
Solar panels are photovoltaic devices (the main part is semiconductor materials). After being irradiated by light, the photovoltaic effect generates electric current. Due to the properties and limitations of materials and light, the generated current is also a volatile curve. If the generated current is directly charged into the battery or directly supplies power to the load, it will easily cause damage to the battery and the load. Reduced their lifespan. Therefore, we must first send the current to the solar controller, use a series of dedicated chip circuits to digitally adjust it, add multi-level charge and discharge protection, and use our unique control technology "adaptive three-stage charging mode (Figure 1)" to ensure the safety and service life of the battery and load. When supplying power to the load, the current of the battery is also allowed to flow into the solar controller first, and after its adjustment, the current is sent to the load. The purpose of this is: one is to stabilize the discharge current; the other is to ensure that the battery is not over-discharged; the third is to carry out a series of monitoring and protection on the load and the battery.
If you want to use AC power equipment, you also need to add an inverter before the load to convert to AC.
main feature:
1. Using single-chip microcomputer and special software to realize intelligent control;
2. Accurate discharge control using battery discharge rate characteristic correction. The end-of-discharge voltage is the control point corrected by the discharge rate curve, which eliminates the inaccuracy of the over-discharge of simple voltage control, and conforms to the inherent characteristics of the battery, that is, different discharge rates have different end voltages;
3. With automatic control of overcharge, overdischarge, electronic short circuit, overload protection, unique anti-reverse connection protection, etc.; none of the above protections will damage any parts, and will not burn insurance;
4. The series PWM charging main circuit is adopted, which reduces the voltage loss of the charging circuit by nearly half compared with the charging circuit using diodes, and the charging efficiency is 3%-6% higher than that of non-PWM, which increases the power consumption time; improves over-discharge recovery Charging, normal direct charging, and automatic floating charging control methods make the system have a longer service life; at the same time it has high-precision temperature compensation;
5. The intuitive LED luminous tube indicates the current battery status, allowing users to understand the usage status;
6. All controls use industrial-grade chips (only for industrial-grade controllers with I), which can run freely in cold, high temperature, and humid environments. At the same time, the crystal oscillator timing control is used, and the timing control is accurate;
7. The potentiometer adjustment control set point is cancelled, and the E-square memory is used to record each work control point, which digitizes the setting, and eliminates the error of the control point due to the vibration of the potentiometer, temperature drift, etc. The accuracy and reliability of the control point are reduced. Sexual factor
8. The digital LED display and settings are used, and all settings can be completed by one-key operation. It is extremely convenient and intuitive to use to control the working status of the entire system, and to protect the battery from overcharge and overdischarge. In places with large temperature differences, a qualified controller should also have the function of temperature compensation. Other additional functions such as light control switch and time control switch should be optional options of the controller.
mode:
1. Pure light control mode: when there is no sunlight, the light intensity drops to the starting point. After the controller confirms the start signal after a delay of 10 minutes, the load is turned on according to the set parameters, and the load starts to work; when there is sunlight, the light intensity rises to start Point, the controller delays for 10 minutes to confirm the shutdown signal and then closes the output, and the load stops working.
2. Light control plus time control mode: the startup process is the same as pure light control, when the load is working to the set time, it will automatically shut down, and the set time is 1 to 14 hours.
3. Manual mode: In this mode, the user can control the opening and closing of the load by pressing the buttons, regardless of whether it is during the day or at night. This mode is used in some special load occasions or during debugging.
4. Debugging mode: used for system debugging. When there is a light signal, the load is turned off, and the load is turned on without a light signal, which is convenient for checking the correctness of the system installation during installation and debugging.
5. Normally open mode: The load has been powered on and keeps the output state. This mode is suitable for loads that require 24 hours of power supply.
The popular solar controllers on the market mainly include ordinary solar controllers, PWM solar controllers and MPPT solar controllers.
Ordinary solar controller is the first-generation technology. The working principle is to directly connect the output of the solar panel to the battery port, and disconnect it when the battery is full. It is difficult to fully charge the battery due to the internal resistance of the battery, and the solar panel It has not been fully utilized, and the charging conversion efficiency is only 70 to 76%, which has been eliminated by the market, and basically few people use it.
The PWM solar controller is the second generation technology, and the most on the market now. The working method is PWM control. Compared with ordinary solar controllers, it has improved a lot and can solve the problem of battery dissatisfaction. The charging conversion efficiency is 75-80%. , But the solar panels are not fully utilized.
MPPT solar controller is the third generation technology, the most high-end solar controller. The MPPT solar controller refers to the solar controller with the function of "Maximum PowerPoint Tracking". It is an upgraded product of the PWM solar controller. The MPPT solar controller can detect the voltage and current of the solar panel in real time, and continuously track the maximum Power (P=U*I), so that the system always charges the battery with the maximum power. The MPPT tracking efficiency is 99%, and the power generation efficiency of the entire system is as high as 97%. It also has excellent management of the battery. It is divided into MPPT charging and constant Voltage equalization charging and constant voltage floating charging. With the advancement of technology and energy conservation, the trend of MPPT solar controllers replacing traditional PWM solar controllers is irreversible.
The new solar controller has the following main functions:
1. Overcharge protection: When the charging voltage is higher than the protection voltage, the battery will be automatically turned off to charge the battery. After that, when the voltage drops to the maintenance voltage, the battery will enter the floating charge state. When the voltage is lower than the recovery voltage, the float charge will be closed and enter the equal charge state .
2. Over-discharge protection: When the battery voltage is lower than the protection voltage, the controller automatically turns off the output to protect the battery from damage; when the battery is recharged, it can automatically restore power.
3. Load over-current and short-circuit protection: After the load current exceeds 10A or the load is short-circuited, the fuse is blown, and it can be used after replacement.
4. Overvoltage protection: When the voltage is too high, the output is automatically turned off to protect the electrical appliances from damage.
5. With anti-reverse charging function: Schottky diodes are used to prevent the storage battery from charging the solar battery.
6. With anti-lightning function: when there is a lightning strike, the varistor can prevent the lightning strike and protect the controller from damage.
7. Solar battery reverse connection protection: The solar battery "+" and "-" are connected reversely, and can continue to be used after correction.
8. Battery reverse connection protection: the battery "+" and "-" are connected in reverse polarity, the fuse is blown, and it can be used after replacement
9. Battery open circuit protection: In case of battery open circuit, if the solar battery is charging normally, the controller will limit the voltage at both ends of the load to ensure that the load is not damaged. If it is at night or when the solar battery is not charging, the controller will have Without power, there will be no action.
10. With temperature compensation function.
11. Self-inspection: When the controller is affected by natural factors or improperly operated by humans, the controller can be self-inspected to let people know whether the controller is intact, reducing a lot of unnecessary man-hours, and creating conditions for winning the quality of the project and the construction period. .
12. Recovery interval: It is the recovery interval for over-charge or over-discharge protection to avoid line resistance or the self-recovery characteristics of the battery from causing the load to move.
13. Temperature compensation: monitor the temperature of the battery, and correct the charging and discharging value to make the battery work in an ideal state.
14. Light control: It is mostly used for automatic lamps. When the environment is bright enough, the controller will automatically turn off the load output; and when the environment is dark, it will automatically turn on the load to realize the function of automatic control.
Installation and precautions:
1. Open the package and fix it in a suitable place (please avoid direct sunlight and humid places).
2. First connect the battery lead (in order to prevent errors in the automatic identification function), and wait for the controller to complete the identification process (after the level indicator indicates the battery power), then connect the solar panel lead, and finally turn off the load. Connect the load line under the circumstances.
3. In order to use safety, do not use excessive load or increase the solar panel too large; use a power supply such as a power supply to replace the solar battery to charge the battery.
4. When charging, remove the solar panel, and the charging current should not be too high.
5. Pay attention to the positive and negative poles of the battery.
Failure and troubleshooting:
1. The load does not work
(1) During the day, the controller has light control.
(2) The power in the battery is insufficient.
(3) Whether the wiring is correct.
(4) Remove all wires, repeat the above installation process, and let the controller re-identify.
2. It can be used in the first few days but not working after a few days
(1) The solar cell wiring is incorrect.
(2) The solar cell is not connected properly.
3. No light control
(1) The solar cell wiring is incorrect.
(2) This function is not set, please reset it.
4. It works when it is turned on, and it cannot be controlled by light or time.
(1) This function is not set, please reset it.
(2) The ambient light of the solar panel is strong enough.
5. The work instruction flashes non-stop
The load is short-circuited or the load is too large.
