What is Combiner Panel ?
A combiner panel or box is a wiring device to ensure the orderly connection and sink function of PV modules in PV power generation system. It means that users can connect a certain number of PV cells with the same specifications in series to form a PV series, and then connect several PV series in parallel to the PV sink box, and after sink in the box, through the controller, DC distribution cabinet, PV inverter, AC distribution cabinet, matching use so as to form a complete PV power generation system and realize grid connection with the utility.
What is the Function of Combiner Box ?
The combiner panel is a device that brings together the current, mainly used in medium and large photovoltaic systems, photovoltaic arrays in the number of module strings, more output, must need a device to collect these outputs so that they can be connected directly to the inverter. The combiner panel is a wiring device that ensures the orderly connection and sink function of the PV modules in the PV power system. This device can ensure that the PV system is easy to cut off the circuit during maintenance and inspection, and reduce the scope of power outage when the PV system fails. The convergence box is used in outdoor desert areas, where the wind and rain are much more serious. So it can meet the requirements of protection and earthquake resistance.
Lightning Protection of Combiner Panel
As the combiner panel is installed in the outdoor environment, lightning protection for the sink box must be considered. For this reason, the DC output part of the combiner panel can be configured with PV DC special lightning protection module, DC fuse and circuit breaker, etc., and set the working status indicator, lightning counter, etc. Once a lightning strike occurs, the lightning protection module will quickly discharge the excessive electrical energy to ensure the stable output of electrical energy and protect the busbar from lightning damage. The lightning protection components installed in the sink box are called photovoltaic lightning protection sink box to ensure the maximum effectiveness of solar photovoltaic power generation system.
Components of Combiner Panel
1. The Panel Box
The box generally uses steel plate spraying, stainless steel, engineering plastics and other materials, simple but aesthetic appearance, durable, easy and convenient installation, protection level of IP54 or more, waterproof, dustproof, to meet the requirements of outdoor long-time use.
2. DC circuit breaker
DC circuit breaker is the output control device of the whole busbar, mainly used for circuit breaking/closing. Its operating voltage is as high as DC1000V. Since solar modules can generate DC power, it is easy to produce arcing when the circuit is opened and closed, therefore, the temperature and altitude reduction factor should be fully considered when selecting the type, and special DC circuit breakers for PV must be selected.
3. DC Fuse
In the event of module backflow current, DC fuse for PV can cut off the faulty string in time, rated working voltage up to DC1000V, rated current generally choose 15A (crystal silicon module). The DC fuse used for PV module is a special fuse designed for photovoltaic system, which is installed with a special closed base to avoid the backflow of current between the strings and burn the module. When the current backflow occurs, the DC fuse quickly takes the faulty string out of system operation without affecting other normal working strings, which can safely protect the PV string and its conductors from the threat of reverse overload current.
4. Anti-reverse Diode
The role of diodes in the combiner panel is different from that of diodes in the module junction box. The diode in the module junction box is mainly to provide continuity channel when the cell is blocked, while the diode in the sink box is mainly to prevent the loop current between the strings.
5. Data Acquisition Module
In order to monitor the working status of the whole power station, the data acquisition module is generally added in the first-level sink box. Using Hall current sensor and microcontroller technology, the current signal (analog) of each PV array is sampled and converted into a digital quantity by A/D conversion, and then transformed into a standard RS-485 digital signal output, which is convenient for users to grasp the working status of the whole power station in real time.
6. DC High-voltage Surge Protection Unit
DC high-voltage surge protection unit for photovoltaic power generation system dedicated lightning protection products, with dual self-protection function for overheating and overcurrent. The modular design makes it possible to replace it with power, and there is a deterioration display window. Also it can be equipped with telematics alarm device, and using data acquisition module, remote monitoring can be realized.
7. Human-machine Interface
The data acquisition unit is equipped with a man-machine interface, through which the working real-time status of the equipment can be viewed, the working real-time status of the equipment can be realized through the keyboard, and the local setting of the equipment parameters can be realized through the keyboard.
Features and advantages
- 1. Multiple access to solar photovoltaic arrays at the same time, the rated current of each channel can reach 10A, the maximum 15A, can meet the needs of different users.
- 2. Each input is independently equipped with solar photovoltaic DC high-voltage lightning protection circuit, with multi-level lightning protection function, to ensure that lightning does not affect the normal output of the photovoltaic array.
- 3. The output is equipped with a PV DC high-voltage lightning protection module, which can withstand a maximum of 80kA lightning current.
- 4. With high-voltage circuit breaker, DC withstand voltage value not less than DC1500V, safe and reliable.
- 5. With lightning record function, easy to know the intrusion of lightning disaster
- 6.With real-time display function of current, voltage and power, easy to observe the working condition.
- 7. Protection grade up to IP65, to meet the use of outdoor installation requirements.
- 8. Remote monitoring function.