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What is a photovoltaic combiner box? The photovoltaic combiner box is a wiring device that ensures the orderly connection of photovoltaic modules and the combining function in the photovoltaic power generation system. It means that the user can connect a certain number of photovoltaic cells with the same specifications in series to form a photovoltaic series, and then connect several photovoltaic cells in series. The photovoltaic series and parallel connection are connected to the photovoltaic combiner box. After the photovoltaic combiner box is combined, the controller, DC power distribution cabinet, photovoltaic inverter, and AC power distribution cabinet are used together to form a complete photovoltaic power generation system. electricity grid.

1. Box

The box body is generally made of steel spray, stainless steel, engineering plastic and other materials, with beautiful appearance, strong and durable, simple and convenient installation, the protection level reaches IP 54 or above, waterproof and dustproof, and meets the requirements of long-term outdoor use.

2. DC circuit breaker

The DC circuit breaker is the output control device of the entire combiner box, and is mainly used for the opening/closing of the line. Its working voltage is up to DC1 000 V. Since the power generated by the solar modules is direct current, it is easy to generate arcs when the circuit is disconnected. Therefore, the temperature and altitude derating factors should be fully considered when selecting models, and a dedicated photovoltaic DC circuit breaker must be selected.

3. DC fuse

When reverse current occurs in the module, the photovoltaic special DC fuse can cut off the faulty string in time. The rated working voltage is up to DC1 000 V, and the rated current is generally 15 A (crystalline silicon module). The DC fuse used in photovoltaic modules is a special fuse specially designed for photovoltaic systems. It is installed on a special closed base to avoid current backflow between the strings and burn the components. When current backflow occurs, the DC fuse quickly withdraws the faulty string from the system 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

In the combiner box, the role of the diode is different from that of the diode in the module junction box. The diodes in the module junction box are mainly to provide a freewheeling channel when the cells are blocked, while the diodes in the combiner box are mainly to prevent circulating currents between the strings.

5. Data acquisition module

In order to monitor the working status of the entire power station, a data acquisition module is generally added in the first-level combiner box. Using Hall current sensor and single-chip technology, the current signal (analog quantity) of each photovoltaic array is sampled, converted into digital quantity after A/D conversion, and then converted into standard RS-485 digital signal output, which is convenient for users to grasp in real time The working state of the entire power station.

6. DC high voltage surge protection unit

The DC high voltage surge protection unit is a special lightning protection product for photovoltaic power generation systems, with dual self-protection functions of overheating and overcurrent; it adopts a modular design, can be replaced with electricity, and has a deterioration display window; The data acquisition module can realize remote monitoring.

7. Human-machine interface

The data acquisition unit is provided with a man-machine interface. Through the man-machine interface, the real-time working status of the equipment can be viewed, the real-time working status of the equipment can be realized through the keyboard, and the local setting of the equipment parameters can be realized through the keyboard.

What is a photovoltaic combiner box? The components of the photovoltaic combiner box are as above. Using the photovoltaic combiner box, the user can connect a certain number of photovoltaic modules with the same specifications in series to form a photovoltaic module series according to the DC voltage range input by the inverter, and then connect several series to the photovoltaic array lightning protection combiner box, The output after the lightning arrester and circuit breaker is convenient for the access of the latter-stage inverter.