In recent years, the photovoltaic power industry has developed rapidly, China's industrial and commercial photovoltaic power stations installed more than 200GW, residential photovoltaic has been accepted by the masses due to various favorable policies, the number of installation is more and more, by the end of October 2021, China's residential photovoltaic installed more than 2 million households.
However, generally speaking, in a good industry situation, many hidden problems are easy to be ignored. The biggest problem in the photovoltaic industry is the hidden danger of fire, especially in schools, gas stations, high-speed rail stations and other important places once a fire occurs in photovoltaic power stations, the consequences are unimaginable. Therefore, how to prevent the fire risk of photovoltaic power stations has become a widespread concern of photovoltaic people, and has also become a problem to be considered by governments of all countries when vigorously developing the new energy industry.
On November 24, the China National Energy Administration issued a notice on "Strengthening the safety work of distributed photovoltaic Power Generation (draft)" (hereinafter referred to as the "notice"), putting forward suggestions on further strengthening the safety work of distributed photovoltaic power generation and promoting the healthy and sustainable development of the industry.
In the notice, the National Energy Administration put forward suggestions on 11 aspects, including site selection, project design, construction safety and operation &maintenance management. Among them, strengthening project design management is extremely important, and the National Energy Administration has put forward clear standard specification requirements:
"Install arc fault circuit breakers or use components with corresponding functions to realize intelligent arc detection and fast cut-off functions," the notice said. "Photovoltaic modules shall have safe turn-off protection function to ensure that the inverter is turned off. After AC power is cut off, the dc voltage outside the system sub-array is lower than the safe voltage".
Previously, in 2017, US. NEC 2017--690.12 (B) explicitly required that PV systems on all buildings be capable of rapid shutdown in case of emergency. Recently, Thailand, the Philippines and other countries have also included rapid shutdown in the new safety requirements. It shows that the rapid turn-off capability of photovoltaic modules is extremely important and is valued by more and more countries.To this, Projoy Electric Co., Ltd. recently launched two products for photovoltaic power stations to choose from.
PROJOY can provide from a single module level to 1500V/50A multiple strings of series of rapid shutdown products, a variety of voltage and current levels, external control box with or without lock, a variety of colors, to meet the needs of different occasions.
PROJOY focuses on the design, research and development and production of special DC switches and quick turn-off for photovoltaic systems, and has a high market share and brand awareness in the subdivided fields. Projoy fast shutdown through UL, TUV, CE, CB and other international certification, Its built-in DC isolation switch (group series type) mainly iec60947-3 (European general standard, applicable to the Asia-Pacific), UL508 (American general standard), UL508i (for photovoltaic system with DC switch American standard), GB14048.3 (domestic general standard) and other certification.
The panel level rapid shutdown introduced by PROJOY also has the following characteristics:
1. Each rapid shutdown can be applied to 1-4 modules, the maximum allowable DC input voltage is 120V, buckle design, easy installation, save a lot of manual installation cost, can be adapted to various types of photovoltaic modules on the market.
2. High on-off capacity, good arc extinguishing effect, arc extinguishing can be carried out within 5ms, the voltage between the photovoltaic module and the inverter is controlled below 30V.
3. It has the function of automatic detection of ambient temperature and automatic turn-off of over temperature, which can cut off high voltage DC once fire occurs. This function is extremely important for some photovoltaic power stations on the rooftop of residential or factories that are unattended.
4. Comply with international standards for firefighter procedures. When a fire occurs in the photovoltaic system, person can directly manually press the emergency stop button to cut off the AC power of the control box; On the other hand, it can also be directly connected to the fire alarm system to directly cut off the AC at the first time when a fire occurs. The rapid shutdown will collect the AC loss signal and automatically disconnect the isolation switch to disconnect the DC side, creating a safe environment for firefighters.
5. Finally, when power is restored after AC power is turned off (for example, during a power outage), rapid shutdown automatically resets and quickly connects the circuit, so the customer does not need to manually reset each time.
6. Choose flame-retardant V-0/ UV resistant materials, flame retardant and high protection grade, high temperature corrosion resistance and impact resistance, can work normally in the harsh environment of -30℃ to 80℃, the service life is up to 25 years.
7. DC24V type: It is powered by external AC power supply. In case of fire or emergency, the modules can be quickly shut off by disconnecting AC power or pressing the emergency stop button above the rapid shutdown.
8. PLC type: Through the module self-power supply, meet UL standards, passed the Sunspec certification, can be with the Sunspec group series inverter or external signal transmission equipment through power carrier communication and other forms to achieve rapid shutdown.
PROJOY rapid shutdown performance is strong, superior quality, relying on PROJOY perfect technical support and after-sales service network, can help the National Energy Administration to strengthen the safety work of distributed photovoltaic power generation, promote the healthy and sustainable development of photovoltaic products.