Recently, the Development and Reform Bureau of Haining City, Zhejiang Province issued the "Notice on Printing and Distributing the Management Measures for the Construction of Distributed Photovoltaic Power Generation Projects in Haining City", which has aroused widespread concern in the photovoltaic circle. This notice puts forward clear requirements for the filing, construction management, operation and maintenance management of distributed photovoltaic projects. Among them, in the "Project Construction Management" chapter, it is pointed out that "PV projects with DC side voltage greater than 120V" in Haining City need "capable of rapid shutdown and management at the panel-level rapid shutdown".

Previously, the Dongguan Municipal Development and Reform Bureau issued the "Notice on Printing and Distributing the Administrative Measures for the Construction of Distributed Photovoltaic Power Generation Projects of the Dongguan Municipal Development and Reform Bureau", which also clearly required Dongguan that "photovoltaic projects must have module level rapid shutdown and management capabilities."

This means that component-level power electronics technology and distributed photovoltaic security are receiving more and more attention. It is foreseeable that the mandatory safety protection standards for distributed photovoltaic power generation will be gradually improved and implemented in the future.

Why is it required to install the panel-level rapid shutdown？

In the past two years, Projoy has repeatedly emphasized the importance of the panel-level rapid shutdown for the safety of distributed photovoltaics. In a photovoltaic power station, multiple components are connected in series, and the internal DC voltage of the system can reach 1500V. Due to problems such as device failure, insulation aging, and poor contact, DC arc faults may occur, increasing the risk of fire and electric shock in the system.

Once the photovoltaic power station catched fire, the DC arc will cause the system to continue to burn, which is difficult to extinguish; and if only the string inverter is turned off after the fire, there will still be hundreds or even thousands of volts of DC high voltage in the series module system. At this time, if firefighters rush to rescue, it will have disastrous consequences. For this reason, first responders usually have to wait for the power station to completely burn down before they can start their work, which often leads to serious delays in firefighting work.

In this regard, Projoy has launched a fire-fighting weapon for high DC voltage of photovoltaic power plants - panel-level rapid shutdown.

Projoy PEFS-PL series DC24V panel-level rapid shutdown, connected in series with photovoltaic panels, so that each module is in an open state, in case of emergency, it can be shut down through the matching control box or AC switch, within 1s the direct current between each component can be cut off, providing a safe rescue environment for firefighters.

Why focus on photovoltaic projects with DC side voltage greater than 120V?

The "GB/T 37655-2019 Acceptance Code for Photovoltaic and Building Integrated Power Generation Systems" defines the safe voltage range of photovoltaic power generation systems as below 120V.

That is, corresponding measures should be taken to control the DC voltage of the photovoltaic power station within 120V.

Under normal circumstances, the open circuit voltage of grid-connected photovoltaic modules is around 45V. If more than three modules are connected in series, the DC voltage in the system will exceed 120V. According to the new notice issued by Haining City, photovoltaic power plants must have panel-level rapid shutdown capabilities.

How to choose Projoy panel-level rapid shutdown?

Projoy PEFS-PL series DC24V panel level rapid shutdown is divided into two voltage specifications of 80V and 120V, and each voltage specification is divided into one-to-one (one rapid shutdown has one input), one-to-two (one rapid shutdown has two inputs) and two models, the maximum allowable input current is 20A, which can meet the needs of 210mm ultra-high current components, and can be applied to photovoltaic power plants in various scenarios.

When the safety voltage of the photovoltaic power station is required to be within 80V, such as in North America, it is necessary to select the fast shutdown of 80V specifications.

When the safety voltage of the photovoltaic power station is not limited to within 80V, 120V fast shutdown can be selected, which is more cost-effective.

Projoy's PEFS-PL series panel level rapid shutdown has dual certifications of North American ETL and EU CE, and has been installed and operated in many countries and regions, effectively ensuring the safe and orderly development of photovoltaic power plants.