Beijing Distributed Photovoltaic Safety Regulations: Stations Must Have DC Arc Protection and Rapid Shutdown Functions! Effective from April 1st!

On December 27, 2022, the Beijing Municipal Administration for Market Regulation issued the “Technical Specification for Electrical Safety of Distributed Photovoltaic Power Generation Systems,” which will be officially implemented from April 1, 2023.

This document addresses the overall electrical safety requirements for distributed photovoltaic power generation systems, with Clause 6 of the safety design section specifically mandating DC series arc protection and rapid shutdown functions for PV systems.

DC Arcing: The Main Culprit of Photovoltaic Safety Hazards

DC arcing is essentially a form of gas discharge, where the insulating medium around a charged body becomes conductive, allowing electrical energy to pass through. When DC arcing occurs in a PV system, the temperature at the conductor contacts can rapidly increase, reaching between 3000-7000°C, potentially destroying components and equipment and causing fires.

According to statistics, more than 80% of fire incidents in PV power stations are due to DC side faults. Moreover, rescue operations for PV power station accidents are extremely challenging. Conventional firefighting methods such as fire hydrants are ineffective, and while chemical dry powder extinguishers can be used, their effectiveness is limited. If the fire grows, the situation can quickly become uncontrollable. Additionally, PV power stations with energy storage devices pose an explosion risk.

Even if the inverter is shut down, the cables from the string to the inverter still carry DC power, making firefighting extremely dangerous and preventing firefighters from performing timely rescue operations.

Module-Level Rapid Shutdown Function: Addressing Firefighter Rescue Risks

The document released by the Beijing Municipal Administration for Market Regulation states that the system should have a rapid shutdown function. When the rapid shutdown device is activated, within 30 seconds, the voltage within a 305 mm boundary extending from the edge of the PV array should drop below 120V, and the voltage outside this boundary should drop below 30V.

The rapid shutdown function addresses the issue of high DC voltage in PV power stations during emergencies, effectively eliminating the risk of electric shock during rescue operations.

Fonrich’s “Four-in-One” Intelligent Safety Protector, features a module-level rapid shutdown function. Based on Fonrich’s module-level safety protection technology, it allows for remote or manual rapid shutdown of connections between each PV module. Within 30 seconds, it can stop the operation of equipment within a 305 mm range of the PV array or reduce the system voltage to below 30V, eliminating the presence of high DC voltage and mitigating rescue risks in PV power stations.

Addressing DC Arc Fire Risks with Fonrich’s Smart Safety Protection Device

Fonrich has long been aware of the serious issue of DC arc faults in PV arrays. After years of dedicated research, Fonrich’s “Four-in-One” smart safety protector now provides component-level arc protection, integrating automatic detection, protection, self/manual reset, early warning, and precise location features. In the event of a DC arc fault, it quickly shuts down and extinguishes the arc, ensuring the safety of people and property.

Additionally, Fonrich’s “Four-in-One” intelligent safety protector includes: Smart Break Protection, Smart Technology Monitoring.

In scenarios such as highways, rivers, etc., where distributed PV power stations may experience disconnection faults due to external forces or accidents, the protector will rapidly shut down all safety protectors in the affected string within 5 seconds, preventing the escalation of accidents.

PLC bi-directional communication, real-time collection of voltage, current, power generation, power generation work point, temperature 5 major data, and uploaded to the server in the form of snapshots. AI station diagnostics, data analysis, and historical queries provide multi-level linked protection and 100% accurate fault module location, significantly reducing power station management costs.

To comprehensively address the risks and rescue challenges posed by accidental DC arc faults in PV power stations, Fonrich has introduced a new “Five-in-One” smart safety optimizer.

This device integrates photovoltaic MPPT (Maximum Power Point Tracking) to continuously track each PV module’s maximum power point, optimizing power output, mitigating module mismatch, and potentially increasing distributed PV system power generation by up to 25%. It addresses power generation declines caused by installation differences, shading, orientation discrepancies, and module degradation over the system’s lifecycle, maximizing each module’s potential and significantly boosting PV station revenue.

As PV power station construction continues to flourish nationwide, becoming closely integrated with daily life, ensuring the “safety” of PV power stations has garnered significant industry attention. Cities like Shenzhen, Dongguan, and Haining have also set regulations regarding DC side voltage, DC arc protection, and component-level rapid shutdown functions.

Fonrich New Energy will continue to delve into the safety of distributed PV modules, creating more “economical, safe, and intelligent” module-level PV safety solutions to ensure the security of PV systems!