On February 16, 2023, the Solar Industry Summit & Awards Ceremony was successfully held in Suzhou, China. A large number of investors, manufacturers, developers, installers and others key industry players participated in this event, and shared their thoughts at the energy storage industry innovation and development forum. 

Nominated and Awarded Best in Fire Protection Solution, Projoy has won general recognition of its comprehensive product series, excellent product quality and powerful R&D capabilities.

During the conference, Ms. Cui Bei, general manager of Projoy electric, has delivered a memorable speech on the topic of “Safety Solutions for PV Storage Systems”. Focusing on two aspects of distributed photovoltaics and household energy storage, few of Projoy’s significant security solutions were well presented and thoroughly explained.

In the speech, Ms. Cui mentioned that while the solar PV industry has grown rapidly in recent years, and more PV systems will be installed in the coming years, safety issues have become an important window for testing photovoltaic power plants. Still, there are major challenges facing solar & energy storage systems today, such as fire caused by high voltage, battery pack could be easily damaged, and shock or electrocution when current takes an unintended path through a human body. And that’s where Projoy’s solar PV & energy storage safety solutions come to play. 

PV Arrays DC High-pressure Side Safety Solution 

In the PV power generation system, as long as there is light irradiating the PV module, the DC side will produce a high voltage of DC600-1500V after multiple components are connected. In general, inverter can only shut down current along the grid side, and the power line between the module and the inverter is still subjected to a voltage of up to DC600V-1000V DC. In case of an emergency, first responders are often exposed to a serious hazard caused by DC high voltage. 

Thus, to reduce shock hazard for technicians and first responders, many countries have already set requirements for rapid shutdown function of PV systems – rapid shutdown installation is a must. Projoy has launched series of Rapid Shutdown (PEFS-EL and PEFS-PL) that can be widely applied from household to large-scale industries and ground power stations, providing a way to quickly de-energize a rooftop solar panel system. 

Projoy PEFS-PL Series Panel-level Rapid Shutdown

According to the requirements of the US national electrical code NEC 2017, within 30S after the start of the rapid shutdown device, the external voltage of the photovoltaic matrix 305mm has to be reduced to less than 30V, and the voltage within 305mm has to be reduced to below 80V, to achieve a panel-level rapid shutdown.

Projoy’s PEFS-PL series panel-level rapid shutdown can disconnect each photovoltaic module. It can be shutdown remotely or manually when there is an emergency. Projoy further divided the series into DC 24V type and PLC type and both have passed the strictest UL certification, to ensure the device is stable and reliable. 

Projoy’s PEFS-EL Series Panel-level Rapid Shutdown

In order to make the rapid shutdown more cost effective, Projoy has released the PEFS-EL series array-level rapid shutdown. It can quickly cut off the direct current between the inverter and the photovoltaic array, preventing the spread of fire that may causing greater losses. Moreover, equipped with arc detection module and PID repair module, the device can prevent fires caused by DC arcing, slow down the attenuation of photovoltaic modules, improve power generation efficiency, and reduce the cost of electricity. 

More features of the products:

1)Various types of model, wide coverage, from 2 strings – 10 strings, 6A~63A, can be applied to all kinds of PV systems from household to large-scale industrial and commercial and ground power stations.

2)Array disconnected, cost-effective, easy to install and use 

3)Optional PID repair module, AFCI integration issues, wireless remote control to simplify wiring

4)Only one photovoltaic array needs to be installed, which greatly saves the investment cost caused by safety and reliability, and making sure everything is well protected

PV Inverter DC Side safety Solution 

Inverter is considered the “core hub” in PV power station. It has no start/stop button in order to ensure sufficient power generation time. As long as there is light, panels can generate electricity, the inverter will be able to work automatically. The problem is, when overhauling the inverter, if the input of the battery panel and the inverter is not cut off first, the DC power will be connected to the DC side of the inverter when plugging and unplugging the DC terminal, which will cause electric shock to technicians and damage to the inverter and back-end equipment. Yet most of the inverters on the market do not have electrical isolation built-in, which leads to a possibility of backfilling from the AC side to the DC side, and if the direct current cannot be physically isolated during maintenance, the risk of electric shock will occur.

Projoy’s PEDS series DC Isolator Switch is often installed in photovoltaic inverters, combiner boxes and DC cabinet to block the DC power between the inverter and the battery panel. Thus, all sectors of the PV power plant can be safely protected through the physical isolation of AC and DC switches. 

More features of the products:

1) Faster on-off and better arc extinguishing effect

2) Special head & optimized shaft design, mechanical life can be increased from 10,000 times to 30,000 times

3) The number of stable poles can be up to 10 layers

4) Each layer has 4 buckles, which has stronger structural stability

Energy Storage Battery Pack Safety Solution

According to the Energy Storage Market Research White Paper, China's energy storage lithium battery shipments has reached 130GWh in 2022, with a year-on-year growth rate of 170%. In addition to distributed PV solar system, Projoy has realized the importance of household energy storage safety. Since the batteries in battery pack are tightly deployed, it can easily cause fire when an internal short circuit occurs, and the battery module becomes overheated. 

Having Projoy’s non-polarity DC MCB deployed inside energy storage battery pack, it can quickly break the circuit under the situations of overload, short circuit, under voltage, etc. 

More features of the products:

1) UL489 standard, can be used for the safety protection of the main circuit

2) The maximum rated voltage is 250V/1P, the rated current can reach 80A, and the breaking capacity can reach 10kA

3) Non-polarity design, can realize the bidirectional protection of energy storage battery pack charging and discharging

4) Long electrical life and longer usage 

Devoted to Photovoltaic Storage DC Security

Fire protection is first priority. Projoy has been firmly rooted in the PV solar field since the beginning, and has been committed to providing the safest solutions for the industry. And projoy will continuously stick with the concept of “Switch to Safety” to promote a green and healthy development of the new energy industry.