Second, the 1500Vdc photovoltaic system core equipment
1. Photovoltaic module
First Solar, Artus, Tianhe, Yingli, and other companies took the lead in launching 1500Vdc photovoltaic modules.
Since the world’s first 1500Vdc photovoltaic power plant was completed in 2014, the application volume of 1500V systems has continued to expand. Driven by this situation, the IEC standard began to incorporate 1500V related specifications into the implementation of the new standard. In 2016, IEC 61215 (for C-Si), IEC 61646 (for thin films), and IEC61730 are component safety standards below 1500V. These three standards complement the performance testing and safety test requirements of the 1500V component system and break the last obstacle of the 1500V requirements, which greatly promotes the compliance of the 1500V power station standards.
At present, China’s domestic first-line manufacturers have launched mature 1500V products, including single-sided components, double-sided components, double-glass components, and have obtained IEC related certification.
In response to the PID problem of 1500V products, the current mainstream manufacturers take the following two measures to ensure that the PID performance of 1500V components and conventional 1000V components remain at the same level.
1) By upgrading the junction box and optimizing the component layout design to meet the 1500V creepage distance and clearance requirements;
2) The thickness of the backplane material is increased by 40% to enhance insulation and ensure the safety of components;
For the PID effect, each manufacturer guarantees that under the 1500V system, the component still guarantees that the PID attenuation is less than 5%, ensuring that the PID performance of the conventional component remains at the same level.
Overseas manufacturers such as SMA / GE / PE / INGETEAM / TEMIC generally launched 1500V inverter solutions around 2015. Many domestic first-tier manufacturers have launched inverter products based on the 1500V series, such as Sungrow SG3125, Huawei’s SUN2000HA series, etc., and are the first to be released in the US market.
NB/T 32004: 2013 is a standard that domestic inverter products must meet when they are marketed. The applicable scope of the revised standard is a photovoltaic grid-connected inverter connected to a PV source circuit with a voltage not exceeding 1500V DC and an AC output voltage not exceeding 1000V. The standard itself already includes the DC 1500V range and gives test requirements for PV circuit overvoltage, electrical clearance, creepage distance, power frequency withstand voltage, and other tests.
3. Combiner box
The standards for the combiner box and each key device are ready, and 1500Vdc has entered the combiner box certification standard CGC / GF 037: 2014 “Photovoltaic combiner equipment technical specifications”.
At present, the 1500V standard for photovoltaic cables has also been introduced.
5. Switch and lightning protection
In the photovoltaic industry in the 1100Vdc era, the output voltage of the inverter is up to 500Vac. You can borrow the 690Vac distribution switch standard system and supporting products; from 380Vac voltage to 500Vac voltage, there is no switch matching problem. However, in the early period of 2015, the entire photovoltaic and power distribution industry did not have 800Vac / 1000Vac power distribution switches and other specifications, resulting in difficulties in supporting the entire product and high supporting costs.