The vast desert, the desolate Gobi. This was once a vast unknown. Photovoltaics, across the geographical latitude and longitude, uses the power of science and technology to awaken the buried vitality and measure the miracle of ecological recovery. This time, together with Shangneng Electric, we walked into the hinterland of Dachaidan, Haixi Prefecture, Qinghai, and found a different kind of scenery in the zero-carbon footprint.

Qinghai New Energy Project Construction

On the shores of Jinel Lake in Qinghai, the Dachaidan 100MW affordable photovoltaic power station invested and constructed by Xiehe New Energy Group Co., Ltd. has been successfully connected to the grid for power generation recently. The project is located on the Qinghai-Tibet Plateau, 3400 meters above sea level, west of Delingha City, covering an area of 3250. mu. In order to achieve the desired power plant revenue, the customer has undergone rigorous evaluation and comparison, and finally selected photovoltaic modules and inverter products with higher power generation and higher reliability: 670W series of ultra-high power 210 modules + 250kW of Shangneng Electric Current string inverter.

The sky is clear and the sun reflects the blue "shadow of the lake", where nature and technology are harmoniously blended. After the project is fully put into operation, it can provide about 220,000 MWh of clean electricity every year, reduce carbon dioxide emissions by about 200,000 tons, bring obvious economic and environmental benefits, and contribute to the local green development. In the not-too-distant future, I believe that as far as you can see and walk in this desert, you will see patches of blue ocean and oasis each other, reappearing everywhere. The entire project is divided into 32 photovoltaic sub-arrays, each with a volume of about 3.5MWp and a total capacity of 112MWp. A single photovoltaic sub-lineup has a large volume, which can greatly reduce the cost of transformers and AC cables, thereby achieving a better LCOE. In order to perfectly adapt to 210 large components, all SP-250K-H string inverters from Shangneng Electric were used in the project, with a total of 416 units.

With the rapid development of the photovoltaic industry, the cost of photovoltaic systems continues to decline, and large-size modules are becoming the mainstream choice in the market. As the industry's first high-current string inverter compatible with ultra-high power components, the SP-250K-H is also one of the few products currently on the market that are fully mass-produced and meet mass supply. The branch circuit current of this product can reach up to 20A, every 2 strings are connected to 1 MPPT, and the maximum input current of each MPPT is 40A, which can effectively avoid the DC limit and significantly guarantee the power generation of the power station. It can be called the "golden partner" of 210 components. .

Because the project is located in a desert area, with high altitude, large wind and sand, and large temperature differences, the natural environment is very harsh, and the requirements for the quality and reliability of the inverter are extremely harsh. The SP-250K-H string inverter has a high protection level of IP66 and adopts first-line device brands at home and abroad, which can easily adapt to complex application environments such as sandstorms and low temperatures. At the same time, the product uses a fuse-free, intelligent air-cooled design, which greatly reduces the machine failure rate and ensures a safer and more stable operation of the photovoltaic system. In addition, the inverter has the ability to continuously and smoothly adjust the active power, can accept AGC power control commands, ms-level fast response, and the adjustment error is less than 1%, which can effectively ensure the power generation and load balance of the power station.

In order to meet the special requirements of Qinghai power grid, the inverter must have high and low voltage ride-through grid-connected performance, and good weak grid adaptability. Based on years of technical accumulation in software control algorithms, Shangneng Electric has innovatively combined the virtual synchronous generator (VSG) grid-connected technology and inverter port impedance reshaping technology for the characteristics of weak power grids. Real-time reconstruction of the grid-connected control characteristics of the situation, while ensuring the safety and stability of the photovoltaic system integrated into the grid, further realizes the grid support function, and can safely deal with the weak grid environment under the condition of SCR≤1.15.

Keywords: engineering construction, engineering news

Under the global consensus on carbon reduction, renewable energy represented by photovoltaics is becoming one of the main forces of "carbon neutrality". It is foreseeable that the supporting applications of more advantageous high-current inverters and ultra-high-power components will become more and more extensive, further accelerating the development of clean energy. As a strong player in the field of power electronics technology, Shangneng Electric will continue to increase research and development, continue to innovate products and solutions, create greater value for customers, promote the construction of zero-carbon power, and accelerate the process of carbon neutrality.Editor/Xing Wentao、Design/Xia Changwang