RXPE provided a set of 34.5kV/150Mvar delta connection STATCOM based on PP-IGBT technology in Mexico in early 2024. The STATCOM device worked together with a group of filtering capacitor banks (H2+H3+H4) with 110Mvar fundamental compensation capacity to control all power quality issues such as voltage fluctuations and flicker and harmonics during the operation of one 135MVA top feeding arc furnace and two refining furnaces (with capacities of 24MVA and 30MVA respectively) in Tenaris TAMSA steel plant in Mexico. The short-circuit capacity of the 230kV power grid on site is about 4563MVA, The short time flicker value PST of the power grid voltage caused by the furnace load without compensation device is about 3.80, and the long time flicker value PLT is about 2.82. According to technical agreement, the short time flicker value PST of the power grid voltage should not exceed 1.0 after the STATCOM system is put into operation, and the long time flicker value PLT should not exceed 0.8. At the same time, the power quality indicators such as harmonic and imbalance of the power grid should meet the requirements of IEC and relevant standards of the Mexican power grid, the average power factor on the 230kV input side should be above 0.95.

The STATCOM system installation and low-voltage commissioning work was all finished on 17th November 2024, the pictures of the STATCOM system after site installation are shown in Figure 2. On 19th November 2024, the STATCOM system was put into formal operation after completing high-voltage related testing work. The HMI interface of the control system during STATCOM system operation is shown in Figure 3, and the daily operating data of the STATCOM system is shown in Figure 4. By 28th November 2024, the STATCOM system have operated continuously without fault or alarm for more than 9 days, and the power factor of the power grid assessment point with the STATCOM system in operation is greater than 0.99. At the same time, the technical indicators of power quality such as voltage fluctuation, flicker, harmonic distortion, and imbalance in the power grid all meet the requirements of the technical agreement and relevant standards of the Mexican power grid. The short time flicker value (PST) of the power grid voltage is less than 0.86, and the long time flicker value (PLT) is less than 0.67. The flicker data curve is shown in Figure 5.

The above data proves that the 34.5kV/150Mvar STATCOM device based on PP-IGBT technology has very good technical and stable performance, and can effectively control the power quality problems caused by the production process of high-power AC electrical arc furnace, ensuring that the power quality indicators of power grid system meet relevant standard limits and technical agreement requirements.