At ZTT Group 2020 Innovation and Entrepreneurship Conference, the "Long Length 500kV Cross-linked Polyethylene Insulated Fiber Optic Composite Submarine Cable System (Including Soft Joint and Repair Joint)" of Zhongtian Technology Submarine Cable Co.,Ltd. (hereinafter referred to as "ZTT Submarine") was awarded with special prize. Xue Jiping-Chairman of ZTT,  personally issued the bonus and certificate to the development team.

In 2007, ZTT submarine fiber optic cable products were initiatively certified with UJ and UQJ from international authoritative organizations; ZTT submarine cables were exported to the United States as representing top level of Chinese submarine cable manufacture in 2011; ZTT realized the "Three-Grade Leap" for the development of ultra-high voltage flexible DC cable system from ± 160kV to ± 200kV and ± 320kV from 2013 to 2015. In 2016, ZTT successfully developed the 500kV XLPE insulated AC submarine cable and system with the highest voltage and maximum length in the world. ZTT won the bid for German wind power Engineering Procurement Construction (EPC) Project; and ZTT ranked among globally Top 10 most competitive enterprises in 2018.

It was learned that global 500kV UHV AC submarine cables developed previously were completely oil-filled ones, which had shortcomings including insufficient mechanical performance and poor oil pressure control and environmental friendliness. A type of UHV AC submarine cable with better performance and more reliable quality and convenient laying in lieu of existing oil-filled cables was expected then. In 2015, ZTT organized and conducted special evaluation and consultation according to the development status and market demand for domestic and overseas cables after China’s three-core 220kV XLPE insulated fiber optic composite cables were produced in batches, and immediately established the project team for " Project 128 " and started to work on the "Large Length 500kV XLPE Insulated Fiber Optic Composite Submarine Cable System " to tackle key problems.

In January 2019, the joint-free 500kV XLPE insulated submarine cable with maximum length and highest voltage independently developed and explored by ZTT, was successfully laid in Zhoushan 500kV Grid-connected Power Transmission and Transformation Project in Zhejiang, and successfully passed the completion acceptance. By visioning global submarine cable field, the highest voltage XLPE insulated AC submarine cable hit 420kV previously, while no engineering application precedent for 500kV was available. The successful laying and grid-connected operation of ZTT 500kV XLPE insulated AC submarine cable made historical record.

ZTT Submarine never stopped by virtue of remarkable achievements, turned the horizon to the deep sea and open sea, and focused on UHV flexible DC submarine cable project. On the basis of successful development of ± 400kV DC submarine fiber optic composite cable and winning the bid of Three Gorges Rudong Wind Power Project, ZTT Submarine continue intensifying the research and development efforts in ± 525kv flexible DC submarine cable, and spared no efforts to set the voltage level of flexible DC submarine cable to a new milestone.