The Zhangbei high-voltage direct current (HVDC) power transmission project in China is the world’s first HVDC power transmission system to utilise multi-level voltage sourced converter (VSC) technology at a rated voltage of ±500kV.

Owned and operated by State Grid Corporation of China (SGCC), it is an advanced VSC-HVDC system with four interconnected converter stations in a ring network, designed to transmit up to 4,5GW of clean energy.

The construction on the £1.4bn ($1.84bn) project was officially commenced in February 2018 following the approval of the National Development and Reform Commission in December 2017.

A test run was successfully conducted to energise the four-terminal ring grid by interconnecting the Zhangbei, Kangbao, Fengning, and Beijing converter stations for the first time in June 2020.

The project is intended to ensure sufficient reliable, low-carbon power supply for the 2022 Winter Olympics to be held in Beijing.

The Zhangbei VSC-HVDC power transmission system will be capable of transmitting approximately 14.1 terawatt-hours (TWh) of clean energy to Beijing while offsetting 12.8 million tonnes of carbon dioxide emission annually.

Zhangbei VSC-HVDC transmission route

The Zhangbei ±500kV VSC HVDC power transmission project passes through Northern Hebie and Beijing.

Located in the Beijing-Tianjin-Hebei area of China, the project enables the integration of wind, solar, and hydro energy generated in Zhangjiakou in North China to Beijing, Tianjin and Hebei regions through a four-terminal transmission ring network.

The overhead transmission line corridor covers 227km in Zhangbei, 126km in Beijing, 219km in Fengning, and 66km in the Kangbao region.

Converter stations

The VSC-HVDC transmission system comprises three supply terminals located in Zhangbei county of Zhangjiakou city, Fengning county of Chengde city, and Kangbao County in the Hebei Province.

Each supply terminal comprises a ±500kV flexible DC converter station featuring bipolar half-bridge modular multilevel converters (MMC).

The fourth ±500kV converter station of the Zhangbei DC power grid is a receiving station located 1.5km northwest of Bangshui village in the Badaling town of Beijing. Equipped with seven converter transformers, the station occupies a total construction area of 36,000m2.

The Zhangbei and Beijing converter stations operate at a power rating of 3,000MW each, while the Fengning and Kangbao converter stations have a rated capacity of 1,500MW each.

The Zhangbei and Kangbao stations are connected to new energy sources being developed in the region, while the Fengning converter station is connected to the Fengning pumped storage power plant. The receiving station in Beijing is connected to the capital load centre.

Equipment deployed for the Zhangbei VSC-HVDC project 

The key equipment deployed for the power transmission project include 16 DC circuit breakers (four sets in each converter station), high-parameter insulated gate bipolar transistors (IGBT), water-cooling converter valves, control and protection systems for DC power grids, and AC energy dissipation devices among others.

Other components include HVDC light valve, wall bushings, transformer components, high-voltage capacitors, power semiconductor devices, water cooling system, switchgear, bridge arm reactor, smoothing reactor, and AC/DC measurement device.

The HVDC link employs TDK’s MKK DCi-R power capacitors measuring 600mm in height, 350mm in length, and 160mm in width.

Contractors involved

ABB was awarded a contract by SGCC for the supply of the VSC-HVDC light valve system, transformers components, capacitors, semiconductors, and wall bushings in November 2018.

TDK supplied EPCOS power capacitors, under a contract signed with SGCC in December 2018.

NR Electric provided converter tower, IGBT valves, water cooling systems, and DC breakers for the project.

Powerchina Fujian Electric Power Engineering Company provided design for the ±500 kV Kangbao converter station.

Sun.King Electronics signed a contract with SGCC for IGBT drivers and IGBT modules in November 2018.

CONDIS® was contracted by SGCC for DC circuit breakers and DC voltage dividers for the Zhangbei VSC-HVDC project.

Jucro supplied circuit breaker, isolation switches, and switchgears for the VSC-HVDC project.