From power to robots

In his latest research projects, Peking-based Ji Long Yao is blending electrification with digitalization.
Inventors of the Year 2018


China has already made huge investments in expanding its power grid capacities, and will continue to do so.
Ji Long Yao, Corporate Technology

Siemens researchers in China are developing new technologies for the world market. Ji Long Yao from Corporate Technology in Peking, is the brains behind a number of the resulting inventions. His novel ideas are responsible for several enhancements to the way HVDC lines are connected to power grids.


One of his key projects is a new measurement system for use in high-voltage applications. Unlike previous devices, Yao’s brainchild needs no electrical supply of its own to measure the voltage and current over transmission lines. The measurements are made using sensors and then sent to the control room by means of optical fiber. As well as being a considerably safer method of measurement, the device brings further benefits in terms of robustness and reliability – these are crucial qualities where high-voltage transmission are concerned, some of which run through extremely remote areas.


Yao’s other “baby” is a safety device that protects transformers by blocking direct current. If direct currents were allowed to flow unimpeded through a transformer, they would eventually cause damage due to severe vibrations and heat build-up. Installed in electrical substations, this DC blocker is no off-the-shelf product – it needs to be custom-made for every grid operator. Until now the products have been built for grid companies in Hong Kong, New Zealand and Germany.


Because HVDC technology, plus its associated systems and devices, has reached a relatively advanced state of technical maturity, Yao has now been able to move on to fresh pastures for his innovations. One of his most exciting research topics is the development of a micro-inverter for robots, and he is also looking into the use of power electronics in low-voltage applications.