How do we control the UHV AC/DC hybrid power grid?

Recently, the State Grid Corporation of China organized 218 units of dispatching, operation and maintenance, and related power plants at all levels to hold the National Grid 2014 Summer Fighting Summer Joint Anti-accident exercise to implement the company's 2014 second quarter work conference and the safe and stable quality service TV. The spirit of the conference call ensures that the power grid will operate safely and stably during the summer peak season and provide reliable power supply. After reading this news, I pondered for a long time.

We know that DC transmission only has a transmission function and cannot form a network. It is similar to a "direct flight" and cannot be placed in the middle. It is positioned at ultra-long-distance, super-capacity "point-to-point" transmission. AC transmission has the dual functions of power transmission and network construction. Similar to the “highway traffic network”, the access, transmission and consumption of electricity are very flexible. It is positioned to build a strong transmission network at all levels and large-capacity, long-distance distance under economic distance. Transmission is widely used in the sending of electric currents.

It is expected that bad weather such as typhoons and thunderstorms will be high in summer this year. The external environment of equipment will be deteriorating. Under severe failure conditions, there will be a greater impact on the sending and receiving power grids. In addition, the structural contradiction between the power grid and “weakness and weak traffic” will be more prominent, and there will be insufficient current transfer capacity. With weak support and insufficient backup, we have ushered in the operational pressure of the UHV AC/DC hybrid power grid and ushered in the greater challenge of reliable delivery and consumption of clean energy.

How to control the UHV AC/DC hybrid power grid for this new and particularly important issue? There is no doubt that first of all, it is natural to have theoretical knowledge. As early as 2012, the national grid UHV AC/DC hybrid power grid research project passed the appraisal, focusing on the near-area tidal current distribution of the UHV AC/DC landing point and the coupling relationship of cross-section transmission power, UHV DC lines, and AC line transmission capabilities. The effect of UHVDC blocking failure on the stable operation of the AC system and the possibility of failure of simultaneous commutation under two-circuit UHV DC injection conditions.

Secondly, an extremely important part, when anti-accident rehearsals, it is also a sublimation of theory. Use theory to analyze reality and use actual verification theory. In this exercise, three major UHV DC faults occurred one after another, and East China III East and West I faults were successively tripped. It is necessary to examine the emergency protection capabilities and coordination capabilities of all units. It is necessary to examine the operational control and control capabilities of UHV AC/DC interconnected power grids and the ability to deal with accidents. It is necessary to increase the joint response of all units to the rapid response to the increase of power grid operation emergency events. ability.

China’s UHV has won the Special Award for the China Machinery Industry Science and Technology Award, the First Prize for the China Power Science and Technology Award (the highest award), the National Major Engineering Standardization Demonstration Award, the National Quality Engineering Gold Award, and the China Industrial Awards. On the basis of awards and other issues, how should this be handled in the face of this new topic in UHV AC/DC hybrid power grids? The State Grid Corporation of China uses its theory and practice to move closer to each other. This traditional, effective, brief and straightforward approach has given us a good lesson.