The basic theory of operation and control of a high-voltage direct-current power-transmission system and its implementation in a system analyser

An account is given of the principal features of the operation and control of a high-voltage direct-current power-transmission system, which is viewed as a tandem convertor consisting of a rectifier in series with an inverter. It is shown how the requirements for the grid control of the main and by-pass valves of the convertor are met in the design and construction of a system analyser with low-power thyratrons simulating the convertor valves. Semiconductor devices are employed throughout in the design of the grid-control circuits. Various significant oscillograms demonstrate the successful operation of the analyser.