Commissioning of a power system stabiliser using a dynamic signal analyser

This paper describes the commissioning of a digital power system stabiliser (PSS) at Connaught Bridge Power Station in Malaysia using an HP 35665A dynamic signal analyser (DSA). A brief description of the digital PSS and the commissioning procedure adopted is reported. Some of the results obtained are presented and these highlight the effectiveness of the procedure to achieve a significant improvement in the dynamic stability of the generating unit. Finally, the advantages of the procedure are summarized. The digital PSS described in this paper is an improved version of an earlier design of White and Zachariah (1989). It is a sophisticated microprocessor-based digital equipment which has been designed using standard off-the-shelf hardware wherever possible. The heart of the system is a 32 bit MC68030 microprocessor which executes the PSS software. The PSS uses the ´OS-9´ operating system to perform all routine ´house-keeping´ jobs associated with a software based system. An industrial version of the OS-9 operating system is used in the PSS which is compact and well suited for real-time control applications. The PSS software is written in the high level language ´Pascal´ which makes the software easy to read and easy to maintain. A sample frequency of 100 Hz has been used in the PSS which is adequate for stabilising even the fastest local mode oscillations.