Influence of load characteristics on the power/voltage stability of HVDC systems. I. Basic equations and relationships

The influence of load characteristics on the power stability of a specific HVDC system configuration has been shown. This points to a more fundamental influence of load characteristics on the power/voltage stability of HVDC systems in general. Thus, a fundamental analysis of the influence of load characteristics on the power/voltage stability of three typical HVDC system configurations is carried out in this two-part work. Three aspects are treated; (i) the basic power/voltage stability equations incorporating load characteristics, the effect of load characteristics and system parameters; (ii) the relationships between the maximum power and voltage sensitivity based methods for all the configurations incorporating load characteristics; and (iii) the most unfavourable load characteristics with respect to degrading power/voltage stability margins and the sensitivity of these margins to load characteristics. This paper presents points (i) and (ii) while part II deals with point (iii)