Conference Paper

Early public electricity supply enterprises in Australian capital cities, and a number of regional cities, were often linked with the introduction of electric trams and vice versa. Public electricity supply was first utilised for artificial lighting in streets and inside buildings. As such, the load on central electricity generating stations was mainly at night-time with the generating plant having, as a consequence, a low net capacity factor. In this context, electric tramways offered a motive power load that could substantially improve the economics of a centralised electricity generating plant. Conversely, the economics of an early electric tramway scheme could be enhanced by also publically supplying electricity.

As the 'battle of the systems' - DC versus AC - came out in favour of alternating current generation and high voltage transmission for supply to more than those areas local to the generating plant, AC to DC conversion became important for the continued operation of existing DC public distribution and for maintaining and extending electric tramways that universally used direct current traction motors. In this, the development of the rotary converter was pivotal. Later on the mercury-arc rectifier offered a higher AC to DC conversion efficiency before it was, in turn, superseded by solid-state semi-conductor devices.

The presentation, co-hosted by Engineering Heritage Victoria (EHV) and the Electrical Energy Society of Australia (EESA), will explore the above topics and how it played out in various cities around Australia.