Computer Simulation Aided Study of a Real-time Energy Benchmarking Parameter for Lift Systems under different Traffic Control Schemes

At present, there are benchmarking procedures to assess the energy performance of lifts, e.g. VDI (4707-1/2) adopted in Germany as a pioneer, then replaced by ISO (BS EN ISO 25745-1:2012 and 25745-2:2015) in Europe, and the other in Hong Kong adopted by The Hong Kong Special Administrative Region (HKSAR) Government. The Hong Kong procedure focuses on the design performance of lift drives. The ISO standard further estimates the annual energy. To facilitate real time monitoring of energy performance of lift systems, a holistic normalization method (So et al 2005, Lam et al 2006) was developed more than ten years ago, which can simultaneously assess both drive efficiency and traffic control performance on a real-time basis, termed which is the name of the parameter measured in unit, J/kgm, and is now adopted by the HKSAR Government as a good practice in the Technical Guidelines of the Energy Code, but not yet enforced in the mandatory code. Values, not just the procedures, for benchmarking are demanded. In this article, such a parameter is evaluated under different drives and lift traffic control scenarios by using computer simulations, with the aim of arriving at a reasonable figure for benchmarking an energy efficient lift system with both an efficient drive as well as an efficient supervisory traffic control. This parameter could also be used to compare the performance of different types of intelligent car dispatchers. The simulation suggested a value of 50 J/kgm as acceptable while 40 J/kgm as good.