Electrical Installations and Systems in Buildings

Researchers:	Dr. Patrick Y. Du Dr. M. L. Chen
Collaborators:	Prof. W. S. Dong, Cold and Arid Regions & Environmental Engineering Institute,Chinese Academy of Sciences, China Prof. Y. J. Zhang, Chinese Academy of Meteorological Sciences, China Prof. Z. C. Fu, Institute of Electrical Power, Shanghai JiaoTong University, China
Research Associate:	Mr. H. B. Wang
Research Students:	Mr Z. H. Yuan Mr. Q.B. Zhou
Research Assistants:	Mr. Po Pei Mr. T. Wang

This research team is in pursuit of innovation of advanced technology in electrical installations and systems in buildings. Current research is focused on power quality & control, electromagnetic environments and protection against lightning.

The topics in the area of power quality & control includes modeling of electrical distribution systems, analysis of power quality events (harmonics, surge, etc.) in systems, harmonic mitigation and control using active power filters or others, and reliability of electrical equipment and systems.
The topics in the area of electromagnetic environments include identification and modeling of low-frequency, high-frequency and pulse interference sources, characterization of electromagnetic environments, mitigation and control of electromagnetic fields, and electromagnetic shielding.
The topics in the area of lightning protection includes characterization of lightning-caused transient currents and fields, model for prediction of probability of lightning striking to a building, effects of bonding and earthing practices on lightning current dispersion, mechanism of building-triggered upward lightning, and development of new lightning detecting/monitoring systems as well as new effective lightning rod/air terminals.

It is anticipated that the research in this group will underpin the development of guidelines, tools and products for quality electrical services in buildings. A design guide of magnetic fields for electrical installations has been developed. A software package for evaluating magnetic fields in buildings is currently available. A package of modeling major building structural elements for analyzing lightning-induced electromagnetic environments is being developed. A novel filtering network for controlling harmonics in building distribution systems is being developed as well. An integrated lightning detector capable of recording the electromagnetic and optical radiations from lightning has been developed and is in operation now. A new type of electric field meter with high sensitivity is being also developed. A single-station lightning location system and a new lightning rod/terminal, with which lightning risk to buildings can be effectively reduced, will be designed and tested soon.

The research team has a strong relationship with local industry, especially in building services industry. The team has been involved in more than 30 consultancy projects in the past five years. Most of the projects were related to investigation, analysis and mitigation of electromagnetic interference associated with electromagnetic fields, harmonics, surges, etc. Design of electromagnetic shielding rooms is another key area of the consultancy service.

Recent Research Projects:

Study of the effect of large building structures on lightning return stroke current using an integrated modeling approach, funded RGC
Development of harmonic impedance database for LV power cables, fund by RGC
The electromagnetic environment in high-rise buildings during direct lightning strokes, funded by RGC
Design guide of magnetic fields for electrical installations in large buildings, funded by RGC
Modeling of high current low voltage busbar and cabling systems in buildings, funded by RGC
Study of lightning electromagnetic pulses and currents for building lightning protection, funded by PolyU
Effect of bonding and earthing practices on lightning currents in buildings, funded by PolyU
Broadband interferometric observations of spatial development and HF/VHF radiations of lightning, funded by PolyU
The development of an integrated, PC based system for making optical and electromagnetic measurements of lightning, funded by PolyU
Control of harmonics over building distribution systems using a coordinated filtering network, funded by PolyU
Electric power and control for building services, funded by PolyU
Architecture shielding in modern building during lightning strokes, funded by PolyU

Recent Publications

Q. B. Zhou and Y. Du, "Using EMTP for Evaluation of Surge Current Distribution in Metallic Gridlike Structures," IEEE Trans. on IA, Vol. 41, No. 4, 2005, pp. 1113-1117
Y. Du and Q.B. Zhou, "Capacitance Matrix of the Screened/Insulated Single-Core Cables of Finite Length," IEE Proc. - Sci. Meas. And Technol. Vol. 152, No. 5, Sept. 2005, pp. 233-239
M. Chen, Y. Du and W. Dong, "Spectral Patters of Lightning Radiations in Intervals of interval of 25 to 100 MHz," Transactions of The IEE Japan, Vol. 125, No.1, January 2005
SM. Chen, Y. Du, and LM. Fan, "Lightning Data Observed With Lightning Location System in Guang-Dong Province, China," IEEE Trans. on Power Delivery, Vol. 19, No. 3, July 2004, pp.1148-1153
L. Xu, Y. Du and Q.B. Zhou, "The magnetic field and induced current arising from a cylindrical shell loop with an unbalanced current," Electric Power System Research, Vol. 71, 2004, pp. 21-26
Y. Du, L. Xu and Q.B. Chou, "Magnetic fields of a cylindrical shell excited by an unbalanced current source," HKIE Trans. Vol. 11, No. 3, Sept. 2004, pp. 5-9
Y. Du and J. Burnett, "Reliability of Standby Generators in HK Buildings," IEEE Trans. on IA, Vol. 39, No. 6, Nov./Dec. 2003, pp. 1592-1595.
Y. Du and K.M. Lau, "A Preliminary Survey of Lightning Protection Practices in Hong Kong Buildings," HKIE Trans. Vol. 10, No. 3, Sept. 2003, pp. 59-65.
C.K. Chau, Y. Du, W.L. Lee, M.S. Tse & J. Burnett, "Monitoring the competitiveness in the supply of low-voltage switchboards, " BUILDING AND ENVIRONMENT, 38 (2003), pp. 797-793
Takagi, N., M. Chen, Y. Du and T. Watanabe, Experiment study of a phased array antenna for lightning observation, Journal of Atmospheric Electricity, Vol.23, No.1, 2003, pp. 41- 48
Chen, M., T. Watanabe, N. Takagi, Y. Du, D. Wang and X. Liu, Simultaneous observations of optical and electrical signals in altitude-triggered negative lightning flashes, Journal of Geophysics Research, Vol. 108, No. D8, 4240, 2003.
W. Dong, X. Liu, M. Chen and Y. Zhang, Broadband interferometer observations of the bi-directional breakdown process in natural lightning, Chinese Journal of Geophysics, Vol.46, No.3, 449-456, 2003.
Y. Du and J. Burnett, "Harmonic Characteristics of Low-Voltage Single-Core Power Cables," HKIE Transaction, Vol. 9 No. 8, August 2002, pp.46-51
Chen Shuiminga and Y. Dub "A Lightning Location System in China: Its Performances and Applications," IEEE T-EMC, Vol. 44, No. pp.555, November 2002.
J. Burnett and Y. Du, "Mitigation of Extremely Low Frequency Magnetic Fields from Electrical Installations in High-Rise Buildings, " Building and Environment, 37 (2002), pp.769-775
C Shuiming, Y. Du, F Lingmeng, and Z Dingzhu, "Evaluation of the Guang Dong lightning location system with transmission line fault data," IEE Proc. - Sci. Meas. and Technol., Vol. 149, No. 1, January 2002, pp.9-16.
Y. Du and J. Burnett, "Magnetic Field Mitigation in Large Commercial Buildings," HKIE Transactions.2001, Vol. 9, No. 1, April 2002, pp. 37-41.
Y. Du and J. Burnett, "Parallel Single-Core Cables in Single-Phase Low-Voltage Installations," IEE Proc. - Gener. Transm. Distrib. Vol. 148 No. 5, Sept. 2001, pp.406-412.
Y. Du and J. Burnett, "Experimental and numerical evaluation of surge current distribution in buildings during a direct lightning stroke," HKIE Transactions Vol. 8 No. 1, April 2001, pp.1-6.
Y. Du and J. Burnett, "Experimental Investigation into Harmonic Characteristics of Low-Voltage Power Cables, " IEE Proc. - Gener. Transm. Distrib. Vol. 147, No. 6 Nov. 2000, pp. 322-328.
Y. Du and J. Burnett, "ELF Magnetic Shielding by Trunking," HKIE Transactions, Vol. 7 No. 3, Dec. 2000, pp. 35-39.
Y. Du, J. Burnett and Z.C. Fu, "Experimental and Numerical Evaluation of Busbar Trunking Impedance," Electric Power system Research, Vol. 55, pp113-119
Y. Du and J. Burnett, "ELF Shielding Performance of Metallic Enclosure for Heavy-Current Conductors, " IEE Proc. - Gener. Transm. Distrib. Vol. 146, No. 3, May 1999, pp. 223-228.
Y. Du and J. Burnett, "Magnetic Field Characteristics of Multi-core Cables in Low-Voltage Installations," IEE Proc. - Sci. Meas. and Technol. Vol. 146, No. 1, January 1999, pp. 2-8.
M. Chen, N. Takagi, T. Watanabe et al., Leader properties and attachment process in positive triggered lightning flashes, Journal of Atmospheric Electricity, Vol.19, No.1, pp.45-59, 1999.
M. Chen, N. Takagi, T. Watanabe, D. Wang et al., Spatial and temporal properties of optical radiation produced by stepped leaders, Journal of Geophysics Research, Vol.104, No. D22, pp.27573- 27584, 1999.