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Lopez-Roldan J.,Powerlink Queensland | Tang T.,Queensland University of Technology
IEEE Electrical Insulation Magazine | Year: 2012

Experience has shown that HV equipment in a switchyard, particularly oil-filled instrument transformers, can fail explosively following dielectric breakdown. Failure of HV equipment can cause injuries to personnel in the vicinity due to fire and explosion, and therefore utilities implement various risk mitigation procedures. © 2012 IEEE. Source


Dahal S.,Powerlink Queensland | Nadarajah M.,Queensland University of Technology
Asia-Pacific Power and Energy Engineering Conference, APPEEC | Year: 2015

In Australia, grid integration of renewable energy (RE) resources has been very popular due to public awareness of climate change and favorable government policies. The initial mandatory renewable energy target (MRET) has been successful and there has been a revised target (RET) set for next decade. On the other hand, there are some regulatory and technical issues posing hindrances to the development of renewable resources. This paper discusses the opportunities and problems associated with renewable energy integration into Australia's National Electricity Market NEM. Issues such as the regulatory frameworks, access standards as per National Electricity Rules (NER), connection process, and transmission pricing frameworks are discussed. © 2015 IEEE. Source


Lopez-Roldan J.,Powerlink Queensland | Birtwhistle D.,Consultant Engineer | Blundell M.,Powerlink Queensland | Tang T.,Queensland University of Technology
IEEE Transactions on Power Delivery | Year: 2012

Modern circuit breakers (CBS) may be susceptible to catastrophic failure possibly because they are designed to be more highly stressed than earlier CB designs with multiple interrupters per pole. Improved performance is obtained with dielectrically well-designed interrupters by taking advantage of advanced controlled switching to achieve a reignition-free window during opening to minimize the risk of nozzle puncture. On occasion, CB owners may wish to check whether equipment is performing satisfactorily and whether controllers are producing reliable and repeatable stress control. The monitoring of voltage waveforms during switching using established methods will provide information about the magnitude and frequency of small reignitions and restrikes. However, waveform measurements at a moderately high signal frequency require plant outages to connect specialized equipment. A nonintrusive measurement technique has been developed to measure the high- and low-frequency voltage waveforms occurring during reactor switching operations without the need for an outage. Results of tests performed in the laboratory and in a 275-kV substation demonstrating the capability of this new method to detect reignitions are presented. © 2012 IEEE. Source


Ingram D.M.E.,Queensland University of Technology | Schaub P.,Powerlink Queensland | Campbell D.A.,Queensland University of Technology
IEEE Transactions on Instrumentation and Measurement | Year: 2012

Transmission smart grids will use a digital platform for the automation of high-voltage substations. The IEC 61850 series of standards, released in parts over the last ten years, provide a specification for substation communication networks and systems. These standards, along with IEEE Std 1588-2008 Precision Time Protocol version 2 (PTPv2) for precision timing, are recommended by both the IEC Smart Grid Strategy Group and the National Institute of Standards and Technology Framework and Roadmap for Smart Grid Interoperability Standards for substation automation. IEC 61850, PTPv2, and Ethernet are three complementary protocol families that together define the future of sampled-value (SV) digital process connections for smart substation automation. A time synchronization system is required for an SV process bus; however, the details are not defined in IEC 61850-9-2. PTPv2 provides the greatest accuracy of network-based time transfer systems, with timing errors of less than 100 ns achievable. The suitability of PTPv2 to synchronize sampling in a digital process bus is evaluated, with preliminary results indicating that steady-state performance of low-cost clocks is an acceptable \pm300 ns but that corrections issued by grandmaster clocks can introduce significant transients. Extremely stable grandmaster oscillators are required to ensure that any corrections are sufficiently small that time synchronizing performance is not degraded. © 2012 IEEE. Source


Ingram D.M.E.,Queensland University of Technology | Campbell D.A.,Queensland University of Technology | Schaub P.,Powerlink Queensland
Conference Record - IEEE Instrumentation and Measurement Technology Conference | Year: 2011

IEC Technical Committee 57 (TC57) published a series of standards and technical reports for "Communication networks and systems for power utility automation" as the IEC 61850 series. Sampled value (SV) process buses allow for the removal of potentially lethal voltages and damaging currents inside substation control rooms and marshalling kiosks, reduce the amount of cabling required in substations, and facilitate the adoption of non-conventional instrument transformers. IEC 61850-9-2 provides an inter-operable solution to support multi-vendor process bus solutions. A time synchronisation system is required for a SV process bus, however the details are not defined in IEC 61850-9-2. IEEE Std 1588-2008, Precision Time Protocol version 2 (PTPv2), provides the greatest accuracy of network based time transfer systems, with timing errors of less than 100 ns achievable. PTPv2 is proposed by the IEC Smart Grid Strategy Group to synchronise IEC 61850 based substation automation systems. IEC 61850-9-2, PTPv2 and Ethernet are three complementary protocols that together define the future of sampled value digital process connections in substations. The suitability of PTPv2 for use with SV is evaluated, with preliminary results indicating that steady state performance is acceptable (jitter < 300 ns), and that extremely stable grandmaster oscillators are required to ensure SV timing requirements are met when recovering from loss of external synchronisation (such as GPS). © 2011 IEEE. Source

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