Insulated Busbar Research Articles

A Coupled Multifield Estimation for Temperature Rise in a Gas Insulated Bus Bar Using ANSYS

Gas Insulated Switchgear (GIS) is an integral part of the urban power systems, which have been developed to address the substantial need for making substations more compact and reliable. The gas insulated bus bar is a crucial component of the power equipment in the substations with voltages over 100kV. In general, the ampacity of the bus bar is constrained by the maximum operating temperature, which has to be predicted, according to the demands of the standard IEC 62271. Therefore, thermal analysis of gas insulated bus bar has to be performed in the design of GIS. However, the mechanisms of heat generation and transfer in the SF6 gas and air are so complicated that it is not a simple problem to predict the temperature rise. Joule’s heat due to current in the main conductor and heat due to induced eddy currents in the tank is calculated via Magnetic Analysis. The heat transfer to the tank and atmosphere is done by means of radiation and natural convection. Heat transfer coefficients are not constant and vary on many parameters such as model geometry and material constants, making them difficult to calculate and apply to the boundaries. By considering the factors stated above, Nusselt number is used to analytically compute the temperature dependent heat transfer coefficients on the boundaries. The proposed research work presents a coupled magnetic and thermal field analysis supported by finite element analysis of extra-high voltage GIS bus bar with the help of ANSYS Maxwell and ANSYS Fluent. The results of the coupled finite element approach accord well with the values derived analytically.

Hotspot Temperature Monitoring of Fully Insulated Busbar Taped Joint

The fully insulated busbar has been extensively used in power and shipboard applications due to its favorable economic efficiency and excellent performance. Because of contact resistance and larger insulation thermal resistance, the joint, in certain circumstances, form a hotspot in the circuit. For hotspot temperature monitoring, therefore, this paper proposed an indirect approach which consists of radial direction temperature calculation (RDTC) in the busbar and axial direction temperature calculation (ADTC) in the conductor. The RDTC is to calculate the conductor temperatures from the surface temperatures of busbar in two different spots near the joint through the transient thermal network. The ADTC is to estimate the hotspot temperature from the conductor temperatures obtained in the RDTC using a fitted functional expression. The influence of solar radiation on the temperature distribution is greatly reduced by averaging the surface temperature in the RDTC and adjusting the functional form in the ADTC. A temperature-rise test on a practical insulated busbar taped joint was performed outdoors in hot summer to validate this approach. The calculated hotspot temperature agrees well with the measured result with a maximum error of only 3.8 K, indicating the high model precision and strong robustness to the solar radiation impact. Some factors in the applications of temperature monitoring are also discussed. This method is expected to be applied to the engineering application, thus improving the condition monitoring of the fully insulated busbar.

Computational and Experimental Analysis of Deformation of Thermal Expansion Compensator for Сast Resin Insulated Busbar Systems

Computational and Experimental Analysis of Deformation of Thermal Expansion Compensator for Сast Resin Insulated Busbar Systems

Development of Simplified Three-phase 550kV Gas Insulated Busbar

Development of Simplified Three-phase 550kV Gas Insulated Busbar

Consideration and research of high voltage insulation strategy for ITER Feeder busbar joint

The ITER Feeder busbar joint is an important component which connects different sections of busbar which run from the high temperature superconducting current leads to the magnet terminals. High voltage insulated bus bar sections will be assembled onto the feeder support structure (called the containment duct), and the joints between sections will be made in situ. The high voltage insulation over the joint is the final step to complete the insulation of the whole bus bar system, and its quality is key to achieving the required electrical performance of the system. The final joint has a complex external configuration with an irregular structure in places, which makes it difficult for the application of the insulation. The limited access in the Feeder and the complex joint external structure make the implementation of the joint insulation hard to solve. The Feeder group at ASIPP has carried out significant R&D for the joint insulation, involving research on the selection of materials, the design of the insulation structure, the curing technology and the quality inspection method. After many rounds of manufacturing and testing, the insulation strategy for the Feeder joint will focus on the so-called “wet-winding” technology. Despite the fact that this process has some intrinsic disadvantages, it is more appropriate for the joint structure compared to other methods. The sub-suppliers to ASIPP have chosen this impregnation method for the feeder qualification activities based on guidance from ASIPP. This paper describes the research procedure of the ITER Feeder busbar joint insulation, summarizes the activities on the joint insulation structure design, describes the trials of the impregnation method, and describes the pre-qualification tests. Even for the preferable “wet-winding” process, some improvements have been applied due to recommendations from ITER IO experts. For example, both the use of a vacuum bag during the process and investigation using non-destructive tests (NDT) have been implemented.

Calculation of Temperature Rise in Gas Insulated Busbar by Coupled Magneto-Thermal-Fluid Analysis

This paper presents the coupled analysis method to calculate the temperature rise in a gas insulated busbar (GIB). Harmonic eddy current analysis is carried out and the power losses are calculated in the conductor and enclosure tank. Two methods are presented to analyze the temperature distribution in the conductor and tank. One is to solve the thermal conduction problem with the equivalent natural convection coefficient and is applied to a single phase GIB. The other is to employ the computational fluid dynamics (CFD) tool which directly solves the thermal-fluid equations and is applied to a three-phase GIB. The accuracy of both methods is verified by the comparison of the measured and calculated temperature in a single phase and three-phase GIB.

The Short Circuit Electromagnetic Force of the Three-Phase Encapsulated Gas Insulated Bus-Bar

The Short Circuit Electromagnetic Force of the Three-Phase Encapsulated Gas Insulated Bus-Bar

The Short Circuit Electromagnetic Force of the Three-Phase Encapsulated Gas Insulated Bus-Bar

This paper discribes various optimum design conditions for a three-phase encapsulated gas insulated bus-bar (3 phase GIB) on the basis of the results of the quantitative analysis and the experiments with respect to the short circuit electromagnetic force. It reveals that the characteristics of the short circuit oscillation in 3 phase GIB are notably different from those in single phase bus-bars. The experiments showed that the fundamental mode oscillation of conductors was dominant with strong attenuation of 10 ~ 12%. The effect of enclosure current should also be taken into account in case of aluminuim enclosure.