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This chapter is related to the insulation coordination study to specify required electrical clearances on the fully composite pylon. The deterministic approach of insulation coordination study is described. Statistical behavior and failure risk of insulation along with the effect of statistical withstand voltage and statistical overvoltage on the risk of failure are implied. The insulation coordination procedure to calculate required electrical clearances on the fully composite pylon are presented. The obtained results are compared with the recommended values of standards and subsequently, internal and external air clearances at the tower top and within the mid-span are specified.

In this chapter, the design of insulation for the unibody cross-arm of fully composite pylon is presented in more details. The design includes the calculation of creepage distances along the unibody cross-arm and allocating proper shed profiles on the shed housing of insulation. Electric field criteria regarding the design of high voltage composite insulators are mentioned. Two design scenarios of utilizing internal and external ground connection for the shield wires are examined by performing numerous finite element analyses. Different conductor clamp designs with various material in used are considered for the attachment points between the phase conductors and the unibody cross-arm and are evaluated by finite element method. Electric field magnitudes in the different regions of interest on the unibody cross-arm are computed and compared with the electric field criteria. An optimization process are carried out to find appropriate dimension and positions for the corona rings at both sides of conductor clamps.

The lightning shielding performance of shield wires in the fully composite pylon has been verified by experimental methods in this chapter. In order to verify the conclusion obtained by electro-geometric model (EGM) analysis in Chap. 6, a scale model test has been performed. Direct lightning strikes to phase conductors are simulated by electrical discharges to scale phase conductors with fast-front and slow-front impulses in the high voltage lab. Shielding failure rate (SFR) is obtained by interpreting the ratio of number of discharges to scale phase conductors to the total number of discharges. Additionally, the maximum shielding failure current is obtained by scale model tests. Comparing results developed by theoretical method—electro-geometric model (EGM) and experimental method-scale model test, it proves that these two methods verify each other and support each other’s application to the lightning shielding investigation in the innovative fully composite pylon. A conclusion can be drawn that, as regards to protection from direct lightning strikes, shield wires in the fully composite pylon can prove acceptable lightning protection for overhead lines.

The verification of electric field performance is one of the main challenges in the electric design of the fully composite pylon. Electric field computation based on numerical methods such as Finite Element Model (FEM) is an useful method to predict its electric field performance. However, verification of these theoretical computation is necessary. In order to evaluate the electric field distribution on the composite cross-arm surface in the fully composite pylon and assess its electrical design in wet conditions, water induced corona discharge tests on the full-scale cross-arm has been performed. According to test results, the corona inception electric field magnitude on the composite cross-arm surface in wet conditions is lower than the maximum electric field magnitude on the composite cross-arm surface with nominal operation voltage. Thus, the configuration design of the cross-arm needs further consideration, aiming to restrain the maximum electric field magnitude on its surface. Additionally, effects of the cross-arm inclined angle \({\varvec{\theta }}_{cross-arm}\) on the water induced corona discharge activities have been investigated, which gives valuable advice for the decision of optimal inclined angle \({\varvec{\theta }}_{cross-arm}\).

The composite cross-arm core is one of the most critical components in the fully composite pylon in the project Power Pylons of the Future (PoPyFu), sustaining the mechanical loading and providing the main electrical insulation. The Fiber Reinforced Plastic (FRP) composite is considered as the most suitable material as the core material of the composite cross-arm. In the present chapter, a fundamental introduction of Fiber Reinforced Plastic (FRP) composites is given and the selection of most suitable Fiber Reinforced Plastic (FRP) composites, from electrical point of view, for the composite cross-arm core is discussed.

In this chapter, environmental effects of fully composite pylon including audible noise, radio interference, corona losses and electromagnetic emissions are investigated. Based on surface gradient on phase conductors, the generated audible noise around an overhead line composed of fully composite pylons are calculated and evaluated. The produced radio noises form the overhead line are also computed and compared with recommended standard values. Corona loss of the line is estimated, and finally, electromagnetic emissions around the overhead line are calculated and the requirements to define necessary right-of-way width at both sides of the line are discussed.

In this chapter, the basic concept of lightning shielding analysis of overhead transmission line using conventional electro-geometric (EGM) method is presented. Since the conventional EGM method is not applicable for the fully composite pylon, therefore, the conventional EGM is modified to be used for the assessment of lightning shielding performance of the pylon. The shielding failure rate (SFR) and shielding failure flashover rate (SFFOR) of the fully composite pylon with a preliminary assigned shielding angle of −60° are calculated using the modified EGM method for the vertical lightning strikes. The lightning shielding behavior of fully composite pylon against possible horizontal lightning strikes is also investigated using rolling sphere method (RSM).

“Simple Switching Transients”, reviews the principles of the Laplace transform and uses it to study simple switching transients, RC-RL-RLC loads for both AC and DC sources. In other words, the chapter demonstrates how analytical analysis of simple systems can be made. These principles will be used in later chapters in the study of more complex scenarios.

“System modelling and harmonics”, starts by proposing a method that can be used when deciding how much of the network to model when doing a simulation of an energisation/restrike together with the possible limitations of the method.The chapter continues by analysing the frequency spectrums of cable-based networks which have lower resonance frequencies than usual because of the larger capacitance of the cables. At the same time, a technique that may help save time when plotting the frequency spectrum of a network is proposed.The chapter ends by proposing a systematic method that can be used when doing the insulation co-ordination study for a line, as well as the modelling requirements, both modelling depth and modelling detail of the equipment, for the study of the different types of transients followed by a step-by-step generic example.