Index IntroductionHigh Voltage Power LinesSignal DetectionSignal TransmissionSignal InterpretationIntroductionElectrical energy is moved from the generation site (source where it is converted from another form of energy) to the load (where will be used) through high voltage voltage transmission lines. High voltage is used to reduce energy loss, however it produces a strong electric field which causes a partial discharge when it exceeds the breaking strength of the insulating material. A partial discharge can cause the insulating material to break down and cause an energy surge. There are several reasons for a partial discharge, such as incorrect cable installation, added wires, and manufacturing defects. Engineers believe partial discharge testing is a good way to identify problems with cables and evaluate the insulation of power equipment. This will be discussed in this document, and first we will talk about the structure of the cablegrams as if the PD occurred. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get Original EssayHigh Voltage Power LinesComponents of High Voltage Power CableConductor, inner semiconductor shield, insulator, outer semiconductor, ground semiconductor shield and protection sheet are the main components of the cable from inside to outside respectively. The conductor is where current is primarily transferred and is usually made of aluminum or copper as they provide the least losses. The internal semiconductor is a single layer that reduces stress on the insulator due to the electric field by acting as a smooth, homogeneous surface. Insulators wrap around electrical wires to separate electrical conductors and prevent current from passing through them, while the external semiconductor prevents contact between the insulator and ground by avoiding voids and gaps that can form due to mechanical and thermal stress. The metal earth shield protects the insulation and conducts the fault current to earth until the system shuts down. Last but not least is the protective sheet that protects the cable from damage. Cable configuration. The components mentioned above are what makes up a cable, however there are other components that are used along cables in the transmission system: joints and terminations. Joints connect the cable together and are used because the length of a single cable is not sufficient to cover the long distances required. The terminations instead interface the cable with the electrical system. Partial discharges usually occur in joints and terminals as they are installed on construction sites - unlike cables which are manufactured and then transported - and this makes them more susceptible to human error. Types of partial discharges: Internal dischargeBreakdown due to internal charging begins when there is a void or cavity in the insulator which will have low dielectric strength: electric field strength in the voids greater than that across the dielectrics. So, even if the voltage operates at its average level, breakdown may occur due to exceeding the breakdown resistance. Surface discharge Surface discharge appearing on the surface of the insulating material occurs when the resistance of the material weakens due to various environmental effects. High stress is what initiates this type of Pd, so it usually occurs on cable accessories since there is no external semiconductive shield. Electric Tree Discharge Electric tree discharge is initiated by an electrical deterioration tree path.