IndexIntroductionInverter ParametersCable ParametersMotor ParametersLiterature IndexIntroductionElectricity is the backbone of our existence in today's world. It is quite difficult to imagine a world without electricity in modern times. We depend on it for much of our daily activities. However, electricity does not exist in natural form and cannot be stored in usefully large quantities. It must be exploited from renewable or non-renewable resources and must be continuously generated to meet consumer demand. The electricity generated from its various sources is delivered to the end users/consumers through transmission and distribution (T&D) lines. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Transmission lines include wires/cables hanging from tall metal towers and carry electricity over long distances at high voltage. Electricity generated at power plants moves through this complex system, often called a “grid,” which includes power lines, transformers, and electrical substations that ultimately connect electricity producers with consumers. A recent development in transmission and distribution networks is the smart grid. A smart grid improves the traditional transmission and distribution system through the use of digital technology and advanced instrumentation that allows utilities and customers to receive updated information from the grid and also allows communication with the grid. The grid is called smarter, as it makes the electric T&D system more reliable and also efficient in reducing transmission losses and allows utilities to quickly detect and resolve problems. The smart grid also allows end users to intelligently manage electricity usage, especially during periods of high demand or when system reliability requires lower energy demand. High-voltage electricity is used in long-distance electricity transmission, as it is associated with low currents and reduces transmission losses, and therefore more efficient and less expensive than low-voltage transmission. However, low voltage electricity is needed in homes and businesses, e.g. end users. The transformers placed in the various stages of the network and in the substations carry out the task of increasing (raising) or reducing (decreasing) the electrical voltage to adapt to the different phases of the movement of electricity, from the source of the power plants up to the long transmission lines remote and low-voltage distribution lines that carry electricity to homes and businesses. The transformer is composed of 2 coils (3 coils for the three-phase system), tightly coupled via a magnetic core. Developments in power electronics technology have improved the switching frequency of devices. Insulated Gate Bipolar Transistor (IGBT) technology is currently capable of switching frequencies in the 10 to 20 khz range, along with rise times of 0.1 µs[1]. The performance of the PWM (Pulse-Width Modulation) voltage inverter as the output waveform has also improved drastically due to this development, thus making them the popular choice for variable speed induction motor drives. Induction motor and PWM inverter are mostly placed in different places, especially in industrial applications and therefore require long cables or motor leads. Fig. 1 shows a practical connection of an induction motor powered by a PWM inverterusing a long cable. Electromagnetic pulses travel at half the speed of light (3*108 m/s), or approximately (150-200 m/μs). If the electromagnetic pulses take more than half the rise time to travel from the inverter output to the motor, complete reflection of the pulse will occur at the motor terminal. This will cause the voltage pulse width to double. Increasing the rise time and fall time of the inverter voltage output pulses will help reduce this pulse reflection caused by fast switching transients. Factors that influence voltage reflection are the rise time of the inverter output voltage pulses, length of the cable used to connect the inverter and the motor, which affects the propagation time, tp of the peak impedance of the inverter 'cable and motor pulseIf tp>tr/2, then a complete reflection of the pulse occurs and causes the voltage amplitude at the motor terminal to double[1][2]. To reduce the dv/dt gradient of the inverter output voltage, a passive du/dt filter with inductor, capacitor and resistor can be used. The main disadvantage of such filters is the large power loss. The magnitude of the reflected voltage depends on the voltage reflection coefficient (ℾm) of the motor and is given by the following equation: ℾm = Zm-Zc/Zm+Zc where Zm is the characteristic impedance of the motor and Zc is the impedance cable characteristic. The peak voltage at the motor terminal (Vm) is given by the following equation, Vm=Vs(1+ ℾm) where Vs represents the source voltage. The reflection coefficient varies with motor size and its value decreases as the motor size increases. To reduce losses in the induction motor, fast switching devices are used in the inverter, but this in turn can cause the appearance of overvoltage at the motor terminals. The shorter rise time or steep voltage slope would cause the motor insulation to break down. J Desmat et al [6] studied and analyzed the impact of the following parameters on overvoltage at the motor terminal. Inverter parameters The influence of carrier frequency, voltage rise and U/f characteristics were analyzed. No difference in surge or slope was detected using the carrier frequency of 2, 5, 8, 12, or 16 kHz. But increasing the frequency leads to an increase in the number of surges per unit time. Changing the motor frequencies to 10,30,50,60 and 70 Hz also did not cause overvoltage. However, an increase in the number of surges per unit time with increasing motor frequency. The startup voltage also had no impact on the overvoltage. The U/f characteristics had the same effect on the overvoltage of the carrier frequency and the motor frequency. Cable parameters The influence of cable length, cable type and cross-section was analysed. Slope and increase in motor voltage as cable length increases. The difference in cable composition affects damping. Increasing the cross section of the cable increases the slope of the voltage at the motor terminals. Engine Parameters Engine power has a slight impact on the engine's reflection coefficient. For motors with power lower than 22kW this effect is not found. It has been observed that some parameters such as the rise time of the voltage on the inverter, the length, section and type of the cable, the motor power and the carrier wave frequency of the inverter have a significant impact on the occurrence of overvoltage . at the end of the engine. The project aims to implement a peak overvoltage prediction systemusing artificial intelligence techniques. The test system consists of a motor driven by a PWM inverter circuit via long leads or cables. Knowing the peak surge voltage is important for coordinating the insulation of long cables. Power parameters and cable parameters must be entered into the proposed system to provide an estimate of the overvoltage value. Literature ReviewMany researchers have worked on the topic of overvoltage in transmission lines. Some research works focus on overvoltage in power lines and others on overvoltage on the motor connected via long cables on inverter-powered systems. Researchers have identified the factors that cause overvoltage. Solutions based on artificial neural networks (ANN) are proposed by few researchers to predict overvoltage on power lines [1] [2]. In the past, researchers [7] also explored Support Vector Machines (SVM)-based classification of induction motor supply voltage. AV Jouanne et al. [1] examines the length of motor cables that affect AC motor drives powered by high-frequency PWM inverters. It is observed that although a high switching speed leads to an improvement in the performance parameters of PWM inverters, it has an effect negative on the motor insulation. Additionally, the length of the cable tends to cause excess voltage on the motor terminal and this puts additional stress on the motor. motor insulation. Voltage reflection is analyzed/investigated and cable transmission theory and cable capacitance analysis are presented. The document also illustrates how the cable length and rise time of the inverter pulse output affect the voltage magnitude at the motor terminals. A. Acharya B et al. [2] specifically designed for motor drives with du/dt filter output. The paper proposed a new procedure to design an LC clamp filter. The output voltage of PWM inverters has a high dv/dt, which can cause a doubling of the peak voltage at the motor terminal connected via long cables. Using the proposed filter it is possible to reduce the phenomenon of doubling the voltage at the motor terminals. There are several mitigation techniques available to implement at the engine level. They are the use of an insulated bearing, the use of an electrostatic shield between the rotor and the stator, increasing the degree of insulation and a termination that matches the impedance of the cable and the motor terminal. At the inverter level, the mitigation techniques that can be adopted are the use of filters, the reduction of the common mode voltage and the resonant switching inverter. The proposed filter targets common or differential mode components. Furthermore, in the filter, the resonant frequency is selected which causes the induction motor to behave as a high frequency inductive load which in turn has the LCL effect of a higher order filter. The effectiveness of this is verified using Pspice simulation. The filter is designed to be compact and can be easily included/placed in the inverter package. Vitor F. Couto et al. [3] proposes an alternative strategy for modeling a transmission line that analyzes the three phase conductors separately. Usually, power transmission lines are modeled as a single quadrupole circuit in a parameter arrangement similar to the shape of the Greek letter Pi. A 230 kV 197 km transmission line is adopted to illustrate the importance of the proposed method. The simulation results clearly show that overvoltages occur along the line although the voltage values ​​at both.