Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 Modelling of Electrical Cable Parameters and Fault Detection using Fourier Series *Hachimenum N. Amadi, Kingsley O. Uwho, Dennis M. Kornom Department of Electrical Electronic Engineering, Rivers State University, Port-Harcourt, Nigeria *Corresponding Author E-Mail Id: hachimenum.amadi@ust.edu.ng ABSTRACT The choice of a reliable and efficient cable has been of utmost concern to power Engineers and researchers for it enables an adequate energy supply. So many models have been considered to design either voltage or current and/or fault locations in cables. In this work, the focus is to model three-phase voltage and current as parameters of a high-voltage cable and to detect possible faults along its length with the aid of MATLAB /Simulink. The parameters of the cable-three-phase voltage and current are measured with their respective Fourier transformations. Equations parameters are determined using the Fourier transform. The system is then checked for the presence of fault and if yes, the type of fault is displayed. It is found that the presence of λ in the modelled voltage equation is significant because it represents how far the current travels along the length of the dendrite. The greater the rm, the membrane resistance, the more the current will remain inside the cytoplasm (internal fluids) of the dendrite to travel longitudinally. The more rL, or intracellular resistance, the harder it is for current to travel through the cytoplasm; hence the shorter the current can travel. Keywords: Modelling, Cable parameters, Fault detection, Fourier transformation, Matlab/Simulink 1.0 INTRODUCTION High-quality electrical power supply is necessary for infrastructural development, job opportunities, wealth creation, and human capital development. Electrical cables constitute a significant part of the electric power system [1]. However, the reliability of an electrical cable rests majorly on its insulation which is affected mostly by partial discharges. These discharges occur due to mistakes (errors) in the insulation of the cable during the manufacturing; and also installation stage. One of the notable defects in electrical cables is the cavity. When there is electrical stress, partial discharges are noticed and can give rise to cable failure. Modelling and of course simulation of partial discharges as a cavity defect in cable insulation is crucial in studying the cable's parameters. Ref [2] used the plasma model in simulating the partial discharges in cavity defect by showing the parameters' influence e.g. type of gas in the cavity, voltage magnitude and frequency imposed on the insulation mechanism. Ref [3] used the field-to-transmission-line (FTL) frequency domain approach to model multi-conductor transmission lines in 3D arrangement and other types of electrical cable bundles subjected to an electromagnetic field (EM). When it is applied to the numerical modelling process, the incident EM fields at the stage of the wires, scattered by the HBRP Publication Page 44-56 2024. All Rights Reserved Page 44 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 whole 3D structure can be calculated and collected in the 3D model on the path of the multi-conductor transmission lines. It is found that the field of the multi-conductor transmission line network is huge. The aim of the field to the transmission line is that the incident field source terms can be estimated as identical for all the wires of the medium transmission line (MTL) model. variable speed drive systems. Ref [7] considered a mathematical model of XLPE(Cross-Link Polyethylene) insulated cable power line with underground installation. The equivalent circuit of the heat process is made using homogeneous bodies method and it takes into cognizance dielectric losses, the ambient temperature and the temperature dependence of the cable core. Ref [4] studied the modelling of ageing distribution cable for replacement planning. The work proposes a reliability model which combines the following models: IEC cable heat, Arrhenius ageing and Weibull probability distribution. The proposed technique is deployed on two medium voltage distribution systems and is found that ageing models have a great impact on the system's reliability. The evaluation of the mathematical model adequacy is carried out by comparing the obtained results with the calculation of thermal and electrical processes using the finite element method via the ANSYS software workbench. The model can be used to control the capacity of cable lines with XLPE insulation and reduce their lifespan due to temperature, and ageing of the insulation. A revised way for calculating high voltage(HV) cable sheath currents and for fault location of cross-bounded high voltage cable systems has been looked at [5]. From the study, the equivalent circuit and the cable impedance per unit length under short circuit fault conditions are revised from those under non-fault conditions. The study found that there is a connection between the fault position and the sheath fault currents, it is therefore easy to spot a fault by looking at or considering the characteristics of the sheath currents when a fault occurs. To tackle the frequency dependency of unshielded power cables per unit length parameters for EMC (electromagnetic cable). Parametric cable designs can be adjudged on measurements or calculated as a function of the cable features and the physical characteristics of the cables by finite-element analysis or by using specific mathematical equations. French Institute of Technology SaintExupery developed an approach where fast, prediction models are compared to different shapes of numerical models [6]. The approach is applied to unshielded two and three-wire cables. Common mode(CM) emissions modelling is therefore proposed to forecast the CM noise currents which are found to be the most turbulent in any The last method results in certain errors due to approximations whereas parametric models adjusted using finite-element analysis need large preparation and simulation durations, so measurementbased parametric models outperform the other options. However, assuming the parameters of cable from measurements is not a simple task, but the models can be accurate for a wide frequency range even in the face of resonance phenomena. The researchers applied iterative genetic algorithm (IGA) optimization in their analysis [8]. Cable models that have distributed parameters can be more exact (accurate) than the ones with lumped parameter models though, it is a function of cable length and signal frequency. However, the later ones give a better HBRP Publication Page 44-56 2024. All Rights Reserved Page 45 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 physical interpretation of the problem while simplifying the mathematical complexity so that they can be easily suited in any electromagnetic transients program. In the past, cables were modelled by discretising the telegrapher's equations into cascaded lumped circuit networks that is based on their per-unit-length (p.u.) parameters and can be gotten by using direct measurements or analytical formulas or with the aid of electromagnetic simulations. Straight measurements of frequency-dependent per unit (p.u.) parameters of a multiconductor cable are rather cumbersome and inaccurate at high frequencies. Analytical formulas are used only for a given set of cross-sectional geometries and model the frequency dependence of the unit length parameters only approximately. Electromagnetic solvers require the cable cross-sectional geometry and electric parameters which are not readily available [9]. Ref [10] presents a new tool for the computation of per-unit-length (p.u) parameters for transmission line and cable models used for simulating electromagnetic transients (EMT). The intended approach is based on the MoMSO theory and state-of-the-art formulations for the computation of the series impedance and shunt admittance parameters. The new tool has major benefits in comparison to ancient approaches available in EMT-type software. These advantages include accurate skin and proximity effect modelling, above-ground cable modelling, modelling of stranded wires in cables, representation of multilayer soil, coupled overhead lines and underground cables, and so on. The researchers present the new tool together with demonstrations of transient simulations for practical examples. Middle voltage cables convey signals poorly with great frequency spectrum e.g. partial discharges. The radiating signals are strongly attenuated and distorted based on the transmitted distance. To solve this problem, Ref [11] provides a model to simulate the transmission of such energy (signals) on middle voltage cables. When compared to earlier approaches, this model neglects not the wave character of the high-frequency signals. Consequently, to explain the transmission signal, a holistic solution of the telegrapher's equations is given. In this solution, the propagation constant of the middle voltage cable used must also be stated; and this can be determined based on the individual cable layers, taking into cognizance all ohmic and dielectric losses. Contrary to past methods, the constants of the primary lines are all modelled to depend on frequency. The model can forecast the spectrum of a signal transmitted at any distance from its origin. From re-evaluation, it is obvious that prediction and measurement agree with reasonable accuracy. The model developed is checked by investigating the transmission of partial discharges on middle voltage cables. Computer-based approach is proposed for electromagnetic transient simulations in power cables dominated by an arbitrary cross-section geometry. The parameters of the cables that are hinged on frequency are calculated via the finite element method, and the threephase cable modelling is done using modal decoupling and fitting techniques. The representation of cables with multiple layers is easier from the calculation of a constant; and a real modal transformation matrix, which gives rise to four independent propagation modes (three phases and cable shield), which are modelled from the addition of frequency HBRP Publication Page 44-56 2024. All Rights Reserved Page 46 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 effect in the classic Bergeron technique. The currents and voltages are stated as a system of differential equations, which are given as state equations and solved using numerical integration methods. The intended modelling technique helps to add time-variable and non-linear elements during electromagnetic transient simulations in the time domain, which is not possible from frequency domain models that are solved with the aid of inverse transforms. The intended model is validated from results simulated using numerical Laplace transform and exact modal transformation matrix for calculation of phase currents and voltages [12]. The major material for cable insulation is XLPE (Cross-linked polyethylene). The breakdown of cable insulation is of safety concern to nuclear power plants. Ref [13] proposed deterministic and probabilistic models to quantitatively forecast the decline in electrical resistance of the insulation as a function of time in thermal degradation. The activation energy of the degradation reaction is determined. The researchers modelled one specimen as the embodiment of two parts-degraded and non-degraded parts having disparate resistivity based on the Dichotomy approach. The volume ratio of the two parts gives the sum resistance. The cumulative density function (CDF) of an exponential distribution is employed to determine the change in ratio as a function of time. The objective of this research is to model the parameters of a high voltage cable three-phase voltage and current using Fourier transformation and to detect faults along its length. 2.0 MATERIALS AND METHODS 2.1 Materials The materials used include the following:i. 50m of 150kV crosslinked polyethylene (XLPE) cable ii. Digital multimeter PCE-DC 41 (voltages up to 600 V, currents up to 600 A and electrical resistance up to 1000 Ω) iii. Frequency meter of 10kHz to 150MHz iv. HP4194A impedance analyzer v. HP41941A impedance probe set vi. Bandpass filter vii. overvoltage protection (TVS-WE-TVS diodes) viii. Digital oscilloscope 2.2 Methods The cable is modelled mathematically with the aid of MATLAB/Simulink. The parameters of the cable-three-phase voltage and current are measured with their respective Fourier transformations. Equations parameters are determined using the Fourier transform. The system is then checked for the presence of fault and if yes, the type of fault is displayed. 2.1 Design of a Flow Chart to Define Fault Detection/Location Indicators Phasor measuring techniques are used for the identification and localization of faults in every three-phase system. Based on the equations developed in this research, a general framework for a comparative Fourier transform detection/location technique is shown in Figure 1. Below is the flowchart diagram of this work which shows how the project is achieved. HBRP Publication Page 44-56 2024. All Rights Reserved Page 47 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 Fig 1: Based on Fourier Transforms, Modal, and Indicator Definition, a Functional Schematic of Transmission Line Detection and Location Design is Shown 2.2 The Cable Equation's Derivation The cable equation must be derived from fundamental ideas. The goal of this research is to distinguish between membrane potential, voltage, and V(x,t) along the dendrite. Branch-like structures called dendrites transport electrochemicals from axons to the neuron. The cable is assumed to be passive in this model, which means that resistance is independent of voltage. r ( L 0 ). (1) V Although either axons or dendrites can be and it has the shape of a cylinder similar to modeled by this equation, dendrites are a the heat-conducting rod that was discussed better fit for the passivity assumption than in class. It is presumed that the crossaxons are. The potential is a function of the sectional area will remain constant along spatial dimension x, and of time t, as the length of the neuron. The components shown by the notation. No matter the of the LRC model may be familiar to string's radial coordinate, the string's physicists and engineers. An illustration of thinness enables each point x of the the cable model and the equation's cylinder to have the same tension. The parameters are shown below. dendrite has a cross-sectional area of πa2, Fig 2.: Dendrite Model (Source: [14]) Where; rL = intracellular resistance found in the neuron’s cytoplasm (internal fluid) HBRP Publication Page 44-56 2024. All Rights Reserved Page 48 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 RL= resistance to the longitudinal flow of current (IL). cm = capacitance of a membrane of a unit length (Δx) of the cable Cm = total capacitance IL = longitudinal current ie= ion flow per unit of membrane area Ιe = total ion flow As was already mentioned, two components make up series resistance: rL, the resistivity between cells, or RL, or the longitudinal resistance of a cable segment. The following equation relates the two: r x RL L 2 a (2) The cable's area serves as the denominator. This ratio demonstrates that longitudinal resistance decreases with surface area. The voltage change is defined as follows: V V ( x x) V ( x) (3) Then, using Ohm's law, which states that the voltage change is equal to the current plus the resistance (V=IR), we introduce the longitudinal current IL, and plug it into the equation. V ( x x) V ( x) I L RL Replacing (2) by (4), we get: I rx V(x+Δx) – V(x) = L 2 a The result of moving Δx over the left side is: I L rL x V ( x x) V ( x) x 2 Now the derivative on the left is Δx 0,, which gives us: V I L rx x a 2 The longitudinal current results in: 2 IL (4) (5) (6) (7) Va xrL (8) As a result of ion flux in and out of the cell, we denote 𝑖𝑒 as the current per unit area. The equation below can be used to represent the total ion flux per unit Δx across the membrane: Ie(x,t) = (2πaΔx)ie (9) Since the total ion flux is simply the ion flux on the membrane times the area, this can be understood. Let cm be the capacitance of the membrane and Cm = (2πaΔx)cm be the capacitance overall. Icap stands for the amount of current necessary to alter the membrane potential at a rate of ∂V/∂t. V (10) t Kirchoff's law, which states that the amount of current that crosses the membrane equals the change in axial current within the cell, results in: Icap (x,t) + Ie (x,t) = -IL(x+ Δx,t) + IL(x,t) (11) Adding (10) and (11) results in: Icap(x,t) = (2πaΔx)cm HBRP Publication Page 44-56 2024. All Rights Reserved Page 49 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 (2πaΔx)cm V + t V ( x x , t ) a 2 V ( x., t ) (2πaΔx)𝑖𝑒 = a 2 x rL rL x (12) Dividing both sides of the equation by 2πaΔx, and taking Δx0 gives us: V a 2V cm ie t 2r L x 2 The ie equals: 𝑖𝑒 = V/rm Where rm denotes the membrane's resistivity. This results in: V a 2V V cm t 2r L x 2 rm For simplicity’s sake, we substitute arm τm = cmrm and λ = to get the Cable Equation: 2rL 2 V 2 V m V t x 2 2. 3 Fourier Solution to the Bounded Cable Equation We now solve the infinite cable equation after first solving the finite cable equation using PDE reasoning. The Fourier method with variable separation is used initially. The cable has a length L. The boundary and initial conditions available to us are the following: (13) (14) (15) (16) i. ii. No current flows where the dendrite ends or branches.: Vx(0,t) = Vx(L,t) = 0; and The current at startup is solely determined by the cable's spatial coordinate: V(x,0) = f(x). The problem mimics an insulated rod with thermally conductive ends according to assumption (I). The equation of the form is taken using the variable separation : V(x,t) = X(x)T(t). Connecting this to the PDE in (17), we get: (17) τmXT' = λ2X"T – XT Rearranging terms and setting them equal to the negative characteristic (-k2) gives us: (18) = 𝑋 − −1 = −𝑘 2 𝑇 This yields equations (20) and (21): (19) τmT' = k2T (20) λ2X"= (1−k2)X Equation (21) yields the solution: (21) 𝜏𝑚 𝑇 ′ 𝜆2 𝑋 ′′ T (t ) ce ( k t / m ) 2 HBRP Publication Page 44-56 2024. All Rights Reserved (22) Page 50 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 As for the solution to (23), we assume thatk2>1, so that the roots of the equation are complex. If k2<1, the roots would be positive and the solution would be in the form of: 1 k 2 x 1k x X(x) = a e + be (23) That is not desirable because in that case the boundary conditions would not be helpful since they would not yield unique values of a and b, resulting in only trivial solutions. So assuming that k2>1, we get the following result: X(x) = acos( 12k x) + bsin( 12k x) (24) 2 The boundary conditions V'(0) = 0 and V'(L) = 0 mean that X'(0)T(t) = X'(L)T(t) = 0 (25) In order to avoid trivial solutions again, we need: X'(0) = X'(L) = 0 (26) Plugging in X'(0) = 0 gives X'(0) = - 1 k 2 sin( 1 k 2 (0)) + bcos( 1 k 2 (0))= 0 (27) Everything associated with the sine term drops out, and leaving us with b = 0, giving us: X(x) = acos( 12k x) (28) Using the second boundary condition X'(L) = 0 X'(L) = - 12k sin( 12k (L)) = 0 (29) In general, since sin(α) =0 means that α =πn, we have: n πn/L and k2= 1 (30) L Now we plug these two equations back into (22) and (18), respectively, resulting in the following: 2 1 k = 2 T(t) = c e(1(n / L) )t / m and nx X(x) = acos( ) L Plug (31) and (32) into (16) and we have: 2 nx Vn(x,t) = acos( ) c∙ e(1(n / L) )t / m L Now we substitute dn = ac nx (1(n / L)2 )t / m Vn(x,t) = dncos( )e L 2 Consequently, we impose this in anticipation of the Fourier cosine expansion: nx (1(n / L)2 )t / m V(x,t) = dncos( )e L n 1 After adding the initial condition V(x,0) = f(x), the exponential term drops out. 1 nx V(x,0) = d 0 dncos( )= f(x) 2 L n 1 This is the Fourier cosine expansion. So we have: HBRP Publication Page 44-56 2024. All Rights Reserved (31) (32) (33) (34) (35) (36) Page 51 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 2 n )d dn = f ( ) cos( L0 L Plugging this back into (33) gives us: L L 2 n nx (1(n / L)2 )t / m 2 f ( )d ( f ( ) cos( )d ) cos( V(x,t) = ) e L L0 L L n1 0 L This is the elegant solution to the bounded Cable Equation. Thus Fourier methods with the proper boundary and initial conditions enable us to obtain an analytical solution for the conductance of membrane potential along the dendrite. Moving on, we now consider a cable of infinite length. 2.4 Fourier Transform of Infinite Cable Equation (37) (38) Neuroscientists often examine the idealized “infinite cable.” With such a notion, the spatial coordinate x extends over [-∞, ∞]. The Fourier transform is used to find the answer. Even though O'Neill's telegraph equation has a different form and produces a very different outcome, we partially rely on its solution in this section. We represent the PDE with this slightly different notation: τm vt = λ2vxx –v (39) To use a Fourier transform we need an initial condition. The initial voltage for the infinite cable depends only on the spatial coordinate x, or in other words, where along the cable: v( x,0) = f(x) (40) To the PDE we apply the Fourier transform. τm {vt } =λ2 {vxx} {v} (41) Then we represent the transformed voltage variable with capital letters. {vt } = V'(ω,t) (42) Applying the Fourier Transform to the PDE gives us τmV’(ω,t) = -λ2ω2V(ω,t) – V(ω,t) (43) which is an ODE with the prime in the equation representing derivation of the transform with respect to t. The derivatives of the variable operating with respect to x are represented by the terms on the right side of the equation. The Fourier transform for the v(x,t) by definition is: V(ω,t) = v(, t )e i x d (44) We derive the following two equations using the Operational Rule for Fourier Transforms: ∞ ∞ 𝜕 𝜕 =𝑖𝜔𝑥 𝑉(𝜔, 𝑡) = 𝑣(𝜔, 𝑡)𝑒 𝑑𝜔 = 𝑖𝜔 𝑣(𝜔, 𝑡)𝑒 𝑖𝜔𝑥 𝑑𝑤 = −𝑖𝜔𝑉(𝜔, 𝑡) (45) ∫ ∫ ∞ ∞ 𝜕𝑥 𝜕𝑥 𝜕2 𝜕𝑥 2 ∞ 𝜕 ∞ 𝑉(𝜔, 𝑡) = 𝜕𝑥 𝑖𝜔 ∫∞ 𝑣(𝜔, 𝑡)𝑒 =𝑖𝜔𝑥 𝑑𝜔 = 𝑖 2 𝜔2 ∫∞ 𝑣(𝜔, 𝑡)𝑒 𝑖𝜔𝑥 𝑑𝑤 = −𝜔2 𝑉(𝜔, 𝑡) With this in mind, we rearrange (43) into canonical form. (1 2 2 ) V'(ω,t) − V (, t ) = 0 m (46) (47) This ODE yields the following solution: (1 2 2 ) t V(ω,t)=k e m (48) Recall our initial condition in (40), v( x,0) = f(x). We assume that f(x) has a Fourier Transform G(ω). HBRP Publication Page 44-56 2024. All Rights Reserved Page 52 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 G(ω) = {f(x)} Applying the initial condition (40), we have: (1 2 2 ) m V(ω,0) = k e ( 0) (49) (50) = G(ω), or k = G(ω) Solving for the Fourier term V(ω,t) gives: (1 2 2 ) t V(ω,t) = G(ω) e m Applying the inverse Fourier transform gives us: 1 v(x,t) = G( ) e 2 (1 2 2 ) m t (51) e ix dω (52) So we found a v(x,t) for which its Fourier transform is G(ω) e (12 2 ) m function s(x,t) whose Fourier transform is S(ω,t) = e would be: s(x,t) = 1 S ( , t )e 2 it d e (1 2 2 ) m t 2 2 e ix d e1/ m e m t ix t (1 2 2 ) t m . We need to find the . The Fourier transform of s(x,t) (53) d We can evaluate the integral using completing the square, with the following rules. az 2 2 2 2 2 ax – b = a(x - b/(2a)) – b /(4a), e dz a e b /( 4a ) e a ( x-b/(2a)) dx e b /( 4a ) e az dz e b /( 4a ) 2 2 2 2 2 a (54) (55) We plug the parameters into the equation. (2 2 ) a= , b=ix (56) m Solving gives us: x 2 m t / m 2 1 𝑠(𝑥, 𝑡) − e 4 t 2𝜋 m 2 x 2 m t / m 4 t e 2 2 4 t m = (57) 2 Using the function u = s * f and that Fourier transforms turn convolutions into multiplication, we get: ( x ) v(x,t) = (s(.,)t * f(.))x) = s( x ) f ( )d m f ( )et / 4 t d (58) 2 4 t m m 2 2 And to state it straight up, the solution to the unbounded Cable Equation is: v(x,t) = t / m f ( )e 2 4 t m ( x ) 2 m 4 2t d (59) 3.0 Algorithm for the Cable and Fault Model (Open-Circuit) function [Zin] = TIL (f, cable_len) % f frequency, cable length % Cable characteristics (Distributed parameters) HBRP Publication Page 44-56 2024. All Rights Reserved Page 53 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 l_m=240e-9; c_m=138e-12; r_m=1.6/10000. *sqrt (f); g_m=0.1. *c_m. *f; fault_loc=17; % velocity of propagation typical vp = 0.535.*3e8; % Characteristic impedance vector Z0=42; % Attenuation coefficient vector alfa = 0.5*1e-6. *f.^0.61; % Propagation coefficient vector beta = 2*pi*f./vp; % Propagation constant gamma = alfa + j*beta; % Fault circuit characteristics (variable parameters) Zc=(1/(2*pi*f.*c_m)); % Capacitive reactance Z1=2*pi*f.*l_m; % Inductive reactance Zf=(Zc*1.5+Z1*0.2); % Fault resistance (zc+Z1*0.4); % % The remaining cable's impedance at the location of the cable fault Zcable = Z0. *coth (gamma.*(cable_len-fault_loc); % 33 % The load impedance at the location of failure % Zload = (Zcable.*Zf)./(Zcable + Zf); % Zload = Zcable.*100e9; % Matrix for the first segment of the cable before the fault TL1 (1,1) = cosh (gamma.*(fault_loc)); TL1 (1,2) = Z0.*sinh (gamma.*(fault_loc)); TL1 (2,1) = (1/Z0).*sinh (gamma.*(fault_loc)); TL1 (2,2) = TL1 (1,1); % Matrix for the second part of the cable after fault TL2(1,1) =cosh (gamma.*(cable_len-fault_loc)); TL2(1,1) =Z0.*sinh (gamma.*(cable_len-fault_loc)); TL2(1,1) =((1/Z0).*sinh (gamma.*(cable_len-fault_loc)); TL2(1,1) = TL2(1,1); % Fault circuit matrix (shunt impedance at the fault location) TL3 (1,1) =1; TL3 (1,2) = 0; TL3 (2,1) = (1/Zf); TL3 (2,1) = TL3 (1,1); % Cascading together various parts of the transmission line % TL=TL1*TL2; % For healthy cable TL = TL1*TL3*TL2; % For faulty cable % Input impedance Zin= ((TL(1,1). *Zload) + (TL(1,2))) / ((TL(2,1).*Zload) + (TL (2,2))); end HBRP Publication Page 44-56 2024. All Rights Reserved Page 54 Journal of Recent Trends in Electrical Power System Volume 7 Issue 2 e-ISSN: 2584-2404 DOI: https://doi.org/10.5281/zenodo.11096455 4.0 CONCLUSION Conclusively, Fourier methods with the proper boundary and initial conditions enable obtaining an analytical solution for the conductance of membrane potential along the dendrite. It is found that the presence λ in the modelled voltage equation is significant because it represents how far the current travels along the length of the dendrite. The greater the rm, the membrane resistance, the more the current will remain inside the cytoplasm (internal fluids) of the dendrite to travel longitudinally. The more rL, or intracellular resistance, the harder it is for current to travel through the cytoplasm; hence the shorter the current is able to travel. Thus a Fourier transformation enables us to solve for the voltage conduction along an infinitely-long cable fiber. REFERENCES 1. Amadi. H.N., Uwho, K.O. & Tebepah, E.A. 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