SINERGI Vol. No. June 2023: 423-432 http://publikasi. id/index. php/sinergi http://doi. org/10. 22441/sinergi. Using Particle Swarm Optimization for Power System Stabilizer and energy storage in the SMIB system under load shedding conditions Mansur Mansur1*. Muhammad Ruswandi Djalal2 Department of Electrical Engineering. Halu Oleo University. Indonesia Department of Mechanical Engineering. State Polytechnic of Ujung Pandang. Indonesia Abstract Generator instability, which manifests as oscillations in frequency and rotor angle, is brought on by sudden disruptions in the power Power System Stabilizer (PSS) and Energy Storage are additional controllers that enhance generator stability. Energy storage types include superconducting magnetic (SMES) and capacitive (CES) storage. If the correct settings are employed. PSS. SMES, and CES coordination can boost system performance. It is necessary to use accurate and effective PSS. SMES, and CES tuning techniques. Artificial intelligence techniques can replace traditional trial-and-error tuning techniques and assist in adjusting controller parameters. According to this study, the PSS. SMES, and CES parameters can be optimized using a method based on particle swarm optimization (PSO). Based on the investigation's findings. PSO executes quick and accurate calculations in the fifth iteration with a fitness function value of 0. The PSO aims to reduce the integral time absolute error (ITAE). With the addition of a loadshedding instance, the case study utilized the Single Machine Infinite Bus (SMIB) technology. The frequency response and rotor angle of the SMIB system are shown via time domain simulation. The analysis's findings demonstrate that the controller combination can offer stability, reducing overshoot oscillations and enabling quick settling times. Keywords: Overshoot. Particle Swarm Optimization. PSS. SMES-CES. SMIB. Article History: Received: May 6, 2023 Revised: July 6, 2023 Accepted: July 11, 2023 Published: October 2, 2023 Corresponding Author: Mansur. Department of Electrical Engineering. Halu Oleo University. Indonesia Email: mansur_naufal@yahoo. This is an open-access article under the CC BY-SA license. INTRODUCTION Due to the governor response being extremely sluggish in comparison to the excitation system response, the dynamic stability research makes the assumption that the torque change caused by the governor response is minimal. The excitation system is therefore the governing factor. Particularly for low-frequency oscillations, adding an amplifier excitation circuit is less effective at stabilizing the system . , 2, . Change at low frequencies between 0. 2 and 2. 0 Hz . Lower frequencies have the potential to cause oscillations between regions, necessitating further controls such as Power System Stabilizer (PSS) management. The PSS, a control mechanism that is added to the generator excitation, further dampens the generator excitation . Additionally, it reduces regional or global oscillations on the generator due to variations in predetermined variable values . Large amounts of power can be simultaneously stored and released using superconducting magnetic energy storage (SMES). While a device for storing and discharging power. Capacitive Energy Storage (CES) stores energy in the form of an electric field in a capacitor . Combining energy storage based on SMES and CES can enhance system performance if the correct parameters are employed. Correct and ideal PSS. SMES, and CES settings are required to stabilize the system and decrease oscillations to achieve the best outcomes . The optimization of Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A SINERGI Vol. No. June 2023: 423-432 intelligent techniques, or what is usually referred to as artificial intelligence, can be used to tune these parameters. The Swarm Intelligence group, one form of paradigm development used to address optimization issues, includes Particle Swarm Optimization (PSO). The behaviour of particles in groups searching for food sources serves as motivation for problem-solving . This study also employs the PSO approach to enhance control parameters like . , 12, . The use of intelligent methods to optimize generator control parameters has been covered in several studies, and the outcomes provided to the system are outstanding in preserving generator stability. Examples of these methods include firefly method . , bat algorithm . , 16, . , flower pollination . , imperialist competitive . , and cuckoo search . The controller's optimal parameter tuning will significantly impact the system's ability to stabilize . An optimization method utilizing PSO is used to quickly get parameter values because the range of equipment parameters is broad and diverse. The objective function minimizes the Integral Time Absolute Error (ITAE), and the response value is determined by examining the overshoot and settling time values . Overshoot is the occurrence when a signal or function exceeds its target, while settling time is the time required to reach the target The case study system is Single Machine Infinite Bus (SMIB). An infinite number of buses are connected to one or more generators as part of the SMIB electric power subsystem . [ . Then compare the simulation outcomes of the system without control. SMIB-PSS. SMIB-SMES. CES. SMESCES, and with the suggested technique PsMES-CES with PSO to examine the simulation The authors of this study used an intelligent PSO-based method to solve the optimization problem of choosing the PSS-SMESCES parameters on the SMIB system. SYSTEM MODELING Synchronous Machine Linear Modeling An infinite bus connected to a generator represents the Single Machine Infinite Bus (SMIB) SMIB made the following assumptions in this paper: the system was supposed to be in balance, the load was assumed to be static. the saturation of the core generator and resistance resistor was minimal . In Figure 1, the SMIB linear model is displayed. Figure 1. Linear Modeling of Synchronous Machines Excitation Modeling The excitation system controls the generator's voltage, current, and power factor. there is a change in the output of the generator, then the excitation system regulates the generator to adjust and establish a new equilibrium point. One component of the method where this exciter can control generator output characteristics like the voltage, current, and power factor is the excitation equipment . The excitation model alludes to the modelling performed by Ie, which is depicted in Figure 2 . KA is the amplifier gain constant. KF is the filtered gain constant. KE is the exciter gain constant. TA is the amplifier response time. TE is the exciter response time. TF is the filtered response time, and AEU2 is the engine control signal change. Governor Modeling To maintain a constant rotor speed for the generation system, the governor, a component of the generator unit, controls the fuel supply . team or wate. A feedback function will take place if the load on the generator changes, which the governor controls to vary the rotation of the rotor. The governor is a controller that modifies the mechanical torque Tm, the generator's input, by changing its value . In Figure 3, governor modelling is displayed. Figure 2. Excitation Block Diagram Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A p-ISSN: 1410-2331 e-ISSN: 2460-1217 Figure 3. Governor Modeling Kg is Gain constant = 1/RG. Tg is the Governor time constant. RG is the Governor groop constant, and iGSC is Governor Speed Changer. Turbine Modeling The steam power turbine model from the Ie model is utilized for the turbine . Figure 4 depicts a turbine model. iY is valve height change. Twi is steam turbine response time. Tga is steam turbine governor response time. Kga is steam turbine governor gain. R is steam turbine governor constant, and iU1 is feedback control signal Modeling Single Machine Infinite Bus (SMIB) Figure 5 displays the overall modeling of the Single Machine Infinite Bus system . Figure 4. Turbine Modeling Power System Stabilizer Modeling A tool called the Power System Stabilizer can be used to make the power system more Figure 6 depicts the PSS modelling used in this investigation. Block Gains are used to modifying the reinforcement amount to produce the required A PSS steady-state output bias from the Washout block will change the generator terminal The PSS is anticipated to only react to brief changes in the generator rotor speed signal, not DC offset signals. To account for the phase lag between the excitation input and the generator torque, the Lead-Lag block performs as a generator with proper phase-lead characteristics. The PSS action on the AVR is as anticipated because the PSS output is constrained. The AVR, for instance, lowers the generator's terminal voltage when there is an unload. The PSS produces a control signal to raise the voltage concurrently . ecause the speed of the generator rotor increases when the load is release. Superconducting Magnetic Energy Storage Modeling SMES is a tool for concurrently storing and releasing enormous amounts of power. SMES uses superconducting coils that a cryogenic system cools to create a magnetic field that holds a SMES with superconducting coils, a cryogenic cooling system, and a power conditioning system (PCS) with control and protective features coupled to the electrical power The power electronics connector of the SMES coil is also called PCS. The SMES schematic diagram is displayed in Figure 7. Figure 6. PSS Modeling Figure 5. SMIB Modeling Figure 7. SMES schematic diagram Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A SINERGI Vol. No. June 2023: 423-432 VSM = D *VDC OeVSM = . Oe D) *VDC I SM = VDC dA I SM 0 LSM Et0 PSM = VSM I SM WSM = LSM I SM Equation . , where VDC is the voltage in the capacitor DC link. D is the duty cycle, and VSM is the voltage in the SMES coil, represents the SMES charging mode. SMES is current is represented by . , while SMES discharging mode is represented by . The energy delivered and stored by SMES is represented by. , while energy stored in the SMES coil is represented by . The SMES arrangement is depicted in Figure To balance the power control on the generator. SMES is installed at the generator From several SMES reference equations, the SMES-PID block diagram can be constructed, as shown in Figure 9. Capacitive Energy Storage Modeling CES is a power storage and distribution CES uses an electric field to store energy in a capacitor. A CES comprises a Power Conversion System (PCS) and a storage The CES schematic is shown in Figure Figure 10. CES A capacitance C is created by connecting several capacitors in parallel. CES uses a resistor R linked in parallel to the capacitor to mimic leaking losses and dielectric capacitor banks. 12-pulse PCS connects the storage capacitor to the grid. A DC rectifier plus a DC to AC inverter make up PCS. In this case, the bypass thyristor offers a conduit for the current Id in case of a converter failure. If the converter fails, the DC Breaker sends the current Id to a location that can drain the energy resistor RD. As in the equation, the bridge voltage Ed considers losses . Ed = 2 Ed 0 cos A Oe 2 I d RD Ed 0 = d max d min . Imagine that the capacitor voltage is too low and that another fault arises before it reaches its average value. In that situation, a failure will demand more energy from the capacitor, which can result in intermittent control. To solve this issue, the lower limit of the capacitor voltage is set at 30% of the rating value Ed0. Ed min = 30 Ed 0 Figure 8. SMES Configuration Figure 9. SMES-PID Modeling . To get ready for the next load disturbance, the CES unit must quickly return to its initial value after the load disturbance. As shown in Figure 11, the CES control loop uses the capacitor voltage deviation as a negative feedback signal to ensure speedy voltage recovery. AEf K CES Ed 0 KVD 1 sTDC AEI d sC 1 AEEd AEI d Eu Ed 0 AEEd -Ei AEPCES Figure 11. CES Block Diagram Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A p-ISSN: 1410-2331 e-ISSN: 2460-1217 METHOD Particle Swarm Optimization PSO population-based Several particle populations initially span a problem space in PSO. Swarms are the name given to these scattered particles. The presence of this particle and any potential value it might have been recorded in this particle. The exchange of information between particles will allow us to determine which ones are in the position that will produce the best movementrelated outcomes. Based on this knowledge, other particles will go there using a velocity motion Each particle chooses its position during flight based on its own experience (Pbes. and the experience of other particles (Gbes. In Figure 12, the procedure for locating Pbest and Gbest is Each particle's speed can be calculated from . ycyco 1 = yc. ycyco yca1 ycycaycuycc y . cEycayceycyc Oe ycu yco ) yca2 ycycaycuycc y . aycayceycyc Oe ycu yco ) . Based on particle velocity. Pbest and Gbest can be computed using . You can get the most current position from . ycu yco 1 = ycu yco ycyco 1 . yco = 1,2 A ycu For the following terms. Xk stands for the search point base. Xk 1 for the search position. Vk for speed. Vk 1 for modified speed. Vpbest for speed based on PBest. Vgbest for speed based on Gbest, n for number of particles in group, m for number of members in particle, pbest-i for Pbest from k. Gbest-i for Gbest from group, w for weight, and ci for weight The positive constants are c1 and c2, and the random numbers are r1 and r2. The following is the iteration function of k and w is the weight of inertia . yc yc. = ycycoycaycu Oe ( ycoycaycu Oe ycycoycnycu ycoycaycu. ycnycyceyc )yyco . In order to ensure that all dimensions move at the same pace, the maximum speed is as follows . yc ycoycaycu = . cu ycoycaycu Oe ycu ycoycnycu ) ycA Table 1 lists the PSO parameters used in this investigation. To test the accuracy of PSO in optimization, the Ant Colony Optimization (ACO) method is used as a comparison. The ACO parameters are shown in Table 1. PSO Implementation for Computing The Integral Time Absolute Error (ITAE) is an objective function used to evaluate a system's . ITAE = t AEA . ) dt The PSS-SMES-CES parameters tuned by Particle Swarm Optimization are Tdc. Ksmes. Kpss. T1. T2. T3. T4, and KDE. The outstanding value will considerably impact the SMIB developed for this study's response performance. To determine the ideal value, the PSO algorithm needs to be calculated. The optimization convergence graph using the PSO technique is shown in Figure 13. The fitness function value of convergence describes an optimization problem's best criteria. The convergence graph for PSS-SMES-CES value optimization using PSO is shown in Figure 13, and it can be observed from the chart that the PSO method completes the optimization process The algorithm's fifth iteration, which discovered the excellent value with a fitness value 007813, demonstrates this. Table 1. Parameters for PSO PSO Parameters Value Particles Most Iterations The quantity of C2 Social Constant C1 Cognitive Constant W Moment Inertia ACO . Parameters Value Number of Ants Max Iteration Pheromone Beta N stands for the maximum iterations. Figure 12. Searching PSO concepth . Figure 13. Convergence Graph Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A SINERGI Vol. No. June 2023: 423-432 Table 2. PSO Optimization Limits and Results Parameter Tdc Ksmes Kpss Tdc1 KDE Limits Lower Upper Results Deviation Uncontrol PSS-PSO SMES-PSO CES-PSO SMES-CES-PSO SMES-CES-PSS-PSO While using the ACO method, the optimization process converges at the 11th iteration, reaching a fitness function value of These results indicate that PSO outperforms ACO in terms of performance. Based on the objective function used, in the 5th iteration. PSO obtains the optimal values of the parameters Tdc. Ksmes. Kpss. T1. T2. T3. T4. Tdc1, and KDE. Table 2 lists the restrictions and outcomes of the PSS-SMES-CES parameters PSO tuned for RESULTS AND DISCUSSION Employing time domain simulation to examine the system frequency response and SMIB rotor angle. Load shedding variations are applied to the SMIB system to verify the system's Load shedding has an impact on the generator due to sudden load shedding. SMIB Frequency Response Reviewing the SMIB system's frequency stability response is the first step of the Figure 14 displays the simulation Figure 14 shows the frequency response simulation results for SMIB using various control According to the simulation results, a change in the load of 0. 01 pu in the first second disturbs the SMIB system. Then, there is a load shedding during the 20th second of 0. 005 pu. When a load is added during the first load shift, the electrical and mechanical torques are not balanced because the electrical power (P. and mechanical power (P. are not equal in this This circumstance likewise alters the electric frequency (AE. The rotor rotation speed(AEA) deviates from equilibrium during this The frequency response graph in this situation declines before stabilizing. The control system's operation must then resume operating in steady-state conditions. Table 3 displays the features of the overshoot reaction in this The system's overshoot characteristics are shown in Table 3 when a load change, like an increased load, happens in the first second. Table 3. Deviation in SMIB Frequency Overshoot . 0002403 & 0. 0001992 & 8. 0001512 & 5. 0001394 & 1. 0001078 & 9. 0001033 & 3. The unmanaged SMIB system had an overshoot of -0. 0002403 & 0. 0001873 pu with a settling period of 15. 2 seconds. The SMIB system controlled by PSS had an overrun of -0. & 8. 215e-05 pu with a settling time of 5. The SMIB system managed by SMES recorded an overshoot of -0. 0001512 & 5. 479e-06 pu with a settling time of 3. The SMIB system operated by CES had an overshoot of -0. 0001394 & 1. 057e07 pu with a settling time of 3. SMIB, managed by SMES-CES, had an overshoot of -0. 557e-07 pu and a settling time of 3. With the suggested method using PSS-SMES-CES, the smallest overshoot is -0. 0001033 & 3. The electrical power (P. then changes due to the following load change, which takes the form of a drop in load. The mechanical and electrical torque are not balanced in this situation because the electrical power is not equal to the mechanical power (P. Pe < Pm. This circumstance likewise alters the electric frequency (AE. The rotor rotation speed (AEA) deviates from equilibrium during this The frequency response graph in this situation increases before stabilizing. The control system's operation must then resume operating in steady-state conditions. Table 4 displays the parameters of the overshoot response under these circumstances. The system's electrical frequency response (AE. is depicted in Figure 14. The characteristics of the system overshoot, when there is a load change at the 20th second are shown in Table 4. The SMIB system's uncontrolled overshoot was -9. 048e-05 & 0001202 pu with a 34-second settling time. settling time of 25s and an overshoot of -4. 088e05 & 9. 764e-05 pu were recorded by the SMIB system under PSS control. Table 4. Deviation in SMIB Frequency Deviation Uncontrol PSS-PSO SMES-PSO CES-PSO SMES-CES-PSO SMES-CES-PSS-PSO Overshoot . 048e-05 & 0. 088e-05 & 9. 145e-06 & 7. 0 & 7. 0 & 5. 0 & 5. Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A p-ISSN: 1410-2331 e-ISSN: 2460-1217 Figure 14. SMIB Frequency Response Figure 15. SMIB Rotor Angle Response A settling time of 24. 74s and an overshoot of 145e-06 & 7. 547e-05 pu were recorded by the SMIB system under SMES control. A settling time 14s and an overshoot of 0 & 7. 547e-05 pu were obtained by the SMIB system under CES A settling time of 22. 43s and an overshoot of 0 & 5. 409e-05 pu were brought by SMIB under SMES-CES control. The smallest overshoot is 0 & 188e-05 pu with the suggested method using PSS-SMES-CES. SMIB Rotor Angle Response The ensuing investigation examines the SMIB rotor's angle response as it operates with PSS-PID control installed. A change of 0. 05 pu in 1s was used in this study's SMIB test. A rise and increase in load are the intended changes. Electrical power will also alter due to the increased load and rise. The rotor can accelerate if the generator's mechanical power is more significant than its electrical power. Compared to the conditions before the disturbance, as shown in Figure 15, this rotor acceleration will have a negative or decreasing effect on the rotor angle The values of overshoot and settling time are the observed reaction to the change in rotor angle, as indicated in Table 5. Table 5. Deviation of SMIB Rotor Angle Deviation Uncontrol PSS-PSO SMES-PSO CES-PSO SMES-CES-PSO SMES-CES-PSS-PSO Overshoot . Mansur & M. Djalal. Using Particle Swarm Optimization for Power System Stabilizer A SINERGI Vol. No. June 2023: 423-432 When there is a change in load in the first second in the form of an additional load. Table 5 displays the overshoot characteristics of the system rotor angle. The SMIB system's uncontrolled overshoot was -0. 03623 pu with an 5s settling period. A settling time of 6. 4s and an overshoot of -0. 02471 pu were attained by the SMIB system under PSS control. The SMIB system under SMES management recorded a 0. 02308 pu overshoot with a 9. 2s settling time. The SMIB system under CES control recorded an overshoot of -0. 02134 pu and an 8-second settling SMIB under SMES-CES management had an overrun of -0. 02233 pu and a 4. 3s settling time. The least overshoot is then achieved using the suggested strategy employing PSS-SMES-CES. Then, at the 20th second, there is the following load change: a decrease in load. In this situation, the generator's mechanical power is lower than its electrical power, which causes the rotor to slow down. The rotor's slowdown will also impact the change in angle, causing the angle response to be more favorable than before the This occurs due to the magnetic connection pushing the stator field toward the rotor field, increasing the generator's rotor angle, as seen in Figure 15. Table 6 displays the system's overshoot characteristics under these Table 6 displays the system rotor angle's overshoot characteristics when the load changes at the 20th second. With a 30-second settling time, the unmanaged SMIB system recorded an overrun of -0. 0159 pu. With a settling time of 17s, the SMIB system under PSS management had an overrun of -0. With a settling time of 24s, the SMIB system under SMES management recorded an overrun of -0. With a settling time of 25s, the SMIB system under CES control recorded an overshoot of 0. 01024 pu. With a settling time of 24. SMIB under SMES-CES management recorded an overrun of -0. 009698 pu. The minor overshoot with the suggested method employing PsMES-CES is -0. 009833 pu with a settling time. Table 6. Deviation of SMIB Rotor Angle Deviation Uncontrol PSS-PSO SMES-PSO CES-PSO SMES-CES-PSO SMES-CES-PSS-PSO Overshoot . The results of this study indicate that there is an increase in SMIB performance when load shedding occurs, utilizing the proposed control scheme based on PSS and Energy Storage. Compared to the previous research conducted . , the proposed control scheme is based on conventional PSS and PID. This study also demonstrates that the PSO-based tuning method yields a lower fitness function compared to the comparison method used in previous studies based on ACO. CONCLUSION This research proposes a PSS-based SMIB control design and energy storage under load shedding conditions. Study of system reliability in this condition is important to do for generator To optimize the performance of PSS-Energy Storage, the PSO method is used for optimal parameter optimization. The PSO algorithm performs optimization well, showing that the optimization time is fast. The PSO computation converges in the 5th iteration, and the optimal parameter tuning is obtained with a fitness function value of 0. Comparing an uncontrolled system to optimal tuning, the SMIB frequency response is Improved system responsiveness, where the controller can offer stability to reduce overshoot oscillations, and quick settling time performance for the system to reach a steady state condition are indicators. Lowering the overshoot in this system requires properly tweaking the SMES-CES-PSS parameters. REFERENCES