1. Introduction
Within the complex and multifaceted landscape of modern power systems, ORPD stands out as a crucial factor that has a significant impact on both the stability of the power grid and the overall efficiency of its operations, making it a central component in the discourse surrounding energy management. The challenges associated with voltage deviation, which frequently arise in power system management, stem from the intricate and sensitive balance that must be maintained between reactive power generation and consumption, emphasizing the importance of careful monitoring and control. Recent investigations by various regulatory authorities and academic institutions studying power systems have revealed a significant and alarming increase in the frequency of power outages and grid instability incidents observed around the world, emphasizing the importance of addressing these issues [
1]. Such disruptions not only disrupt the usual flow of everyday activities for individuals and communities but also have far-reaching economic consequences for a wide range of sectors and enterprises that rely largely on continuous and dependable energy supply. As a result, the importance of ORPD cannot be overstated, as it plays a critical role in ensuring the stability and reliability of power systems by optimizing the flow of reactive power, whereas demand response analysis provides a strategic method for effectively managing electricity consumption and strengthening the grid’s resilience against various challenges [
2]. Over the years, a multitude of mathematical models have been methodically built to handle the complexity and constraints connected with ORPD, demonstrating continued attempts to improve power system management. Newton’s Method [
3], the Interior Point Method [
4], the Quadratic Programming Method [
5], the Linear Programming Method [
6], and the Nonlinear Programming Method [
7] are some of the traditional techniques used to address the initial stages of ORPD problems, with each contributing to a better understanding and resolution of these complex issues. As we work toward a sustainable and ecologically friendly energy future, it is becoming increasingly important to discover and implement creative solutions that can successfully solve the various difficulties confronting the power sector today. With growing concerns about environmental deterioration and the need for a thorough energy transition, optimizing reactive power dispatch and managing voltage deviations are emerging as major goals that require immediate attention.
These efforts go beyond technical projects; they symbolize our ethical responsibility to protect the environment while guaranteeing fair access to energy resources for everyone. The authors of [
8] discussed the various challenges associated with optimizing microgrids, including the unpredictability of renewable energy sources, fluctuations in electricity prices, resource allocation, fuel cost minimization, and battery system degradation. They suggest using a backcasting method to successfully manage the intermittent nature of renewable energy, as well as Light GBM approaches for precise solar and load forecasts. Furthermore, an innovative evolutionary algorithm is used for optimization, which smoothly integrates forecasting and optimization processes with a cost model for battery deterioration and demand response tactics. The findings of their analysis show a surprising 14.22% decrease in power costs, illustrating the significant benefits that may be obtained through intelligent scheduling and smart battery management procedures. In [
9], the authors investigated the transformational potential of blockchain technology in the field of decentralized energy management and demand response systems. They highlight the prospective use of smart contracts, which enable energy transactions while improving transparency and security in the energy industry. The outcomes of this study show that using such a strategy can result in considerable cost savings, improved dependability, and increased consumer trust. This decentralized management of energy resources, as noted in their research, leads to significant cost reductions and promotes a wider integration of renewable energy sources into the grid. In [
10], the authors looked into the possibility of connecting electricity and gas systems to improve decentralized demand response, leveraging the flexibility provided by the line pack to manage the delicate balance of demand and supply more efficiently. Their detailed research shows that this integrated technique not only enhances system dependability and flexibility but also lowers operational costs while optimizing the use of available energy resources.
In [
11], the authors presented a unique multi-objective optimization technique that efficiently solves the challenging task of tackling the complexities associated with the actual and reactive power dispatch problem, which is an important component of power system management. The authors use mixed-integer nonlinear programming, the ε-constraint method, and fuzzy satisficing principles to minimize active power losses and generation costs, resulting in optimal results. The usefulness of this approach was thoroughly evaluated on the well-known IEEE 30 bus system, indicating a significant improvement in optimization performance when compared to earlier optimization methods used in the sector. In [
12], the authors tackled the important difficulty of properly predicting and forecasting the behavior of distributed energy resources (DERs), particularly in settings where there is a paucity of relevant data for study. They significantly enhanced the prediction accuracy by strategically applying modern machine learning techniques while also controlling power flow in a very effective way. The findings of their thorough research show a significant improvement in power flow management systems and a more exact assessment of capacity. The authors of [
13] proposed a revolutionary strategy to encourage demand-side responsiveness through the creative use of discount scheduling, which is enabled by the use of hybrid quantum optimization techniques. This strategy improves the stability and efficiency of the electrical grid by actively encouraging customer engagement in demand response programs, resulting in considerable cost savings and more efficient use of energy resources. In [
14], the authors provided an evolutionary programming approach that focuses on optimum reactive power dispatch (ORPD) with the stated objective of reducing both transmission losses and voltage variations within the power system architecture. Their method, which was rigorously tested on the IEEE 30 bus system, was found to be highly effective in successfully reducing transmission losses while improving voltage stability, demonstrating evolutionary programming’s significant potential in the context of power system optimization. To achieve lower loss and a higher voltage profile, the innovative Gaussian Mutation-Based Teaching–Learning Optimization (GMBTLO) technique is used to derive the critical control variable settings, such as terminal voltages, transformer taps, and the output power of shunt reactive compensators (VAR), as shown in [
15]. The authors of [
16] successfully handled the inherent uncertainty involved with the integration of renewable energy sources by applying both stochastic optimization approaches and rigorous uncertainty modeling methodologies. Their multimodal approach significantly improves the reliability and efficiency of power systems that contain renewable energy sources, resulting in a strong and dependable solution for efficiently controlling the inherent unpredictability of power generation in this context.
The authors of [
2] examined the intricacies of ORPD challenges, which are crucial for maintaining the stability and economic viability of electrical power systems. These challenges encompass nonlinear optimization processes aimed at minimizing real power losses and augmenting voltage profiles through the strategic optimization of an array of control variables, encompassing both discrete and continuous types. The authors introduced a novel algorithm termed Lévy-flight Phasor Particle Swarm Optimization (LPPSO), which is specifically designed to address the complexities associated with ORPD. The principal objective of reference [
17] was to tackle the SORPD by optimally integrating various renewable energy sources, including photovoltaic (PV) systems and wind energy turbines, alongside the Unified Power Flow Controller (UPFC). The proposed PSOSHO algorithm [
18] signifies a notable progression within the domain, offering a robust solution to the challenges introduced by the increasing prevalence of electric vehicles, thereby facilitating the sustainable operation of power systems in the context of electromobility. Reference [
19] presents a data-centric framework devised to quantify the demand response capability of industrial consumers. This framework leverages data from smart electricity meters to scrutinize operational behaviors and delineate a flexibility boundary that quantifies the load flexibility accessible within the industrial consumer’s system. The authors of [
20] explained the importance of Peak Demand Management (PDM) within smart grid infrastructures, accentuating the challenges engendered by rising power demand and the transition towards low-carbon energy alternatives. The authors of [
21] described essential terminology pertinent to demand response, encompassing accumulated workload and power consumption for EVs and Thermostatically Controlled Loads (TCLs). They introduced a mean field term to capture power consumption across diverse demand-side resources, thereby establishing a comprehensive framework for analytical assessment.
This work makes numerous significant contributions to the broad field of power system optimization by thoroughly addressing both the intricate aspects of ORPD and the implementation of DR programs, which are becoming increasingly important in modern energy management. The main contributions can be categorized as follows:
This paper provides a detailed and comprehensive examination of a variety of ORPD methodologies as well as DR programs, all to reduce voltage deviation, limit operational costs, and minimize power losses within the energy distribution network. This in-depth research not only clarifies the present landscape of these approaches but also evaluates their efficacy and usefulness in real-world circumstances, thus improving our understanding of their practical applications.
The fundamental aims of this study are clearly stated, with an emphasis on decreasing both total system costs and related losses while also reducing voltage variations. These objectives are extremely important since they play a critical role in improving the efficiency, dependability, and stability of power systems, all of which are required to fulfill contemporary society’s expanding energy demands.
The implementation of a demand response program results in a significant reduction in both costs and load demands, a finding that has far-reaching implications for consumers, as it highlights the economic benefits that can be gained by thoughtfully incorporating DR considerations into the overarching framework of power system operations. This discovery is especially pertinent in light of rising energy prices and the need for more sustainable consumption behaviors.
This research successfully employs the Grasshopper Optimization Algorithm (GOA) as a methodological approach to effectively resolve the ORPD problem, demonstrating the GOA’s promising capabilities as a powerful optimization tool for use in power system applications. This novel technique demonstrates the algorithm’s versatility and efficiency in handling difficult optimization issues in energy management.
This work is rigorously evaluated utilizing the IEEE-30 bus system, which provides a standardized benchmark for testing the GOA’s efficacy and performance in a well-defined and controlled environment. This thorough evaluation not only allows for a comparative analysis of the GOA against other existing optimization methods, but it also plays an important role in confirming the GOA’s efficiency and competitive edge in addressing the ORPD problem, demonstrating its potential superiority or equivalence to alternative optimization algorithms commonly used in the field.
Overall, this comprehensive study not only introduces the Grasshopper Optimization Algorithm (GOA), an innovative and highly effective optimization tool, but it also provides a wealth of valuable insights into the seamless integration of Optimal Reactive Power Dispatch (ORPD) and demand response (DR) programs, both of which are critical for significantly improving the performance and economic viability of modern power systems. Minimizing power losses helps create more sustainable power systems as less energy is wasted and demand is better managed. This contributes to promoting sustainable consumption behaviors, as DR encourages consumers to adjust their power usage. This study contributes to the literature by demonstrating the integration of GOA with DR programs for solving ORPD problems. This represents an advancement in both fields by combining optimization and demand-side management.
4. Results and Discussions
To comprehensively evaluate the Optimal Reactive Power Dispatch (ORPD) while taking into consideration the demand response (DR) program, we must present three carefully selected case studies that will be developed by utilizing the IEEE 30 bus system as a fundamental framework for our study. According to reference [
23], this network consists of 20 unique loads, six functioning generators, and an array of 41 transmission lines. The data provided in reference [
24] include critical information about the maximum and minimum power requirements designated for the generators, the specific quantities of both active and reactive power that are required for optimal performance, as well as comprehensive details about the transmission lines, all of which are kept within acceptable limits, along with all other control variables relevant to the IEEE 30 bus system. A single-line diagram of the considered IEEE system is depicted in
Figure 2. The IEEE-30 bus system serves as a well-recognized benchmark for evaluating optimization algorithms in power systems. The GOA’s effectiveness was demonstrated through significant reductions in voltage deviations and operational costs.
The first scenario focuses on minimizing voltage variation, especially for the load buses within the power system architecture. The objective function, which incorporates this goal, is thoroughly specified in Equation (8), while the appropriate range of control variables is methodically described in
Table 1. To efficiently determine the optimal control settings that would result in a considerable decrease in voltage deviation at the load buses, both the GOA and the DA are used in tandem. Given that randomization is a key feature of meta-heuristic algorithms, it is critical to undertake a significant number of trial runs before deciding that any single solution is the best one. As a result, each algorithm is exposed to a rigorous set of 50 separate test runs, with the most beneficial consequence emerging as the ultimate perfect response. Furthermore, these findings are thoroughly compared to several newly created algorithms that have been thoroughly described in the current literature. In this regard,
Table 1 gives a detailed and complete comparison of Case 1. The statistics in the table clearly show that the Grasshopper Optimization Algorithm (GOA) results in a significant reduction in voltage deviation recorded at load buses across the power system network. Reducing voltage deviations ensures the power system remains stable and operates efficiently. Voltage deviations can lead to equipment malfunction, increased losses, and power outages.
The results that are thoroughly presented in
Table 1 encapsulate a detailed and comprehensive analysis as well as a meticulous comparison of a variety of distinct optimization techniques that have been employed specifically to minimize the total voltage deviation (TVD) within the intricate framework of the IEEE-30 bus system. Each row within this table delineates the progressive evolution of control variables that are associated with the different optimization algorithms, which include, but are not limited to, Particle Swarm Optimization (PSO), the Bacterial Foraging Optimization Algorithm (BFOA), the Firefly Algorithm (FA), the Gravitational Search Algorithm (GSA), the Bat Optimization Algorithm (BOA), DA, and the GOA. Through a methodical examination and comparison of the various parameter values utilized in this context, it is particularly noteworthy to mention that the analysis prominently included the GOA, which yielded the most favorable results, alongside a comparative evaluation between the DA and the GOA, in addition to a thorough assessment of other existing algorithms within the same category.
From the insights in
Table 1, it becomes clear that the GOA demonstrates superior performance by successfully reducing the total voltage deviation (TVD) to a significant value of 0.984 per unit (p.u.), which constitutes a significant decrease of 90.701% when compared to the initial value of 1.0582 p.u. This performance distinctly outperforms the DA, which, while commendable, achieves a total voltage deviation of 0.09990 p.u., thereby marking a slightly lesser reduction of 90.5594%. These results serve to highlight the efficiency of the GOA in adeptly addressing and mitigating voltage deviation issues that are commonly encountered in contemporary power systems.
Figure 3 provides a visual representation of the total voltage deviation (TVD) for all load voltages within the IEEE-30 bus system, showcasing the performance of various optimization algorithms used in this analysis. From the information presented in
Figure 3, it can be conclusively verified that the GOA consistently yields better results in comparison to the other algorithms that have been implemented within this study.
The primary objective behind tackling the Optimal Reactive Power Dispatch (ORPD) problem is fundamentally centered on the imperative goal of decreasing the total voltage deviation (TVD), which is recognized as a critical factor that significantly influences the stability and reliability of power systems. By optimizing the reactive power dispatch, one can effectively maintain the voltage levels within designated safe limits, thereby enhancing the overall performance and operational efficiency of the entire system.
Figure 4 illustrates the load voltages of the IEEE 30 bus system when utilizing both the GOA and the DA. Moreover, the visual representations in
Figure 4 meticulously verify the conformity of these load voltages to the predefined violation limits, thereby ensuring that they remain compliant throughout the entire optimization process that is aimed at minimizing the total voltage deviation.
The convergence curves associated with each algorithm serve to effectively illustrate their overall efficiency as well as the remarkable speed at which they are capable of reaching the optimal solution that best addresses the problem at hand. The characteristics of convergence regarding the total voltage deviation, specifically for the IEEE-30 bus system, are depicted in the graphical representation in
Figure 5. This illustration demonstrates how the various optimization algorithms progressively work to lower the total voltage deviation (TVD) through a series of multiple iterations that reflect their operational dynamics. Notably, the curve associated with the GOA stands out as it particularly illustrates a remarkably swift and consistent decrease in the TVD, thereby highlighting its exceptional search capabilities along with its efficient exploration of the solution space. This rapid convergence proves to be highly advantageous in real-time scenarios that necessitate prompt decision making to respond to dynamic conditions. The iterative refinement process executed by the optimization algorithms is graphically showcased, effectively presenting the gradual reduction in the TVD that occurs across successive iterations, allowing for a clear visual representation of their performance.
The comparative analysis conducted also compellingly demonstrates that the GOA significantly outperforms the other algorithms in terms of both the accuracy and speed of convergence, thereby establishing it as an invaluable tool for the management of reactive power in the increasingly complex landscape of modern power systems.
The implementation of incentive-based demand response (DR) strategies has resulted in a significant maximum load reduction that can reach up to 10% for the selected buses within the power system under consideration. The specific load buses that were selected for this evaluation include the numbers 7, 8, 12, 17, 19, 21, and 30, which will be used to thoroughly assess the impact of the demand response strategies on the overall operation of the power system as documented in reference [
25].
By optimizing the generation schedules, the demand response strategies play a crucial role in helping to mitigate voltage deviations while simultaneously enhancing the stability of the overall system. The numerical results that detail the load reduction achieved in the context of responsive loads are presented in
Table 2, while
Figure 6 visually illustrates the extent of load reduction observed at the response buses. The data indicate that incentive-based demand response strategies can effectively shift the electrical load away from peak periods, thus contributing to a significant reduction in the overall system demand during critical times that require careful management. This strategic load shifting not only aids in the maintenance of voltage stability but also serves to diminish the necessity for costly peak generation resources that can strain the system during high-demand periods.
Figure 6 is an exemplary representation that captures a key notion regarding the significant effects produced by the aforementioned method under examination. The computations for the cost functions were carefully constructed and assessed in compliance with the criteria specified in Equation (9). The deployment of the demand response (incentive-based) tactics has resulted in a significant and noticeable decrease in the value of the cost function.
The strategies associated with incentive-based demand response (DR) have unequivocally contributed to a notable and discernible decrease in the values associated with the cost function, which is meticulously illustrated in the data presented in
Table 3. The empirical findings derived from this analysis compellingly indicate that the strategic integration of incentives aimed at enhancing consumer participation within demand response programs has a substantial effect in diminishing the total incurred costs.
Table 4 comprehensively illustrates the outcomes of the IEEE 30 bus system, which has been evaluated under a cost minimization objective while simultaneously taking into consideration the implications of the incentive-based demand response program. To ensure the robustness and reliability of the results obtained, the GOA (Grasshopper Optimization Algorithm) was initially employed to achieve cost minimization objectives; subsequently, the outcomes derived from this algorithm were meticulously juxtaposed with those yielded by the DA results. In addition to this comparative analysis, it is pertinent to note that the results obtained from both algorithms were also compared against the performance metrics of other previously published algorithms, specifically the Ant Colony System (ACS) and Multi-Objective Evolutionary Algorithm based on Decomposition (MOEA/D), as referenced in reference [
26]. Upon an examination of the data encapsulated in
Table 4, it becomes clear that the GOA consistently produces superior results when compared to the performance outcomes of the other algorithms evaluated in this study.
From
Table 4, it can be discerned that the GOA presents a cost of USD 786.8352 per hour when the demand response (DR) program is taken into account, whereas the cost rises to USD 798.9780 per hour when the DR program is not considered, thereby highlighting a significant difference in operational expenses associated with the presence or absence of this program. It is clear that the incorporation of the DR program results in a noticeably reduced operational cost for the overall system when compared to the situation where the DR program is not implemented, illustrating the financial advantages of such strategies.
The depiction in
Figure 7 effectively illustrates the voltage levels at the load bus, both in scenarios that include the demand response program and those that do not. Upon analyzing
Figure 7, it becomes evident that there is a marked increase in voltage across nearly all load buses when the implementation of the DR program is in effect, indicating the positive impact of such programs on voltage stability and overall system performance. Increasing voltage levels within a power system assumes supreme importance for the preservation and enhancement of voltage stability, which serves as a foundational criterion for the reliable functioning of electrical networks. When the optimization of voltage levels is pursued and achieved, it not only aids in ensuring that the entire system operates within prescribed safe limits but it also significantly mitigates the potential risks associated with voltage collapse or instability, thereby safeguarding the integrity of the power infrastructure. This consideration becomes especially critical in the context of complex power systems, where even minor fluctuations can precipitate substantial operational challenges and complications. Through the strategic optimization of reactive power dispatch, it becomes possible to effectively minimize the total voltage deviation (TVD), which serves as a crucial metric for evaluating voltage uniformity across the grid. A reduced TVD is indicative of a situation where voltage levels throughout the system exhibit greater uniformity and stability, which is fundamentally essential for the reliable and uninterrupted operation of various electrical equipment and devices. This enhanced uniformity not only aids in the prevention of potential equipment malfunctions but also plays a significant role in diminishing energy losses, thereby contributing positively to the overall efficiency of the power system. The maintenance of elevated voltage levels can improve the operational efficiency within the power system. When voltage levels are maintained in a stable manner and remain within the desired operational range, the power system is positioned to function with greater efficacy, thereby minimizing the necessity for corrective measures and simultaneously enhancing the overall performance metrics of the electrical grid. This consideration holds particular relevance in the contemporary landscape of power systems, which are increasingly confronted with a myriad of both internal and external challenges that can disrupt normal operations.
Figure 8 provides a comprehensive illustration of the pronounced differences in cost function values between the scenarios in which the demand response integration is present and those where it is absent. Notably, the introduction of incentive mechanisms reveals a clear and significant reduction in total costs when compared to situations lacking any demand response strategies, serving to emphasize the substantial economic advantages that can be realized through the encouragement of consumer participation in demand response programs. By motivating consumers to either decrease or shift their energy consumption during peak demand periods through the provision of financial incentives, the total electricity costs can be effectively reduced. This decrease in costs is primarily facilitated by lessening the necessity for expensive peaking power plants and alleviating the pressure placed on the electrical grid. The economic advantages associated with incentive-based demand response programs are considerable as they provide a viable and cost-efficient approach to harmonizing supply with demand while simultaneously ensuring the stability and reliability of the grid system.
Table 5 serves to represent and illustrate the diverse values of incentives that have been allocated and paid to various load buses, particularly in the context of the integration of a demand response (DR) program that is designed to encourage participation. The incentives, which were meticulously derived from the equations presented in (5), function as a significant catalyst that motivates consumers, thereby incentivizing their active involvement in initiatives aimed at reducing load demand, consequently leading to enhanced efficiency in the overall system.
Figure 9, on the other hand, depicts the specific incentives that have been distributed among the various participants actively engaged in the market, providing a clear visual representation of these financial allocations. In addition to this,
Figure 10, which illustrates the convergence curve associated with the cost minimization process both with and without the incorporation of demand response initiatives (specifically those that are incentive-based) for the IEEE-30 bus system, offers a concise yet informative depiction of the dynamics involved in algorithmic convergence. This curve effectively delineates the iterative refinement process that is systematically undertaken by various optimization algorithms in their pursuit of minimizing the total cost function, and it is important to note that the graphical representation of each algorithm’s convergence trajectory vividly showcases the gradual reduction in cost that occurs across successive iterations, thus highlighting the efficiency of the optimization strategies employed.
The component of the multi-objective optimization framework engages in the intricate consideration of both the minimization of voltage deviation—derived from the ORPD problem—and the minimization of the cost function, which is analyzed in conjunction with demand response (DR) strategies. To thoroughly investigate the ramifications of demand response within the context of the ORPD problem, this scholarly article delineates two distinct scenarios that take into account the aforementioned objective functions:
The comprehensive statistical analysis of the multi-objective optimization process is systematically encapsulated within
Table 6, which elucidates the findings. In the context of this research endeavor, the Multi-Objective Grasshopper Optimization Algorithm (MOGOA) is meticulously employed to derive the optimal compromise solution for the given scenarios. Furthermore,
Table 6 illustrates the best, worst, and mean values pertinent to both the cost function and the total voltage deviation (TVD) for the scenarios previously delineated.
The comprehensive solution encompassing the various weights can be regarded as the most plausible resolution to the multi-objective optimization problem, as delineated in the detailed presentation of
Table 7. Upon a meticulous examination of the data presented in
Table 7, it becomes evident that within the confines of Scenario 2, the associated costs are notably minimized when juxtaposed against those observed in Scenario 1. Furthermore, this table elucidates the resultant values of the cost function corresponding to each scenario, thereby clearly indicating the significant influence that adjustments to the control variables exert on the overarching objective function.
Figure 11 depicts the load bus voltage profile with and without the DR program using the MOGOA. The comparative analysis of the Pareto optimal front for multi-objective optimization is effectively depicted in
Figure 12. This graphical representation serves to underscore the intricate trade-off that exists between minimizing the total voltage deviation (TVD) and reducing costs across both scenarios under consideration. The empirical findings reveal that Scenario 2, which uniquely integrates incentive-based demand response (DR) mechanisms, accomplishes the objective of achieving the lowest overall cost while simultaneously upholding acceptable levels of the TVD. Through a thorough examination of the Pareto front, decision makers are allowed to pinpoint solutions that provide the most favorable equilibrium between the imperative of minimizing voltage deviation and the necessity of lowering operational expenditures. This strategic approach guarantees that the operations of power systems are optimized effectively while considering multiple objectives concurrently.
This study demonstrates the GOA’s potential as a robust tool for optimizing energy management in complex systems by minimizing power losses and improving system efficiency. The findings have practical applications for operators who can use the GOA to manage power dispatch and DR programs effectively. Stakeholders can benefit from reduced costs and enhanced system stability. The limitations of the presented work include the focus on a single network (IEEE-30 bus system) and the absence of a distribution network analysis. Future research could explore larger and more complex systems like the IEEE-33 bus system and test the approach under varying system constraints and DR policies.