ارائۀ یک فیلتر فعال موازی بهینه‌شده برای بهبود کیفیت توان در یک کارخانۀ فولاد مبتنی بر تئوری P-Q توسعه‌یافته

امروزه مسئلۀ کیفیت توان، پارامتری مهم برای مصرف‌کنندگان انرژی الکتریکی به‌ حساب می‌آید. المان‌های غیرخطی همچون تجهیزات الکترونیک قدرت، کوره‌های قوس الکتریکی، دستگاه‌های فرکانس‌بالا و...) دلیل اصلی وجود مشکلات مربوط به کیفیت توان و ایجاد هارمونیک در شبکه است. در این مقاله، یک روش جدید برای بهبود کیفیت توان در یک کارخانۀ فولاد ارائه شده است. در این روش، برای حذف هارمونیک‌های جریان و ولتاژ که کوره‌های القایی در یک کارخانۀ فولاد ایجاد می‌کنند، از یک فیلتر فعال موازی استفاده شده است. برای بهبود عملکرد فیلتر فعال موازی یک کنترل‌کنندۀ جدید که بر اساس تئوری pq و کنترل‌کنندۀ pid طراحی گردیده، پیشنهاد شده است. همچنین در راستای افزایش عملکرد مناسب فیلتر و بهبود شاخص‌های کیفیت توان، از یک روش بهینه‌سازی مبتنی بر الگوریتم بهینه‌سازی گرگ‌های خاکستری اصلاح‌شده برای تنظیم پارامترهای کنترل‌کننده استفاده گردیده است. با شبیه‌سازی یک کارخانۀ فولاد 10 باسه شامل 6 کورۀ القایی و استفاده از فیلتر فعال موازی ارائه‌شده در محیط نرم‌افزار matlab/simulink و آنالیز شاخص‌های هارمونیکی، کارایی ساختار پیشنهادی در افزایش کیفیت توان شبکه قدرت نشان داده شده است.

Power Quality Improvement in a Steel Plant by an Optimized Shunt Active Power Filter Based on Developed P-Q Theory

Introduction: Nowadays, the issue of power quality is an important parameter for electricity consumers. Nonlinear elements (such as electronic power equipment, electric arc furnaces, high frequency devices, etc.) are the main reasons for the problems related to power quality and the creation of harmonics in the network. In this paper, a new method to improve the power quality in a steel plant is presented. A shunt active power filter is used to eliminate current and voltage harmonics of electric arc furnaces in a steel plant in this method. To improve the performance of the shunt active power filter, a new controller based on PID controller and PQ theory has been proposed. Also, an optimization method based on the modified gray wolf optimization (MGWO) has been used to adjust the control parameters to improve the proper performance of the filter and the quality indices. A 10bus steel plant, including 6 electric induction furnaces and a shunt active power filter is simulated by MATLAB/Simulink. The analysis of harmonic indices shows the efficiency of the proposed structure to increase the power quality of the power system. Materials and methods: In this paper, a threephaseactive filter has been used to improve the power quality of a 10bus steel plant. This plant has six induction furnaces with two different structures which are based on real information. The results of power quality improvement with the proposed control structure have been obtained by simulating this plant. In this filter, by developing the PQ theory and calculating the active power lost on the rectifier DC bus and adding it to the active power in the PQ theory, more suitable reference currents are created to produce the required pulses for the active filter rectifier. In the proposed model, the modified gray wolf optimization algorithm is also used to determine the power loss and optimal selection of the parameters of a PID controller. The objective function in the optimization algorithm is to minimize the THD percentage of current and voltage. Result: The steel plant with the shunt active filter has been simulated using the MATLAB / SIMULINK software environment. The simulations were performed in four steps as shown below and the results of the simulations has been presented in the form of graphs. bull;The simulation of steel plant without an active filter. bull; Steel plant simulation in the presence of a classic shunt active filter. bull; Steel plant simulation in the presence of a developed shunt active filter. bull;The simulation of steel plant in the presence of a developed and optimized shunt active filter with the MGWO optimization algorithm.The threephase input voltage and current wave form of the steel plant along with the harmonic components of voltage and current was shown in all four steps. Indices such as THD, TDD and HCR were also used to measure power quality and harmonics for further investigation and comparison. The values ​​of power quality measurement indices and the study of harmonic distortions were also expressed for the four stages of simulation. Also, in order to show the performance of the modified gray wolf optimization algorithm, a developed filter was implemented using the particle swarm optimization algorithm (PSO) and the values ​​have been presented.The results show that the better compensation is provided in the simulation of the steel plant in the presence of an optimized active filter with MGWO algorithm. Also, the efficiency of the proposed method is better than the other methods for all indices (both current and voltage indices). The best values ​​of power quality measurement indices and harmonic distortion for the developed and optimized filter with MGWO have been obtained. Notably, all indices for the proposed method are in the range of IEEE5192014 standard. Discussion and Conclusion: In this paper, a new control method for threephase shunt active filters is presented to improve the power quality and harmonic elimination. The new control structure is based on PQ theory, PID controller and modified gray wolf optimization algorithm, which has led to the improvement of power quality indices. To show the efficiency of the proposed method, a steel plant with six induction furnaces in the presence of a filter is simulated in MATLAB / SIMULINK software environment. The results of the simulation demonstrate that the proposed filter offers a better compensation in comparison with the classical methods. Also, optimizing the filter can increase the amount of such compensation. Since this simulation is done using the real information of a steel plant, it can greatly help industrial users to improve the power quality of industries.