نشریه تحقیقات نوین در سیستم های قدرت هوشمند
سال نهم شماره 1 (پیاپی 21، بهار 1399)

To improve the stability of the power system, the design of a PSS and STATCOM controller parameters using ABC is presented as an optimization problem in this paper. The ABC is a collective intelligence based on the optimization algorithm and inspired by the bee feeding behavior in finding food. Fast convergence and high accuracy are the capabilities of this algorithm. The effectiveness and robustness of the bee colony algorithm are shown by nonlinear simulation of a two-area power system consisting of four machines and compared with the particle swarm optimization method. Simultaneous design of power system controller and stabilizer parameters with bee cloning algorithm over non-optimized mode increases oscillation damping speed and improves power system stability. The simulation results are presented using MATLAB software for different system conditions.

In this paper, the method of correction of network current distortion with controllable inductive power filter (CIPF) is proposed to solve the quality problems of the power available in the induction furnace load. This method is based on the equilibrium potential theory of magnetic potential combined with controlled inductive power filter technology. First, the structure of the system and the filter wiring scheme are presented, and the equivalent circuit is performed along with the mathematical models of the filtering system. A modified control strategy is then designed to achieve better filtering performance. Technical characteristics such as the elimination of harmonics due to nonlinear load and intensification damping are shown by the analysis mechanism. Finally, the simulation model of the filtering system is implemented in the Simulink environment of MATLAB software. The simulation results confirm the theoretical analysis and show that the proposed method with appropriate control efficiency can effectively eliminate the harmonics passing through the transformer and improve the distortion in the network current caused by the induction furnace load.

The simplest model of mechanical resonance systems is a two-mass system, in which oscillations are a major barrier to increasing system performance. Twisting performance is a nonlinear phenomenon, and the linear and mathematical model is a good tool for examining, diagnosing, and designing against this phenomenon. In this paper, the dynamic behavior of a two-mass oscillation system with a PID controller for the coupling controller is analyzed using simulations of special values ​​for a two-mass intensification system. To design the controller, the equations describing the system in the state space and the mathematical model of the two-mass system are expressed based on the transfer functions. The simulation results are shown for the closed loop and the open loop of the system and show the effect of changing the stability index in the coefficient diagram (CDM) method on the stability of the system.

In this paper, a wearable dual-band filter with Jeans substrate is designed, simulated, and fabricated for medical applications and performance in standards GPS and WLAN/HiperLAN2 wireless frequency bands. The proposed filter is capable of covering the frequency ranges of 1.563-1.678 GHz and 5.15-5.825 GHz for the mentioned applications. These standards are widely used in the design of telecommunication-medical systems. To design this filter, a Jeans substrate with dielectric constant of 2 and height of 1 mm was used. CST Microwave Studio 2019 full-wave software is also used to simulate the filter. The final dimensions of the proposed filter are 6×4 cm2 or 0.38×0.25 λg2 at 1.57 GHz. Finally, a filter was fabricated to confirm the simulations. The results of the measurement of the filter properties and the simulation results are in good agreement with each other.

Due to the low voltage level and as a result of high current, the distribution networks have high losses and high voltage drop, which has always been the biggest contributor to the losses and reduced reliability of the electricity distribution network. Various methods have been proposed to reduce losses, improve voltage profiles and increase reliability in these networks, one of which is redistribution. Rebuilding Distribution Networks with Switching Keys is to find the best combination of all switches in the network to minimize power losses and load balancing in situations where load distribution constraints, grid radial topology and The minimum voltage required is a very cost-effective and low cost method that reduces losses, improves voltage profiles and increases reliability in power distribution networks without adding additional equipment to the grid. Reliability calculations have used the Cut-Set method to speed up compared to the Monte Carlo method. The rearrangement of distribution networks is a large-scale nonlinear hybrid optimization problem involving a number of constraints. In this paper, a new meta-heuristic algorithm based on the behavioral pattern of wild mice is used to reconfiguration of power distribution networks to reduce losses, improve voltage profiles and increase reliability. The wild mice colony algorithm is a suitable algorithm for finding the optimal answer to complex problems. The effects of  distribution system reconfiguration on two distribution networks 33 Bus and 69 Bus of IEEE standard are implemented and the results are evaluated.

Today, the distance relay is widely used in transmission and over-distribution lines. Due to the zoning of the protection zone, the distance relay provides a simple and economical way to detect faults. The current-transformer saturation in high-voltage substation causes faults in the protection zones of the distance relay and the operating time of the distance relay zones is not correct when an error occurs. To solve this problem, this article suggests optical current transformers. Initially, the simulated optical current transformer model was presented, the optical current transformer was compared with the conventional current transformer in IEEE 9 bus network substation using DIGSILENT software. The results show that the proposed optical current transformer covers well the faults of relay distance caused by the saturation of the normal current transformer.