rasool kazemzadeh

Overcoming the problem of transmission lines or a region of the power system congestion is one of the important issues facing the operators. In the meantime, in addition to choosing the appropriate method to relief transmission line congestion, the process should be implemented with the aim of minimizing the imposed costs. In this article, in order to optimally control the transmission lines congestion, an integrated method including management of the production and demand side of the systems along with the use of the flexibility of multi-carrier energy systems (electricity, gas and heat) is presented. The congestion alleviation technique is analyzed in the two modes of independent operation of the power system and integrated operation of multi-carrier systems, and their results have been compared. Also, taking into consideration the scenario of transmission line congestion with the simultaneous outage of a power generation unit, the effect of energy storage in solving this problem has also been studied. The simulation of scenarios and the evaluation of the effectiveness of the proposed method have been implemented in a multi-carrier energy system including the IEEE 39 bus power system in combination with the Belgian 20-node gas network and several energy hubs. The evaluation of the obtained results shows a significant reduction in the congestion management costs in the mode of integrated operation with the rescheduling of generation and consumption compared to the independent operation of the power system. In addition, it was proved that the properly storage and discharge of all types of energy can be successful in order to optimize (at least 10%) the imposed costs.

Wind powers are very unstable in voltage fluctuations, especially in short circuit error and sharp and sudden voltage drops, which one of its main reasons is the use of induction generators in these power plants and thus need to reactive power and high magnetizing current. To improve the ride_through voltage from WECS in error conditions and damping the oscillations of the induction generator rotor, a UPFC is used the controller FOPID is used in UPFC controllers for the first time. Since FOPID has two parameters more than IOPID, it has recently attracted much attention (needing more work and research motivation) as it gives more flexibility to a control system designing and a better opportunity to adjust the system dynamics, especially, if a system is to be controlled be a fractional system. The investigations indicate that controller FOPID adjusted by presented PSO algorithm, show improved dynamic performance than traditional PID and feedback controller in a wide range of operating conditions.

Steady-state and transient response of the active power filter based on instantaneous power theory compensation method is dependent on the accurately and quickly extract the DC component of load active power. In this paper, for improving the response of this method, the numerical filter based on recursive least squares with variable forgetting factor in order to separation of DC component of load active power is proposed. Unlike conventional low-pass filters, the feature of designed numerical filter is independent of load harmonic components, quick and precision of the answer. Also, using wavelet transform the performance of active power filter under the non-ideal voltage condition is improved. Finally, the second order delta-sigma modulation is used to generate the switching pulses. Simulation results on MATLAB / SIMULINK software shows that the proposed method is properly

This paper presents a comparative analysis between two current control strategies, constant source power and generalized Fryze current, used in active power filter (APF) applications having three different modulation methods. The hysteresis band (HB) and first-order Delta-Sigma modulation (DSM) as well as the second-order DSM is applied. The study has been applied to a three-phase system with different rectifier as a load of power system. The power section of the active power filter is viewed as an analogue to digital converter (ADC), then as a result a three-phase shunt active filter modulator controller which uses Delta-Sigma analogue to digital converter is presented to improve modulator performance. Simulation results show that by using the first and second order Delta-Sigma control strategies, total harmonic distortion (THD) can be significantly decreased. Moreover, active filter based on the second-order DSM with constant source power has better performance and provides lower source current THD.

In this paper, a combinational optimization algorithm is introduced to obtain the best size and location of Static Compensator (STATCOM) in power systems. Its main contribution is considering contingency analysis where lines outages may lead to infeasible solutions especially at peak loads and it commonly can be vanished by load-shedding. The objective of the proposed algorithm is firstly to prevent infeasible power flow solutions without undesired load-shedding, which is critical in contingency analysis; and secondly to mitigate overall power losses and costs. Moreover, active and reactive powers generation costs are considered in the proposed objective function. Since there are various constraints such as lines outages number, cost and their duration that must be taken to account, Bacterial Foraging oriented by Particle Swarm Optimization (BF-PSO) algorithm combined with Optimal Power Flow (OPF) is used to solve and overcome the complexity of this combinational nonlinear problem. In order to validate the accuracy of the proposed method, two test systems, including IEEE 30 bus standard system and Azarbaijan regional power system of Iran, are applied in simulation studies. All obtained optimization results show the effectiveness of the suggested combinational method in loss and cost reduction and preventing load-shedding.