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This paper presents a practical search algorithm using detailed dynamic simulations to identify plausible harmful N − k contingency sequences. Starting from an initial list of contingencies, progressively more severe contingency sequences are investigated. For that purpose, components, which violated conservative protection limits during a N − k co...
This paper derived the mathematicalmodel of indirect field oriented control (IFOC) applied in pump storage toobtain the variable speed. The two identical seven level H-bridge multilevel converters connected in cascade have been used togenerate 6KV on the rotor side. The inputof power cell of H-bridge cascaded multilevel converter fed from a phase-s...
Citations
... Given the low rate of harmonics in the converter output voltage, DC capacitance is designed as follows [21]: ...
... It is assumed for reactor design that the multilevel STATCOM output voltage and current is sinusoidal and the reactor resistance is ignored. Thus, inductance of the reactor is defined as follows [21]: . Because the reactor resistance is neglected, reactor resistance is 0.1 of the reactor reactance and is placed equal to ...
Static synchronous compensators (STATCOM) are increasingly implemented in power systems. Moreover, cascaded multilevel converters (CMC) are more frequently taken in consideration because of their strong capabilities. In this paper, the design and simulation of a multilevel STATCOM for voltage regulation of load is presented. Design of the passive components, active and reactive power controller, and balancer of capacitor voltage are parts of proposed system design. The pole placement method was used for the design of the controller. Simulation results with MATLAB/SIMULINK show good performance of voltage regulation in full load and dynamic load conditions.
ABSTRAK: Penyelaras pengimbang statik (STATCOM) semakin dilaksanakan dalam sistem kuasa. Selain itu, penukar pelbagai aras tingkatan (CMC) lebih diutamakan kerana mempunyai banyak kelebihan. Dalam kajian ini, reka bentuk dan simulasi bertingkat STATCOM bagi pelbagai voltan beban dibentangkan. Reka bentuk komponen pasif, penyelenggara kuasa aktif dan reaktif dan pengimbang voltan kapasitor adalah sebahagian daripada sistem yang dicadangkan. Bagi reka bentuk penyelenggara, kaedah penempatan titik telah digunakan. Hasil simulasi melalui MATLAB/SIMULINK menunjukkan keputusan yang baik pada regulasi voltan pada beban penuh dan pada keadaan beban dinamik.
... By suitable modelling of these signals, good tracking of the frequency is obtained so as to reduce the deviation from the reference signal which in turn results in the stability of the ac system in case of transient responses. The gain of the phase control and frequency control unit is controlled by the voltage control unit output (Hawley 2004). The voltage control unit output also tracks the specified input magnitude which results in compensation of the voltage during transient disturbances in the ac system. ...
This research aims at the special needs of phase locked loops (PLLs) for a typical application with FACTS devices. An adaptive PLL system comprising of three independent control units i.e. frequency, phase angle and voltage magnitude has been proposed. The output angle is used to generate the synchronised pulses for thyristors in FACTS devices which control the operation of these devices. The proposed controller reduces the phase and frequency error efficiently. The stability of the system is also increased even transient disturbances occurred in the system. In this paper, the design of proposed adaptive PLL is suggested using MATLAB, Simulink as a simulation tool. The total harmonics distortion are calculated in case a fault occurs in the system and compared with that of the system without any fault. The simulation results are simulated using MATLAB block-set and noticeable improvements are discussed.
... Traditionally, series compensation of transmission lines has been performed by fixed type thyristor controlled series reactance, either inductive or capacitive, depending on the power system requirement. The switching based converter Static Synchronous Series Compensator (SSSC) provides another degree of freedom to series compensation in that the voltage source converter (VSC) used for series compensation has the ability to maintain a constant capacitive and inductive compensating voltage independent of the transmission line current up to the rated current for the line [7]. For the capacitive voltage compensation, the output voltage leads the line voltage by 90 degrees and for the inductive one; the output voltage lags the line voltage by 90 degrees. ...
This paper presences an accurate and robust fault location algorithm for transmission lines utilizing Static Synchronous Series Compensator (SSSC). The presence of SSSC on a transmission line has a great influence on the measured impedance at the relaying point. Firstly a detailed model of the SSSC and its control is proposed and then a precise fault location algorithm employing adaptive neuro fuzzy (ANFIS) is presented. A MATLAB_SIMULINK test system is modeled to investigate the proposed algorithm. The results obtained allow concluding that the fault location algorithm is accurate with respect to SSSC presence.
... The LC circuit consists of a fixed series capacitor and variable inductive impedance as shown in figure (3). The following assumes that the line current i s (t) in figure (3) will be [8,9,10]: ...
... The TCSC has two operating ranges; one is when α Clim ≤ α ≤ π/2, where the TCSC is in capacitive mode. The other range of operation is 0 ≤ α ≤ α Llim , where the TCSC is in inductive mode as shown in figure (4) [8,9,11]. ...
Thyristor Control Series Compensator (TCSC) can be considered as one of the solutions for increasing power demand nowadays. This paper presents design of control system that is able to change the impedance of the TCSC by controlling thyristors firing angle (α) of three stages TCSC using constant power control strategy for thyristor control series compensators to increase the capability of reactive power compensation of the transmission line. Matlab Simulink implemented to evaluate the performance of the proposed control circuit for the duration of peak load and half load of the transmission line where the simulation shows a good results where two third of the total amount of reactive power is compensated and transmission line capacity is extended.
