Fig 6 - uploaded by Ali Badri
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shows SSSC injected voltage and Transmission line current changes during above real and reactive power variations at t=0.05 and 0.15sec, respectively. It is observed that line current changes proportional to real and reactive power variations and also change in real power results severe variation in line current with respect to reactive power. In either cases increasing active or reactive powers the SSSC injected voltage is increased. Phase angles of injected voltages are varied in such a manner that in the case of increasing active power it remains in quadrature with line current. However in case of increasing reactive power it tends to remain in phase with line current.
Source publication
In this paper, two vector control systems for investigating the performance of
Static Synchronous Series Compensators (SSSC) in steady state conditions are presented
that are based on famous d-q axis theory. The workability of proposed method to simplify
the SSSC mathematical expressions is shown. The performance of SSSC with two different
vector c...
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Citations
... In this situation, the series voltage injected can delay or advanced the line current. This means that the SSSC can be uniformly controlled in any value, in the VSC working slot [1][2][3][4]. ...
... Despite much advancement, the LLC structure and PID-based controller remain as an engineer's selection for many industrial applications because of their simple structure, low cost and high reliability. Despite these advantages, these controllers do have limitations such as inability to adaptation with the variations of the system and have no resistant to the disturbance [1][2][3]. Therefore nowadays many approach absorbed to use of the other controller such as artificial intelligence-based controllers. These types of controllers compensate many shortages of the classic types such as robustness and adaptation. ...
... For objective function calculation, the time-domain simulation of the power system model is carried out for the simulation period. It is aimed to minimize this objective function in order to improve the system response in terms of the settling time and overshoot [1][2][3]. ...
Static Synchronous Series Compensator (SSSC) is a series compensating Flexible AC Transmission System (FACTS) controller for maintaining to the power flow control on a transmission line by injecting a voltage in quadrature with the line current and in series mode with the transmission line. In this work, an Adaptive Network-based Fuzzy Inference System controller (ANFISC) has been proposed for controlling of the SSSCbased damping system and applied in a Single Machine Infinite Bus (SMIB) power system. For implementation of the learning process of this controller, we use from one approach of the learning ability that named as Forward Signal and Backward Error Back-Propagation (FSBEBP) method for improving of the system efficiency. This artificial intelligence-based control model leads to a controller with adaptive structure and improved correctness of the system, and finally cause to enhancing to the high damping ability and dynamic performance. System implementation is easy and requires 49 fuzzy rules for inference engine of the system. As compared with the other complex neuro-fuzzy systems, this controller has medium number of the fuzzy rules and low number of the layers, but it has high accuracy. In order to demonstrate of the proposed controller ability, it is simulated and its output compared with that of the classic Lead-Lag-based Controller (LLC) and PI controller. © 2014, Iran University of Science and Technology. All rights reserved.
... SSSC works as inductive reactance, by injecting a voltage in series, leading the line current and makes both the line current and power flow to decrease. On the other hand, it works in capacitive mode by injecting a voltage lagging the line current which in turn causes the line current and power flow to increase [27]. ...
Static Synchronous Series Compensator (SSSC) is a series compensating Flexible AC Transmission System (FACTS) controller with primary objective of power flow control on a line by injecting a voltage in series with transmission line. However, it can efficiently be used for improving the system stability by using a supplementary damping control system. In this work, Adaptive Neurofuzzy Wavelet Control (ANFWC) paradigm for SSSC supplementary damping control system has been proposed and successfully applied to a Single Machine Infinite Bus (SMIB) power system. Gradient descent based backpropagation algorithm, being simple with sufficient efficiency, has been used to update the controller parameters. The robustness of the proposed control strategy has been validated using nonlinear time domain simulations for different faults and various operating conditions of power system. Finally, the results have been compared with Conventional Adaptive Takagi-Sugino Controller (CATC) on the basis of different performance indices.
This work explores the potential of Bspline based Adaptive NeuroFuzzy Wavelet control to damp low frequency power system oscillations using Static Synchronous Series Compensator (SSSC). A comparison of direct and indirect adaptive control based on Hybrid Adaptive Bspline Wavelet Control (ABSWC) is presented by introducing the online identification block. ABSWC with Identification (ABSWCI) provides the sensitivity information of the plant to control system. The parameters of the control and identification block are updated online using gradient descent based back propagation algorithm. The robustness of the proposed control algorithm has been evaluated for local and inter-area modes of oscillations using different faults. The nonlinear time domain simulation results have been analyzed on the basis of different performance indices and time-frequency representation showing that ABSWC effectively damps low frequency oscillations and incorporation of online identification optimizes the control system performance in terms of control effort which reduces the switching losses of the converter.
In this paper a decoupling technique for improving the vector control model of SSSC is presented. In the present vector models for SSSC, which are based on d-q line currents so called indirect control methods, there is a coupling between d and q axis, and therefore a coupling between P & Q control channel is seen. Obviously it would be more interesting to completely separate the controlled parameters which in the case of a SSSC are active and reactive powers in such a way that the deviation of one of the parameters affects the other one as least as possible. By the technique presented here, an independent control of P and Q is achieved while other control parameters of the SSSC (such as rise time, settling time, overshoot and ...) are also improved and a faster and more precise response is achieved. Simulation results are presented to prove the validity of this technique
