scholarly journals Low Frequency Damping Control for Power Electronics-Based AC Grid Using Inverters with Built-In PSS

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2435
Author(s):  
Ming Yang ◽  
Wu Cao ◽  
Tingjun Lin ◽  
Jianfeng Zhao ◽  
Wei Li

Low frequency oscillations are the most easily occurring dynamic stability problem in the power system. With the increasing capacity of power electronic equipment, the coupling coordination of a synchronous generator and inverter in a low frequency range is worth to be studied further. This paper analyzes the mechanism of the interaction between a normal active/reactive power control grid-connected inverters and power regulation of a synchronous generator. Based on the mechanism, the power system stabilizer built in the inverter is used to increase damping in low frequency range. The small-signal model for electromagnetic torque interaction between the grid-connected inverters and the generator is analyzed first. The small-signal model is the basis for the inverters to provide damping with specific amplitude and phase. The additional damping torque control of the inverters is realized through a built-in power system stabilizer. The fundamentals and the structure of a built-in power system stabilizer are illustrated. The built-in power system stabilizer can be realized through the active or reactive power control loop. The parameter design method is also proposed. With the proposed model and suppression method, the inverters can provide a certain damping torque to improve system stability. Finally, detailed system damping simulation results of the universal step test verify that the analysis is valid and effective.

As electrical power system is a complex system, there are more chances of stability issues may arise. One of the stability issues is Low Frequency Oscillations (LFOs) which makes the system unstable. As these oscillations are having low frequency i.e. large time constant with slowly increasing magnitude, they are referred to small signal stability. The main reason of these oscillations is due to lack of sufficient damping torque. Automatic Voltage Regulator (AVR) action in generator is providing sufficient synchronizing torque for system stability. This is possible with high gain and low time constant AVR which results in reduction of damping torque. Power System Stabilizer (PSS) is used together with AVR for providing necessary damping torque to minimize the LFOs. For effective damping, the PSS performance is improved by optimizing its parameters. In this paper, Single Machine Infinite Bus (SMIB) system is considered for studying the effect of LFOs. The SMIB system is simulated for a step disturbance in reference voltage and the results are carried out for different optimizing techniques Particle Swarm Optimization (PSO), Cat Swarm Optimization (CSO), Teaching and Learning based Optimization (TLBO)


Author(s):  
Yanghai Li ◽  
Tao Yang

Low frequency oscillation is one of the most important factors that restrict the tie-line power flow of network. Its effective suppression is necessary to ensure safety and stability of the power system. The conventional power system stabilizer (PSS) is still insufficient in suppressing consider the frequency range and types of oscillation, so it is necessary to study the auxiliary suppression of the oscillation from the turbine side by using the electro-mechanical coupling theory. In this paper, a governorside power system stabilizer (GPSS) based on active power signal is designed, and its working principle, system structure and parameter setting method are introduced, the effective response frequency boundary of oscillation is also analyzed. Theoretical analysis and simulation results show that this GPSS can suppress in the whole frequency range of low frequency oscillation, and it is suitable as an auxiliary means of low frequency oscillation suppression. (CSPE)


2018 ◽  
Vol 7 (3) ◽  
pp. 24-46
Author(s):  
Sourav Paul ◽  
Provas Roy

In this article, an Oppositional Differential search algorithm (ODSA) is comprehensively developed and successfully applied for the optimal design of power system stabilizer (PSS) parameters which are added to the excitation system to dampen low frequency oscillation as it pertains to large power system. The effectiveness of the proposed method is examined and validated on a single machine infinite bus (SMIB) using the Heffron-Phillips model. The most important advantage of the proposed method is as it reaches toward the optimal solution without the optimal tuning of input parameters of the ODSA algorithm. In order to verify the effectiveness, the simulation was made for a wide range of loading conditions. The simulation results of the proposed ODSA are compared with those obtained by other techniques available in the recent literature to demonstrate the feasibility of the proposed algorithm.


Author(s):  
Sourav Paul ◽  
Provas Kumar Roy

Low frequency oscillation has been a major threat in large interconnected power system. These low frequency oscillations curtain the power transfer capability of the line. Power system stabilizer (PSS) helps in diminishing these low frequency oscillations by providing auxiliary control signal to the generator excitation input, thereby restoring stability of the system. In this chapter, the authors have incorporated the concept of oppositional based learning (OBL) along with differential search algorithm (DSA) to solve PSS problem. The proposed technique has been implemented on both single input and dual input PSS, and comparative study has been done to show the supremacy of the proposed techniques. The convergence characteristics as well authenticate the sovereignty of the considered algorithms.


2015 ◽  
Vol 781 ◽  
pp. 397-401
Author(s):  
Nur Safura Ab Khalid ◽  
Mohd Wazir Mustafa ◽  
Rasyidah Mohamed Idris

This paper presents a new approach for designing the Power System Stabilizer. As in power system network, low frequency oscillation always occurs for a long period of time that will decrease the power transfer capability. Power System Stabilizer known as PSS is being installed as one of the control devices in a generating unit. The conventional PSS (CPSS) is the most commonly used in power system, which uses lead-lag compensation. The lack in CPSS has drawn an interest of designing the new approach of PSS to outperform the conventional one. Thus, Bees Algorithm (BA) which is known as one of the numerous intelligent optimization methods is proposed in this paper. It is appears to aid the system stability by optimizing the PSS parameters tuning. The PSS with the BA approach is labelled as BA-PSS and being tested on single machine infinite bus system (SMIB) in Matlab/Simulink environment. BA-PSS performance is compared with CPSS as to validate the ability of the proposed method to achieve great performance in power system stability enhancement. Different type of mechanical input is being injected into the system and the result shows that BA-PSS is capable to optimize the parameters tuning of PSS. BA-PSS also improved the unstable or poorly stable modes as the system achieve the stability with lower overshoot and less time settling. The superior response of BA-PSS controller proved the ability of BA approach in which is capable to solve the lack in CPSS with better performance in enhancing the system stability.


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