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This paper proposes an algorithm based on the use of the S-transform for time-frequency analysis of the capacitor-switching transients. With no prior knowledge about system parameters, the time-frequency analysis of the voltage and current transient signals due to switched capacitor banks are used to simply but accurately estimate the relative location of the switched capacitor whether it is upstream...
In the modern industry, most of the equipment use semiconductor devices and microprocessors which are sensitive against power disturbances. Among all power disturbances, voltage sags are considered as the most frequent type of disturbances and their impact on sensitive loads is severe. To monitor these disturbances, voltage sag recorders (VSR) must be installed. However, installation of VSRs at all...
Voltage sag is considered as one of the most common power quality problems. It may cause sensitive equipment to malfunction and process interruption. This paper presents the application of network reconfiguration and DSTATCOM to mitigate voltage sags in power distribution networks. The proposed method first reinforces the system voltage profile during voltage sag by network reconfiguration. Then DSTATCOMs...
In this study, the problem of simultaneous and coordinated tuning method for thyristor-controlled series capacitor (TCSC) power oscillation damping controllers and conventional power system stabilizer (PSS) controllers in multi-machine power systems is considered. For a multi-machine power system, the tuning of the PSS and TCSC controllers is generally formulated as an objective function with constraints...
Voltage sag and swell are the common problem for sensitive load. The impact range from load disruptions to substantial economic losses. The DVR is the best solution to protect the sensitive loads. This paper present a fast DVR with controller to compensate the short outage, reduced the harmonic distortion and transient voltage for balanced and unbalanced load. In-phase method with continues two vector...
Many of the electrical systems throughout the world are experiencing problems with aging insulation. When an insulation system fails, the results are usually catastrophic. Insulation failure can cause sustained interruption which can cause substantial financial loses due to lost production and damage to expensive equipment. These losses can amount to thousands of ringgit (RM) per hour. With the ability...
In most parts of the world, the quality of the electrical power has become a major concern for many electricity users especially the industrial customers. To the power utility, all power quality disturbances must be detected, classified and diagnosed accurately so that proper mitigation measures can be implemented. This paper presents the application of the S-transform and support vector machine (SVM)...
This paper presents the design and construction of voltage acceptability curves for fluorescent lighting systems. It is derived from mathematical representation of actual light output variations of fluorescent lamps (FLs) during voltage sags and a predefined malfunction criterion called the light standard. Light standard may be thought of a standard based on a minimum acceptable light output, below...
Voltage sags are an important power quality problem for which the dynamic voltage restorer (DVR) is known as an effective device to mitigate them. This paper presents a new control algorithm for dynamic voltage restorer (DVR) that mitigates voltage sag by low active power injection with short time delay. This work is based on two-vector control technique using 12 pulse inverter. A smooth control technique...
Power system disturbances have been present since the inception of the electric utility industry. However, yesterdaypsilas loads are more forgiving of disturbances than todaypsilas modern equipment. The proliferation of sensitive electronic equipments such as PCs, variable speed drives and industrial programmable controllers has made us more aware of power system disturbances, which went unnoticed...
Conventional methods currently used by power utilities for detecting power quality disturbances are primarily based on visual inspection of the rms value of voltage and current waveforms recorded by power quality recorders. The disturbance detection and classification results can help to identify any potential degrading trends in the electrical system. Once identified, inspection and preventive maintenance...
This paper deals with the modeling of synchronous static compensator (STATCOM) of a power system based on dynamic phasor model to investigate the performance of STATCOM for power quality analysis and compared with EMTP like simulation. The dynamic phasor model and EMT model of the STATCOM including the system is implemented in Matlab/Simulink toolbox and PSCAD/EMTDC, respectively. Details dynamic...
This paper focuses on a novel automatic software tool to locate three major power quality disturbances, i.e. voltage sag, transient and harmonic. The software tool developed is to locate the source of these disturbances relative to a monitoring point. The methods employed in the software only require the current and voltage data. For locating the source of voltage sag, the product of the RMS current...
Real time detection and classification of power quality disturbances is important for quick diagnosis and mitigation of such disturbances. This paper presents the development of a software tool based on MatLab for power quality disturbance analysis and classification. Prior to the development of the software tool, the disturbance signals are captured and processed in real-time using the TMS320C6711DSP...
Dynamic voltage restorer (DVR) is a custom power device used for mitigating voltage sags in power distribution systems. This paper presents a simulation model of a 12-pulse DVR using photovoltaic as a means of providing an alternative energy source for the DVR. For the development of DVR model, two models were considered by using user-defined model and existing component model. To achieve stable characteristic...
Power system transients are power quality disturbances that can be harmful especially to electronic equipment. This paper presents a new method to locate the source of lightning transient relative to the monitoring point. The proposed method is based on complex wavelets energy which is calculated from the voltage and current data obtained at the monitoring point. The data is transformed to its complex...
This paper presents a digital signal processor based prototype instrument to provide real-time analysis of power disturbances that can be used to perform quick power quality monitoring. The proposed instrument uses the Texas Instrument TMS320C6711DSP starter kit with a TIADS8364EVM 250-kHz, 16-bit, 6-channel and an analog digital converter mounted on the daughter card. For real-time analysis of power...
In this paper, fuzzy logic is applied for identifying and classifying the short duration voltage variations of 8, 32 and 128 cycles waveforms. A program is written in Matlab to determine the parameters such as duration, maximum and minimum root mean square voltages of a disturbance by using the fast Fourier transform analysis. Based on these parameters, a fuzzy inference system has been developed...
Automatic recognition of power quality (PQ) disturbances with regards to PQ monitoring is highly desired by both utilities and commercial customers. This paper presents the development of the intelligent power quality data analysis (IPQDA) software tool for the purpose of automatic disturbance classification. The main capabilities of the software include analysis of disturbance waveforms, classification...
This paper presents the design of a prototype distribution static compensator (D-STATCOM) for load compensation in an unbalanced distribution system. The D-STATCOM is intended to replace the widely used static VAr compensator (SVC). The compensation scheme of the D-STATCOM is derived using the symmetrical component method. In this work, the 12-pulse D-STATCOM configuration with IGBT has been designed...
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