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This paper presents an evaluation of power quality, experienced at UCSI University's North Wing Campus. A power quality recorder is installed at the main feeder switch board for 24/7 campus wide monitoring and recording. It is found from the recorded data that the university campus experiences up to 4 power quality abnormally monthly. There are voltage sags, interruptions, oscillatory transients and...
Power quality (PQ) problem is the deviation of voltage and current from their standard waveforms. Penetration of renewable energy (RE) sources such as wind and solar photovoltaic (PV) system into the utility network affects the quality of power supplied. This paper presents the detection of power quality disturbances in the distribution network with various scenarios in the presence of solar PV system...
There are difficulties in detecting low voltage ride through (LVRT) ability of offshore doubly fed induction generator (DFIG) because of complexity of sea condition. In this paper, a new scheme is put forward to solve this problem. This new scheme takes into account the effect of submarine cables on transient process of circuit, and the influence on short-circuit capacity of remote point. It proposes...
Voltage sags and switching transients are the most common power quality disturbances which affect many customers in the distribution system. Detection methods are required to quantify these aspects of the quality of the power supply. Voltage sags and switching transient which occur at higher voltages will normally spread through a utility system and will be transmitted to lower voltage systems. In...
An idea of empirical mode decomposition (EMD) with Hubert Transform (HT) as well as cross-section of smoothed pseudo Wigner-Ville distribution (SPWVD) and instantaneous distortion index (IDIN) are investigated in point of detection of high frequency inrush power quality disturbances. Application and assessment of mentioned techniques are performed using disturbances recorded by wide area power quality...
This paper presents a new method for relative location of voltage sags and capacitor switching transients based on voltage measurements only. Voltage sags caused by network faults and transients caused by bank capacitor energizing are considered in this work. The algorithm automatically operates for assessing power quality, characterising and extracting information from voltage records obtained from...
This paper presents a comparison of the performances related to compensation and transient response of active and passive power filters when operation relies on distorted mains voltages. MATLAB/Simulink models are used. Measurements acquired with a dedicated data acquisition system provided the parameters required by the real system simulation, namely a static excitation system of a power generator...
Capacitor switching transients is an important power quality concern. The power quality impact of a capacitor switching event is traditionally evaluated with the Electromagnetic transients (EMT) simulation program. This requires the creation of EMT cases for studying the event, which can be a very time consuming process. All utility companies conduct load flow and short-circuit studies for their systems...
Although capacitors provide voltage support and correct displacement power factor on power distribution lines, capacitor switching transients are the second most common power quality events, after voltage sags. Capacitor switching transients can disrupt loads that are sensitive to overvoltage sub-cycle transients, including adjustable speed drives, data communication systems and process controls....
Wind power injection into an electric grid affects the power quality due to the fluctuation nature of the wind and the comparatively new types of its generators. On the basis of measurements and norms followed according to the guidelines specified in IEC-61400 (International Electro-technical Commission) standard, the performance of the wind turbine and thereby power quality are determined. The power...
Transformers are generally energized by closing the circuit breakers at random times. Consequently, this operation generates high transient inrush currents as a result of the asymmetrical magnetic flux produced in the windings. In light of these facts, this paper presents a strategy to control the switching phenomena which occurs during power transformer inrush. The general idea consists of calculating...
Heat pumps are vitally important for achieving low carbon and renewable energy targets. There is a rapid increase in heat pump installations in the UK and Europe in the last few years for their supporting role towards green energy and demand-side management. The increase in heat pump installation prompts research work on the impact of high penetration of heat pumps on the low voltage network. This...
This work is concentrated on transfer of power quality disturbances in active distribution network containing small hydro power plants (SHP). Investigations are based on the dispersed synchronized measurements using power quality recorder installed in the two substations connected to the same medium voltage line. Dynamic aspect of SHP work represented by switching on capacitor banks are tracked in...
This paper presents an integration of S-Transform and Probabilistic Neural Network (PNN) technique for identifying the location of a switched capacitor causing a power quality problem. The transient caused by the capacitor switching is one of the important power quality (PQ) problems since it may adversely affect the system as well as sensitive loads. S-Transform has the ability to detect the disturbance...
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...
Circuit breaker switching operation will generate transient voltage and inrush current. The synchronous switching control strategies research can effectively reduce the transient effect and improve power quality. The transient operation process of vacuum circuit breaker is analyzed by deriving the system voltage and current expressions when vacuum circuit breaker switching reactive compensation capacitor...
Connecting distributed generators to the normal radial distribution system improve the power quality and increase the capacity of the electric grid. However, they disturb the radial nature of the network and thus give rise to many problems. Unintentional islanding is one of the encountered problems. In this paper a neuro-wavelet islanding detection technique has been developed. The method is based...
Identification of voltage and current disturbances is an important task in power system monitoring and protection. In this paper, a new algorithm for online characterization of a wide range of voltage disturbances based on two dimensional wavelet transformation is proposed. This algorithm is more complicated than algorithms based on one dimensional wavelet transformation, but it's more precise and...
Capacitor bank switching classification using scale selection continuous wavelet transform is an approach to develop power quality diagnostic feature to analyze the origin and possible cause of transient disturbance in the industry facility. The scale selection wavelet transform selectively perform continuous wavelet transform from scale 1 to scale 70 at the dilation interval of one per scale whereby...
In this paper, a new method is proposed for tracking and finding the location of shunt switched capacitor banks in distribution systems. The technique is based on measurement of voltage and current transients created by capacitor switching. The hypothesis states that: ??the slope of voltage and current transient waveforms created by capacitor switching immediately before and after the switching instant...
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