International Journal of Applied Power Engineering (IJAPE)
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A wide area fault detection algorithm for transmission networks equipped with series compensation units
Get PDFIn this paper, a wide area back-up protection (WABP) algorithm is presented based on phasor measurement units (PMUs) measurements placed across the transmission network. The proposed algorithm computes a selected index named as positive sequence power index (PSPI) to detect faults in the network. Firstly, the network is subdivided into back-up protection zones. For each zone, the PSPI index is computed as absolute the value of the difference between the positive sequence sent and received phasor powers across the terminals of the zone. For each zone, the PSPI is compared to a predefined threshold to detect faults. One of the contributions in this paper is the usage of mathematical formulation to set the threshold values for each zone rather than experimental trials usually used in previous literature. In addition, the algorithm doesn’t depend iterative solutions nor line parameters of the network as usually used in WABP schemes. These advantages enhance the degree of confidence in decisions of the algorithm and reduces computational burdens to trivial amount. The presented algorithm (Level-1) could be enhanced into (level-2) if PMUs are available on all buses and in such case, the faulty line could be detected directly in a single step. WSCC 9-bus system and NE 39-bus systems were considered to accomplish this study. Severe cases for series compensated lines were taken into consideration including voltage or current inversion. Simulation results emphasis on algorithm’s robustness and adaptability
Development and sizing of a grid-connected solar PV power plant for Canaanland community
Get PDFHigh costs of installation and maintenance as a result of storage units discourage the use of solar Photovoltaic system for power generation. To reduce these costs, Solar PV systems can be installed without storage units alongside conventional power generation systems. Such that the Solar systems cater for the daytime loads while the conventional generation system caters for loads at other times. This research paper explored the potential of installing Stand-Alone solar PV systems without storage to satisfy the daytime load demand of the Canaanland community. The load profile analysis of the Canaanland community was carried out from load consumption data and the solar power plants were designed based on this analysis. Simulation was carried out using the PV Syst 6.43 software and the result from the design was analyzed. The study revealed that the solar power plant will serve the daytime load of the community during the period of 10:30am-4:30pm daily satisfying the peak and base loads (5.16MW and 0.78MW) of the Canaanland community respectively
Utilization of the finite element method for the calculation and examination of underground power cable ampacity
Get PDFCurrently, the use of underground electric cables is a regular feature of present-day power transmission and distribution schemes. Issues related to economical limitations and the lack of adequate space led to the need for cables with an elevated current carrying capacity (ampacity). In order to achieve this objective, public services around the globe are focusing not only on better designs, but also on improving the level of precision in the context of cable parameter values. Precise parameter values are essential for ensuring that the replicated outcomes correspond sufficiently close to actual circumstances. While the conventional approach to ampacity calculation is through the IEC-60287 procedure, the numerical route is considered more specific and flexible. This endeavour harnesses the finite element method to conceive an innovative process for calculating the thermal field and ampacity of a cable. This process involves the crafting of a temperature field distribution model for scrutinizing temperature distribution in the region of an electric cable, and the deployment of the linear interpolation procedure for computing its ampacity. Subsequent to its formation, the model was put into operation on the underground cable 33KV XLPE
Performance and FMECA of a wind turbine based on SCADA and lidar data
Get PDFThis paper presents an approach to identify risks for different failures that could affect wind turbine performance, and reduce the measured annual electrical production (MAEP). The proposed approach is based on FMECA (failure mode, effects and criticality analysis) and wind turbine performance study. We present firstly the methodology of performance calculation based on IEC 61400 standard, then we identify the energy gap between the MAEP and WAEP for the case study, we present an extended and reviewed FMECA, by introducing definition of factors related to environment, health and security. As a result we present an actions plan for similar failures deduced from wind performance study and risk-based FMECA, in order to reduce failure risks and optimize production by consequence. The case study is a 2.3 MW onshore wind turbine, different data that are used in this paper were collected from SCADA and lidar
New studies on network frequency responses considering dynamic loads
Get PDFThe dynamic model construction of transmission network components that include generator buses, load buses and power branches, within MATLABSimulink environment is presented. The degree of frequency deviation of buses when the power of motor loads and static loads vary, is studied. Furthermore, the influence of motor loads with different inertia constants are considered in the control technique of load frequency using a PID controller. The results show that the frequency oscillation of the dynamic load is greater than the frequency oscillation of static load. Also the speed of frequency control of the dynamic load is greater than the speed of the frequency control of the static load and the inertia constants of the dynamic load has significant influence on the frequency control characteristics
A novel wavelet packet transform based fault identification procedures in HV transmission line based on current signals
Get PDFThis paper presents an adaptive fault identification algorithm bases on wavelet packet transform (WPT) for two-terminal power transmission lines. The proposed scheme performs four functions which are the fault detection, fault classification, distinguishing among the temporary and the permanent faults, and detection of the arc extinguish instant. The presented algorithm only uses the measured current at one terminal reducing the required cost. Also, it can mitigate the error resulting from the load variations via updating the presetting value. Consequently, it does not need retesting under changing the transmission system configurations. The proposed scheme is deduced in the spectral domain and depended on the application of the WPT. The db6 wavelet packet is used for decomposing the faulty phase current waveform (level 7) to get the energy coefficients. The presented algorithm is assessed under various fault conditions such as fault distances, inception angles, and faults nature via simulating different secondary arc models via using ATP/EMTP. The obtained results are investigated and evaluated
Enhancement of power system performance with wind farm disturbances
Get PDFThis paper discussed how wind farm disturbance, especially wind speed variability, can affect the performance of the power system. Also, it discussed how blades angels of wind turbine can be controlled to increase the energy efficacy of the power system. It showed that the optimized pitch angel controller using harmony search algorithm could enhance blades angels’ adjustments performance. First part, the paper explained the advantages of doubly fed induction generator in wind turbine system. Paper also enumerated the most probable ways to tame the wind speed variability challenge focusing on the pitch angle controller technique. After that, paper compared the system parameter`s result before optimization with values after optimized pitch angle controller gain (Kp). This comparison would be held in three cases, case of variable wind speed with normal operation condition, constant wind speed with line to ground fault condition and variable wind speed with line to ground fault condition. Finally, It demonstrated the MATLAB/SIMULINK model used illustrating results appeared and conclusion
A comparison study between fuzzy PWM and SVM inverter in NSMC control of stator active and reactive power control of a DFIG based wind turbine systems
Get PDFIn this work, we present a comparative study between space vector modulation (SVM) and fuzzy pulse width modulation (FPWM) technique in neuro-sliding mode control (NSMC) of stator reactive and stator active power control of the doubly fed induction generator (DFIG) for wind turbine system (WTS). Two controls approach using NSMC-SVM and NSMC-FPWM control scheme are proposed and compared. The validity of the proposed control techniques is verified by simulation tests of a DFIG. The reactive power, rotor current and stator active power is determined and compared in the above strategies. The obtained results showed that the proposed NSMC with FPWM strategy has stator reactive and active power with low powers ripples and low rotor current harmonic distortion than SVM technique
Modelling and Control Design for Energy Management of Grid Connected Hybrid PV-wind System
Get PDFThis paper deals with the control of hybrid PV-WIND power conversion structure. This paper develops a very important contribution which is the use of a single DC to DC converter, linearization of control of the three- level boost converter (TLBC) considering the imperfections of the passive components. The (TLBC) control provides balancing of capacitor voltages and maximum power operation of PV generator. For reasons of simplicity, a linearization based on the dynamic compensation of the disturbance is proposed. A sensorless maximum power point tracking (MPPT) algorithm is used to maximize a power extracted of the wind generator. The proportional relation between the rotational speed and the output voltage of the rectifier allows to use a voltage sensor to estimate the DC bus voltage reference instead of a mechanical speed sensor. The control of the three-phase inverter allows a transfer of the active power, the power factor close to the unit and thus a limitation of the reactive power injected into the grid. The external control loop performs the regulation of the common DC bus voltage while the internal control loop regulates the dq components of the currents injected into the grid. The simulation results showed the validity of the control approach. The proposed power conversion structure based on a single static converter has shown very good performance in terms of efficiency, the quality of the energy produced, complementarity between the two renewable sources and reliability. The paper ends with conclusions
Multicarrier SPWM Control Techniques for Three Phase Eleven Level Diode Clamped Multilevel Inverter and Hybrid Inverter with Reduced Number of Components
Get PDFA comparative analysis of three phase eleven level diode clamped multilevel inverter (DCMLI) and hybrid inverter is performed in this paper in which the later requires fewer carrier signals, less number of devices and gate drive circuits. The performance is evaluated using phase disposition (PD), alternate phase opposition disposition (APOD) and carrier overlapping (CO) sinusoidal pulse width modulation (SPWM) methods. The hybrid multilevel inverter has superior features over diode clamped multilevel inverters and is more efficient since the positive levels of the inverter that are generated by high frequency switches (level generation part), are reversed by low frequency switches (polarity generation part) when the voltage polarity is required to be changed for negative polarity. Therefore, the overall cost and complexity of the hybrid inverter are greatly reduced particularly for higher inverter output voltage levels. Simulation is performed for three phase eleven level diode clamped multilevel inverter and hybrid multilevel inverter using MATLAB/Simulink for induction motor load and the total harmonic distortion is evaluated at different load torques