Performance evaluation of different configurations of system with DSTATCOM using proposed Icos⁡ϕ technique

The proposed Icos⁡ϕ control technique has been applied for power quality improvement using different configurations of system with distribution static compensator (DSTATCOM). Modeling, design and control of DSTATCOM are analysed in detial. Three phase reference current are extracted with this technique. The proposed technique has been used for power factor enhancement, voltage regulation, harmonic suppression and load balancing under dynamic condition with non-linear load. The proposed control is very effective for three different configurations of system with DSTATCOM for power quality improvement. Results for each configuration of system with DSTATCOM are simulated using MATLAB/Simulink sim power tool box. For teaching the power quality course, these can also be helpful.

Real Time Sustainable Power Quality Analysis of Non-Linear Load under Symmetrical Conditions

Voltage sag is one of the most significant power quality problems in the industry and has a significant impact on induction motor safety and stability. This paper analyzes the characteristics of voltage dips in power systems and induction motors with a special emphasis on balanced dips with the help of virtual grids (regenerative grid simulator), as per IEC 61000-4-11. Three phase induction motors with 3.3 kW, 16 A coupled to a DC generator with 3.7 kW, and 7.8 A rated are considered for the test analysis. This paper aids in the development of an induction motor to achieve improved precision by taking different voltage sags into account. The experimental results benefit the design modifications of induction motors at industrial and other commercial levels of consumers regarding major power quality issues and the behavior of the induction motors. A proposed modification employing ANSYS is provided to further examine the precise performance of induction motors during sag events.

Experimental verification of DSTATCOM for various non-linear load

This paper elaborates a hybrid synchronous reference frame method has been proposed for the distribution static compensator (DSTATCOM) to enhance the compensation performance. This controller is designed in such a way that it generate the reference with respect to the change in load to reject the harmonics. Furthermore, a hysteresis controller is employed for switching pattern generation. Fuzzy logic controller is also implemented in MATLAB/simulink environment here to analyze the total harmonic distortion. Experimental analysis of the DSTATCOM demonstrates the potency and reliability of proposed controller over existing control strategy in the from of total harmonic distortion.

Performance of Neutral Point Clamped Five Level Inverter Using Space Vector Modulation Control Fed by DPC-VF-SVM Rectifier

The purpose of this paper is to develop a control and regulation method for the input DC voltage of a five level neutral point clamping (NPC) inverter feeding a induction motor. In this context, the authors propose in the first part, the control strategy of three-phase pulse width modulation rectifier, they propose the virtual flux-based direct control (DPC_VF) with vector modulation (SVM), this method is applied for the enhancement of network power quality by compensation of harmonic currents produced by an non linear load, and good regulation of DC-bus voltage. The second part of the paper is dedicated to the presentation of the model of the three phase, five-level NPC voltage source inverter with its space vector modulation (SVM) control method. The performance of the proposed strategy in terms of out-put voltage and THD has studied successfully and shown using MATLAB/Simulink.

Investigation of the Emission Higher Harmonics into the Generator Grid

The article considers a section of the grid with generator voltage busbars (GRU-10 kV) of one of the hydroelectric power plants HPP-I of a large cascade HPP, which supplies electricity to an aluminium plant via two busbars. It is described that the plant load includes converter units, including: transformers, bridge rectifier blocks and saturation chokes, which are powerful sources of harmonic disturbances. An overview of the developed model and the principles of its construction for studying the influence a powerful non-linear load on the generator is given. Analysis of the results calculations on the model showed that the load of an industrial enterprise creates current and voltage distortions in the electrical s not only of the plant itself, but also in urban grids, and on the busbars of the generator voltage HPP-I. The article analyzes the influence of the current effects of a large industrial enterprise load in asymmetric modes on hydrogenerators by evaluating torsional vibrations and tangential vibrations in generators. It is shown that tangential forces of double frequency (100 Hz) practically do not create significant vibration displacements when the natural frequency of the frontal parts basket is adjusted.

Analysis of loss on single-phase dry transformers with non-linear load

The paper studies power losses in transformers due to non-linear loads. The research aims to analyze the power loss in a single-phase dry transformer under a non-linear load. The research uses an SW43W Power supply type, FlukeView Power Quality Analyzer as a DC or AC power supply on the primary side of the transformer. The non-linear load is connected to the secondary side. The loading test of the dry transformer was carried out at non-linear loads. The load variations used 0 %; 12.5 %; 25 %; 37.5 %; 50 %; 62.5 %; 75 %; 87.5 % and 100 %, as well as variations in the THD value by adjusting the ignition angle (α). The non-linear loads used are Half-Wave Rectifier and Controlled Half-Wave Rectifier with resistive loads with variations in THD values. The results showed that the transformer losses comprised Pno load and Pload. The operation of the transformer with constant input voltage and frequency with THDv<5 % resulted in a constant Pno load value at all load values. The greater the percentage of the load, the higher the load. The increase in THD because of non-linear load will increase the load on the transformer. The value of the derating factor is obtained by connecting the increase in losses (∆PLosses), which is influenced by THD and the increase in temperature T(°C) in dry transformers. When the transformer is loaded with a non-linear load, the derating factor<1. THD and derating factor form a linear relationship, when THD increases, the derating factor value decreases. Linear load on the transformer causes a decrease in its capacity, but if it gets a non-linear load with THD=39.1 %, it can withstand a load of 84.294 %, besides the increase in total harmonic distortion will increase losses and reduce transformer capacity

Identification of the Technical Condition of Induction Motor Groups by the Total Energy Flow

The paper discusses the method of identifying the technical condition of induction motors by classifying the energy data coming from the main common power bus. The work shows the simulation results of induction motor operation. The correlation between occurring defects and current diagrams is presented. The developed simulation model is demonstrated. The general algorithm for conducting experiments is described. Five different experiments to develop an algorithm for the classification are conducted: determination of the motors number in operation with different power; determination of the motors number in operation with equal power; determination of the mode and load of induction electric motor; determination of the fault and its magnitude with regard to operation and load of induction motor; determination of the fault and its magnitude with regard to operation and load of induction motor with regard to non-linear load in the flow. The article also presents an algorithm for preprocessing data to solve the classification problem. In addition, the classification results are shown and recommendations for testing and using the classification algorithm on a real object are made.

Comparative power quality analysis of Conventional and Proposed enhance SRF SOGI-FLL control based DSTATCOM

This paper expresses about comparative power quality analysis in between conventional and proposed control techniques of DSTATCOM under different loading conditions. The goal of DSTATCOM is to reduce power quality problems, that occur due to an unbalanced load, non-linear load, power electronics based load and polluted grid. The performances of DSTATCOM are different in the different control techniques. Three conventional and one proposed control techniques have been employed in the DSTATCOM. Synchronous reference frame (SRF), Sliding mode control (SMC) and ADALINE based LMS control are the conventional techniques while enhanced SRF SOGI-FLL is the proposed technique. The control techniques of DSTATCOM have been compared in terms of load balancing, power factor enhancement, DC link voltage regulation and minimization of harmonics. These control techniques extract reference current for the PWM which generates switching pulses for the DSTATCOM. The complete H-bridge DSTATCOM system along with these control techniques have been implemented in MATLAB /Simulink platform and after execution, superior power quality features of proposed control technique has been investigated.