total harmonic distortion
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Abstract As power electronics devices dependability is very significant to guarantee Multi Level Inverter (MLI) systems stable functioning, it is imperative to identify and position faults as promptly as possible. Due to the fault occurrences, the Total Harmonic Distortion (THD) on the system gets a hit. In this perspective, to improve fault diagnosis accuracy and efficient working of a Cascaded Multi level Inverter System (CHMLIS), a quick and accurate fault diagnosis strategy with an optimized training algorithm using Artificial Neural Network (ANN) is presented. Also, Total Harmonic Distortion (THD) is analyzed for each switch Fault simulated using MATLAB/Simulink and the results are presented. Results shows the efficacy of Algorithm in identifying the fault. The auxiliary cell is replaced while the fault occurs in the main cell thus making the uninterrupted working of the Multi-Level Inverter (MLI) in the Induction Motor Drive (IMD).

Because the harmonics in the production process of copper electrowinning have an important impact on the electrical energy consumption, it is necessary to suppress the harmonics effectively. In this paper, a copper electrowinning rectifier with double inverse star circuit is selected as a study object in which a large number of harmonics mainly including the 5th, 7th, 11th, and 13th harmonics are generated and injected back into the power grid. The total harmonic distortion rate of the power grid is up to 29.19% before filtering. Therefore, a method combining the induction filtering method and the active filtering method is proposed to carry out comprehensive filtering. Simulation results demonstrate that the total harmonic distortion rate of the system decreases to 4.20%, which indicates that the proposed method can track the corresponding changes of harmonics when the load changes in real time and filter them out. In order to ensure and improve the effect of active filter, a current harmonic tracking control method based on linear active disturbance rejection control is proposed. Simulation results show that the total harmonic distortion rate decreases to 3.34%, which is also lower than that of hysteresis control. Compared with the conventional single filtering method, the new filtering method combining induction filtering with active filtering based on linear active disturbance rejection control in the copper electrowinning rectifier has obvious advantages.

Abstract 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.

Penggunaan sumber tegangan non-sinusoidal atau beban non-linier pada sistem kelistrikan berdampak pada terbangkitkannya gelombang harmonisa arus. Gelombang harmonisa arus dapat mengakibatkan berbagai masalah, salah satunya adalah terjadinya kesalahan pada berbagai alat ukur yang terpasang pada sistem kelsitrikan tersebut. Dalam tulisan ini akan dibahas pengaruh gelombang harmonisa arus yang muncul sebagai akibat penggunaan beban-beban non-linier terhadap keakuratan hasil pengukuran konsumsi energi listrik oleh kWhmeter analog. Analisisnya dilakukan berdasarkan data yang diperoleh melalui pelaksanaan dua uji laboratorium berbeda yaitu pengukuran konsumsi energi listrik dengan beban linier (yang tidak menghasilkan gelombang harmonisa arus) dan pengukuran konsumsi energi listrik dengan beban non-linier (yang menghasilkan gelombang harmonisa arus dengan tingkat distorsi (total harmonic distortion, disingkat THD) berbeda. Hasil pengukuran konsumsi energi listrik dengan kWhmeter analog dan Power Quality Analyser (PQA) untuk masing-masing uji laboratorium akan dibandingkan untuk melihat perbedaannya dengan hasil pengukuran oleh PQA sebagai acuan.  karena PQA memiliki kemampuan untuk pengukuran true rms berbagai besaran listrik yang mengandung gelombang harmonisa. Analisis  terhadap data uji laboratorium menunjukkan bahwa harmonisa memiliki dampak atau pengaruh terhadap kesalahan pengukuran pemakaian energi oleh kWhmeter analog. Meski tidak meningkat secara signifikan namun semakin tinggi kandungan harmonisa arus maka akan semakin tinggi pula kesalahan pengukuran pemakaian energi listrik oleh kWhmeter analog. Lebih jauh, pengaruh harmonisa terhadap kesalahan pengukuran pemakaian energi oleh kWhmeter analog lebih signifikan untuk sistem kelistrikan tiga-fasa jika dibandingkan dengan sistem kelistrikan satu-fasa

In this paper, a single phase multifunctional integrated converter is proposed for electric vehicles (EVs) with single stage power conversion. The main objective of the proposed topology is to reduce the weight, size, and cost of the power electronic converter system used in EVs compared to the existing topologies that are already available in the industries. The novelty of the proposed topology includes: (i) single converter for charging, propulsion and regenerative braking; (ii) reduction of number of switches to reduce the switching and conduction losses; (iii) improving the efficiency by reducing the value of inductor; (iv) power factor correction for AC grid; and (v) improving the total harmonic distortion of the grid current. The complete analysis of the various modes of operation of the proposed topology is analyzed and implemented through MATLAB/Simulink software simulation and a power factor of 0.9999 and a current total harmonic distortion (THD) of 2.16% is achieved. The proposed topology is also compared with the existing topologies in terms of number of switches, diodes, inductors and capacitors used.

Abstract: The standalone grid connected Photovoltaic (PV) systems have been gradually increasing for generation of electrical energy due to ever increasing fuel and coal prices, as well as the environmental issues posed by conventional power plants. In this transition phase, power quality is at its expense, resulting in damage to equipment or appliances and lost in production. Inadequate power quality can be caused by network failures and switching operations, which primarily cause voltage dips, interruptions, transients, and network disturbances from loads which primarily produce flicker i.e., rapid voltage changes, harmonics and phase imbalance. In this paper PV is used as an external DC source for D-STATCOM (Distributed Static Synchronous Compensator) which is a FACTS device that can maintain and repair power quality limitations such as power factor correction, voltage control, load balancing and harmonic reduction. The PV-STATCOM system inverter is implemented by impending MPPT method using P&O algorithm so as to provide DC link voltage control and to improve transient response along with counteracting power quality issues. MATLAB/Simulink based simulation results are presented for the proposed PVSTATCOM model. The simulation results proves that the PV-STATCOM system has better Total Harmonic Distortion (THD) and good reactive power compensation at different irradiance levels. Keywords: Photovoltaic (PV) systems, D-STATCOM (Distributed Static Synchronous Compensator), Total Harmonic Distortion (THD), MPPT (Maximum Power Point Tracking), FACTS (Flexible AC Transmission System)

Abstract: PV systems are becoming more popular now a days, due to increase in the energy demand and it also reduces the environment pollution around the world. This paper proposes a reduced switches count of five-level H-bridge inverter with integrated boost converter in solar PV system. The proposed 5-level reduced switches count H-bridge MLI configuration requires less no.of power semiconductor devices compared to that of conventional MLI topology. In this paper INC MPPT control technique is used, which provides a duty ratio for controlling dc-dc boost converter and allowing the PV cells to operate more efficiently and extract maximum solar energy. The phase shifted sinusoidal pulse width modulation (PSCPWM) control technique is used for controlling the gating pulse of 5-level reduced switches H-bridge inverter. To improve the quality of PV based 5-level reduced switches h-bridge inverter output parameters mainly contribute switching losses and total harmonic distortion. The proposed model is modeled and simulated in MATLAB/SIMULINK software. Keywords: PV array, H-bridge multilevel inverter, boost converter, phase shifted PWM, maximum power point tracking (MPPT), incremental conductance, total harmonic distortion (THD).