Input Current Harmonic Distortion Research Articles

Switched capacitor and coupled inductor based high power factor charger for E-2/E-3 wheelers

This paper introduces a modified Zeta converter topology designed specifically for charging low voltage electric vehicles (LVEVs), enhancing performance for electric two (E-2) and electric three (E-3) wheelers. Unlike traditional Zeta converter, which offers buck-boost gain, an AC-DC converter in this study, utilizes a switched capacitor configuration to efficiently step-down voltage in a single phase, bridging the gap between the AC grid and low potential battery assemblies. This design incorporates a coupled inductor structure and operates in discontinuous inductor current mode (DICM), reducing the size of magnetic components and overall dimensions of converter and power factor correction (PFC) rectifier. DICM operation provides intrinsic PFC and minimizes switching losses, ensuring exceptional grid-side performance with unity power factor and minimal input current harmonic distortions, while maintaining an optimal battery charging profile. The meticulously developed hardware prototype, rated at 450 W, features precise component selection and carefully designed modes of operation. Performance analysis reveals a converter peak efficiency of 94.7 %, total harmonics distortion (THD) in input current at 2.7 % under rated conditions, and near unity power factor with zero phase displacement between input voltage and current.

Optimal Switching Method Using Variable Additional On-Time Control for CRM-Operated Multicell Series-Parallel Converter

Unlike the conventional boost-derived power-factor-correction (PFC) converter, the multi-cell series-parallel (MCSP) converter can step-up/step-down the output voltage. Its modular concept has a flexibility to select the voltage rating of switches depending on the number of cells. Based on its high degree-of-freedom (DOF) in combination of switching states, this paper proposes an optimal switching method that can suppress the amplitudes of switch currents while improving converter efficiency by synthesizing pentagonal inductor current waveform in critical conduction mode (CRM) control. In addition, a total harmonic distortion of input current (iTHD) is improved with variable additional on-time control. Thanks to an inherent capacitor voltage balancing feature of the MCSP converter, it does not require additional balancing control. The feasibility of the proposed control is verified by experiments in the 300 W prototype.

ПОКАЗНИКИ ЯКОСТІ ЕЛЕКТРОЕНЕРГІЇ ТА ЇХНЄ ПОЛІПШЕННЯ АКТИВНИМИ ФІЛЬТРАМИ

This article discusses power quality and the role of active filters in improving power quality. The characteristic of this article discusses power quality and the role of active filters in improving power quality. Power quality characteristics, including voltage non-sinusoidality, voltage unbalance, input current harmonic distortion and the ratio of active to full power, are considered. Various technical means of compensating reactive power and improving current and voltage spectra, including active filters, and current standards governing their requirements are considered. The benefits of active filters, such as reduced energy losses, suppression of higher harmonics, power factor correction and flicker re-duction, are described. A correct definition of apparent power is presented to justify an energy efficient control strategy for a shunt active filter to minimize power losses in the transmission line. To facilitate the distributed compensation of unbalance power, the corresponding current vector is represented by four orthogonal components, which produce separate contributions to the transmission line loss power. The use of active filters in power systems can improve power quality and ensure efficient use of electrical equipment. Ref. 14. Keywords: power quality, efficiency, technical means, active harmonic filters, nonlinear load.

An Efficient Battery Charger Control Scheme for Electric Vehicles

This work suggests a practical control scheme for a battery charger for an electric car that employs a cascade of buck converters and symmetrical bridge-less power factor-corrected converters. Both converters are increasingly common in the industrial sector thanks to their high efficiency, low price, and small size. The entire battery charging mechanism is made substantially more efficient by integrating the two converters. Furthermore, at any input voltage, this charger's design can deliver the correct battery current and voltage without ripple. In order to achieve a unity input power factor and zero input current harmonic distortion, the proposed control approach employs duty ratio feed-forward control technique in both the current and voltage control loops. In addition, a phase-locked loop (PLL) block establishes the current loop's reference, producing a pure sinusoidal input current despite the input voltage waveform's distortion. The viability and utility of the suggested approach are demonstrated using simulation and experimental data with an 110V/60Hz ac line input and a 1.5kW-72V dc output of the battery charging system.

Improved control scheme for simultaneous reduction of common-mode voltage and current harmonic distortion of the Vienna-type rectifier with balanced and unbalanced neutral-point voltages

As a non-generative-boost rectifier, the Vienna-type rectifier has been proposed and applied in several applications, such as wind power generation systems, battery charging system, etc. This paper further proposes an improved control scheme for reducing common-mode voltage (CMV) and input current harmonic distortions under balanced and unbalanced neutral-point (NP) voltages. At first, the operating fundamentals of the Vienna-type rectifier are presented. The zero-sequence voltage and its corresponding ranges are carefully derived to control the dc-link capacitor voltages separately. Considering the specific constraint of this rectifier, the zero-sequence voltage is further revised to reduce the current harmonic distortions around the zero-crossing points. Doing so, the simultaneous reduction of CMV and input current harmonic distortions can be realized, which is applicable to balanced and unbalanced NP voltages. The comparisons of the proposed scheme, the conventional zero-sequence voltage injection scheme, and the CMV reduction method under balanced NP voltage condition are conducted, which demonstrate the salient advantages of the presented scheme.

Bridgeless Isolated CUK Converter Using BLDC Motor

The CUK topology is used to propose three novel rectifiers with single phase AC-DC Power Factor Correction (PFC) without a bridge. When compared to a standard CUK Power Factor Correction rectifier, the lack of enhanced heat control and reduced conduction losses are achieved by using the current flows; there are only two semiconductor switches and one input diode bridge channel throughout each period of the switching cycles. The proposed topologies are made to operate in the mode of discontinuous conduction, resulting in a deciding element of almost unity as well as low input current Harmonic Distortion in total. Additional benefits in Discontinuous Conduction Mode operating includes zero current is switched on in the power switches, and in the output diode, zero current is turned off, as well as simplified control circuitry. The power switch can be turned on or off.

A Hybrid Control Scheme with Fast Transient and Low Harmonic for Boost PFC Converter

In this study, a new control strategy was proposed to improve transient response and the input current harmonic distortion of power factor correction (PFC) regulators operating in an average current mode. The proposed technique required only two additional gain selectors and a peak detector circuit on the feedforward voltage loop and output voltage feedback loops. It provided a direct reading for the average voltage value of feedback control loops and the peak voltage of feedforward control loops, producing PFC boost regulators with fast dynamic responses and low-input current harmonic distortion. The use of digital potentiometers for directly changing the gain of control loops did not require any divider or squarer to reduce the complexity of control circuits. The operating principles and control strategies of 300 W boost PFC with the new control strategy are presented with detailed analysis and discussion. The experimental results were satisfactory.

Power Factor Preregulation in Interleaved Luo Converter-Fed Electric Vehicle Battery Charger

This work deals with the design and implementation of a new interleaved Luo power factor preregulator (PFP)-based electric vehicle (EV) battery charger, which is suitable for low-cost and improved power quality (PQ)-based EV charging. By interleaving two Luo converter cells, the input current is divided between them, which provides reliable and efficient charging of the battery at high-power discontinuous conduction mode (DCM) operation. This reduces the switch conduction loss due to reduced device current stress and thus, the charger efficiency is improved. The interleaved Luo converter incorporates low input and output current ripple due to ripple cancellation. This charger operates in constant current mode up to certain battery state of charge (SOC). However, for higher SOC range, it maintains constant voltage charging using a flyback converter at the next stage. Two converters are designed in DCM to provide inbuilt zero current switching and circuit diodes show good reverse recovery. An inherent PF preregulation is obtained at input mains over a wide range of supply voltages as well as dc-link voltage. The total harmonic distortion of input current is obtained as per PQ regulations. Its prototype is built and tested to validate its improved performance over two-stage solutions.

Single‐stage PFC bridgeless converter

A power factor correction (PFC) charge-pump (CP) bridgeless converter for LEDs is presented. In the input stage, coupled inductors, together with CP capacitors, are integrated into a half-bridge inverter, thus characterising the single stage. This topology even being bridgeless due to the positioning of the load operates with a bus voltage below the bending voltage. The CP configuration is used to reduce the LED's current ripple. The prototype achieves an output power of 60 W with high power factor, achieving the efficiency of up to 94%, 127 Vac input, total harmonic distortion of input current, with harmonic magnitudes within the IEC 61000-3-2 standard class C the device limits and flicker in conformed with the recommendation of IEEE 1789.

Power Quality Improvement in Induction Heating System Using Vienna Rectifier Based on Hysteresis Controller

—Induction heating (IH) technology is increasingly implemented in domestic, industrial as well as medical applications in the modern era. Designing of modern IH system incorporates high frequency (HF) resonant converter that results in the generation of HF harmonics. The HF harmonics has an inherent tendency to back flow toward the supply side and deteriorates the power quality at the grid side. So, in order to mitigate this power quality issue, a single phase Vienna rectifier (1-ø VR) based IH system has been proposed. Hysteresis and pulse density modulation controller is employed in the proposed IH system. The unidirectional nature of VR protects the overall IH system from the HF harmonics. VR also improves the power factor of the input supply along with low total harmonic distortion of input current. The feasibility of the proposed IH system is validated through MATLAB/Simulink environment. Finally, an experimental prototype of 1200 W has been developed and further correlated with the simulation results to verify the uniqueness of the proposed IH system.

DSP‐based comparison of PFC control techniques applied on bridgeless converter

A comparison of fuzzy self-tuning (FST), sliding mode control (SMC) and conventional proportional-integral (PI) control methods is performed under unbalanced grid conditions using a bridgeless power factor correction (PFC) converter. The bridgeless PFC converter operates the correction of AC line current to obtain a DC output voltage without full bridge rectifier based on these control methods. These control methods generate the duty cycles to provide higher unity power factor and lower total harmonic distortion of input current, even if AC line voltage is distorted. This study focuses on the performance analysis of FST and SMC methods adaptation to the input current for the bridgeless PFC converter and comparing with the conventional PI controller. Although the SMC method is only used in the current control loop, the FST method is used in both current and voltage control loops for eliminating harmonics of input current and regulating of output voltage. The performance of control methods is evaluated with a TMS320F2812 digital signal processor. The simulation and experimental results are compatible with the limits for harmonic current emissions, IEC 61000-3-2 and show that the FST and SMC are better than the conventional PI control method and FST is superior to the SMC.

Control for Three-Phase LCL-Filter PWM Rectifier with BESS-Oriented Application

This paper deals with a battery energy storage system (BESS) in only one of its multiple operating modes, that is when the BESS is charging the battery bank and with the focus on the control scheme design for the BESS input stage, which is a three-phase LCL-filter PWM rectifier. The rectifier's main requirements comprise output voltage regulation, power factor control, and low input current harmonic distortion, even in the presence of input voltage variations. Typically, these objectives are modeled by using a dq model with its corresponding two-loop controller architecture, including an outer voltage loop and a current internal loop. This paper outlines an alternative approach to tackle the problem by using not only an input–output map linearization controller, with the aim of a single-loop current control, but also by avoiding the dq modeling. In this case, the voltage is indirectly controlled by computing the current references based on the converter power balance. The mathematical model of the three-phase LCL-filter PWM rectifier is defined based on the delta connection of the filter, which accomplishes the requirements of a 100 kW BESS module. Extensive simulation results are included to confirm the performance of the proposed closed-loop control in practical applications.

A Remotely Central Dimming System for a Large-Scale LED Lighting Network Providing High Quality Voltage and Current

Standard TRIAC-based dimmers introduce power quality issues especially for a large-scale lighting network. Other existing dimming protocols involve additional wiring systems and/or additional controllers to light emitting diode (LED) drivers. This paper proposes a central dimming system for a large penetration of LED lamps. The dimming system is remotely controlled through a webpage or a desktop application. Dimming is achieved while maintaining high voltage and current quality waveforms, which results in a high power factor and a low input current harmonic distortion. The system does not require additional wiring or specific adjustments to commercial dimmable LED drivers. The system allows scheduling a dimming profile to endorse energy saving. In the proposed dimming system, dimming function is achieved by connecting a voltage source converter (VSC) between the grid and the LED lamps. An advanced feature is added to the VSC dimmer to remotely send/receive messages between the system and the user through a graphical user interface. Thus, the user can communicate with the VSC dimmer by sending commands and receiving feedback information. The influence of communication delay on system stability is analyzed by using small signal models. A VSC dimmer prototype (500 VA/120 V) has been built with a communication module to provide remote control. Experimental results and comparisons between utilizing the TRIAC-based dimmer and the VSC dimmer for dimming function are discussed in the paper.

Flyback PFC With a Series-Pass Module in Cascode Structure for Input Current Shaping

A flyback power factor corrector (PFC) using a series-pass module (SPM) to shape its input current is presented. The input current is profiled by the SPM with its waveform controlled to be in the same wave shape and phase with the supply voltage and its magnitude controlled to regulate the output voltage. The SPM is constructed by two series-connected power semiconductor devices in a cascode structure. One of them is a high-voltage device of low on -state resistance for sharing major voltage stress, while the other one is a low-voltage device with high-output impedance for profiling the current through the SPM. The SPM has a local control for clamping the voltage across the low-voltage device. Such arrangement allows the PFC to exhibit lower total input current harmonic distortion than that using a single high-voltage series-pass device. To minimize power loss, the operating point of the low-voltage device is regulated around the boundary between its high-gain and fully turn- on operating region by adjusting the duty cycle of the main switch in the flyback converter. A 100-W 85–265-Vac/36-Vdc prototype has been built and evaluated. The conducted electromagnetic interference under different supply voltages will also be given.

Design and analysis of a simple predictive power controller for a 1.0‐kV single‐phase NPC PWM rectifier

SummaryThis paper proposes a 1‐kV single‐phase neutral point clamped (NPC) PWM rectifier with a simple predictive power controller (PPC). It includes the three‐level NPC converter and a simplified PPC. This system achieved to feature multi‐level converters and the ability to provide high voltage gain, and a control with accurate and straightforward predictive strategy without the need of PLL and PI controller. It also takes advantages of a digital delay compensator unit, a user‐friendly single‐phase three‐level space vector modulation (SVM) with neutral point balancing, and bidirectional active and reactive power flow. The proposed rectifier provides low input current harmonic distortion (THD < 2%), input sinusoidal current waveforms, zero or desired reactive power flow, fast dynamic response (=5 cycles), high stability, high efficiency, and the lower DC voltage ripple (<6%). Simulations have been carried out for a 1 kV/20 kW rectifier under different conditions. In this analysis, various practical conditions have been investigated and discussed in details. Furthermore, the proposed system was compared with the other literature and conventional methods.

A Multimode Space Vector Overmodulation Strategy for Ultrasparse Matrix Converter With Improved Fundamental Voltage Transfer Ratio

In order to increase fundamental voltage transfer ratio for ultrasparse matrix converter, a novel multimode space vector overmodulation strategy is proposed. First, the relationship among voltage transfer ratio (VTR), the output voltage harmonic distortion rate under three inverter modulation methods and the input current harmonic distortion rate under two rectifier modulation methods is analyzed. After that, according to minimum principle of output voltage and input current harmonics, the three overmodulation modes are divided: the output voltage minimum-phase-error, input current minimum-magnitude-error (MME), and output voltage MME overmodulation strategies are realized in overmodulation mode I, II, and III, respectively. The proposed multimode overmodulation strategy not only extends the maximum VTR to 1.05, but also reduces the output low-frequency harmonic voltage components of the overmodulation mode I and mode II. In addition, the harmonic components of output voltage and input current in overmodulation mode are analyzed by double Fourier integral transform method. Finally, the effectiveness of the proposed multimode overmodulation strategy and the correctness of harmonic analysis method are verified by experiments.

Current-Sensorless VSC-PFC Rectifier Control With Enhance Response to Dynamic and Sag Conditions Using a Single PI Loop

This paper presents the design, modeling, implementation, and experimental results of an advanced current-sensorless control scheme for voltage source converter–power factor correction rectifiers. This proposal is aimed to reduce the complexity of the control while maintaining desirable features for ac/dc conversion, such as unity power factor, low total harmonic distortion in input current, continuous regulation of the dc voltage even facing ac voltage sags and dynamic load changes. Unlike other proposals, this scheme has a single feedback proportional-integral loop, uses few mathematical operations, and the dq 0 reference frame is not included in the control scheme. These characteristics simplify the implementation of the proposed control thus improving its efficiency. The theoretical analysis and simulation validate the technical feasibility of the proposed control, and finally, various cases of study and experimental results obtained with a laboratory scale-down prototype are presented to confirm the viability and performance of the control.

Reduction of Input Current Harmonic Distortions and Balancing of Output Voltages of the Vienna Rectifier Under Supply Voltage Disturbances

This paper proposes a modified proportional resonant (PR) based control scheme for a three-level Vienna rectifier that reduces the input current harmonic distortion [total harmonic distortion (THD)] for harmonic contaminated and unbalanced supply voltage conditions. Low-order current harmonics that are present in the source side currents can be selectively eliminated using this proposed control strategy. In addition, the complete control technique includes the proportional integral (PI) based voltage balancing technique to balance the output voltages of the Vienna rectifier. This method includes the advantages of both hysteresis-based current control (fast transient response) and PI-based vector control (fixed frequency operation) methods. Various computational blocks such as space vector modulation (SVM) block, current/voltage transformation blocks, etc., are not necessary to implement this control method. Therefore, this scheme is relatively easy to implement using inexpensive digital controllers. A 1-kW prototype of the rectifier is built and tested in the laboratory environment using the proposed control method. The converter provides a unity power factor operation with low-current THD at the input side, balances the capacitor voltages, and tracks the voltage reference at the output side.

Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter

In order to achieve a good dynamical response of a full-bridge AC-DC voltage source converters (VSC). The bandwidth of PI controller must be relatively wide. This leads to the voltage ripple produced in the control signal, as known that its ripple frequency has twice of the line frequency and cause the 3rd harmonic of an input current. A Ripple Voltage Estimator (RVE) algorithm and Feed-Forward Compensation (FFC) algorithm are proposed and added to the conventional control. The RVE algorithm estimated the ripple signal to subtract it occurring in the voltage loop. As a result, the 3rd harmonic of the input current can be reduced, and hence the Total Harmonic Distortion of input current (THDi) are improved. In addition, the FFC algorithm will offer a better dynamical response of output voltage. The performance evaluation was conducted through the simulation and experiment at 110Vrms/50Hz of the input voltage, with a 600 W load and 250 V<sub>dc</sub> output voltage. The overall system performances are obtained as follows: the power factor at the full load is higher 0.98, the harmonic distortion at AC input power source of the converter is under control in IEC61000-3-2 class A limit, and the overall efficiency is greater than 85%.

A Family of Ripple Estimation–Cancellation Methods Based on Switched-Resistor Circuits and Their Application in Fast-Response PFC Preregulator

Power-factor-correction (PFC) preregulator commonly suffers from slow dynamic response due to the need to operate with small closed-loop bandwidth for realizing low total harmonic distortion of input current. Ripple cancellation is one of the widely adopted strategies to achieve high power factor and fast dynamic response simultaneously. The main idea is to eliminate the double-line frequency component in the sampled output voltage by means of subtracting a replica of the output voltage ripple from the sampled output voltage. In this paper, a systematic derivation and analysis of the main figures of merit of PFC preregulator incorporating ripple cancellation is presented. Based on the equations obtained, three variants of a family of ripple cancellation methods based on switched-resistor circuits are proposed. The performances of these methods are experimentally investigated and compared by implementing them in a 200-W average-current-mode-controlled boost PFC preregulator. By comparing the measured figures of merit, it is shown that near-perfect ripple cancellation is achievable when the amplitude and phase angle of the sampled output voltage ripple are estimated independently, whereas a more cost-effective solution is provided by another approach that tracks the ripple amplitude only at the expense of decreased power factor and increased total harmonic distortion.