Filter Component Values Research Articles

Design of a 22-kW Transformerless EV Charger With V2G Capabilities and Peak 99.5% Efficiency

This paper outlines the design process of a high-efficiency (99.5% peak) transformerless DC EV fast charger in conjunction with relevant UL standards on conducted harmonics and leakage current. The topology is a non-isolated transformerless design which allows for the elimination of the additional transformer volume and losses that are present in galvanically isolated topologies. Methods for calculating optimal switching frequency and inductance to minimize loss as a function of chosen switching device and power level are provided. Filter sizing and component values are chosen in conjunction with the previously determined optimal switching frequency and inductance. Heatsink design rationale are then derived. Experimental efficiency, switching waveforms, and output voltage and current quality results are provided. Industrial topology feasibility is shown through experimental adherence to relevant UL, IEC, IET, and IEEE standards.

Estimation of Output Voltage Ripple in Phase-Staggered Series-Connected Two-Quadrant Power Converters for Electromagnets in Particle Accelerators

Abstract In booster synchrotron, fast-ramped power converters (FRPCs) are used for ramping up the magnetic field of electromagnets connected in series, at a fast rate, typically 1,000s of ampere per second. In large accelerators, the number of electromagnets is large. Therefore, during ramping, the peak value of driving voltage becomes prohibitively large considering the insulation requirement of the magnets and cables. The power converter is therefore developed by connecting a suitable number of smaller voltage rated modules in series. The series-connected modules are operated in phase-staggered mode to reduce the output voltage ripple or to reduce the filtering requirement to meet the prescribed ripple voltage. Since the filter component values predominantly decide the dynamic response, the achievable small-signal bandwidth of the control loop and hence the achievable tracking accuracy of the ramping output current are essentially governed by the filter components. To optimise the filter design, quantification of overall ripple voltage is crucial, that too under the most practical conditions considering non-ideal conditions. In this paper, estimation of overall ripple voltage is performed for series-connected two-quadrant power converters (TQPCs) operating in phase-staggering mode for ideal and non-ideal conditions. Simulation and experimental verification results are shown to be in good agreement with the analytical results.

A novel approach for optimal sizing of stand-alone solar PV systems with power quality considerations

Designing reliable and cost-effective solar PV systems with compliance to national and international power quality standards is critical for their economical, efficient, and safe operation. The conventional approaches currently being used to optimally size the solar PV systems generally ignore power quality criteria during the initial design phase. This paper fills this gap by presenting a novel Genetic Algorithm (GA) based strategy to design a stand-alone solar PV system featuring optimal system size with conformance to power quality standards. MATLAB/Simulink environment was used to develop a detailed model of solar PV system, including a robust control mechanism for maximum power point tracking, battery bi-directional control, and inverter output control. An optimisation algorithm based on the single-objective GA was then designed to find the optimal PV array size, battery capacity, and the values of harmonic filter components so that the total investment cost is minimised and load demand as well as power quality criteria over the studied period are satisfied. The simulation results, corroborated with insightful discussions demonstrate that ignoring power quality criteria by selecting improper non-optimal system parameters can lead to inadmissible voltages and THD levels in the system. In contrast, the proposed design strategy can successfully devise a solar PV system that is optimally sized and complies with power quality standards.

A Seven-Switch Current-Source Inverter Using Wide Bandgap Dual-Gate Bidirectional Switches

Conventional current-source inverters (CSIs) using silicon-based reverse-blocking (RB) switches typically suffer from high conduction loss, low switching frequency, and bulky size. New bidirectional (BD) switches (also called four-quadrant switches) built from wide bandgap semiconductor materials such as gallium nitride and silicon carbide offer both reverse-voltage-blocking capability and low conduction loss that make them appealing candidates for increasing the CSIs efficiency. This article proposes a new modulation scheme for an emerging three-phase CSI topology (H7-CSI) to enable it to operate safely with BD switches to achieve higher efficiency (as much as 3%) compared to the conventional H6-CSI topology or the emerging H7-CSI using RB switch. In addition, this modulation strategy combined with the proposed H7-CSI-BD topology is capable of significantly reducing the conducted common-mode (CM) EMI up to 20 dB⋅μV. Based on this improvement, a promising CM EMI filter network consisting of a CM choke and Y-capacitor has been designed for the H7-CSI-BD topology to meet EMI standards. The required filter component values for the H7-CSI-BD topology are significantly lower than those required in conventional CSIs. Analysis, simulation, and experimental results are provided that confirm the advantages of the proposed BD switch-enabled H7-CSI over conventional H6-CSI and emerging H7-CSI topologies using RB switches.

The Design of a Low Noise, Multi-Channel Recording System for Use in Implanted Peripheral Nerve Interfaces.

In the development of implantable neural interfaces, the recording of signals from the peripheral nerves is a major challenge. Since the interference from outside the body, other biopotentials, and even random noise can be orders of magnitude larger than the neural signals, a filter network to attenuate the noise and interference is necessary. However, these networks may drastically affect the system performance, especially in recording systems with multiple electrode cuffs (MECs), where a higher number of electrodes leads to complicated circuits. This paper introduces formal analyses of the performance of two commonly used filter networks. To achieve a manageable set of design equations, the state equations of the complete system are simplified. The derived equations help the designer in the task of creating an interface network for specific applications. The noise, crosstalk and common-mode rejection ratio (CMRR) of the recording system are computed as a function of electrode impedance, filter component values and amplifier specifications. The effect of electrode mismatches as an inherent part of any multi-electrode system is also discussed, using measured data taken from a MEC implanted in a sheep. The accuracy of these analyses is then verified by simulations of the complete system. The results indicate good agreement between analytic equations and simulations. This work highlights the critical importance of understanding the effect of interface circuits on the performance of neural recording systems.

A Comprehensive Review of EMI Filter Network Architectures: Synthesis, Optimization and Comparison

This paper presents a volumetric comparison among three possible optimized three phase EMI filter structures, a three phase PFC converter used in cutting edge applications, such as avionics, space or shipboard power systems. The size minimization of each of the filter structures, described in the paper, was performed utilizing the volumetric optimization methodology proposed in the paper. This paper theoretically demonstrates the design steps for choosing the appropriate filter component values and number of filter stages to achieve the smallest volume of the DM filter stage for any given EMI filter structure. While the validation of the proposed design methodology was done through a MATLAB simulation, an experimental verification was also performed by designing and comparing the optimized EMI filter structures for a 2.3 kW proof-of-concept of a three-phase boost PFC converter for more electric aircraft (MEA) applications to comply with the stringent EMI requirements of the DO-160F standard.

DRLA: Dimensionality ranking in learning automata and its application on designing analog active filters

In this paper, a learning automata (LA) method is introduced based on dimensionality ranking (called DRLA), and its application for designing analog active filters is investigated. The basic idea in the DRLA is that the number of iterations and ordering selection of dimensions for the next phase is according to effect of each dimension in the fitness improvement of the current phase or previous phases. This strategy improves the exploration of search space and escaping the local minimums. Also, to achieve the proper balance in exploration and exploitation, the control parameter τ is changed by a linear control manner. To validate the applicability, accuracy, and performance of the proposed approach, it is first evaluated on 23 benchmark functions and then, as a new application of LA, applied to the optimal design of two different analog active filter topologies as real-world engineering problems. The filter component values are estimated within E96 series for resistors and capacitors, and a single-objective function is also considered as average quality factors deviation and cut-off frequency deviation. Simulation results compared to some rival single-objective metaheuristic optimization methods reveal that the improved method has competitive performance in terms of fitness, convergence, statistical analyses, box plot, and bode curve as well as runtime.

Reliability and Performance Improvement of PUC Converter Using a New Single-Carrier Sensor-Less PWM Method With Pseudo Reference Functions

A new single-carrier sensor-less pulsewidth modulation (PWM) method using suggested pseudo reference functions is proposed for packed U-cell (PUC) converter to improve performance and reliability of the PUC converter. It is composed of one PWM carrier signal and two suggested pseudo reference functions. By employing the proposed modulation method, the PUC dc capacitor voltage ripple is substantially decreased, and faster sensor-less capacitor voltage balancing is obtained. Moreover, the power losses are evenly distributed among all power switches. Consequently, notable reduction of the PUC dc capacitor voltage ripple and even distribution of the power loss among switches enhance the PUC converter's reliability and lifetime. In addition, odd multiples of the switching harmonic clusters are eliminated from the output voltage; thus, the values of output passive filter components are halved. Hence, applying the proposed single-carrier sensor-less PWM method remarkably improves the performance, power density, reliability, and lifetime of the PUC converter and notably simplifies implementation of the switching pattern. Provided experimental results and comparisons as well as reliability analysis verify the viability and effectiveness of the proposed PWM method.

Design approach and performance analysis of trap filter for three-phase PV grid integration systems using evolutionary search algorithms

The main objective of this article is to provide an efficient design approach of passive grid filters based on evolutionary search algorithms. The case study is conducted on a passive trap filter (one of modern high order passive filters that can provide better performance compared with first order scheme) to be incorporated with a three-phase grid-tied inverter fed from PV array and a battery bank, forming a typical PV grid integration system. The filter design approach is mainly based on particle swarm optimization technique (PSO) as one of the efficient evolutionary search algorithms meanwhile Genetic Algorithm (GA) has been utilized as well for comparison purposes. The developed PSO algorithm searches for the optimum numerical values of filter passive components that can optimize a customized objective function of multiple terms. Unlike single-term objective function, the adopted approach has the advantage of involving multiple items in the customized objective function, such as harmonic attenuation factor and the numerical values of passive filter elements to be minimized. Moreover, the evolutionary search-based design approach is characterized by offering several groups of solutions for the same optimization problem. Thus, the obtained solution is not unique. Consequently, the choice between those solutions depends on the system designers who can select the most convenient solution among several alternatives based on component availability in market, the overall cost of the filter and the desired upper limit of THD of grid currents. The obtained results of this study demonstrate also the capability of evolutionary search approach to get optimum values of filter components that achieve good harmonic attenuation and satisfy the related grid codes such as the IEEE standard 519. Compared with traditional filter design method, the obtained results indicate that the PSO technique achieves lower numerical values of filter parameters in the most of parameters, resulting in an overall reduction in the size and cost of the passive grid filter. In addition, the employed GA succeeded to provide satisfactory numerical values of trap filter as well. However, the PSO technique is better than GA in several terms such as lower final value of objective function and lower numerical values of filter elements and convergence to the optimal solution(s) irrespective the initial guess values.Matlab® has been employed as a simulation platform for PSO and GA algorithms. While the overall grid integration system has been modelled and studied using professional version of PSIM software®.

The design of multiple feedback topology Chebyshev low-pass active filter with average differential evolution algorithm

This study presents the design of a tenth-order multiple feedback Chebyshev low-pass filter (MF-C-LPF). Component selection and gain calculation of filters are generally achieved over long periods of time using traditional methods. For 1-dB and 3-dB gains, the component values of the filter were optimized for both continuous and discrete values using four different metaheuristic algorithms. In the first case where continuous values were used, component values were accepted as ideal and unlimited in order to minimize gains. In the second case, industrial E196 series component values were used to transform the design problem into a discrete optimization problem. In this case where the design problem became more complex, the performance of the metaheuristic algorithms was compared. The literature review shows that this study is the first attempt to design a 10th-order MF-C-LPF for E196 series values. The average differential evolution algorithm is proposed to determine the optimal component values of the tenth-order MF-C-LPF. The performance of the proposed method was compared with three commonly used algorithms (PSO, CSS and DE). The optimal filter component values and quality factors (Q) were presented for each stage. We believe that the quality factor values will be a reference for future studies.

Multi-objective design approach of passive filters for single-phase distributed energy grid integration systems using particle swarm optimization

This article presents a non-conventional design approach of high order passive filters incorporated with distributed energy grid integration systems based on particle swarm optimization (PSO) as one of multi-objective evolutionary search algorithms. Two topologies of passive grid filters (third order passive damped LCL-filter and trap filter) are chosen as case studies. The presented grid filter design is based searching the optimum values of filter passive elements that can optimize an objective function composed of several terms such as harmonic attenuation factor and size (value) of passive elements (inductors and capacitors). The employed multi-objective design approach has three main advantages: (1) The PSO algorithm offers several groups of solutions to the same optimization problem. Accordingly, the most convenient solution can be chosen based on several factors such as cost of realization, availability in the market and the corresponding THD of grid current. (2) Multi-objective design approach is flexible enough to include other factors in the customized objective function to achieve different design criteria in accordance with new (or updated) versions of grid codes. (3) The PSO algorithm converges to the optimum solution(s) regardless the initial search values (initial guess). Consequently, the algorithm does not need any prior knowledge about filter numerical valuesThe PSO algorithm has been developed in Matlab®, while the overall hardware grid-integration system has been modeled and studied using PSIM® software package. The obtained results demonstrate the effectiveness of the proposed approach to get practical and applicable values of filter components that result in good harmonic attenuation and satisfy the related codes of grid integration such as the IEEE standard 519.The main contribution of this paper is the utilization of evolutionary optimization technique to achieve an optimum design of passive grid filters that can optimize simultaneously several contradictory goals such as achieving the maximum possible harmonic attenuation at the lowest possible filter size. Compared with conventional design approach, the PSO-based filter design approach results in lower numerical values of filter components, which leads to considerable reduction in the size and cost of the passive grid filter. Moreover, grid filter design based on evolutionary search approach permits accommodation of several design criteria in the customized objective function with arbitrary weighting factors upon system design requests and new grid codes constrains.

A hybrid genetic algorithm for analog active filter component selection

Analog filters are circuits that process electrical signals on a frequency-dependent basis. Analog filter circuits can be implemented using resistors, capacitors and inductors and they can also be implemented with only resistors and capacitors with the use of active circuit equipments. The selection of optimum component values is difficult because of the number of possible filter combinations. This paper presents an effective algorithm that hybridizes the Genetic Algorithm (GA) to form a Hybrid Genetic Algorithm (HGA) and proposes the use of Tabu Search (TS) for the analog active filter component selection. The GA has a powerful global searching ability and so is used to perform exploitation and because TS also has good local searching ability, it too is applied to perform exploitation. Thus, the proposed HGA will have very good searching ability. In this study, a band-pass Sallen-Key filter circuit was used, and the filter component values were found using HGA with LabVIEW. The results are compared to other reported state-of-the-art algorithms, such as the artificial bee colony (ABC) and differential evaluation (DE) to demonstrate the effectiveness and efficiency of the developed method. It can be said that the developed LabVIEW based HGA gives satisfactory results with regard to amplitude response, the minimum fitness values and the computational time.

Modulation Components and Genetic Algorithm for Speaker Recognition System

In this paper, the aim is to investigate weather or not that changing the filter-bank components (of the speaker recognition system) could improve the system performance in identifying the speaker. The filter is composed of 30 Gamatone filter channels. First, the channels are mel distributed of the frequency line. Then the components´values (center frequencies and bandwidths) changes with each run. Genetic algorithm (GA) is adopted to improve the filter component values that, in a result, improve the system performance. At each GA run, a new set of filter components will be generated that aimed to improve the performance comparing with the previous run. This will continue until the system reach to the maximum accuracy or the GA reach to its limits. Results show that the system will be improved at each run, however, different words might response differently to the system filter changing. Also, in terms of additive noise, the results show that although the digits affected differently by the noise, the system still get improving with reach GA run.

An Ultralow Loss Inductorless $dv/dt$ Filter Concept for Medium-Power Voltage Source Motor Drive Converters With SiC Devices

In this paper, a novel $dv/dt$ filter is presented targeted for 100-kW to 1-MW voltage source converters using silicon carbide (SiC) power devices. This concept uses the stray inductance between the power device and the converter output as a filter component in combination with an additional small RC -link. Hence, a lossy, bulky, and costly filter inductor is avoided and the resulting output $dv/dt$ is limited to 5–10 kV/ $\mu$ s independent of the output current and switching speed of the SiC devices. As a consequence, loads with $dv/dt$ constraints, e.g., motor drives can be fed from SiC devices enabling full utilization of their high switching speed. Moreover, a filter-model is proposed for the selection of filter component values for a certain $dv/dt$ requirement. Finally, results are shown using a 300-A 1700-V SiC metal–oxide–semiconductor field-effect transistor ( mosfet ). These results show that the converter output $dv/dt$ can be limited to 7.5 kV/ $\mu$ s even though values up to 47 kV/ $\mu$ s were measured across the SiC mosfet module. Hence, the total switching losses, including the filter losses, are verified to be three times lower compared to when the mosfet $dv/dt$ was slowed down by adjusting the gate driver.

Design and Control of a Grid-Connected Interleaved Inverter

This paper is concerned with the design and control of a three-phase voltage source grid-connected interleaved inverter. This topology enables the use of low-current devices capable of switching at high frequency, which together with the ripple cancelation feature reduces the size of the output filter and the inverter considerably compared to an equivalent classical two-level voltage source inverter with an LCL output filter using high-current devices with considerably lower switching frequency. Due to its higher switching frequency and low-filter component values, the interleaved inverter also has a much higher bandwidth than the classical inverter, which improves grid voltage harmonics disturbance rejection and increases the speed of response of the inverter and its capability to ride through grid disturbance (e.g., voltage sags and swells). The paper discusses the selection of the number of channels and the filter component values of the interleaved inverter. The design of the digital control system is then discussed in detail. Simulation and practical results are presented to validate the design and demonstrate its capabilities.

Systematic Design Centering of Continuous Time Oversampling Converters

We address the practical problem of determining the loop filter component values in a single-loop continuous-time delta sigma modulator. Conventional techniques to design center the converter to achieve a desired noise transfer function are cumbersome and not numerically stable. We present a robust procedure that can be used to determine the loop filter coefficients when real opamps (with finite gain, arbitrary Digital to Analog Converter (DAC) pulse, and multiple internal poles/zeros) are used. The method can also account for excess loop delay. We illustrate our technique with second-order low-pass and fourth-order bandpass examples.

Continuous-Time Digital Controller for High-Frequency DC-DC Converters

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper introduces a voltage mode digital controller for low-power high-frequency dc-dc switch-mode power supplies (SMPS) that has fast transient response, approaching physical limitations of a given power stage. In steady state, the controller operates as a conventional pulsewidth modulation regulator and during transients it utilizes a novel fast voltage recovery mechanism, based on real-time processing of the output voltage in digital domain. This continuous-time digital signal processing mechanism is implemented with a very simple processor consisting of a set of asynchronous comparators, delay cells, and combinatorial logic. To eliminate the need for current measurement and calculate the optimal switching sequence of the power stage transistors, the processor performs a capacitor charge balance algorithm, which is based on the detection of the output voltage peak/valley point. The effectiveness of the controller is demonstrated on an experimental 5 W, 5 V to 1.8 V, 400 kHz buck converter. The converter recovers from load transients through a single on-off action of the power switch, virtually reaching the shortest possible time, limited by the values of the power stage filter components only. </para>

Power Line Filter Design for Conducted Electromagnetic Interference Using Time-Domain Measurements

A time-domain technique for the design of passive power line conducted electromagnetic interference (EMI) filters in the frequency range 150 kHz-30 MHz is described. A digital storage oscilloscope (DSO) with adequate sampling, storing and processing features is sufficient for the design using the proposed technique. Accordingly, Agilent's Infiniium Oscilloscope (Model 54810A) has been used. The signals from LISN are directly fed into the two channels of the DSO where they are added and subtracted to separate the CM and DM components, thereby eliminating the need for common-mode-differential mode (CM-DM) separator. These components are stored in the DSO. A specially designed filter design software (FDS), residing in the DSO, estimates the noise spectrum by computing the Bartlett and Welch periodograms. It also computes the filter component values. Thus, the sampling of the conducted noise, separation of CM and DM components, signal processing, and filter value computations are all done using one DSO. A spectrum analyzer is not required. Bartlett periodograms have been preferred over Welch periodograms due to low memory storage requirements of the former. The proposed technique has been applied to the design of power line filter for a switched mode power supply (SMPS), and satisfactory results have been obtained. The proposed measurement scheme is compact, economical, and convenient. All the details of this work are presented

Bandwidth enhancement for transimpedance amplifiers

A technique for bandwidth enhancement of a given amplifier is presented. Adding several interstage passive matching networks enables the control of transfer function and frequency response behavior. Parasitic capacitances of cascaded gain stages are isolated from each other and absorbed into passive networks. A simplified design procedure, using well-known low-pass filter component values, is introduced. To demonstrate the feasibility of the method, a CMOS transimpedance amplifier (TIA) is implemented in a 0.18-/spl mu/m BiCMOS technology. It achieves 3 dB bandwidth of 9.2 GHz in the presence of a 0.5-pF photodiode capacitance. This corresponds to a bandwidth enhancement ratio of 2.4 over the amplifier without the additional passive networks. The transresistance gain is 54 dB/spl Omega/, while drawing 55 mA from a 2.5-V supply. The input sensitivity of the TIA is -18 dBm for a bit error rate of 10/sup -12/.

A new space-vector-based control method for UPS systems powering nonlinear and unbalanced loads

In this paper, a new real-time space-vector-based control strategy is presented for three-phase uninterruptible power supply systems powering nonlinear and unbalanced loads. The proposed control strategy generates the inverter reference and gating signals in closed loop and guarantees high-quality output voltages at the load terminals. The approach, which is implemented on a digital signal processor, adapts to a wide variation of nonlinear and unbalanced load conditions without specific knowledge of the output filter (L-C) component values. Analysis and experimental results on a 10-kVA prototype are presented. The results show that the output voltage is restored at heavy nonlinear and unbalanced load.