Power Filter Research Articles

Power Loss Analysis with Dispersed Generation in Multifunction Power Conditioner Design to Improve Power Quality

The recent modification in utilizing Multifunction Power Conditioner (MPC) such as Unified Power Quality Conditioner devices in power systems has led to different degrees of power losses, owing to electronic power impacts. This paper presents a detailed comparison of power loss analysis in various configurations of MPC, that is, the conventional unified power quality conditioner (UPQC) and the UPQC with distributed generation (〖UPQC〗_DG). The independent losses based on inverter design and distributed generation interfacing to the distribution form the basis for each configuration case. The investigation considered conventional UPQC as the base case for power losses, and the study was extended to 〖UPQC〗_DG at steady state operating condition. In all configurations, Switching Losses (SL) and conduction losses were considered using simulation studies carried out in MATLAB/SIMULINK, and the results obtained in all cases were used for comparative studies. Finally, the outcome indicates that the losses in 〖UPQC〗_DG is more than conventional UPQC based on simulation results in all cases.

Co-simulation-based conventional exergy evaluation of a hybrid energy generation-vanadium redox flow battery-air source heat pump system

A conventional exergy assessment approach permits determining the magnitudes of irreversibility that have happened within the investigated system components, which indicates the potential for improvement for these components. In this study, this approach was applied to a hybrid powered air source heat pump with vanadium redox flow battery system through co-simulated (solar photovoltaic and wind turbine) TRNSYS integrated with MATLAB Simulink) work. Due to the absence of a sophisticated VRFB model in the TRNSYS application, the battery model created in the Matlab Simulink environment was utilized and then summoned into the TRNSYS simulation studio by use of the TRNSYS utility model.Exergy destruction and exergy efficiency were used as performance criteria for evaluating the conventional exergy performance of the utilized components in the established co-simulation model. While yearly cumulative exergy destruction values ranged from 194.2 kWh for R to 23318.2 kWh for the PV field, annual average exergy efficiency amounts varied between 0.0494 for ASHP and 0.9345 for R. The PV field with the highest exergy destruction and relatively low exergy efficiency causing the highest improvement priority, but the opposite is true for power conditioning equipment, specifically IR and R.

Development of Power Conditioning Unit for KY Converter in Fuel Cell Power System

The world's growing economy and demographic advancement are driving an increase in global energy demand. As worries about carbon emissions grow and the demand for electrical energy production continues to rise, it is necessary to develop new methods of electricity production. Fuel cell energy system is one of the promising factors for addressing this problem due to its low emissions, easy accessibility, and fuel flexibility. In this paper, a mathematical model of Solid Oxide Fuel Cell (SOFC) is designed and used as an input for the KY converter. As the output voltage of the fuel cell is low, a KY Converter is desired to raise the output voltage for required applications. To regulate the electrical output voltage of the KY Converter, PID, Fuzzy Logic Controller (FLC), hybrid fuzzy PID, and an ANFIS feedback control mechanism have been simulated and investigated. The function of a fuel cell with a KY Converter, as well as state-space modelling, is developed. The Ziegler-Nichols technique is used to determine the gain parameters of a PID controller, which are Kp, Ki, and Kd. The fuel cell with a Closed-loop system of KY converter is developed using MATLAB/Simulink software. Thus, the fuel cell power system can be used for a variety of applications, including rural and military.

Research on Low-Frequency Stability under Emergency Power Supply Scheme of Photovoltaic and Battery Access Railway Traction Power Supply System

Photovoltaics and batteries can be connected to a traction power supply system through a railway power conditioner (RPC) to switch between different control strategies. This can address power quality issues or provide emergency traction for locomotives that unexpectedly lose power and even break through traditional energy barriers in the railway field, achieving a low-carbon power supply for railway energy, and a mutual backup with substations. However, methods to coordinate the control strategies of PV and the battery locomotive traction have not been clearly revealed, nor has the actual stability of the system. In this study, to address the above issues, an emergency power supply scheme is proposed for the first time that utilizes a dual-mode RPC inverter combined with a coordinated control strategy for the PV and battery, achieving the traction of locomotives. In addition, a one-dimensional impedance model was established for the PV system, battery system, locomotive (CRH3), and RPC projected onto the dq coordinate system, and the critical amplitude margin (CAM) was defined to quantitatively analyze the sensitivity and laws of different parameters concerning the low-frequency stability of the system. At the same time, impedance ratios and passive criteria were used to reveal the stability mechanism, and parameter adjustment criteria and design suggestions were put forward. Finally, the feasibility of the emergency power supply scheme of the “PV–battery locomotive network” coupling system and the correctness of the low-frequency stability study were verified using the Starsim semi-physical experiment platform.

Hybridization of Solar PV Configurations for Maximum Power Extraction Under Partial Shading Conditions

ABSTRACT In the current era, the solar-based energy demand is exponentially progressing, because of its streamlinedness towards the environment. However, an optimized version of the photo voltaic (PV) configuration is required even though there are conventional PV configurations. In the purview of an optimized PV system, vital factors that affect the performance of the PV system are the type of configuration, partial shaded conditions, the efficiency of the PV array and power conditioning units. In this paper, an optimized configuration of a PV array under different partial shaded conditions is taken as a focal point. Therefore, a hybrid configuration of the PV system has been designed for extracting maximum power, such as Bridge Link with Triple Tied Cross Link (BL-TTCL), Honey Comb with Triple Tied Cross-Link (HC-TTCL), etc. The proposed hybrid configurations are simulated in MATLAB/SIMULINK software. The performance analysis of proposed hybrid PV configurations was analysed with the conventional configurations in terms of global maximum power point, local maximum power point, open circuit voltage, short circuit current, mismatch losses, voltage and current at maximum power point and efficiency. The outcome of both conventional and hybrid PV configurations reveals that, more cross ties result in optimized PV configurations under various partial shaded conditions due to more bypass paths, but there should be trade-off/balance between capex and technical behaviour. Therefore, the hybrid configurations balance cross ties and behaviour under various partial shaded conditions.

Simultaneous enhancement of dielectric properties and temperature stability in BaTiO3‐based ceramics enabling X8R multilayer ceramic capacitor

AbstractModified BaTiO3 ceramics that possess high dielectric permittivity and acceptable temperature stability have been widely utilized as multilayer ceramic capacitors (MLCCs) for high‐frequency bypass and power filtering in automotive applications. However, since the increasing demand for high‐capacity and small‐size, high‐permittivity materials that can serve as dielectric layers in MLCCs are urgently required. In this work, we design and fabricate a special BaTiO3‐0.03Mg‐0.02Y‐0.02CaZrO3 ceramic with a high dielectric permittivity of 3000 and the dielectric variation below ±13% in the temperature range of ‐55–150°C, fulfilling the requirements of X8R capacitors. To achieve these results, we employed grain size engineering and cation doping, using BaTiO3 precursors with a particle size of 240 nm to prepare the BaTiO3‐based ceramics with fine grains, while Mg and Y co‐doping was used for improving the temperature stability due to dielectric dispersion. Utilizing these high‐permittivity BaTiO3‐based materials, we fabricated MLCCs that satisfy the X8R criterion, possessing a high dielectric constant of 2950 and a high breakdown field (410 kV/cm).

Experimental Evaluation of the Performance of One-Axis Daily Tracking and Fixed PV Module in Baghdad, Iraq

An attempt was made to evaluate the PV performance of one-axis daily tracking and fixed system for Baghdad, Iraq. Two experimental simulations were conducted on a PV module for that purpose. Measurements included incident solar radiation, load voltage and load current. The first experiment was carried out for six months of winter half of year to simulate the one-axis daily tracking. The azimuth angle was due south while the tilt angle was being set to optimum according to each day of simulation. The second experiment was done at one day to simulate the PV module of fixed angles. It is found that there is a significant power gain of 29.6% for the tracking system in respect to the fixed one. The one-axis daily tracking was much more effective near winter solstice as compared to other months. The efficiency, fill factor for the one-axis and fixed module were 5.1%, 0.57, 4% and 0.52 respectively. Finally, it is concluded that power conditioning system is needed for load matching to improve PV performance.

Design and control of LCL-type grid-tied PV power conditioning system based on inverter and grid side currents double feedback

ABSTRACT Solar energy as a limitless, clean, and cost-effective energy source could be converted to electrical power by photovoltaic cells. In this paper, a photovoltaic power conditioner, which is connected to the low voltage grid via an LCL filter, is presented. This power conditioning system supplies high-quality current and has high stability against disturbances. Since the generated PV voltage is lower than the grid voltage, a DC-DC converter is utilized. Also, DC voltage is also converted to AC by an LCL-type inverter. To ensure the resonance elimination yielded from the LCL filter, inverter and grid side currents, a double feedback strategy is employed. By considering resonance damping, stability margin, and the grid-connected requirements, a systematic design procedure for the suggested strategy is investigated to ensure the system stability in the low-voltage network. In comparison with the conventional strategies, the suggested strategy gives suitable resonance damping capability, higher marginal stability, and better grid-connected properties. Simulation results of the PV power conditioning system illustrate the accurate performance of the control system, suitable tracking of the PV array maximum power point, and high-quality current injection into the grid.

Design guides for artificial photosynthetic devices consisting of voltage-matched perovskite/silicon tandem solar-cell modules and electrochemical reactor modules

We clarified the design guides for H2- and CO-producing artificial photosynthetic devices. The combination of a voltage-matched (VM) tandem solar-cell (SC) module and an electrochemical (EC) module was adopted. The parallel-connected top and bottom SC modules, in which multiple organic–inorganic hybrid perovskite (PVK) SCs with a bandgap of 1.7 eV and crystalline-silicon SCs were connected in series, respectively, powered the EC module consisting of series-connected multiple EC reactors. It was found that the design parameters of the series connection numbers must be optimized under slightly greater solar intensity and higher temperature than the average values to minimize the mismatch between the device operating voltage and SC maximal power voltage. This is in contrast to that the annual electricity production of the VM SC module coupled with a power conditioner is not sensitive to the optimization conditions. Increases in the bandgaps of the PVK SCs do not affect the annual production significantly.

Barrier function-based adaptive terminal sliding mode control of plug-in hybrid electric vehicle with saturated control actions

Plugin hybrid electric vehicles in contrast to traditional hybrid electric vehicles (HEV) are getting enormous attention in the modern electric transportation market as they address the environmental issues, fuel economy crisis, and CO2 emission. Fuel cell-based PHEV with smart charging mechanism is an important application of the clean energy generation and storage system. There are two main subsystems in a PHEV: A hybrid energy storage system (HESS) and an integrated charging unit (ICU). In this study, an effective control strategy for the charger and HESS comprising three power sources: Fuel cell (FC), battery, and a superconducting magnetic energy storage (SMES) connected to the DC bus is presented. Due to the non-linearity of power conditioning circuits in ICU and HESS, designing a robust nonlinear controller is still a challenge. A barrier function-based adaptive terminal sliding mode controller is proposed to ensure the finite-time convergence of the output variable. It also maintains it in a predefined neighborhood of zero without overestimating the control gain and hence exhibits better dynamic performance in the presence of external disturbances of unknown upper bound. The asymptotic stability of the system has been ensured by using the Lyapunov stability criterion. Finally, the energy management algorithm in HESS using the state of charge of the battery and SMES as the decisive factor is incorporated to maintain the stability of the system under varying load conditions. The performance of the proposed controller has been compared with conventional nonlinear control techniques like adaptive terminal sliding mode control (ATSMC) and supertwisting sliding mode control (STSMC) by using MATLAB/Simulink. The performance of the system is further validated by using a C2000 Delfino F28379D MCU dual-core microcontroller with a hardware-in-the-loop (HIL) setup.

Impedance Modeling and Mechanism Analysis of Low-Frequency Oscillations in Single-Phase MMC-RPC Integrated Vehicle-Grid Coupling System

The single-phase modular multilevel converter-based railway static power conditioner (MMC-RPC) has significant advantages in governing the power quality problems in the traction power supply system. The mechanism analysis of low-frequency oscillations (LFOs) in the MMC-RPC integrated vehicle-grid coupling system when electric multiple units are put into operation is a critical issue, which has been investigated in this article. The third-order ac admittance models of single-phase MMC-RPC and vehicle rectifiers are developed for the first time. To comprehensively study the small-signal stability of the MMC-RPC integrated vehicle-grid coupling system, this article proposes a modal analysis method based on modal phase margin and parameter sensitivity and combined with the generalized Nyquist stability criterion. It is found that LFOs around 10 Hz or 48 Hz are prone to occur due to the interactions of MMC-RPC or vehicle rectifiers with the traction power grid. To reveal the LFO mechanism, dominant modes and key parameters leading to LFOs in different working scenarios are clarified, and a series of guidelines are proposed for LFO elimination. Furthermore, the effects of control loops and power flow of MMC-RPC on system stability are revealed in detail. Finally, real-time hardware-in-the-loop experimental results validate the theoretical analysis.

A QUASI-Z-SOURCE Converter Using a Single-Stage Switched-Inductor Boost DC-DC Converter

Abstract: This paper introduces a new topology, yet simple and efficient, for a grid-connected wind-solar cogeneration system. A permanent magnet synchronous generator-based full-scale wind turbine is interconnected to the utility grid. The dc-link capacitor has been utilized to directly interface a photovoltaic solar generator. No dc/dc conversion stages are required, and hence, the hybrid system is simple and efficient. Moreover, the proposed topology features an independent maximum power point tracking for both the wind and the solar generators to maximize the extraction of renewable energy. This paper presents a quasiZ-source inverter (qZSI) that is a new topology derived from the traditional Z-source inverter (ZSI). The qZSI inherits all the advantages of the ZSI, which can realize buck/boost, inversion and power conditioning in a single stage with improved reliability. In addition, the proposed qZSI has the unique advantages of lower component ratings and constant dc current from the source. All of the boost control methods that have been developed for the ZSI can be used by the qZSI. One of the more commonly used techniques is the incremental conductance method. In this paper, an improved particle swarm optimization- (IPSO-) based MPPT technique for photovoltaic system operating under varying environmental conditions is proposed. Basically, an Artificial Neural Network (ANN) based approach is utilized to automatically detect the global maximum power point of the PV array by using a preselected number of power measurements of the PV system. The approach of linearly decreasing scheme for weighting factors and cognitive and social parameters is modified. The proposed control scheme can overcome deficiency and accelerate convergence of the IPSO-based MPPT algorithm. Detailed small-signal models for the system components are developed to characterize the overall stability. The influence of the utility-grid faults on the performance of the proposed system is also investigated. Nonlinear time-domain simulation results under different operating conditions are presented to validate the effectiveness of the proposed topology.

Balancing the Active Power of a Railway Traction Power Substation with an sp-RPC

The railway system is one of the safest, most efficient, and environmentally friendly means of land transport for people and goods. However, as the demand for mobility has increased, the current railway system has shown some weaknesses, requiring an increase in catenary power in order to be able to supply power to longer trains and faster locomotives, as well as to increase rail traffic. This paper proposes a control algorithm to be implemented in a sectioning post-Rail Power Conditioner (sp-RPC). The sp-RPC is connected to the neutral section between two traction power substations (TPS). With the control algorithm, it is possible to minimize the existing unbalance of the active powers of each TPS. In a regenerative braking condition, this surplus energy can be used to assist the traction of another locomotive on the existing overhead line. In this way, it is possible to increase the capacity of the overhead line. The analysis was performed with computer models using a modular multilevel converter (MMC) topology for the sp-RPC. Quantitative results for different consumption events of the locomotives and the analysis of the response to these variations are presented.

Power Conditioning and Power Protection for Electronic Systems

Electrical energy is the most convenient form of energy, and modern society takes it for granted that it is always available by our side [...]

Solar PV fed FSVSI based Variable Speed IM Drive using ASVM Technique

This research article discloses a solar photovoltaic (SPV) fed 3-φ induction motor (IM) drive aimed at water pumping applications using a three-phase four-switch voltage source inverter (FSVSI). The inverter used has a lower number of switches, reduced gate driver circuits, less switching losses, and is less costly than the orthodox six-switch voltage source inverters (SVSI). Here, the overall system consists of two power conditioning units for duty ratio control of the DC-DC boost converter and a 3-φ FSVSI for controlling and power conversion of DC/AC at a desired level. Moreover, using a boost converter and the P&O maximum power point tracking (MPPT) algorithm, the maximum power is extracted from the SPV system. The indirect vector control (IDVC) is utilized for the IM to provide effective speed control. The SPV system output power depends upon solar irradiation. Hence, the DC voltage and currents vary according to the irradiation. Here, the constant DC-link voltage is achieved using voltage control of the inverter. The anticipated SPV-fed FSVSI IM operation is executed at different insolation stages in the MATLAB as well as validated experimentally using DSPACE DS-1104.

Decoding LoRa Collisions via Parallel Alignment

The massive connection of LoRa brings serious collision interference. Existing collision decoding methods cannot effectively deal with the adjacent collisions that occur when the collided symbols are adjacent in the frequency spectrum. The decoding features relied on by the existing methods will be corrupted by adjacent collisions. To address these issues, we propose Paralign , which is the first LoRa collision decoder supporting decoding LoRa collisions with confusing symbols via parallel alignment. The key enabling technology behind Paralign is tha there is no spectrum leakage with periodic truncation of a chirp. Paralign leverages the precise spectrum obtained by aligning the de-chirped periodic signals from each packet in parallel for spectrum filtering and power filtering. To aggregate correlation peaks in different windows of the same symbol, Paralign matches the peaks of multiple interfering windows to the interested window based on the time offset between collided packets. Moreover, a periodic truncation method is proposed to address the multiple candidate peak problem caused by side lobes of confusing symbols. We evaluate Paralign using USRP N210 in a 20-node network. Experimental results demonstrate that Paralign can significantly improve network throughput, which is over 1.46× higher than state-of-the-art methods.

Research on Coordinated Control Strategy of Energy Storage Type Railway Power Conditioner

In order to improve the power quality of high-speed railway traction power supply system and enhance the robust stability of railway power conditioner (RPC), a coordinated control strategy based on the energy storage system (ESS) integrated RPC (ESS-RPC) is proposed in this article. It is found that the dc impedance characteristics of the back-to-back system are different when the parameters of the ESS-RPC system are perturbed under conventional control, which will affect the dc voltage of the back-to-back system and then affect the power quality of the traction system. In this article, it is analyzed that the stability difference of the bidirectional power flow of ESS-RPC under parameter perturbation is due to the negative impedance of the dc terminal and the right shift of the dominant pole. After the analysis, a coordinated control strategy of ESS-RPC is proposed to solve this problem. The small-signal analysis of the ESS-RPC system under conventional control and coordinated control is carried out, respectively, and the robust stability of the two control strategies is judged by the Nyquist stability criterion. Simulation and experimental verification are carried out in the MATLAB/Simulink environment and semisimulation platform (Modeling Tech) to analyze the impact of the proposed coordinated control strategy on the power quality of the traction power supply system and verify the effectiveness and accuracy of this coordinated control strategy.

A simulated study on the performance evaluation of amorphous silicon solar PV module for temperature, irradiance and tilt angle dependence

The performance of an amorphous silicon solar PV module is tested at various irradiance levels, operation temperatures and tilt angles using a solar simulator. Electrical efficiency, V-I characteristics and power conditioning curves are generated at various solar irradiance levels of 400, 700 and 1000 W/m2, cell operation temperature range of 40 to 100°C and various panel tilt angles of 0°, 15°, 30°, 45° and 60° with horizontal. Solar equations are used to compute the maximum swing angle of the sun away from the normal position of the panel at noon (l) during different months and latitudes. Analogy between the simulated study and l (for real operation conditions) for polar mounted inclinations of PV panels, winter & summer maximization inclinations of the PV panels and south facing vertical walls/windows for different months of the year and at various latitudes is established and the effect of l on the percent reduction in maximum power produced (Pmp) by the PV solar panel is studied. The tilt angle dependence shows that the panel produces highest Pmp at l = 0° (tilt angle of the panel when the light source is normal to the panel surface). It is also observed that Pmp decreases by about 9%, 14 % and 19% when l is 15°, 30° and 45° respectively as compared to the normal position of the panel. Newton-Raphson’s technique is used to theoretically compute Imp, Vmp & Pmp and compared with the experimental values generated using the solar simulator within less than 5% deviation.

Boosting the Electrostatic MEMS Converter Output Power by Applying Three Effective Performance-Enhancing Techniques.

This current study aims to enhance the electrostatic MEMS converter performance mainly by boosting its output power. Three different techniques are applied to accomplish such performance enhancement. Firstly, the power is boosted by scaling up the technology of the converter CMOS accompanied circuit, the power conditioning, and power controlling circuits, from 0.35 µm to 0.6 µm CMOS technology. As the converter area is in the range of mm2, there are no restrictions concerning the scaling up of the accompanied converter CMOS circuits. As a result, the maximum voltage of the system for harvesting energy, Vmax, which is the most effective system constraint that greatly affects the converter's output power, increases from 8 V to 30 V. The output power of the designed and simulated converter based on the 0.6 µm technology increases from 2.1 mW to 4.5 mW. Secondly, the converter power increases by optimizing its technological parameters, the converter thickness and the converter finger width and length. Such optimization causes the converter output power to increase from 4.5 mW to 11.2 mW. Finally, the converter structure is optimized to maximize its finger length by using its wasted shuttle mass area which does not contribute to its capacitances and output power. The proposed structure increases the converter output power from 11.2 mW to 14.29 mW. Thus, the three applied performance enhancement techniques boosted the converter output power by 12.19 mW, which is a considerable enhancement in the converter performance. All simulations are carried out using COMSOL Multiphysics 5.4.

The Effects of γ-Radiation on the Physical and Electrical Properties of Silicone Encapsulation for Electronic Power Conditioners

Since the electronic power conditioner (EPC) is a crucial part of a space traveling-wave tube amplifier (STWTA), its reliability issue must be considered. The most effective way to prevent insulation breakdown is potting. Silicone elastomers are commonly used as an encapsulant for the EPC because of their good physical and electrical properties. The properties of the encapsulant and the interfaces change under the influence of γ-radiation, which may result in the failure of the potted modules. In this work, a comprehensive evaluation methodology is proposed for silicone-based potted modules, where besides physical and electrical properties, the effect of γ-radiation on the encapsulated interface is also considered. The results show that with the increase of the irradiation dose, the crosslinking density, hardness, elastic modulus, volume resistivity, dielectric constant, and storage modulus are increased by 301.6%, 76.3%, 289.7%, 396.1%, 5.0%, and 589.8%, respectively. In contrast, the elongation at break and dielectric loss factor are decreased by 83.8% and 57.8%. In addition, the tensile strength and breakdown strength first increase and then decrease, while the coefficient of thermal expansion of the interface shows the opposite trend. Since the interface bonding state does not change and the electric field strength of the tip decreases slightly with an increasing dielectric constant, the average value of the partial discharge inception voltage increased slightly.