Harmonic Power Research Articles

Orthogonal-Frequency Simultaneous Wireless Power and Data Transfer for High-Power Wireless EV Charging

In a simultaneous wireless power and data transfer (SWPDT) system using common coils, achieving high-speed communication in high-power wireless charging systems is challenging due to power transfer interference on communication. Based on high-frequency data carrier-based SWPDT (HFDC-SWPDT) technology, this paper proposes an orthogonal-frequency simultaneous wireless power and data transfer (OF-SWPDT) method to minimize interference where the data carrier frequency is orthogonal to the power carrier frequency and its harmonics. In addition, a guard band is inserted between the spectra of power harmonics and data in order to further separate the power and data spectra. Thus, a high-power, high-speed SWPDT system is achieved. Finally, an 11 kW prototype with 64.125 kbps full-duplex communication is developed to validate the proposed method.

Integration of electric vehicle into smart grid: a meta heuristic algorithm for energy management between V2G and G2V

Recently, Electric Vehicles (EV) have been providing fast response and substantial progress in the power generation model. Further, EVs are exploited as adaptable Energy Storage Systems (ESSs) and show a promising performance in ancillary service markets to increase the demand of Smart Grid (SG) integration. The expansion of Vehicle-to-Grid concept has created an extra power source when renewable energy sources are not available. Yet, numerous operational problems still are required to be considered for EV implementation to turn out to be extensive. Even the development of Photo-Voltaic (PV) technology creates a problem in SGs when used for EV charging. Because of this, the Energy Management System (EMS) is required to handle charging requirements and deal with the intermittent generation. Here, in this research, an Improved Honey Badger algorithm (IHBA) is proposed for integrating SGs with EV parking lot, solar panels, and dynamic loads at the Point of Common Coupling (PCC). The proposed IHBA uses a dynamic programming method to optimize the charging Grid-to-Vehicle (G2V) or discharging Vehicle-to-Grid (V2G) profiles of the EVs using the forecasts of PV generation. This algorithm considers user preferences while also lowering reliance on the grid and maximizing SG effectiveness. The study’s findings show that the Honey Badger method is efficient in resolving issues involving large search spaces. The developed method is used to optimize charging and discharging of EV which is tested in MATLAB to obtain a stable load profile. From the evaluation of obtained results, it is evident that the IHBA controller outperforms the WOA and EHO controllers in terms of total harmonic distortion voltage (3.12%), power loss (0.197 kW) and efficiency (98.47%).

NOVEL SHUNT ACTIVE POWER FILTER BASED ON NINE-LEVEL NPC INVERTER USING MC-LSPWM MODULATION STRATEGY

This paper presents a novel shunt active power filter (Shunt APF) system based on a nine-level neutral point clamped (NPC) inverter, which can reduce current harmonics under various nonlinear loads. These loads can introduce harmonic currents within the system, which causes excessive power losses and alters the voltage systems' characteristics. Today, multi-level inverters are more suitable for high-voltage applications; their advantages are low harmonic distortions, low switching losses, low electromagnetic interference, and low acoustic noise. The reference signals required to compensate harmonic currents use the synchronous detection method (SDM) with phase disposition sinusoidal pulse width modulation (PD-SPWM) control due to its low complexity and superior performance. The proposed shunt APF configuration simulation is evaluated using MATLAB-Simulink and SimPowerSystem environment with inductive and capacitive non-linear loads. The simulation results show the efficiency of the proposed shunt APF in terms of harmonic compensation and power quality improvement. The results of comparative studies with other less multi-level inverters confirm the superiority of the proposed shunt APF system.

Stability Analysis of Input-Series/Output-Parallel Solid-State Transformers Equipped With Second-Order Harmonic Active Power Filters

Stability Analysis of Input-Series/Output-Parallel Solid-State Transformers Equipped With Second-Order Harmonic Active Power Filters

Interval harmonic power flow for microgrids: an approach using the second-order Taylor series

Interval harmonic power flow for microgrids: an approach using the second-order Taylor series

Harmonic suppression control strategy of distribution networks based on the distributed power flow controller

New energy and multiple loads, such as distributed wind–solar storage and charging, are connected to the distribution network through power electronic converters, which increases the harmonic content in the distribution network and causes operational safety risks. In this paper, the mathematical model of harmonic current and harmonic power content in a distribution network is constructed by an equivalent circuit and vector diagram. The distributed power flow controller is proposed for harmonic control of the distribution network. The mathematical expressions of the harmonic current and harmonic power based on a distributed power flow controller are constructed, and the control strategy of the distributed power flow controller for harmonic control is proposed. The simulation results show that the proposed method can effectively suppress the fifth and seventh harmonics of the distribution network.

Upper control limit calculation for bad data detection in spatiotemporal power quality massive data and its application to harmonic load flow study

The current monitoring of modern distribution networks by operators with the aim to improve the network visibility and thus detect and mitigate challenges such as power quality issues has resulted in massive data generation. Such data need to be analysed and technical observations realised. Thus, this paper presents bad data detection for spatiotemporal harmonic power quality field measurements obtained from six power quality analysers (installed at the connection points of customer-owned photovoltaic and small-scale energy storage and the mains units) with high level of granularity (1s interval). A total of 4.1 billion measured values have been evaluated in the bad data detection. Multivariate statistical methods (principal component analysis and Hotelling’s T2 statistic) have been combined with Bag of Little Bootstrap (BLB) to analyse the massive data. Specifically, the BLB technique has been deployed for calculating the upper control limit for the bad data detection, thus, the spatiotemporal nature of the data has been fully captured. The method has been applied to harmonic load flow analysis of a practical distribution network. The findings reveal how the neglect of spatiotemporality could conceal the actual harmonic penetration levels in a data-driven harmonic load flow analysis. Other interesting technical findings are presented.

Improvised direct torque control of a permanent magnet synchronous motor

Permanent magnet synchronous motor (PMSM) is widely used in different applications because of their different key operation features. But despite having important key features, PMSM suffers from torque ripple when simple control techniques like direct torque control (DTC) are employed. Several approaches have been raised by many researchers to lessen the ripple when DTC is used for controlling the PMSM drive. In this work, duty ratio-optimized DTC control, which has the same simplicity as conventional DTC (CDTC), and delay compensation for input signal prediction are proposed. In the proposed system, to determine the duty ratio, slope manipulation was made by considering the minimization of torque error and forcing the developed torque to be equal to the reference torque at the end of the span. An online slope determination approach was employed to compute the duty ratio. MATLAB 2021b is used for simulation purposes. The dynamics and steady-state performance of the proposed scheme were tested for both variable-load and variable-speed operations. In addition, the harmonic performance and ratio of harmonic power loss to total active power loss of the motor were evaluated. In general, the proposed scheme performs effectively in reducing steady-state ripple and harmonic.

Enhancing Power Quality with PDO-FOPID Controller in Unified Power Quality Conditioner for Grid-Connected Hybrid Renewables

Addressing the pressing research problem of power fluctuations and grid harmonics in the integration of renewable energy, our  proposed control strategy utilizes the Prairie Dog Optimization Fractional Order Proportional Integral Derivative (PDO-FOPID) controller  within a Unified Power Quality Conditioner (UPQC) system. This innovative approach is tailored to mitigate harmonics and meet load  requirements in grid-connected hybrid renewables. The UPQC system is instrumental in regulating coupling point voltage, countering  voltage and current harmonics to enhance overall power quality. The PDO-FOPID controller dynamically adapts control parameters to system dynamics and load changes, ensuring a stable power supply despite the variability of renewable sources. Simulations in MATLAB/ Simulink confirm its superiority over traditional control strategies, such as PI, sliding mode, and fuzzy control, in harmonics mitigation,  load fulfilment, and power stability. By effectively addressing these challenges, our proposed solution not only contributes to resolving a  critical research problem but also advances the seamless integration of Hybrid Renewable Energy Sources (HRES) into power systems,  thereby enhancing overall grid performance and the efficacy of renewable energy integration. 

Design of a 16–bit 500 MS s–1 SAR-ADC at 45 nm for low power and high frequency applications

This study gives a thorough analysis of the performance of a 45 nm CMOS process-designed 16-bit 500 MS/s successive approximation register analog-to-digital converter (SAR-ADC). 16-bit R-2R DAC double-tail dynamic latch, Widlar current method, variable body-biasing technique, sample and hold block, 16-bit SAR, and 16-bit latch are used to design proposed SAR-ADC block. The SAR-ADC design and simulations were carried out using Cadence Virtuoso software. This powerful electronic design automation (EDA) tool facilitated the design, layout, and simulation of the ADC, ensuring a comprehensive analysis of its performance characteristics. MATLAB was used for post-simulation data analysis, processing, and visualization. The proposed SAR-ADC is compared with few existing examples listed as ADS8881, LTC2380–16, ADS8344, LTC2368, and MAX11156 on the performance metrics including signal-to-noise ratio (SNR), figure of merit (FOM), total harmonic distortion (THD), resolution, delay, power consumption and figure of Merit (FOM). This work is highlighting different aspects of the suggested architecture and demonstrates how it outperforms benchmark of ADCs in terms of power usage, SNR, THD, and FOM. A SAR-ADC attains a power consumption of 39.2 μW while operating at sampling frequency of 500 MS s–1 at supply voltage of 1 V. The results provide fresh perspectives for potential improvements in existing work in terms of reduction in power consumption and high-speed ADC at 16-bit resolution and also Jitter is scrutinized across various stages of the SAR-ADC. The proposed low power, high speed and high-resolution SAR ADC is targeted for high-quality analog-to-digital signal conversion useful in industrial automation systems, medical devices, IoT and audio processing modules.

Power harvesting enhancement from PV array and power quality improvement in grid connected PV interleaved inverter using hybrid LSE-WHO approach

In this manuscript, a hybrid approach is proposed for multi-functional grid connected photovoltaic (PV) interleaved inverter using power quality(PQ) enhancement. The proposed method is the integration of Spherical Evolution Search Algorithm (LSE) and Wild Horse Optimizer (WHO), thus it is called LSE-WHO method. The key objective of the proposed method lessens the DC voltage fluctuation and enhances the PQ. At the grid side, the interleaved inverter is used and it consists of 4 legs and every leg has a power electronic switch and a diode. Because of the structure of interleaved inverter, the shoot-through effect overcomes. The system performance is improved by the utilization of interleaved inverter. The operation of proposed method is divided into 2 parts, like harmonics reduction and power harvesting. The LSE method is used to improve the maximal power of photovoltaic and the WHO method is used to lessen the harmonics distortion and eliminated the DC-link voltage fluctuation by double band hysteresis current controller (DBHCC). The switching losses are low because the DBHCC gives lesser switching frequency. Then, the LSE-WHO method is done in MATLAB, and its performance is compared to the existing methods. From the simulation, it conclude that the LSE-WHO method provides the THD as 2.12% and improves the PQ.

Calculation of probabilistic harmonic power flow based on improved three-point estimation method and maximum entropy as distributed generators access to distribution network

Uncertainty and volatility are the features of distributed generation (DG), which can impact greatly on the operational status of distribution network. Thus, an improved three-point estimation method and maximum entropy theory (ITPEM&ME) for calculating the probabilistic harmonic power flow in distribution network is proposed in this study. Firstly, the probabilistic model is constructed according to the uncertainty of input variables and the improved three-point estimate method is utilized to convert a probabilistic problem into a deterministic problem. Secondly, in order to obtain the distribution of the random harmonics in distribution network, the maximum entropy theory is adopted to reconstruct the statistical characteristics after the deterministic calculation is realized for each harmonic voltages. The case of an IEEE-33 system under various conditions is conducted. The results by the different algorithms indicate that the proposed method ITPEM&ME has a smaller error than the traditional method, as well as the fitting effect of the probability density function (PDF) is much closer to the practical engineering. It is feasible and accurate in dealing with probabilistic harmonic power flow problems.

Design analysis of intelligent controller to minimize harmonic distortion and power loss of wind energy conversion system (grid connected)

<p>The controlling of internal parametric variations in addition to the non-linearity of a large conversion system of wind energy (WECS) is prime challenges to make the most of the generated energy, with less power loss and secure the proficiency (η) integration conventional grid. An adjustable speed control structure of grid-connected conversion system of wind energy (WECS), with the help of a Permanent Magnet Type Synchronous Generator with intelligent controller minimizes the power loss. The control system incorporates a pair of controllers dedicated to the converters of both the generator and grid edge. The controller at the generator side has the main function is to optimize power that can be withdrawal from the wind by intelligently regulating the turbine’s rotational speed. Meanwhile, the grid edge converter effectively manages active and reactive power by manipulating the d & q-axis current components, respectively. This paper discusses about the improvement in performance of the system when using Neuro-Fuzzy system as compared to Neural Network and Management of energy deliver system via direct control method. The findings reveal that the training time for Artificial Neural Networks (ANNs) is substantial, leading to the Neural Network-Direct Power Contol (NN-DPC) approach being the slowest option among the alternatives. Additionally, the NF-DPC system is less time-consuming than the NN-DPC, with a recorded duration of 24 seconds compared to the NN-DPC’s observation of 8 min and 5 s. However, it is worth noting that the NF-DPC system is somewhat more time-intensive than Common-Direct Power Contol (C-DPC).</p>

Spectral Engineering for Optimal Signal Performance in the Microwave SQUID Multiplexer

AbstractWe describe a technique to optimize the dynamic performance of microwave SQUID multiplexer (µMUX)-based systems. These systems proved to be adequate for reading out multiple cryogenic detectors simultaneously. However, the requirement for denser detector arrays to increase the sensitivity of scientific experiments makes its design a challenge. When modifying the readout power, there is a trade-off between decreasing the signal-to-noise ratio (SNR) and boosting the nonlinearities of the active devices. The latter is characterized by the spurious free dynamic range (SFDR) parameter and manifests as an increment in the intermodulation products and harmonics power. We estimate the optimal spectral location of the SQUID signal containing the detector information for different channels. Through the technique, what we refer to as Spectral Engineering, it is possible to minimize the SNR degradation while maximizing the SFDR of the detector signal, thus, overcoming the trade-off.

Alternative Performance Indices-Based Control Technique for a Unity Power Factor Three-Phase Rectifier

The implementation of a unity power factor (UPF) three-phase rectifier has the potential to enhance the power factor (PF). However, the PF and total harmonic distortion (THD) experience degradation in low-output regions due to the utilization of a “critical input inductor” under rated load conditions. In this study, an analysis of the operation principle of a UPF three-phase rectifier is conducted and a reference compensation current technique based on alternative performance indices is proposed. The optimal control algorithm is utilized to calculate the single harmonic phase delay of each phase and determine the compensator gain, taking into account factors such as the single harmonic distortion limit, THD limit, PF, and active power consumption. The output of the current compensator serves as the desired current source, which in turn drives the bidirectional switches. The simulation and experimental results demonstrate that the proposed control technique can significantly mitigate power supply current distortion, and the input power factor has been effectively improved within a wider load range.

Analysis of factors influencing electric energy measurement in power systems

This article focuses on summarizing and analyzing the causes of errors in electric energy meters under harmonic conditions, clarifying the relationship between errors and frequency characteristic curves, and pointing out that the positive and negative errors mainly depend on the direction of each harmonic power relative to the fundamental power, the properties of the load, the differences in physical properties of electric energy meter manufacturing and material formation, etc.

Multi-Power Carriers-Based Integrated Control for Series-Cascaded Microgrid

Series-cascaded microgrids (SCMGs) indeed provide control flexibility and high-voltage synthesis capabilities. However, the power distribution in SCMGs based on distributed generation (DG) sources stays understudied. This paper proposes an SCMG topology using non-dispatchable DG sources and battery energy storage, with an integrated power-routing control. The objective is to address power distribution limitations and stabilize SCMG output voltages under varying conditions. A case study validates the control methodology, considering zero irradiation levels for photovoltaic (PV) and maximum power sharing. The battery modules play a crucial role by providing power, voltage support, and maintaining capacitor voltage at a reference value of a PV-integrated module. This is achieved through a third harmonic current injection in the fundamental frequency current, coupled with proportional power distribution using a third harmonic power signal. The effectiveness of the proposed SCMG topology and control is demonstrated through MATLAB/Simulink and hardware-in-loop analyses (Typhoon HIL). The results present an extended power distribution between series-cascaded DG sources-based units while ensuring stable SCMG output voltages, even in adverse conditions like PV module intermittency. Future work aims to extend the proposed topology to a ring/delta-connection SCMG, where third harmonic current aids power distribution among SCMG legs and between series-cascaded DG sources-based units.

AI Algorithm Based Green Hydrogen Static Compensator for Harmonic Mitigation, Power Balancing, and Power Factor Correction in Nano-Grids

Nano-grids are emerging as a vital solution for sustainable energy distribution, particularly in integrating intermittent renewable energy sources. In this context, this research paper aims to address the challenges faced in Nano-grids through the innovative use of a Green Hydrogen Static Compensator (GHSC). The purpose of this study is to overcome issues related to harmonic pollution, power factor correction, and real power balancing within the Nano-grid system. The method employed involves a two-fold approach. Firstly, a modified instantaneous p-q algorithm is proposed to enhance the effectiveness of GHSC. Secondly, artificial intelligence (AI) algorithms, including deep neural networks, random forest, and XGBoost, are utilized to further refine the system's accuracy. These AI algorithms were trained using the modified p-q method, and the simulation of GHSC was performed using SimScape Toolbox in MATLAB-Simulink. The results of the study clearly demonstrate that the proposed GHSC approach, combined with the AI algorithms, outperforms traditional methods in terms of effectiveness in mitigating harmonic pollution and correcting power factors. However, it is noted that the current implementation lacks flexibility for real-time self-learning. In conclusion, the paper underscores the novelty and potential of the GHSC in conjunction with AI algorithms, while also pointing out areas for future research. Specifically, future efforts may focus on developing an automatic weight updating deep neural network that responds to real-time feedback of THD, power factor, and frequency, enhancing the system's adaptability and efficiency.

Analysis of the Influence of the 6-Pulse Thyristor-Bridge Input Reactor Size on the Shunt Active Power Filter Work Efficiency: A Case Study

This paper presents a case study in which the influence of the 6-pulse thyristor-bridge input reactor size on the shunt active power filter (SAPF)’s work performance is investigated. The purpose of using an SAPF in the power system is in most cases for fundamental harmonic reactive power compensation, harmonics and asymmetry mitigation. The work efficiency of such a filter depends not only on the designed control system, interface filter and dc-link capacitor parameters, but also on the parameters of the electrical system in which it is connected. Therefore, it is necessary to study and know the power system (supplier and consumer sides) before its installation. For instance, in the electrical system with diode or thyristor-bridge as loads, the SAPF performance efficiency may not be satisfied due to the high rate of current change (di/dt) at the points of commutation notches. In this paper, the performed simulation and laboratory experiments show that for a better operating efficiency of the SAPF, the input reactor parameters should be selected based not only on the effective reduction in the inverter switching ripple or the control system demand, but also on the parameters of the load, such as the parameters of the diode or thyristor-bridge input reactor. Apart from the experimental demonstrations on how the input reactor size influences the SAPF work efficiency, the novelties in this paper are: the formulated recommendations on how to choose the SAPF input reactor parameters (the SAPF is more efficient in terms of harmonics, asymmetry and reactive power mitigation when the inductance of its input reactor (L-filter) is smaller than the one of the diode or thyristor-bridge input reactor); the proposed SAPF control system; the proposed expressions to compute the SAPF input reactor inductance, DC voltage and capacitor.

Local spherical harmonic power spectra from local magnetic or gravity data

SUMMARY We present a method to calculate local spherical harmonic power spectra directly from spacecraft magnetic and gravity data with varying spacecraft altitude. Previously published applications of local spherical harmonic power spectra have been formulated for data that are available at a single collection altitude, such as data evaluated from a global spherical harmonic model. Our approach consists of first solving for local models from local data and then obtaining local multitaper spectra from the local models. We demonstrate with numerical tests that this approach can produce reliable results. Our method is particularly useful in situations where data coverage does not allow for calculating global magnetic or gravity field models, or where data quality or quantity varies regionally and where local models could yield superior resolution or quality over global models.