Harmonic Suppression Research Articles

Planar dual-band bandpass filter with regular harmonic suppression

Abstract This paper presents a dual-band bandpass filter with regular harmonic suppression. The proposed third-order filter consists of two microstrip stepped impedance resonators and single substrate integrated waveguide resonator. The mismatches in their higher order resonant frequencies are utilized to suppress the regular harmonics. The passbands are centered at f1 = 2.4 GHz and f2 = 3.5 GHz with fractional bandwidths of 5% and 7.5%, respectively. The measured midband insertion and return losses are better than 2.55 and 14.5 dB for the first, whereas for the second band, they are better than 1.95 and 14 dB. The filter offers at least 33 dB suppression of first three higher order regular harmonics of f1 and f2.

Interline hybrid continuous converter impedance control-based tuning filter: effective harmonic suppression in DG-integrated electrical power grid

Interline hybrid continuous converter impedance control-based tuning filter: effective harmonic suppression in DG-integrated electrical power grid

LCL APF control strategy based on model predictive control

In order to further control harmonic current in distribution network, a LCL APF control strategy based on model predictive control is proposed. Firstly, APF mathematical model is established. Then, a multi-objective optimization model predictive control strategy (MPC) is proposed, which comprehensively considers the performance of AC side and DC side of APF. This strategy solves the delay problem existing in the existing MPC strategy: while improving the performance of APF, there is no need to set weight factor; Then, Kalman filter is used to predict the inverter current, thus simplifying the APF measurement system. Finally, the simulation results show that the proposed control strategy can simplify the measurement system and make APF have stronger harmonic suppression ability when it only participates in power conversion and better active filter performance when it participates in harmonic control.

An Overview of the R&D of Flywheel Energy Storage Technologies in China

The literature written in Chinese mainly and in English with a small amount is reviewed to obtain the overall status of flywheel energy storage technologies in China. The theoretical exploration of flywheel energy storage (FES) started in the 1980s in China. The experimental FES system and its components, such as the flywheel, motor/generator, bearing, and power electronic devices, were researched around thirty years ago. About twenty organizations devote themselves to the R&D of FES technology, which is developing from theoretical and laboratory research to the stage of engineering demonstration and commercial application. After the research and accumulation in the past 30 years, the initial FES products were developed by some companies around 10 years ago. Today, the overall technical level of China’s flywheel energy storage is no longer lagging behind that of Western advanced countries that started FES R&D in the 1970s. The reported maximum tip speed of the new 2D woven fabric composite flywheel arrived at 900 m/s in the spin test. A steel alloy flywheel with an energy storage capacity of 125 kWh and a composite flywheel with an energy storage capacity of 10 kWh have been successfully developed. Permanent magnet (PM) motors with power of 250–1000 kW were designed, manufactured, and tested in many FES assemblies. The lower loss is carried out through innovative stator and rotor configuration, optimizing magnetic flux and winding arrangement for harmonic magnetic field suppression. Permanent magnetic bearings with high load ability up to 50–100 kN were developed both for a 1000 kW/16.7 kWh flywheel used for the drilling practice application in hybrid power of an oil well drilling rig and for 630 kW/125 kWh flywheels used in the 22 MW flywheel array applied to the flywheel and thermal power joint frequency modulation demonstration project. It is expected that the FES demonstration application power stations with a total cumulative capacity of 300 MW will be built in the next five years.

Design of a miniaturized 90-degree quadrature hybrid coupler with harmonic suppression ability using π-shaped lumped elements

This research presents a new design and fabrication of a quadrature hybrid coupler using π-shaped lumped elements. The proposed π-shaped elements have resulted in ultra-size reduction and harmonic suppression ability simultaneously. The proposed coupler correctly works at 800 MHz, the insertion loss is less than 0.15 dB and more than 26 dB, isolation and return loss are obtained at the operating frequency. The size of the proposed coupler is only 12.8 mm ×12.2 mm, which is equal to 0.046 λg × 0.044 λg, where λg is of the guided-wavelength at 800 MHz. The conventional coupler has a large size of 0.25 λg × 0.25 λg, which is equal to 68.5 mm × 68.5 mm. The proposed coupler provides about 96% size reduction compared to the conventional coupler. Moreover, the proposed quadrature hybrid coupler has wide harmonic suppression from 2.1 GHz to 10 GHz.

A Novel Transformer Winding Design Strategy for Efficiency Improvement and Harmonic Sup-Pression in Industrial Power System

A Novel Transformer Winding Design Strategy for Efficiency Improvement and Harmonic Sup-Pression in Industrial Power System

Harmonic Suppression Strategy of Permanent Magnet Synchronous Motor Based on PCI and ADRC Methods

Harmonic Suppression Strategy of Permanent Magnet Synchronous Motor Based on PCI and ADRC Methods

A ridged waveguide filter design with ultra-wideband and harmonic suppression

In this paper, a new structure for wide-band rectangular waveguide bandpass filters with distinguished harmonic suppression is presented. The filter is realized by using ridged waveguides in both resonant cavities and coupling windows and a metal plate, which performs like a low-pass filter and makes it arduous to form parasitic passbands. According to the field analysis and out-of-band response, the ridge structure can expand pass bandwidth and obtain a wide stopband by harmonic suppression. The filter is designed to perform a passband of 67% fractional bandwidth at center frequency at 75 GHz. The harmonic suppression of the design is increased from 1.5 times to 3.6 times the center frequency of the filter with 20 dB suppression levels. Finally, the measurement results validate the proposed design.

Stochastic optimal harmonic suppression with permissible photovoltaic penetration level for grid-linked systems using Monte Carlo-based hybrid NSGA2-MOPSO

Stochastic optimal harmonic suppression with permissible photovoltaic penetration level for grid-linked systems using Monte Carlo-based hybrid NSGA2-MOPSO

Review of Key Technologies of the High-Speed Permanent Magnet Motor Drive

The high-speed permanent magnet motor has been widely used in the industrial field because of its high-power density, fast dynamic response, and wide speed range. High efficiency and stable operation are the premises for the high-speed permanent magnet motor to exert its advantages. Firstly, this article analyzes the problems existing in the drive technology of high-speed permanent magnet motors from three aspects: current harmonics, rotor position detection, and low carrier ratios. Aiming to address the above problems, the status of the latest research is summarized from the aspects of harmonic suppression, position sensorless, and control strategies. In addition, future research trends for high-speed permanent magnet motors are discussed.

Multifunctional Control Strategy for a Hybrid Solid-State Transformer Applied to Modern Distribution Electric Grids

This paper presents the control and hardware design for a Hybrid Solid-State Transformer (HSST) applied to modern distribution systems. The HSST combines the advantages of conventional transformers, such as high efficiency and low cost, with those of Solid-State Transformers (SST), such as multifunctionality and fast dynamic response. Real-time simulation using a Typhoon HIL404 device is performed to validate the proposed multifunctional control strategy. The corresponding results validate the HSST’s capability to provide, while only processing partial system power, a regulated output voltage with grid voltage harmonic suppression and, at the same time, current load reactive and harmonic compensation to ensure a high-power factor and improved power quality to the grid.

Enhanced Hybrid Power Grid System Using Adaptive Fuzzy Logic Controller by Supraharmonics Reduction

Hybrid Systems meet the growing needs of electrical energy in the countries. The mismatching of hybrid systems leads to the phase shift in the three-phase signals, producing more harmonics in the band of 2 to 150kHz.However, due to various factors, harmonics have arisen from the RITHAPF and TCR which act as the phase shift controller in hybrid systems. Therefore, the Adaptive Fuzzy controller is employed with RITHAPF and TCR to maintain the phase shift and attenuate the harmonics produced. which outperforms the Hysteresis controller by 17.5% approx. in harmonic suppression and the simulation carried out for various phase angles.

Torque dynamic performance enhancement of five‐phase permanent magnet synchronous motor with open‐circuit fault

AbstractMultiphase permanent magnet synchronous motors (PMSMs) have attracted much more attention for their high efficiency, low torque ripple and good fault tolerance. However, open‐circuit fault results in asymmetrical motor behaviour, and deteriorates torque performance, especially dynamic response. This paper proposes a novel fault‐tolerant direct torque and flux control (DTFC) strategy to restrain fluctuating torque and enhance torque dynamic performance of a five‐phase PMSM with open‐circuit fault. The novelty of the proposed strategy is the development of DTFC based on stator flux orientation under the open‐circuit fault condition and the third harmonic current suppression with carrier‐based pulse width modulation technology. Consequently, the decoupling control of torque and stator flux can be achieved under the open‐circuit fault condition, and the third harmonic current can be restrained without additional control. Combined with deadbeat control, the heavy computation burden can be reduced. Thus, the proposed strategy not only can enhance torque dynamic performance under open‐circuit fault operation, but also keep smooth torque with circular stator flux trajectory before and after open‐circuit fault. The effectiveness of the proposed strategy is verified by the simulation and experimental results.

On‐Demand Generation and Control of Giant Terahertz Nonlinearity with Metasurfaces

AbstractSimultaneous control of the optical linearity and nonlinearity of the materials plays key roles in next‐generation electronics and optics as it offers the potential of manipulating the fundamental properties while generating new frequencies of light. Such control is exceedingly challenging at the technologically important terahertz (THz) frequencies due to the severe scarcity of high‐performance nonlinear materials. Here, a unique method is introduced for achieving THz second‐order nonlinearity through Lorentz force‐driven anharmonic oscillations of free electrons in metasurfaces. It does not depend on natural nonlinear materials and provides ultrahigh design freedom. Using this approach, efficient THz second harmonic generation (SHG) is experimentally demonstrated with remarkably large values of the effective nonlinear susceptibility at room temperature. By engineering the geometry of the metasurfaces, the generation and suppression of the second harmonics can be controlled and customize their polarization states at will. This efficient, configurable, room‐temperature, and ultra‐compact platform for THz SHG provides new perspectives for developing high‐performance THz sources, frequency multipliers, and other nonlinear devices.

Research on Electromagnetic Performance and Rotor Eddy Current Loss Suppression of Ultra‐Low Temperature and High‐Speed Permanent Magnet Motor Materials for LNG Pumps

AbstractThere is no unified material selection principle for ultra‐low temperature and high‐speed permanent magnet motors used in liquefied natural gas (LNG) pumps, and high rotor eddy current losses can easily lead to vaporization of the transported LNG. This article first studies the electromagnetic performance of motor structural component materials at room temperature and ultra‐low temperature environments, and proposes the material selection principles for this type of motor. Based on the experimental measurement results of material electromagnetic performance, the loss characteristics of motors under ultra‐low temperature and room temperature environments were compared. Based on the mechanism of rotor eddy current loss and considering the influence of environmental temperature on the material properties of motors, three optimization methods for rotor eddy current loss are proposed. The impact of different suppression measures on rotor eddy current loss is revealed. The suppression of magnetic conduction harmonics can be achieved by opening stator auxiliary slots and optimizing their size and position. High conductivity metal shielding layers are used and their materials and sizes are optimized, And the use of magnetic slot wedges can simultaneously suppress three types of harmonics. Finally, the suppression principles of different optimization methods on rotor eddy current losses were analyzed, and the optimization effects and advantages and disadvantages of different methods were discussed, providing theoretical reference for the optimization design of high‐speed permanent magnet motors operating in ultra‐low temperature environments. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

LADRC‐based non‐characteristic harmonic suppression strategy for pumped storage power plants

AbstractThe static frequency converter (SFC) in a pumped storage power plant often causes harmonic problems in the dragging processes, which may lead to the false operation of automatic devices in the power station, and even damage to the power equipment. These harmonics caused by SFC contain both characteristic and non‐characteristic degrees, and the components are more complex. Hence, the existing harmonic suppression methods using active power filter or passive power filter compensation all have some problems. The SFC starting control strategy based on linear active disturbance rejection control (LADRC) is proposed here to reduce the non‐characteristic harmonics. First, the factors affecting the non‐characteristic harmonic content are analysed, and a mathematical model of the conventional SFC starting transfer function is established. On this basis, the LADRC controller is used as the speed loop of SFC starting to replace the proportional integral (PI) controller. The stability is judged by drawing the Bode plot and the zero‐pole plot. Finally, a Matlab/Simulink simulation model of LADRC‐based SFC starting is established in a pumped storage power plant with actual parameters, and simulation accurate measurements verify the effectiveness of the proposed control strategy for non‐characteristic harmonic current suppression.

A control strategy of DC transmission system for offshore wind power based on hybrid converters

Abstract As the DC transmission system of modular multilevel converters for offshore wind power suffers problems like large volume, heavy weight, difficulty in platform transportation, and high cost, a DC transmission scheme for offshore wind power based on diode rectifier units and modular multilevel converters is put forth in the present work; Meanwhile, the features of active-power coordination, the DC harmonic current, and the AC harmonic current of the hybrid converter in this proposed scheme are analyzed to propose control strategies for active power coordination control, DC harmonic current suppression, and AC harmonic current suppression of the hybrid converter, respectively. The performance and feasibility of the proposed strategies are verified by testing the hardware in the loop real-time simulation system for transmission of offshore wind power through hybrid converters based on RTDS. It is found that the proposed strategies could improve the stability, flexibility, and reliability of the system.

Harmonics Suppression and Stability Improvement for Power Router in Nonideal Grid Conditions: A Multiport Passivity-Based Collaborative Control Scheme

Harmonics Suppression and Stability Improvement for Power Router in Nonideal Grid Conditions: A Multiport Passivity-Based Collaborative Control Scheme

Decoupled Modulation Strategy for Harmonic Current Suppression in Five-Phase Series-End Winding PMSM Drives

Decoupled Modulation Strategy for Harmonic Current Suppression in Five-Phase Series-End Winding PMSM Drives

Active damping control based bus voltage resonance suppression in electrolytic capacitorless PMSM application

Abstract The structure of electrolytic capacitorless in automotive electronic applications has the advantages of lower cost and better reliability. However, motor drive systems using this structure may experience unstable bus voltage. To this end, this paper proposes an active damping control strategy based on virtual impedance. By modelling the electric drive system and conducting stability analysis, the cause of bus voltage resonance due to the use of small capacitors is revealed. Based on the extracted DC bus voltage harmonic signal, additional voltage vectors are added in the d-axis and q-axis voltage vectors, eliminating the impedance mismatch problem in the drive system caused by the reduction of bus capacitance, effectively suppressing the voltage oscillation on the machine side of the drive system. Simulation data shows that under the condition of using small-capacity ceramic capacitors, the method proposed in this paper achieves a harmonic suppression capability similar to that of large-capacity electrolytic capacitors, effectively ensuring the application safety of automotive drivers with electrolytic capacitorless architecture.