Resonant Network Research Articles

Wireless Shaded-Pole Induction Motor With Half-Bridge Inverter and Dual-Frequency Resonant Network

This article presented a single-phase shaded-pole induction motor (SPIM) system, which aims to work in an isolated environment. Compared with the previous wireless SPIM, this system employs less controlled switches and can work at full-resonant condition, while retaining the merit of secondary controllerless. The key is to employ a half-bridge inverter and a proper dual-frequency resonant network; thus, only two controlled switches are adopted at the motor side. Since the SPIM is purposely designed with a dual-stator winding, the system robustness and efficiency can be significantly improved. In this article, simulation has been conducted to verify the system's feasibility and self-drive ability. Meanwhile, a 30-W prototype has been built for the experimental verification, and the results show that this motor can achieve flexible speed control with the transfer distance of 20 mm and the transmission efficiency of 77%.

Light-Load Performance Enhancement Technique for LLC-Based PEV Charger Through Circuit Reconfiguration

In <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> -based plug-in electric vehicle (PEV) charging system, light-load condition occupies a large portion of the charging process. However, at light load, the parasitic capacitance of full-bridge <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> converter leads to poor voltage regulation. Besides, the magnetic core loss and circulating loss are load-independent and jeopardize the light-load efficiency. To resolve those two issues in a coupled manner, a light-load performance enhancement technique is proposed in this article. At light load, the primary side is reconfigured as a half-bridge inverter and the secondary side is reconfigured as a voltage doubler rectifier, while the voltage gain is roughly unchanged. Therefore, both the equivalent resistance and capacitance of the secondary resonant network are effectively reduced, which contributes to an enhanced voltage-regulation capability. Moreover, the core loss and circulating current-induced conduction loss are both effectively reduced, which contributes to a boosted efficiency. A 2-A rated, which converts 390-V input to 250–450-V output, converter prototype is designed and tested to validate the concept. The light-load mode exhibits an obvious efficiency improvement. The frequency regulation range is also effectively squeezed.

Sensitivity analysis of wireless power transmission

The compensation networks that realize constant current/constant voltage in the wireless power transfer are high-order resonant networks, and there are multiple resonance frequency points to achieve load-independent constant current/constant voltage output. However, the output characteristics of wireless power transfer based on high-order resonant networks are extremely susceptible to the effects of resonant network parameters. Therefore, the analysis of the resonance point of the wireless power transfer is helpful to select the appropriate resonance frequency point and achieve stable output. This article analyzes the resonance conditions of the double-sided LCC compensation network and then gives a parameter design method to achieve load-independent CC/CV output characteristics under ZPA conditions. The effects of the resonant network’s primary/secondary series compensation capacitor parameters on the resonance point and output characteristics of the wireless power transfer system are analyzed. Finally, the correctness of the parameter design of the resonance network and the accuracy of the theoretical analysis are verified.

Low‐power dual‐band voltage‐controlled oscillator using a fourth‐order resonant technique

AbstractA low‐power dual‐band voltage‐controlled oscillator (VCO) using a fourth‐order resonant technique implemented in 0.18‐μm CMOS process is presented in this letter. By utilizing a fourth‐order LC‐type resonant network and a current‐reused technique, the proposed VCO operates in the dual‐band mode and improves the overall performance. The tuning ranges of band 1 and band 2 are from 3.39 to 3.68 GHz and from 7.2 to 7.57 GHz controlled by a controlled‐voltage VC, respectively. The measured phase noises at 1 MHz frequency offset are −117.39 dBc/Hz and −113.58 dBc/Hz for output frequencies of 3.68 and 7.21 GHz, respectively. Besides, the figures‐of‐merit (FOM) at 3.68 and 7.21 GHz output frequencies are −182.5 and −184.5 dBc/Hz, respectively. The proposed VCO core consumes 4.2 mW from a 1.2‐V supply.

Analysis and Design of a Nonisolated Bidirectional DC–DC Converter Based on CLC Network

This article proposes a nonisolated bidirectional dc–dc converter based on the π type resonant network for renewable energy sources. The circuit consists of a front-stage boost inverter, a CLC resonant network and a poststage voltage doubled rectifier. The proposed converter has simple structure and smaller volume without conventional transformer, easier to achieve modularity and integration. Under bidirectional power flow, the switches can achieve zero voltage turn- on and the rectifier diodes can achieve zero current turn- off with the wide load range. In this article, the operation modes, output power characteristics, soft-switching conditions, and the optimization design of the circuit are analyzed. A 200 W prototype based on GaN device is implemented and tested to verify validity of the proposed converter. The prototype can achieve a peak efficiency 95.4% in boost mode and 94.1% in buck mode.

Analysis and design of four-plate capacitive wireless power transfer system for undersea applications

This paper presents a four-plate undersea capacitive wireless power transfer (CPT) system for underwater applications such as autonomous underwater vehicles (AUVs). Generally, a CPT system transfers the power based on electric fields. The complex resonant compensation networks are used to make the CPT system work in the resonant condition. The resonant voltage is always very high. It will be a big challenge to the human safety. In this paper, a virtual electrons periodic reciprocating flow theory is proposed for the CPT system. In one switching cycle, the electrons firstly flow in the forward direction through the forward path and then flow in the inverse direction through the inverse path. The CPT system has been deeply studied with the vacuum dielectric or the air dielectric. However, for the CPT system, there are few papers to show the underwater application. In this paper, an undersea four-plate CPT system is designed and studied in the underwater condition. The two coupling capacitors and other elements of the CPT system could build a closed-loop path. A small value inductor is adapted as a resonant compensation network for the four-plate CPT system. The DC voltage is inverted to the AC voltage in the primary side with the single-phase full-bridge inverter. The resonant voltage is rectified to the DC voltage in the secondary side with the single-phase full-bridge diode rectifier. A 100 W power level CPT system is constructed to verify the theory analysis and the calculation. The theory analysis is verified by the simulated and experimental results. The stable output voltage and load power are achieved in this paper.

High step-up isolated DC-DC converter based on resonant network for DC offshore wind farms

At present, the use of DC convergence and DC transmission (abbreviated as all DC) is recognized as the most effective technical solution and inevitable trend to solve the flexible access of large-scale new energy generation. However, the high-voltage and large-capacity DC-DC converters used in the DC convergence of the full DC system are still in the preliminary research stage. This paper presents a high voltage and large capacity isolated DC-DC converter topology, which is composed of three-stage boost circuit. The simulation results show that the topology can increase the output voltage of wind turbine from 1kV to 320kV, effectively improve the boost ratio of converter, and provide a theoretical basis for the realization of full DC offshore wind power system.

UWB bandpass SSL filter with an adjustable notched band and four transmission zeros

UWB suspended stripline (SSL) bandpass filter with an adjustable notched band and four transmission zeros (Tzs) is proposed here. To prevent interference signals from the wireless local-area network (WLAN) entering UWB system, a short-stub resonant network is introduced to this UWB filter. In addition, utilizing different resonant modes of the two short–stubs, four Tzs are generated to improve the skirt selectivity. Both the centre frequency of the notched band and the positions of Tzs can be controlled by tuning the structural parameters. The UWB SSL bandpass filter is designed, fabricated and tested. The measured results are in good agreement with the simulated results.

Research on CLLLC Resonant Bidirectional DC-DC Converter

Based on the single-phase full-bridge LLC DC-DC converter, the LC series resonant network is introduced in the secondary side of the high frequency transformer to form the bidirectional CLLLC resonant DC-DC converter. Firstly, the bidirectional CLLLC resonant DC-DC converter was used for mathematical modeling. By extending the description function, the large-signal steady-state model of the converter was obtained, and the DC voltage gain when the DC-DC converter was running forward was deduced. The gain characteristics and frequency characteristics of the model are compared with those of the basic wave equivalent model. Secondly, the small-signal perturbation model of CLLLC DC-DC converter is modeled, and the small-signal perturbation is brought into the large-signal steady-state solution to obtain the transfer function when the CLLLC resonant converter is running forward. Finally, a 20kW CLLLC DC-DC converter is designed, and the simulation analysis is carried out to verify the correctness of the proposed scheme.

Reliable [formula omitted] filtering for the SP resonant ICPT system with stochastic multiple sensor faults

The inductively coupled power transfer (ICPT) system is one of the most important system in the wireless power transfer field. In this paper, the reliable H∞ filtering problem is considered for the ICPT system based on the series–parallel (SP) resonant compensation network. A more general SP resonant ICPT system model is proposed with considering external disturbances and multiple sensor faults. The sensor faults are assumed to happen in a random way, which are described by a set of stochastic variables satisfying certain statistical features. The main purpose of the addressed problem is to design an H∞ filtering scheme such that the filtering error dynamics are asymptotically mean-square stability (AMSS). For this purpose, a generalized state-space averaging (GSSA) model is built to characterize dynamical behaviors of the SP resonant ICPT system first. Then the filtering-error system with stochastic sensor faults is established via the GSSA model. By virtue of an extended Lyapunov function, a sufficient condition is given to achieve the AMSS of the system and H∞ performance requirement. Subsequently, the H∞ filtering gains are obtained by solving a set of linear matrix inequalities. Finally, a simulation example is provided to verify the availability and reliability of the proposed filtering scheme.

High-Order Network Based General Modeling Method for Improved Transfer Performance of the WPT System

In wireless power transfer system, zero phase angle (ZPA), zero voltage switching (ZVS), load-independent output voltage, and current are key to improve transfer performance, like efficiency and output power over load change. More concerned, it is hard to realize those expected electrical characteristics in a topology simultaneously. To solve the issue, this article proposes a general modeling method based on the high-order resonant network. The equivalent impedance of passive components in each circuit branch is replaced by jX and then, according to the analysis of Kirchhoff principle, the conditions to realize load-independent output and simplified calculation of input impedance are given out. Hence, the proper passive components can be chosen to get expected electrical characteristics. A specific prototype, using the proposed modeling method for parameter design, is implemented to verify the validity of proposed modeling method. In the prototype, load-independent constant voltage and constant current modes can be switched by restructuring the passive network; meanwhile, ZPA or ZVS could also be realized by regulating only one component. The experimental results fit well with the theoretical analysis.

Optimal Design Method of LLC Half-Bridge Resonant Converter Considering Backflow Power Analysis

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> half-bridge converters have been extensively studied in low power industrial applications. However, the phase shift angle between the voltage and current of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> resonant network makes the converter have power circulation, that is, backflow power. The increase of the backflow power will increase the converter conduction loss, which restricts the improvement of the converter efficiency. The existing literature often improves the backflow power from the control aspect, which greatly increases the control complexity. To solve this problem, this article proposes an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> half-bridge resonant converter analysis method that takes the backflow power into account. Based on the analysis of operating mode and ac equivalent model of the converter, backflow power is indirectly characterized by the phase-shift angle of the resonant network voltage and current. Based on this, this article analyzes the internal relationship between resonant parameters and backflow power to reduce backflow power by optimizing resonant parameters. Under the setting operating conditions, converter can achieve zero voltage switching (ZVS) switching, voltage gain conditions, and minimum backflow power. Compared with the existing methods, the proposed optimization method avoids additional auxiliary circuits and control complexity, improves the stability of the circuit. Experimental results verify the accuracy and feasibility of the theoretical analysis.

Further Improvement of Customized Vibration Generator for Machine–Human Feedbacks with the Help of Resonant Networks

Modern industrial, household and other equipment include sophisticated power mechanisms and complicated control solutions and require tighter human–machine–human interaction, forming the structures known as cyber–physical–human systems. Their significant parts are human–machine command links and machine–human feedbacks. Such systems are found in medicine, for example, in orthopedics, where they are important for operation and functional abilities of orthopedic devices—smart wheelchairs, verticalizers, prosthesis, rehabilitation units, etc. The mentioned feedbacks may be implemented based on the haptic perceptions that require vibration actuators. In orthopedics, such actuators can also be used for diagnostic purposes. This research brings forward the idea of the use of resonant operation of the driver of vibration actuator. The corresponding driver has been built and experimentally tested. It has been found that (1) the point of maximal current is actually defined by the resonant frequency, (2) change of the capacitance allows shifting of the point of maximal current output and (3) damping factors make the above-described effect less obvious. Further development of the proposed idea requires a comprehensive comparison of four-quadrant and two-quadrant schemes in this application and development of a real-time programmable capacitor pack consisting of several binary weighted capacitors and a commutating circuit, which is installable to these schemes.

Investigation into Class E/F3 with Parallel Network

The system of equations for processes in the amplifier output network is analytically formulated. This system of equations considers parameters of resonant networks at higher harmonics. To calculate amplifier output network, the system of five equations was built for five unknowns, to which the condition of positive second voltage derivative at extremum of drain voltage was added. Two equations correspond to class E conditions, another two — quadrature waveforms at load and at additional resonant network. The last equation is the condition of extremum at the point near middle of drain voltage pulse. This system was solved using computer algebra program. The circuit elements and waveforms were calculated using the derived parameters. By choosing different parameters, it is possible to obtain various amplifier realizations, which will demonstrate features of different class F variants. The obtained amplifier parameters drain voltage and current waveforms were verified with calculated ones using the harmonic balance simulating software. The variant, which is closer to class E/F3 mode, was chosen to build an experimental amplifier prototype on frequency 2MHz using IRF530 MOSFET as a switch. The prototype was tested in the range of supply dc voltage up to 24V with the output power greater than 6W, while the amplifier efficiency was &gt;80%. In the experiment, the ratio of peak drain voltage to dc supply voltage was measured to be 3.3 at the duty ratio 50%, unlike class E amplifier, where this value is around 3.65, and on practice, considering non-linear drain to source capacitance, it may achieve 4. The experimental second harmonic level amounted to be -20 dB relatively to fundamental, and the third one — 28.5 dB, which is due to an additional second harmonic filter. The paper results are useful for introduction of such circuits to practice.

Design of High Performance Low-Noise Amplifier Circuit Based on Complementary Metal Oxide Semiconductor Technology

This paper designs a body-biased (BB) differential cascode low-noise amplifier (LNA) with current bias (CR) and capacitor cross-coupling (CCC) technology that meets the bandwidth requirements of 5 GHz wireless applications. In the design, the CCC technology in the differential cascode topology is used to effectively suppress the common mode noise, thereby improving the noise figure. The series resonant network eliminates parasitic capacitance at the input and output ends, thereby improving the power transmission efficiency. The CR technology formed by the intermediate capacitor shares the DC current input to the output device, thereby increasing the gain. This paper uses BB technology in the design to lower the threshold of the cascode device and improve the transconductance, which further improves the gain and reduces the power consumption. The CCC technology used in the paper improves linearity by eliminating the non-linear components present in the input device, which will not interfere with the transconductance of the output stage. This article has obtained excellent performance parameters including gain, noise figure (NF) and linearity without affecting the power consumption, integration and cost of the proposed design.

Bandgap coupling effects between hybrid nonlinear synchronized switch damping and linear two-order resonant bandgaps in piezoelectric meta-structures

To study the bandgap coupling mechanism between nonlinear synchronized switch damping and multi-order linear resonant bandgaps, this research investigates the bandgap coupling effects between nonlinear synchronized switch damping and two-order linear resonant bandgaps in a piezoelectric meta-structure. Specifically, a piezoelectric meta-structure with hybrid nonlinear synchronized switch damping and linear two-order linear resonant electrical networks is proposed. Based on the theoretical modeling of the proposed structure, band structure and vibration transmittance performance are investigated in detail. Results showed that bandgap coupling can produce a trade-off with the advantages of both nonlinear and two-order linear resonant bandgaps. The new bandgap can not only realize broadband wave attenuation performance but also greatly enhance the attenuation in selected frequency bands, which provides a new method to manipulate elastic waves in a diversified way.

Resonant Machine Learning Based on Complex Growth Transform Dynamical Systems.

Traditional energy-based learning models associate a single energy metric to each configuration of variables involved in the underlying optimization process. Such models associate the lowest energy state with the optimal configuration of variables under consideration and are thus inherently dissipative. In this article, we propose an energy-efficient learning framework that exploits structural and functional similarities between a machine-learning network and a general electrical network satisfying Tellegen's theorem. In contrast to the standard energy-based models, the proposed formulation associates two energy components, namely, active and reactive energy with the network. The formulation ensures that the network's active power is dissipated only during the process of learning, whereas the reactive power is maintained to be zero at all times. As a result, in steady state, the learned parameters are stored and self-sustained by electrical resonance determined by the network's nodal inductances and capacitances. Based on this approach, this article introduces three novel concepts: 1) a learning framework where the network's active-power dissipation is used as a regularization for a learning objective function that is subjected to zero total reactive-power constraint; 2) a dynamical system based on complex-domain, continuous-time growth transforms that optimizes the learning objective function and drives the network toward electrical resonance under steady-state operation; and 3) an annealing procedure that controls the tradeoff between active-power dissipation and the speed of convergence. As a representative example, we show how the proposed framework can be used for designing resonant support vector machines (SVMs), where the support vectors correspond to an LC network with self-sustained oscillations. We also show that this resonant network dissipates less active power compared with its non-resonant counterpart.

Analysis and Design of Three-Level Full-Bridge LLC Resonant Converter Based on Pulse Frequency Modulation

Aiming at the problem of serious switching loss in high-power and high-voltage occasions, the traditional LLC resonant network is difficult to adapt, the DC gain is difficult to obtain intuitively, and the voltage stress on the switch is too high, resulting in large switching losses and difficult selection of the switch. This paper uses a three-level full-bridge LLC resonant converter topology, the First Harmonic Approximation (FHA) is used to analyze the LLC resonant converter gain characteristics, and the parameter design ideas are given. A simulation experiment of a three-level full-bridge LLC resonant converter based on frequency modulation control is presented. The simulation results show that each primary side switch transistor can achieve zero voltage switching (ZVS), the secondary side diode realizes zero current switching (ZCS), and can obtain higher working efficiency, which verifies the feasibility of the design.

Computer aided design of ferrite lumped element circulators

The results of integrity of narrowband and wideband lumped element circulators design methodology to the computer aided design system of microwave devices AWR Microwave Office are presented in the article. The calculation method of narrow band circulators circuits which consist of serious and shunt tuning capacities is investigated. The simple and visual method of wideband ferrite isolators optimize design based on circulation impedance calculation is described here. The results of design of the ultra wideband circulator with shunt capacity, serious resonant matching circuit and serious resonant circuit between common terminal and ground are considered. The new theoretical results of calculation of two schematics of wideband high power circulators with serious tuning capacity are presented. The first schematic is formed with matching resonant network being connected in serious at each terminal. It is shown that double hump characteristic is realized. The second schematic is formed with serious resonant network connected between common terminal and the ground. It is shown that four-order Tchebycheff characteristic is realized.

Faulted Feeder Identification Based on Active Adjustment of Arc Suppression Coil and Similarity Measure of Zero-Sequence Currents

Existing faulted feeder identification methods in the resonant grounded distribution network are primarily based on feature extraction of the fault-generated transient currents. The reliability of these approaches is significantly compromised by the fluctuating transient signals and interfering on-off operation of the neighboring switches. To sidestep the problems, a novel method is proposed to identify the faulted feeder by consecutively tuning the arc suppression coil around the full compensation state. Once a series of steady states are reached after tuning, the trajectories of the corresponding zero-sequence currents for both the sound and the faulted feeders are obtained to formulate an adjustment trajectory matrix (ATM). With the ATM, the similarity measure of the adjustment trajectories of all feeders is then employed to identify the faulted feeder based on the selected Deng's grey relational analysis. Results show that the adjustment trajectories of the two sound lines share a high similarity degree, while the similarity between the sound and the faulted lines is much lower. The effectiveness of the proposed method is validated via simulation and some case studies are provided. The results show that the faulted feeder can be correctly identified with high reliability and robustness compared to the existing fault-generated signal-based techniques.