Impedance Regulator Research Articles

Control Optimization Method for Ship Direct Current Microgrid Based on Impedance Reshaping

In response to the constant power negative impedance characteristics on the load side of a ship DC microgrid, leading to voltage oscillation issues in the DC bus, this paper proposes a control optimization method based on impedance reshaping using bus voltage feedback. First, a simplified small-signal diagram of a lithium battery energy storage system converter is analyzed. Combining active damping control technology, an impedance regulator is introduced, and its parameters are optimized to effectively reduce the output impedance magnitude on the power source side. Subsequently, a ship DC microgrid simulation model is constructed using MATLAB R2022a/Simulink for validation, and comparative analysis is conducted on the anti-interference ability of the DC bus voltage before and after impedance reshaping. Finally, a model is built on a semi-physical simulation platform to experimentally verify the proposed method. The research results indicate that the proposed control optimization method can effectively increase the system’s stability margin, suppress DC bus oscillations, and enhance the anti-interference ability of the ship DC microgrid’s bus voltage when facing significant power load variations.

Nanoarchitectonics of integrated impedance gradient MXene/PPy/polyester composite fabric for enhanced microwave absorption performances

Different from the traditional layer-layer impedance gradient materials, in this work, integrated impedance gradient composite fabric (MP-IIGF) was constructed by using PET spacer fabric as matrix, MXene as conductive filler and polypyrrole as impedance regulator. The collaborative design of continuous impedance gradient structure and composite absorber not only enables the material to absorb microwave, but also makes the composites have the potential of infrared stealth brought by thermal insulation. MP-IIGF-2 has the reflection loss of −27.96 dB at 8.04 GHz, and the effective absorption bandwidth covers the entire X-band. The continuous impedance gradient distribution is realized in the thickness direction of the fabric, which solves the problems of the existence of air medium, easy separation and impedance stepping between the layers of traditional multilayer microwave absorption materials. Therefore, this work provides a new design direction for the research and development of flexible and broadband microwave absorbing materials.

Combined Control System for the Coordinates of the Electric Mode in the Electrotechnological Complex “Arc Steel Furnace-Power-Supply Network”

To stabilize the electrical mode of an arc steelmaking furnace in the initial stages of melting, it is advisable to use a high-speed current-limiting system, in addition to the traditional electrode movement control system. This system is implemented by including the primary winding of the furnace transformer choke, controlled by thyristors. The use of such a system, on the one hand, reduces the negative impact of the arc steel furnace on the the power supply network operation and, on the other, affects the operation of the electrode movement system, built on the principle of an impedance regulator. In order to analyze the mutual influences between such systems, a mathematical model for the power supply and control system of the arc steelmaking furnace was created. The developed model can work in real time, which corresponds to the world trends of modern control system synthesis for complex technological objects. In the created model, the work of the combined control system with different approaches to the formation of the control effect in the high-speed circuit and the effect of the combined control system on the power supply system of the ASF are analyzed.

Human muscle rigidity identification by human‐robot approximation characteristics framework on internet of things platform

AbstractIn the health care system and Internet of Things (IoT) platform, medical care robotics is becoming one of the quickest expanding areas of robot technology. The integration of robotics and human knowledge identifies human muscle rigidity from the healthcare data obtained from the wearable sensor. In an IoT platform, Electromyography is a method used for evaluating and tracking the electrical activity of muscles. The transferring of human muscle rigidity to a robot facilitates the robot to obtain resistive management initiatives in a useful and effective way while carrying out physical interaction activities in unstructured surroundings. The major challenges to overcome the unpredictability during physical interaction allow a robot to realize the individual behaviour with adaptability and versatility of muscles. Therefore, in this article, Human‐Robot Approximation Characteristics Framework (HRACF) has been proposed for developing physiological communication between humans and robots. HRACF permits robots to understand differential resistive abilities of muscles from human presentations. The pulses collected from Electromyography are used to retrieve human arm muscle rigidity during activity presentation. The characteristics of motion and rigidity are concurrently modelled using an estimation and approximation model with a logistic regression obtained by IoT devices. The analysed human arm muscle rigidity is then connected to the robot impedance regulator. HR model uses an optimized resistive approximator to measure the creative variables of the robot and continue driving to monitor the quoted pathways at the time of interaction. The relationship between motion data and rigidity data is systematically coded in the HR model. HRACF makes it possible to detect uncertainties through space and time that facilitates the robot to meet rigidity specification to 98[Nm/Rad] and error rate to 0.15% during physical interaction.

Impedance-Shaping-Based Stability Control of Point-of-Load Converter Integrated With EMI Filter in DC Microgrids

The point-of-load (POL) converters integrated with the input <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> filter are essential to supply the ac load in the dc microgrid. The interaction between the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> filter and the POL converter will bring instability problems to the dc-link voltage. This paper proposes a series-connected virtual impedance regulator based on the detailed small-signal model of the POL converter that feeds a linear three-phase load. The proposed method can improve the stability by modifying only the phase of the input impedance of the POL converter within the interaction frequency range. Therefore, the impact of the regulator on the converter’s dynamic performance is minimized. The experiments show that the proposed stabilization methods exhibit good performance under different linear load scenarios.

A High-Speed Microturbine PMa-SynRG Emulation Using Power Hardware-in-the-Loop for Wind Energy Conversion Systems

In this paper, a high-speed microturbine (MT) permanent magnet assisted synchronous reluctance generator (PMa-SynRG) real-time emulation based on linear impedance regulator (LIR) using power hardware-in-the-loop (PHIL) for wind energy generation tests is presented. The LIR is designed without any feedback control loop for reshaping the $s$ -domain performances of the current filter along with the converter inside the PMa-SynRG emulated system. The PHIL platform not only provides a method for eliminating the high cost of using real renewable energy hardware but also it enables the developers to create new, rapid, and reliable controllers for renewable energy testing. This platform can be used in investigating the performance of energy system under various conditions even if the generator prototype is not yet developed or unavailable. PMa-SynRG mathematical model is emulated in the real-time using PHIL platform while the output voltage of the proposed emulator imitates the generated voltage through the simulated model. In addition, a voltage source converter is employed as a voltage amplifier for imitating the PMa-SynRG performance when supplying nonlinear/linear loads. In this paper, the proportional-integral resonant (PIR) controller is utilized at the voltage control loop for tracking the distorted output reference signal voltage. In order to investigate the performance of the proposed PMa-SynRG emulator, it has been simulated and compared with MATLAB/SIMULINK environment.

Stability analysis of high power factor Vienna rectifier based on reduced order model in d-q domain

For a DC distributed power system, system stability can be predicted by dividing it into source and load subsystems, and then applying the Nyquist criterion to the impedance interaction between the source and load model. However, the generalized Nyquist criterion is extremely complicated and cannot directly reveal effective control strategies to reduce interaction problems of cascade three-phase AC systems. Specifically, as a current force rectifier, this characteristic makes it difficult to judge the stability of a cascade three-phase Vienna AC system. To deal with the aforementioned problems, a simplified small signal stability criterion is presented for an AC distributed power system. Based on the criterion, the small signal model and impedance based on the reduced order model in the d-q domain are studied theoretically. For the instability issue, an impedance regulator design method is presented. The correctness of the simplified stability criterion and the effectiveness of the proposed impedance regulator method are validated by extensive simulation and experiment.

A 1-pJ/bit, 10-Gb/s/ch Forwarded-Clock Transmitter Using a Resistive Feedback Inverter-Based Driver in 65-nm CMOS

An energy-efficient forwarded-clock transmitter that offers a scalable pre-emphasis equalization and output voltage swing is presented. A resistive-feedback inverter-based driver is used to overcome the drawbacks of the conventional drivers. Moreover, half-rate clocking structure is employed in order to minimize power consumption in 65-nm CMOS technology. The proposed transmitter consists of two data lanes, a shared clock lane, and a global impedance regulator. The prototype chip is fabricated in 65-nm CMOS technology and occupies an active area of 0.15 mm $^{2}$ . The proposed transmitter achieves 100–250 mV single-ended swing and exhibits the energy efficiency of 1 pJ/bit at the per-pin data rate of 10 Gb/s.

A Novel Filter Topology With Active Motor CM Impedance Regulator in PWM ASD System

This paper presents a novel hybrid output filter topology for the inverter-motor system. It is shown that the proposed filter drastically reduces the common mode (CM) voltage at the motor terminals. The proposed filter is composed of a conventional LC filter cascaded with an active motor CM impedance regulator. The active circuit, utilizing an integrated high-voltage op-amp, is very efficient in decreasing the motor CM equivalent capacitance, as well as damping the high common voltage on the motor terminal. Therefore, the motor impedance is also used as part of the filter, and the common voltage can be eliminated dynamically in the active impedance regulator by feedback control. Furthermore, the size of the passive filter can be reduced to a large extent. Experimental verification of the filter topology is provided with a laboratory system consisting of a 380-V inverter and a 0.37-kW induction motor.

Разработка усовершенствованной системы автоматического управления положением электродов дуговых сталеплавильных печей и агрегатов ковш-печь

The paper deals with consideration of the improved mathematical model of the automatic electrodes’ position control system of electric arc furnaces (EAF) and ladle furnaces (LF). As a simplification the mathematical model has been presented in one-phase form. It consists of: 1) model of furnace’s electric circuit with non-linear equation Cassie describes instantaneous admittance of electric arcs, 2) model of hydraulic electric drives with servovalves which have non-linear regulation characteristic, 3) adaptive non-linear impedance regulator. Comparison between traditional structures of the non-linear impedance regulators using inside electrodes position control systems “ARCOS” (Siemens VAI) and “HI-REG” (Danieli) and improved regulator in new control system “RADUGA PK” is considered.

Impedance Controllers for Electric-Driven Robots

This article presents a proposal of impedance controller, which is able to infulence the compliance of a robot, based on information obtained from a lowlevel controller about robot interaction with the environment. The proposed system consists of a lowlevel controller with proximity sensor, based on which mechanical impedance is adjusted. The intention of the creators was to develop a universal impedance regulator in the sense of hardware and software layers. Because of TCP/IP architecture, the designed regulator can be easily adapted to different robot controllers. Experiments were conducted on a real 1-DOF manipulator driven by BLDC motor, as well as using simulation on a 2DOF planar robot.

Synthesis of adaptive impedance control for bipedal robot mechanisms

The paper describes the impedance algorithm in locomotion of humanoid robot with proposed parameter modulation depending on the gate phase. The analysis shows influence of walking speed and foot elevation on regulator's parameters. Chosen criterion cares for footpath tracking and needed energy for that way of walking. The experiments give recommendation for impedance regulator tuning.

A finite element iterative simulation of coupled electrothermal effects in an electric smelting furnace

The problem of predicting the electrothermal conditions within the slag bath of an electric smelting furnace is considered. A method of decoupling the electrothermal and fluid flow aspects of the problem is described. The steady state temperature and power distributions in the conducting slag bath are efficiently calculated using a Finite Element-simulation. A unique feature of the simulation is the incorporation of an impedance regulator that adjusts the immersion of the electrode as the electrothermal iteration proceeds. It is shown that the simulation predicts the terminal characteristics of the furnace with very good accuracy.