Current Controlled Voltage Source Research Articles

Implementation of Shunt Active Power Filter Using DSP Controller Based on Synchronous Reference Frame for Harmonic Mitigation

This research paper introduces the concept of a shunt active power filter (SAPF) that leverages synchronous-reference-frame (SRF) theory to mitigate harmonics in the power system. The SAPF works by injecting a compensating current at the point of common coupling (PCC) to counteract the harmonics in the line and restore sinusoidal current waveforms. It employs a three-phase current-controlled voltage source inverter (VSI) with a DC link capacitor for active filtering. An SRF algorithm is designed for a low-voltage laboratory prototype utilizing the TMS320F28335 Digital Signal Processor (DSP). The experimental findings affirm that the control strategy effectively aligns with the recommended harmonic standard limits of IEEE 519-1992.

Improved Reference Current Extraction Method for Electric Aircraft Active Power Filter Application

This paper proposes a robust reference current extraction method useful for active power filters (APFs) connected to the More Electric Aircraft (MEA) grid for addressing power quality issues. Hence, it is essential to investigate and develop better APF harmonic compensating control algorithms that can eliminate the impact of harmonics emerging from the nonlinear loads connected to the MEA grid. The proposed method envisages a half-cycle moving window discrete Fourier transform filter approach to rapidly extract the fundamental positive sequence (FPS) from a polluted three-phase grid voltage. Thus, allowing the harmonic cancelation method to generate desired clean reference current which is in phase with FPS component of the grid voltage. This reference current is used in conjunction with the hysteresis current controller to generate appropriate gate pulses for the current-controlled voltage source APF. The employment of the digital filter in the control structure of the APF ensures improved power quality for the MEA grid as compared to traditional filtering algorithms. The numerical and experimental results demonstrate that the proposed control solution helps to reduce the total harmonic distortion under abnormal grid disturbances, thus, indicating the potential benefits of the proposed work for addressing power quality issues in MEA applications.

Effect of Semiconductor Materials on the Current Control Voltage Source Trancitor Hall Voltage

Effect of Semiconductor Materials on the Current Control Voltage Source Trancitor Hall Voltage

Circuit design of a high scanning frequence and fast response laser methane remote sensor

To solve the problem of slow detection of laser methane sensors based on tunable diode laser absorption spectroscopy (TDLAS), a methane detection system with a high detection rate was proposed. Focusing on the hardware circuit design of the system which consists of a laser driver circuit, laser temperature control circuit, optical amplifier and filter circuit and main control circuit based on FPGA+ARM, this circuit is designed to achieve a laser scanning frequency of 50 kHz. A voltage-controlled current source is designed to drive the laser diode (LD). A TEC controller is designed to keep the operating temperature of the laser diode stable. Since the photocurrent can be very weak, to ensure the quality of signals from the photodiode (PD), a signal collection circuit consisting of the transimpedance amplifier, gain-controlled amplifier and low-pass filter was designed. An experiment is carried out to test system measurement capabilities. The results show the circuit can reach a response time of 2.5 ms while ensuring a measurement error of less than 4.3%.

A novel CMOS active inductor with high quality factor, high linearity and mutually independent tuning of inductance and quality factor

A novel CMOS active inductor (CAI) circuit topology is proposed. It consists of two identical gyrators, a voltage-controlled negative resistance cell (VCNRC) and a voltage-controlled current source (VCCS). And each gyrator is composed of a feedforward transistor, a feedback transistor, a cascaded transistor, a common-source (CS) transistor, and a feedback resistor. Moreover, these two gyrators are symmetric and form a differential structure. By above building blocks configuration and cooperation, the CAI can achieve following different performances. First, high quality factor (Q) can be achieved by a combination of the VCNRC, the cascaded transistors and the feedback resistors due to the decrease in the equivalent resistance losses; Secondly, high linearity can be realized by the additional CS transistors due to the compensation for the nonlinear drain current of the feedback transistors. Thirdly, mutually independent tuning of inductance (LCAI) and Q can be achieved by tuning three external bias voltage terminals respectively configured in the cascaded transistors, the VCNRC and the VCCS. The verification results show that at the frequency of 2.0 GHz, the peak Q can be tuned from 555 to 2780 with a large tuning range of 400.9 %, while the LCAI can be maintained within a small variation of only 0.9 %; on the other hand, LCAI at 2.0 GHz can also be tuned from 158 nH to 212 nH while the Q value has a variation of only 4.2 %; moreover, the CAI also is demonstrated to have inductance linearity as high as +0.17 dBm, and occupies a compact effective area of 43 μm × 52 μm. In addition, the output noise voltage at 2 GHz is 3.1 nV/√Hz, and both LCAI and Q values also exhibit good robustness against process corner and temperature variations. These comprehensive results highlight the CAI excellent performances in terms of size, Q value, linearity, mutually tunability of LCAI and Q, noise performance as well as the robustness against process and temperature variations.

A voltage-controlled current source for temporal interference stimulation: Analysis, design, and study.

The temporal interference stimulation is a new technique to modulate brain activity by applying multiple channels of voltage-controlled current source (VCCS) simultaneously to the receptor surface. In this paper, the envelopes of the overlapped current waves at several areas of the receptor were analyzed and discussed with different circuit structures of VCCS. A complementary differential current source (CDCS) was designed to fit the best circuit topology based on the analysis of the enhanced Howland current source structure. Experiments were conducted by injecting current to a swine tissue using the CDCS and conventional VCCS and acquiring the voltage waveform data from different parts of the tissue. The waveforms were compared and analyzed, revealing that the conventional VCCS may generate an interference envelope in unexpected regions, while the CDCS did not. The CDCS design approach in this paper provides a new solution for temporal interference stimulation VCCS.

An Enhancement of Power Quality With Efficient Active Power Transfer Capability in a PV–BSS-Fed UAPF for Microgrid Realization

This article investigates the enhancement of power quality with an efficient active power transfer capability in a universal active power filter (UAPF) integrated with a photovoltaic (PV) and battery storage system (BSS). The UAPF operates as a bidirectional interface between the PV–BSS and point of interconnection for microgrid realization. A new control strategy is proposed to extract fast and accurate voltage and current reference signals to operate the system in a desired manner. Here, the extraction of load voltages and calculation of load and reference powers are used to generate the reference signals, thereby comparing with actual signals with hysteresis controller to produce switching pulses of converters. As a result, the shunt and series converters form a robust system by acting as a current-controlled voltage source and voltage-controlled current source, respectively. It eliminates the need for adaptive filters and low-pass filters to extract the fundamental component of the load current. Furthermore, it increases the conversion efficiency of converters and improves the static and dynamic performance of the system. The proposed system is developed with a 1-kVA prototype laboratory setup using a field-programmable gate array controller and extensively tested with various test conditions such as grid voltage fluctuations, nonlinear and imbalanced load, and change in irradiance.

An open source Modelica implementation of the IEC 61400-27-1 type 4 wind turbine model for power system stability assessment

This paper presents a Modelica open-source implementation of the IEC 61400-27-1:2020 wind turbine and wind power plant models and proposes a modified version in which the high level control remains unchanged while an inner current loop is added together with a more detailed representation of the phase-locked loop. Accordingly, the dynamics of the output filter are also introduced within the generator system, which is now modeled as a current-controlled voltage source instead of a current injector inspired by recent work on grid forming controls. The original wind turbine model has been successfully validated, using both OpenModelica and Dyna ω o, a hybrid Modelica/C++ suite of simulation tools, with respect to Eurostag results considering the 2015 Neplan test case. In addition, satisfying performances of the modified generator and control systems were obtained. Finally, the wind power plant models were integrated into the IEEE 14 bus system by replacing one of the synchronous generators. • A Modelica implementation of IEC 61400-27-1:2020 wind turbine and power plant has been proposed. • A version with a current loop and a more detailed phase-locked loop is proposed. • The dynamics of the output filter are also introduced within the generator system. • The models have been successfully validated, using both OpenModelica and Dyna ω o. • Satisfying performances of the modified generator and control systems were obtained.

Analysis and practical implementation of a high-power Howland Current Source

This work presents the theoretical and error analysis, implementation, and validation measurements of a high-power grounded-load voltage-controlled-current-source (VCCS) based on the Howland Current Source (HCS) topology. The VCCS theoretical design can output up to ±2.5 A with ±27.5 V compliance. Typically, biomedical applications use the HCS in the micro and milli-amperes range, and accuracy characterization and error analysis are unseen in the proposed high-current/voltage conditions. Commercially available high-voltage/current operational amplifiers have poor precision specifications compared to precision ones, which makes it a non-trivial problem. The work discusses the HCS theory and presents a thorough analysis of the non-linear errors in the circuit. Practical implementations using different conditions and amplifiers display the effect of those errors in the output current accuracy and linearity. The final design using an OPA544 amplifier yields an accuracy superior to 0.075% after a first-order calibration when driving up to a ±2.10 A current.

Research on control algorithm of strong magnetic interference compensation for MEMS electronic compass

In view of the complicated data acquisition process of traditional MEMS electronic compass compensation methods and the inability to achieve high-precision compensation under strong magnetic interference, this paper studies a compensation method with an external three-axis coil. Firstly, the error modeling of the magnetometer is carried out, and two methods of compensation without heading reference based on M−estimates and compensation with heading reference are introduced. We built a hardware circuit on the basis of a physical coil, used a PXI industrial computer as the data acquisition and processing center, provided current excitation for the coil through a voltage-controlled constant current source, and used LabVIEW to design a control program. Finally, we comprehensively evaluate and verify the feasibility and compensation accuracy of the proposed scheme through vehicle-mounted tests. The test results show that: a heading reference compensation algorithm has higher compensation accuracy, the compensated heading error is within ± 1.5°, and the standard deviation is below 0.8°, which meets the needs of car navigation.

An equivalent circuit model of NBTI effect for short-channel P-MOSFET

An equivalent circuit model of the negative bias temperature instability (NBTI) effect in 65 nm P-MOSFET is presented in this paper. Based on an existing P-MOSFET model of a 65 nm CMOS foundry PDK (Process Design Kit) and several basic electrical components and arithmetic cells in the EDA (Electronics Design Automation) library, an equivalent circuit model for NBTI degradation has been achieved. The electrical components and arithmetic cells include voltage source, voltage-controlled voltage source, voltage-controlled current source, adder, and multiplier. The equivalent circuit model includes five tunable input parameters: gate width (W), gate length (L), temperature (temp), stress time (t), and process corner (typical/fast/slow). The model takes into account the effects of drain-source, drain-gate, and gate-source voltage stress states. The effect of process corner on NBTI is also considered. The simulation results show that the performance curve of this P-MOSFET equivalent circuit model is consistent with the measured data in some published literature. This equivalent circuit model can be utilized for long-term reliability IC design.

Simplified Inverter-Based Generation Model for Protection and Short-Term Stability Studies in Electromagnetic Transient Resolution

The new dynamics of inverter-based generation (IBG) and the lack of accurate models jeopardize the safety of power systems. Additionally, most of the detailed models for electromagnetic transients (EMT) from manufacturers are black boxes. For this reason, the objective of this work was to propose a generic IBG model in EMT resolution suitable for short-circuit, protections, and short-term voltage stability studies. For this purpose, the model considered different functionalities, such as synchronization in case of unbalanced voltage sags, flexible negative sequence current injection, peak current limitation, dynamic reactive power control, and fault ride-through (FRT). This model allowed grid operators to meet the challenge of performing accurate simulations with high integration of renewable resources in their energy matrix. The model was also based on a voltage-controlled current source in the ATP/EMTP software. The short-circuit response was evaluated in a simulation scenario for different fault events presenting a reliable behavior due to the consideration of technical and regulatory requirements and constraints of IBGs. Finally, the proposed model has a fast initialization and is suitable for simulations with large time steps, making it valuable for EMT simulations in large grids.

Accurate High-Frequency Modeling of the Input Admittance of PWM Grid-Connected VSCs

This article addresses high-frequency admittance modeling of current-controlled voltage source converters (VSCs). Recent studies have shown that harmonic instability may also occur at frequencies above the Nyquist frequency. To form an accurate multiple-frequency model in this frequency range, sidebands that originate from modulation and sampling must be examined. In this article, an accurate small-signal model is developed taking into account an adequate digital pulsewidth modulator (DPWM) representation, which allows to predict dependence of the frequency response on the steady-state dc (SS-dc) operating point. It is shown that when center-pulse sampling is implemented, pulsewidth modulation sidebands do not create additional loops leaving only sampling sidebands to be considered. Using the same approach as for SS-dc operation, a model that accurately represents admittance measurements during sinusoidal ac (S-ac) operation is developed. Its basis is a novel DPWM model suitable for S-ac regime, which allows to predict dependence of the VSC’s input admittance on the grid voltage magnitude. Experimental and simulated admittance measurements, performed on a single-phase two-level VSC during various SS-dc and S-ac regimes, match with the proposed models up to twice the sampling frequency.

Comparative Study of Measurement Methods for Embedded Bioimpedance Spectroscopy Systems

Bioimpedance spectroscopy (BIS) is an advanced measurement method for providing information on impedance changes at several frequencies by injecting a low current into a device under test and analyzing the response voltage. Several methods have been elaborated for BIS measurement, calculating impedance with a gain phase detector (GPD), IQ demodulation, and fast Fourier transform (FFT). Although the measurement method has a big influence on the measurement system performance, a systematical comparative study has not been performed yet. In this paper, we compare them based on simulations and experimental studies. To maintain similar conditions in the implementation of all methods, we use the same signal generator followed by a voltage-controlled current source (VCCS) as a signal generator. For performance analysis, three DUTs have been designed to imitate the typical behavior of biological tissues. A laboratory impedance analyzer is used as a reference. The comparison addresses magnitude measurement accuracy, phase measurement accuracy, signal processing, hardware complexity, and power consumption. The result shows that the FFT-based system excels with high accuracy for amplitude and phase measurement while providing the lowest hardware complexity, and power consumption, but it needs a much higher software complexity.

Modeling and Analysis of Multiple Inverters With Dual-Loop-Based Virtual Oscillator Control

Virtual oscillator control (VOC) is an emerging decentralized control technique for grid-forming inverter applications. In contrast to conventional phasor-based droop control or virtual synchronous machine control, VOC is a time-domain controller designed to emulate the dynamics of a nonlinear oscillator. VOC is a current-controlled voltage source, lacking the ability to regulate the inverter terminal voltage, which will result in significant voltage deviations caused by dead-time effects, nonideal semiconductor devices, and output filter voltage drops. In this article, a voltage and current dual-loop control structure augments the VOC to compensate for these voltage deviations and regulate the inverter output variables directly. A complete small-signal model for a multiple inverter-based microgrids with the proposed control structure is presented in order to assess system stability using eigenvalue and participation factor analysis. Analytical results show that the parameter related to the frequency regulation and the integral gain of the voltage controller affect the location of the system’s dominant modes significantly. The stability margin is determined by modifying these control parameters. Experimental results on a laboratory test microgrid verify the predication from the small-signal analysis and time-domain simulations.

Design and real-time validation of PI and Fuzzy Logic tuned photovoltaic integrated DSTATCOM to improve power quality.

Power loss and malfunctioning of equipment due to current and voltage harmonics produced by nonlinear loads are major concerns for both power suppliers and consumers. This paper employs DSTATCOM to mitigate these harmonic distortions in distribution systems. DSTATCOM is a current controlled voltage source PWM converter with passive components. It supplies compensating current that eliminates current harmonics and provides reactive power compensation thereby providing a smooth source current. The performance of DSTATCOM is controlled using proportional integral and fuzzy logic-based control (FLC) schemes to improve power quality at dynamic loading. As the penetration of photovoltaic (PV) systems in energy production is significant, the power quality issues for PV-integrated systems have also been investigated. The maximum power point for a PV array is tracked using perturb and observe and FLC methods. The complete system is simulated in MATLAB and extensively investigated for a large range of balanced and unbalanced nonlinear load conditions. The simulation results are validated in real time through the hardware in loop (HIL) test bench using Opal-RT controller. The proposed PV-integrated DSTATCOM with FLC yields better performance in terms of DC link voltage settling time, total harmonics distortion, and smooth source current as compared to other schemes.

Gyrator-capacitor based modelling and simulation of forward converter

PurposeThis paper aims to propose an efficient model for analysis of power electronic circuits with integrated magnetic components.Design/methodology/approachThe inductance modeling technique is used as the traditional method for analyzing magnetic components. This model is simple and enough to generate for individual components, that is, an inductor and a transformer. However, it becomes difficult to realize this model for the integrated magnetic structures. This paper shows an appropriate model for individual magnetic components as well as integrated magnetic components and its application to magnetically coupled DC–DC converters. Gyrator–capacitor (G–C) modeling offers a unified, reasonable way of understanding the magnetic components commonly met with in power electronics and the other disciplines.FindingsG–C model allows any electrical and magnetic circuit to be simultaneously simulated with circuit simulators. In this regard, this paper gives a complete simulation model and analysis as an illustrative example. There is no limitation of this paper or future works. The proposed G–C model can be applied to all power electronic circuits having integrated magnetic components.Originality/valueIn the proposed model, the magnetic circuit is converted to a pure electric circuit with capacitors and controlled sources; every winding is replaced with a pair of current controlled voltage sources, namely, a gyrator.

Load Flow and Short-Circuit Methods for Grids Dominated by Inverter-Based Distributed Generation

The use of power-electronics-based devices in distribution generation seeks to improve energy quality and reduce costs. The inverter-based distributed generator, that works in different operation modes, has emerged as a promising technology. In a high distributed generation penetration scenario it is important to know the voltage profile and fault information due to the uncertainty in the generator operation and the impact that have on the network. This study aims to use two proposed methods of analysis: for power flow, based on backward/forward sweep method, and short-circuit, based on hybrid impedance matrix, that considers the inverter operation modes and represents each generator as a voltage-controlled current source. The chosen network is the IEEE 34-Node Test Feeder with a generator on each load per phase. The voltage profiles obtained will be validated with a Simulink/Matlab phasorial model. The results show an average error of 2.39% and a gain in voltage profile processing time of 2185.24%, making its use consistent for larger systems.

A Scalable Model for Snapback Characteristics of Circuit-Level ESD Simulation

It is challenging to simulate the snapback behaviors under electrostatic discharge (ESD) stresses due to the limitation of simulation program with integrated circuit emphasis (SPICE) simulation tools. In this paper, a new model is proposed to investigate the avalanche breakdown effect using the voltage-controlled current source (VCCS), which greatly facilitates the calculation of the avalanche multiplication factor M and improves the convergence characteristics. In particular, this new method transfers the exponential relationship of M into the linear relationship of the VCCS gain. The versatility of the model is validated by its operations in various ESD protection circuits with MOS as the discharge device, while the scalability is demonstrated by its applications in varied device sizes.

An efficient multidisciplinary design research for the integrated low speed permanent magnet motor system based on analytical and numerical hybrid analysis

This paper proposed an efficient high-accuracy multidisciplinary design process for the integrated system of low speed permanent magnet synchronous motor (PMSM). The method combined the analytical models and numerical models together to get an efficient way to design the integrated motor. In the proposed method, a magnetic equivalent circuit (MEC) model of the motor is established first based on one modular structure of the motor, and the finite element analysis (FEA) numerical model is used to correct the results of the analytical model next. Then the iron loss, copper loss, and switching loss from the results of the electromagnetic model are loaded to a proposed simplified lumped parameter fluid-thermal model. This fluid-thermal coupled analytical model cuts the fluid flow into several parts depends on the parameters of the cooling path, each parts act as a current controlled voltage source coupled with these parameters. And because this coupled model has controlled sources, the conventional node voltage method is not suitable anymore, so a more universal list parameter calculation method is proposed for this coupled model. Finally, the computational fluid dynamics (CFD) model is used to correct the results of the analytical model as well. The aim of the above analytical models is to quickly get the suitable multidisciplinary pre-design or design trends, and this pre-work or trends will reduce the design process time of the high-accuracy numerical models.