Current Controlled Voltage Source Research Articles

Simulation of an Indirect Rotor Flux Oriented Induction Motor Drive using Matlab/Simulink

Indirect Field Oriented Control (IFOC) is very popular technique in industries due to its simple designing and structure, in comparison to the direct method since it requires flux and torque estimators. This paper presents detail calculation of all values needed for the development of an indirect rotor flux oriented induction motor model fed by a current-controlled voltage source inverter. With the calculated values for 1 hp 50 Hz 3 phase induction motor; an indirect rotor flux oriented model is developed using MATLAB/Simulink. The simulation results are outlined and discussed.

A novel quasi-master-slave control frame for PV-storage independent microgrid

In microgrid, photovoltaic (PV) and storage are always combined as a droop-controlled ideal source, which is not very practical. Alternatively, this paper introduces a PV-storage independent system via allocating the PV-storage separately. For this structure, a novel quasi-master-slave control frame is proposed without communication. Storages work as master voltage sources, and PVs operate as current controlled voltage sources (CCVS). For the slave PVs, a MPPT-based power droop control and an adaptive reactive power control are proposed. Thus, PVs can simultaneously achieve maximum energy utilization in real-time and the voltage/frequency regulation. Compared with the conventional master-slave frame, this quasi-master-slave frame is more applicable for allowing a high PV penetration and for unifying islanded and grid-connected modes. Furthermore, the small signal stability of entire system is analyzed to design the physical and control parameters, such as, the minimum capacitance value of DC side, droop coefficients. Finally, simulation and experimental results are presented to verify the system effectiveness.

Galvanically Decoupled Current Source Modules for Multi-Channel Bioimpedance Measurement Systems

Bioimpedance measurements have become a useful technique in the past several years in biomedical engineering. Especially, multi-channel measurements facilitate new imaging and patient monitoring techniques. While most instrumentation research has focused on signal acquisition and signal processing, this work proposes the design of an excitation current source module that can be easily implemented in existing or upcoming bioimpedance measurement systems. It is galvanically isolated to enable simultaneous multi-channel bioimpedance measurements with a very low channel-coupling. The system is based on a microcontroller in combination with a voltage-controlled current source circuit. It generates selectable sinusoidal excitation signals between 0.12 and 1.5 mA in a frequency range from 12 to 250 kHz, whereas the voltage compliance range is ±3.2 V. The coupling factor between two current sources, experimentally galvanically connected with each other, is measured to be less than −48 dB over the entire intended frequency range. Finally, suggestions for developments in the future are made.

Power Quality Enhancement Using Linear Quadratic Regulator Based Current-controlled Voltage Source Inverter for the Grid Integrated Renewable Energy System

This paper presents an optimal control strategy using linear quadratic regulator (LQR) applied in current-controlled voltage source inverter (CCVSI) to control the real and reactive power flow between the renewable energy system (RES) and the grid. It also compensates harmonic current components drawn by the load from the grid terminal. A simplified equivalent circuit is used to develop the reduced order state space model of the three-phase grid connected renewable energy system. This makes the analysis and design of control law simpler by reducing the number of weighing variables used in LQR. The extension real–reactive power (p–q) method implemented in a–b–c frame is used to generate the reference current for controlling the real and reactive power to the grid to minimize the total harmonic distortion (THD) and to achieve unity power factor (UPF) operation at the grid side. The stated technique makes the grid current sinusoidal even under unbalanced grid voltages and the harmonic distortion factors are well within the IEEE limits. The system is simulated under changes in the real power fed from RES to the grid for both balanced and unbalanced grid conditions. The simulation results are validated by the experimental results.

A high output swing current-steering DAC using voltage controlled current source

As the supply voltage decreasing to near 1V, the output swing of the CS-DAC (current-steering digital-to-analogue converter) is limited by the minimum biasing voltage of the current source array, which is approximately 0.4V. This voltage takes one-third of the 1.2V power supply, which makes the single-ended CS-DAC not practical. To eliminate the output swing limitation, a voltage-controlled current source (VCCS) is proposed to realize high-swing single-ended voltage output for CS-DAC. The VCCS has the same input voltage as the biasing voltage. It generates a matching output current to make the minimum output voltage of the single-ended CS-DAC be able to reach the ground. The VCCS adopts a cascode structure in the output path, thus its performance is independent of DAC output changes. Careful matching is made inside VCCS, as well as between VCCS and DAC. Consequently, this design is robust to the process, supply voltage, and temperature (PVT) variations. The proposed CS-DAC, implemented by 180-nm CMOS technology, has a 1V output swing under 1.25–1.5V power supply at 25°C temperature. For all PVT variation corners, the measured minimum DAC output voltage, designed as 0.11V, varies between 0.05V and 0.113V. The measured DNL and INL are normally less than 0.2 LSB and 0.5 LSB, respectively. The measured slewing time for rising and falling step input are 80ns and 90ns, respectively. The measured total power consumption is 1.5mW.

Phillips-Heffron model for current-controlled power electronic generation unit

This paper presents a Phillips-Heffron model for the generation unit with current-controlled (CC) voltage source converter (VSC) as the interface. A concept of current angle is put forward for the CC-VSC, and the relationship between the current angle and the power angle is also quantified. Based on the current angle, a Phillips-Heffron model is established for the generation unit with CC-VSC, considering the dynamic of phase-locked-loop (PLL) in the weak grid. The model demonstrates that small-signal dynamics of the generation unit is similar to that of the traditional synchronous generator (SG) which is characterized by the electromechanical swing equations. Then the dynamics can be depicted by the famous inertia, synchronizing and damping coefficients. Small-signal stability of a CC-VSC-based single machine infinite bus system is analyzed by means of the traditional theory of power system. Based on the relationship between the current angle and the power angle, the Phillips-Heffron model of the CC-VSC is also used in stability analysis of multi-machine power system, and parameter optimizations of the CC-VSC are also studied for stability improvement.

Common- and Differential-Mode Conversion Induced by Asymmetry and Dielectric Coating in a Transmission Line System

The asymmetry/coating-induced mode conversion (ACIMC) effect in a transmission line system is discussed in this letter. This effect is proved only to be induced when asymmetry and coating exist simultaneously. The reason for ACIMC is that asymmetry and coating lead to the inconsistency of current division factors for electric and magnetic effects. Based on this idea, ACIMC is modeled by adding common-mode current-controlled voltage sources in differential circuits, and the results agree well with those obtained by the method of moments. Moreover, it is proved that balanced-state-matched terminal loads do not exist for a asymmetric and coated transmission line system, but approximate ones at low frequencies could still be found.

Active Current Source IGBT Gate Drive With Closed-Loop di/dt and dv/dt Control

This paper proposes an active current source gate drive (ACSD) method based on voltage controlled current source(VCCS) feedback control strategy for high-power IGBTs. Unlike the common voltage source gate drive, the proposed ACSD method provides constant drive current to charge and discharge an IGBT. With a large gate drive current, high switching speed and low switching losses can be achieved in a power converter. However, a high-current/voltage overshoot occurs. To solve this problem, a feedback current proportional to the di/dt or dv/dt signal is generated to the IGBT gate. Thus, direct control of the net gate drive current is produced. Then, the current/voltage overshoot is controlled with little sacrifice in switching time, and the switching losses are lower than that with the conventional gate drive method operating simply by gate resistance switchover. The operation principle and circuit implementation of the proposed ACSD method are presented. The experimental results from a 1200 V/800 A IGBT module verify the performance of the proposed method.

An EMTP Comprehensive Model of Tower Grounding and its Simulation Analysis

For the purpose of designing the grounding device of the poles and towers an improved EMTP model is put forward in this paper. The impulse characteristics of the tower grounding under impulse currents are simulated and analysed based on circuit theory. Only the non-linear effects caused by soil ionization are considered in the current studies. And the interactions deriving from the coexistence of segmented grounding electrodes have been neglected. Consequently, the calculated results of the impulse grounding resistance of the complex grounding device such as the tower grounding are not enough accurate using the traditional models. The soil ionization effects are simulated through the non-linear resistance. The current-controlled voltage sources are introduced in the model to take into account the interactions of the segmented grounding electrodes. Then the comprehensive model of the tower grounding is established. Comparison of simulation results with experimental data implies that the tower grounding model proposed in this paper is more accurate and effective than the traditional model.

Fault Analysis Method for Power Distribution Grid with PCS-based Distributed Energy Resources

In this study, we propose a fault analysis method for a power distribution grid with PCSbased DERs. We first explain the characteristics of a PCS-based DER. According to the characteristics, the DER is considered as a current-controlled voltage source, which produces varying voltages within a certain limit so that currents equal to given references flowing from the DER to the grid (currents controlled). So, we introduce the symmetrical equivalent models in the form of varying voltage source for fault analysis and then, construct a convex optimization problem to solve the fault problem associated with the equivalent models and grid conditions. Thus, the proposed method enables to perform a proper fault analysis considering the characteristics of the DER, which are currents controlled, voltage limited, and unity power factor achievement. To verify the validity of the proposed method, we perform computer simulations with the proposed method and with MATLAB Simulink, and the results are compared.

Exploring the High-Power Inverter: Reviewing critical design elements for electric vehicle applications

The key components in an electric vehicle (EV) propulsion system are the dc energy source (either a battery or a fuel cell), the inverter, the motor, and the gear reduction. This article will focus on the inverter unit and highlight unique requirements, constraints, and important design considerations. The top-level function of the inverter is to convert dc bus quantities to high-fidelity ac current and voltage required to drive the traction motor. The automotive industry has largely converged on the three-phase current-controlled voltage source inverter as the topology of choice for this application. Other topologies may be considered, though their overriding design constraints are similar and hence will not be discussed here. In particular, the inverter must be powerful, efficient, and reliable and must accomplish these objectives while maintaining low cost, size, and weight. Figure 1 shows a prototype power inverter with every component designed specifically to meet the demanding requirements of today's EV.

The Derived Equivalent Circuit Model for Magnetized Anisotropic Graphene

Due to the static magnetic field, the conductivity for graphene becomes a dispersive and anisotropic tensor, which complicates most modeling methodologies. In this communication, a novel equivalent circuit model is proposed for graphene with the magnetostatic bias based on the electric field integral equation. To characterize the anisotropic property of the biased graphene, the resistive part of the unit circuit is replaced by a resistor in series with current-controlled voltage sources (CCVSs). The CCVSs account for the off-diagonal parts of the surface conductivity tensor for the magnetized graphene. This proposed method is benchmarked with numerical examples. This communication also provides a new equivalent circuit model to deal with anisotropic materials.

Online Loss Parameters Diagnosis Device Development of Power Cable Insulation

In southern China, power cable lines often running in water, and the state of XLPE insulation is difficult to detection effectively. This paper studied loss parameters online diagnosis technology of power cable insulation. An online loss parameters diagnosis device was development, which consists of current comparator, voltage controlled current source (VCCS), standard capacitor, GPRS wireless transmission system, control system and the data processing unit. 108 cables were detected using this device, and it was found out that one cable appeared to middle aging and eight cables appeared to slight aging. The butterfly water trees were observed in middle aging cable, which prove the effectiveness of online testing in the loss current measurement.

Online learning control for harmonics reduction based on current controlled voltage source power inverters

Nonlinear loads in the power distribution system cause non-sinusoidal currents and voltages with harmonic components. Shunt active filters U+0028 SAF U+0029 with current controlled voltage source inverters U+0028 CCVSI U+0029 are usually used to obtain balanced and sinusoidal source currents by injecting compensation currents. However, CCVSI with traditional controllers have a limited transient and steady state performance. In this paper, we propose an adaptive dynamic programming U+0028 ADP U+0029 controller with online learning capability to improve transient response and harmonics. The proposed controller works alongside existing proportional integral U+0028 PI U+0029 controllers to efficiently track the reference currents in the d-q domain. It can generate adaptive control actions to compensate the PI controller. The proposed system was simulated under different nonlinear U+0028 three-phase full wave rectifier U+0029 load conditions. The performance of the proposed approach was compared with the traditional approach. We have also included the simulation results without connecting the traditional PI control based power inverter for reference comparison. The online learning based ADP controller not only reduced average total harmonic distortion by 18.41 U+0025, but also outperformed traditional PI controllers during transients.

A PSpice Circuit Model for Single-Photon Avalanche Diodes

In this paper, we present an improved circuit model for single-photon avalanche diodes without any convergence problems. The device simulation is based on Orcad PSpice and all the employed components are available in the standard library of the software. In particular, an intuitionistic and simple voltage-controlled current source is adopted to characterize the static behavior, which can better represent the voltage-current relationship than traditional model and reduce computational complexity of simulation. The derived can implement the self-sustaining, self-quenching and the recovery processes of the SPAD. And the simulation shows a reasonable result that the model can well emulate the avalanche process of SPAD.

Surge arrester modeling using Micro-Cap

In this paper the results of circuit simulation of metal-oxide surge arrester using the Micro-Cap evaluation version are presented. Nowadays a surge arrester is the most common type of overvoltage protection device and appropriate modeling of such power system’s component is a significant task. Moreover, metal-oxide arresters have dynamic characteristics that are significant for studies involving lightning and other steep-front surges. Two methods of metal-oxide surge arrester modeling are described. The main innovation introduced by the paper lays in the usage of analog behavioral voltage-controlled current source and current-controlled voltage source for non-linear varistor modeling. The residual voltage test results obtained by the manufacturers were compared with the results of simulations performed with the Micro-Cap evaluation version. Both proposed models fits with a high accuracy the arrester performances reported in the data sheet. Two different lightning current waveforms were used. One of them has its first derivative equal to zero at the initial moment of time and other one does not. For both waveforms maximal residual voltages obtained in the simulation are almost equal. Effectiveness and simplicity of use make the proposed way of modeling a useful tool for insulation coordination and lightning protection studies.

Aircraft Landing Gear Embedded Buffer Controller Design Based On Magneto-Rheological Fluid

Based on problem that the magneto rheological damper damping force of aircraft landing gear is not controllable in the process of aircraft's landing and taxiing. A method of embedded buffer controller of aircraft landing gear based on magneto rheological fluid is presented and the buffer control system is designed to control the magneto rheological damper damping force in my article, which mainly includes the selection of embedded digital signal processor（DSP），the principle design of control system, and the design of power generation circuit modules, reset circuit modules, JTAG emulation circuit module, clock oscillator circuit module, A/D sampling correction module, D/A converter module, E2ROM circuit and the voltage controlled current source driver module. Through the simulation of circuit module, the current that is generated by voltage-controlled current source in the control system is acceptable to the MR damper, the magneto rheological buffer controller can control damping force and play a role in adjusting the aircraft landing gear.

Back to Back Voltage Source Inverter untuk Kontrol Self Excited Induction Generator

Wind is one of the most develop renewable energy to help human meet the electricity needs as availability is abundant. Instrument which can be used to convert wind energy into electrical energy is an induction generator. In this final project will discuss about the operation of the wind turbine with induction generator controlled using back to back voltage source inverter with grid connected system low voltage 380 V. Switching of back to back voltage source inverter was designed in average model. In back to back voltage source inverter, there are two converters that are machine side converter and grid side converter. Machine side converter has function to regulate the voltage and frequency of generator and turbine speed in order to the wind turbine can generate maximum power at any wind speed with method volt / hetrz constant control. Grid side converter has function to adjust the DC voltage keep be contant by synchronizing the phase angle between the converter output and grid using current controlled voltage source inverter method. The simulation results showed that wind turbine always generated the maximum power at any wind speed. Voltage and frequency of Generator is stable and directly proportional to the wind speed and the dc link voltage is always constant so the power flow can bidirectional. Therefore, back-to-back voltage source inverter is suitable for controlling wind turbine using an induction generator.

High stability voltage controlled current source for cervical cancer detection using electrical impedance spectroscopy

The design of a high stability voltage controlled current source (VCCS) for cervical cancer detection (CCD) applying electrical bio-impedance spectroscopy (EBS) is presented. The circuit was designed, simulated and fabricated in TSMC 130 nm CMOS technology at 1.3 V power supply. The proposed Howland current source is based on self-biased complementary folded cascode (SB-CFC) operational amplifier (OA). Complying with the requirements for medical electrical equipment of international standard ABNT-NBR-IEC-60601-1 the sinusoidal current peak amplitude was settled at 10 μA. In accordance with the requirements of the EBS for CCD, the specifications for the SB-CFC-OA were calculated to meet the 100 Hz---1 MHz frequency range for the sinusoidal output current and the output impedance higher than 1 Mź at 1 MHz frequency. Post-layout simulations were run and the main results were: 10 ± 0.0335 μA for the output current peak amplitude over the specified frequency range and with 5 kź load impedance; values above 1.6 Mź output impedance at 1 MHz; nominal current amplitude variations lower than 0.4 % for load impedances in the range of 10 ź up to 5 kź. And the experimental result for maximum non-linearity was 2.19 % of full scale. From these results, the performance of the VCCS is adequate for EBS-CCD applications.

Fault Immune Pico-Hydro Powered Base Station of Remote Telecommunication Tower

This paper presents the dynamic excitation control of a siphon-turbine coupled pico-hydro powered cage rotor induction generator and load matching for off-grid electricity generation. Through the proposed dual-role of the current-controlled voltage source converter (VSC), acting as static synchronous compensator and load controller, real and reactive power are dynamically controlled in a decoupled manner with a self supported DC-bus. The proposed scheme entails minimal computation for ensuring the rated (set) capacity of real power. The scheme also exhibits fault immunity for protection, thus enabling the effective handling of constant power electrical loads presented by base telecom station towers in remote locations. The performance of the system is evaluated under MATLAB/Simulink and is experimented through a developed hardware prototype. Simulation and experimental results show close conformity and validate the effectiveness of the proposed scheme.