RLC Load Research Articles

Design and implement of pulse width modulation with low-cost hardware in the loop

<p>The paper presents a low-cost hardware in the loop based on Arduino. Sinusoidal Pulse Width Modulation (SPWM) designing, analyzing, and implementation is experimented as hardware in the loop. Sinusoidal Pulse Width Modulation implementation via MATLAB\Simulation demonstrates in this work. In this paper, Arduino Mega2560 platform, microcontroller, introduce as hardware. A comparative study of the both techniques is presented. Arduino interfaces with PC Target MATLAB environment. Three phases Voltage Source Inverter directs by the generated pulses that loads with three phases RLC. The obtaining output current and voltage waveform of RLC load of Hardware-in-the-Loop validates to the MATLAB\simulation output waveform. The compering shows the output waveforms are primarily having the same pattern. Arduino consider as the lost cost as microcontroller which could be used in real application.</p>

Large‐signal model of pulsed power load for analysis of dynamic voltage and frequency

The characteristics of pulsed power loads (PPLs), which contain several power electronic components, are different from the conventional RLC loads. If a PPL is directly connected to a sole power supply that has limited generation and small inertia (e.g. diesel generator), the sudden increase of energy demand could cause the huge voltage sags and the significant frequency drop upon the power supply. For this reason, this study proposes a large-signal model of PPL for analysing the dynamic voltage and frequency during PPL deployment. The proposed model can be described by non-linear differential-algebraic equations and established based on the equivalent circuit of PPL and the corresponding switching functions. According to the case study, the proposed model is compared with the conventional state-space averaged model and the time-domain simulation, by analysing the dynamic voltage and frequency. Finally, the test results verify the effectiveness of the proposed model and demonstrate that the proposed large-signal model would help for the study on the stability of the case-study system as well as the interaction between the diesel generators and the PPLs.

Optimal design and implementation of a half-cycle generator with the range of 400 A and 100 kHz frequency

In this paper, a double-layer half-cycle generator (HCG) has been designed and built. The proposed HCG creates sinusoidal flow with 400 A peak and 5 µs pulse width which feeds RLC load with 100 kHz work frequency, within resonance mode. Previous HCGs have been designed based on saturable reactor (SR). It should be noted that SR is a nonlinear element, and it will be distanced from its desirable performance upon change of temperature and under impact; however, a double-layer HCG has been proposed with no such defects. In proposed HCG, thyristor has been used instead of SR which is controllable, and it has none of aforementioned problems. Also, when SR is eliminated, its reverse retrieval needs no minority carriers. This way, sweep-out circuit may be also eliminated. From among other advantages of proposed HCG, reduction in number of circuit layers may be referred to, comparing to previous HCG. This results in reduction in number of equipment which in turn optimizes proposed HCG, in terms of volume and manufacturing costs. Finally, proposed HCG has been simulated in Matlab, while it has been implemented practically. Comparing simulation results and laboratory sample confirms correctness of relationships, in analytical design of HCG.

Decentralized Output-Feedback-Based Robust LQR V-f Controller for PV-Battery Microgrid Including Generation Uncertainties

Maintaining nominal voltage and frequency ( V-f ) for an isolated microgrid (MG) with photovoltaic (PV)-battery system needs stringent control arrangement due to generation arbitraries of renewable energy sources. In present article, a robust V-f controller based on decentralized output-feedback optimal linear quadratic regulator principle is proposed. As state-feedback is not involved, it avoids the usage of any estimator or observer, which makes it computationally more efficient. Moreover, its decentralized structure works on local parameter measurements that eliminate expensive communication infrastructure, making it economical. All possible uncertainties from both source and load sides, neighboring bus parameters are considered for V-f regulation using the resistive-droop mechanism that is more accurate for low voltage resistive network. For this purpose, a novel lower-order simplified small-signal MG model including two PV-battery with exclusive parallel RLC loads and LV network is used, which accounts for intermittency as variable dc-bus link dynamics. The whole MG model is segregated into two subsystems with inclusion of interconnection dynamics. The viability of proposed controller is verified by comprehensive tests, viz., variable solar irradiance, voltage set-point tracking under continuous-bounded and large-scale load perturbations, nearby bus parameter disturbances using hardware-in-the-loop simulations with real-time digital simulator and MATLAB via dSPACE controller.

Simulator Fungsi Dummy Load Menggunakan Kontrol Komputerise

ABSTRACT
 Dummy Load is used as an imitation load on the loading practice on a PLTD or PLTS generator. The existing dummy load currently installed is the conventional resistive dummy load type which is dominant at active power. The problem is that the dummy load does not yet represent the actual actual load condition, namely the RLC load. The power consumption by the dummy load is controlled by varying the firing angle ‘α’ of the thyristor- pair [1] Therefore it is necessary to improve the function of the dummy load by improving and developing the design and construction. The design of the construction improvement and development will be carried out on the main components and the digital computerized monitoring and control system for its operation. In this paper, the microcontroller-based electronic load controller (ELC) as a voltage and frequency stabilizer is designed when the dummy load is operated. This tool can prevent damage due to the frequency and output voltage of the distribution system. The result of the reconstruction is to make the PLTD / PLTS dummy load that has the ability of dummy load RLC balanced load / unbalanced load for operating loading practices, where in operation it uses a digital computerized control system that can programmed manually / auto and has a facility / feature event recorder.
 Keywords: Dummy Load, RLC, Function Enhancement, Computer Control System

Charge-discharge properties of (Pb, Ba)Nb2O6-NaNbO3-SiO2 glass-ceramics under high electric fields

In the work, 6 PbO-4 BaO-20 Na2O-40 Nb2O5-30 SiO2 glass-ceramic plates with large size were successfully fabricated. The sizes of glass ceramic dielectrics are 100 mm×100 mm×4 mm and the corresponding capacitances is 4.5 nF. Charge-discharge properties of glass-ceramic capacitors were investigated by measuring their hysteresis loops and pulsed discharge current-time curves with different RLC load and discharged voltages. The results show that the glass ceramic capacitors have high discharge energy efficiency at high electric field. The discharged energy efficiency is 92% calculated from P-E curves under 15kV/mm. Moreover, for the capacitor with the capacitance of 4.5 nF, over 73% of stored energy was released within 200 ns under 11.25 kV/mm. The glass-ceramic capacitors are very promising for pulsed power applications.

A new passive islanding detection approach considering the dynamic behavior of load in microgrid

In this paper, a new passive detection approach is proposed to solve the islanding problem of microgrid which consists of synchronous and inverter-based distributed generators. The test system for islanding detection is introduced first, and then derivative of the equivalent resistance with respect to time for test system is utilized as the islanding detection index. Under the islanding condition, the index approaches zero. However, the result of grid-connected condition is opposite. In addition, most of islanding detection methods focus on the steady-state behavior of parallel RLC load where the active power of load is directly proportional to the square of voltage. However, in fact, the active power of load would vary with change in voltage and grid frequency, which also significantly impacts islanding detection. Therefore, a new passive islanding detection method considering the dynamic behavior of load is proposed, at the same time, the threshold is obtained. The performance of proposed method has been studied in comparison with other passive islanding detection methods. Simulation results verify that the proposed method has good reliability under islanding and system disturbance conditions.

The Load Performance of Multi-Level Alternating Voltage Provided by Upgrade Effect

In this paper, the applications of the multi-level inverter with a partial inductor are investigated on different loads. The operation of the inverter is given according to different conditions of the circuit at the six-part duty times. Mathematical equations for the inverter are forming according to the load which is resistive (R), inductive (L), and Capacitive (C) in serial connection. After describing the circuit structure, Matlab SIMULİNK also simulates the circuit for loads that are RLC, and a single-phase asynchronous motor. While the voltage and current measurements for the RLC load are performed; measurements of the main winding current, auxiliary winding current, electromagnetic torque, speed are made on the asynchronous motor. RLC loads are operated at high current values such as 297A in order to examine the suitability of the proposed system for systems that may require high current. When the current harmonic distortions of RLC loads are observed, the distortion values are acceptable values that are lower than % 5 that is international standards of the IEEE. In another hand, despite the voltage is insufficient for supplying the motor at the motor application, the voltage is upgraded with the boost effect of the inverter. So, the voltage is both a multilevel and sufficient. According to the obtained results, it is shown that multi-level inverter design has been successfully performed by using partial inductor source.

Simplified Modeling and HIL Validation of Solar PVs and Storage-Based Islanded Microgrid With Generation Uncertainties

In microgrid (MG) modeling, the renewable energy sources (RESs) are mostly represented by the detailed small-signal modeling (SSM) of its interfacing inverter. In these models, the input dc-bus link voltage is assumed to be constant. However, due to generation intermittency of RESs, viz., solar photovoltaics (PV) or wind turbines, this assumption is not appropriate. Also, the effects of storage devices are ignored. Now, this detailed SSM of inverters alongside loads and network gives a system of systems architecture to the MGs, modeling of which leads to a higher-order system with a large number of states. In this work, the SSM of a standard MG system is developed using simplified lower-order models of solar PVs and batteries that incorporate generation uncertainties by considering the dynamics of both input dc and output ac terminals of the inverter. The obtained reduced order model is computationally more efficient. The MG test system includes two PV sources having dedicated parallel RLC loads and low voltage feeder. The proposed model is validated by performing comprehensive time and frequency domain analysis for transient and steady-state operations by MATLAB based simulations and hardware-in-loop tests using the real-time digital simulator (RTDS) and dSPACE processor board.

Case Studies for Non-Detection of Islanding by Grid-Connected In-Parallel Photovoltaic and Electrical Energy Storage Systems Inverters

In Korea, there is a rule for Renewable Energy Certification with weighting 5.0, to expand grid linkage capacity and to improve the stability of the grid to accommodate photovoltaic (PV) systems in a distributed power system. Due to this rule, many power companies and operators are trying to install electrical energy storage systems that are able to operate in conjunction with PV system power. These systems operate in parallel at the same grid connection point. This paper presents the results of case studies on the failure to detect islanding operation. Test evaluation devices that could be bi-directionally charged and discharged were implemented for an islanding detection test. Testing was conducted under a variety of operating conditions. When a single inverter was operated under the islanding condition, it was stably stopped within 0.5 s using the Korean grid-code standard. However, when two inverters were operated at the same time under the islanding condition, islanding detection failed and the two inverters continued to feed the connected RLC (resistor, inductor, capacitor) loads in the isolated section known as an island. Different algorithms used by PCS (power conversion system) manufacturers to detect islanding might cause this phenomenon. Therefore, it is necessary for a new PCS test standard to detect islanding.

DG System Using PFNN Controllers for Improving Islanding Detection and Power Control

In this study, an intelligent controlled distributed generator (DG) system is proposed for tracking control and islanding detection. First, a DC/AC inverter with DC power supply is adopted to emulate a DG system and control the active and reactive power outputs. Moreover, in order to comply with the standard for interconnection with the power grid, a novel active islanding detection method is proposed for the inverter-based DG system. In the proposed active islanding detection method, a perturbation signal is designed to inject into the d-axis current of the DG system which causes the frequency at the terminal of the RLC load to deviate when the power grid breaks down. The feasibility of the proposed active islanding detection method is verified according to the UL 1741 test configuration. Furthermore, in order to improve the tracking control of the active and reactive powers of the inverter-based DG system, and to effectively reduce the detection time of islanding phenomenon, two probabilistic fuzzy neural network (PFNN) controllers are adopted to take the place of the conventional proportional-integral (PI) controllers. In addition, the network structure and the online learning algorithm of the adopted PFNN are presented in details. Finally, some experimental results of the proposed active islanding detection method using PFNN controllers are proposed to validate the effectiveness and feasibility of the tracking control and islanding detection.

Using High-Bandwidth Voltage Amplifier to Emulate Grid-Following Inverter for AC Microgrid Dynamics Studies

AC microgrid is an attractive way to energize local loads due to remotely located renewable generation. The AC microgrid can conceptually comprise several grid-forming and grid-following power converters, renewable energy sources, energy storage and local loads. To study the microgrid dynamics, power-hardware-in-the-loop (PHIL)-based test setups are commonly used since they provide high flexibility and enable testing the performance of real converters. In a standard PHIL setup, different components of the AC microgrid exist as real commercial devices or electrical emulators or, alternatively, can be simulated using real-time simulators. For accurate, reliable and repeatable results, the PHIL-setup should be able to capture the dynamics of the microgrid loads and sources as accurately as possible. Several studies have shown how electrical machines, dynamic RLC loads, battery storages and photovoltaic and wind generators can be emulated in a PHIL setup. However, there are no studies discussing how a three-phase grid-following power converter with its internal control functions should be emulated, regardless of the fact that grid-following converters (e.g., photovoltaic and battery storage inverters) are the basic building blocks of AC microgrids. One could naturally use a real converter to represent such dynamic load. However, practical implementation of a real three-phase converter is much more challenging and requires special knowledge. To simplify the practical implementation of microgrid PHIL-studies, this paper demonstrates the use of a commercial high-bandwidth voltage amplifier as a dynamic three-phase power converter emulator. The dynamic performance of the PHIL setup is evaluated by identifying the small-signal impedance of the emulator with various control parameters and by time-domain step tests. The emulator is shown to yield the same impedance behavior as real three-phase converters. Thus, dynamic phenomena such as harmonic resonance in the AC microgrid can be studied in the presence of grid-following converters.

Improved Time Responses of PI & FL Controlled SEPIC Converter based Series Resonant Inverter fed Induction Heating System

This work deals with the Power Factor Corrected Single-Ended Primary Inductor Converter (PFC-SEPIC) based voltage fed closed loop full bridge series resonant induction heating system for household induction heating applications. The output voltage of the front end PFC-SEPIC converter fed series resonant inverter governs the controllers, which may be PI controller or Fuzzy Logic Controller (FLC). The analysis and comparison of time responses are presented in this paper. The PFC-SEPIC converter is used to improve the output power and the THD of source side current are compared for PI and FLC controllers. PFC-SEPIC converter maintains improved current and voltage at unity power factor through the input mains. The SEPIC converter based Voltage Fed Full Bridge Series Resonant Inverter (VFFBSRI) converts the voltage at a frequency of 10 kHz to a level suitable for household induction heating. A 1 kW SEPIC converter based VFFBSRI with RLC load is designed and simulated using MATLAB/ Simulink and hardware is fabricated.

DSPWM multilevel technique of 27-levels based on FPGA for the cascaded DC/AC power converter operation

Summary In this paper, a digital sinusoidal pulse width modulation (DSPWM) multilevel technique of 27-levels based on field programmable gate array (FPGA) is introduced, as an alternative to control of the direct current/alternating current multilevel power converters. The implementation of this technique with an FPGA XC3S500E model is achieved in the Xilinx Spartan-3E FPGA platforms. An experimental prototype is implemented by 3-cascaded H-bridges controlled by the DSPWM multilevel technique, generating high efficiency, low cost, and lower harmonic content. The efficiency of the DSPWM multilevel technique using R, RL, RC, and RLC loads connected to the power network is verified.

Powering RLC load by an array of self-sustained oscillators

This work deals with the analysis of the voltage amplitude generated in a linear load by an array of Van der Pol (VDP) and Hindmarsh–Rose (HR) oscillators. For the array of Van der Pol oscillators, it is found that after a threshold number of oscillators under which the power is equal to zero, the power increases with the size of the array. A high order nonlinearity in the damping of the Van der Pol oscillator increases the power. In the case of the array of HR oscillators, it is shown that varying the coupling coefficient leads to the appearance of chaotic dynamics in the system. Contrary to the case of the VDP oscillators, it is found that the voltage amplitudes decrease when the size of the array of the HR oscillators increases. These results can be linked to the mechanism of biological oscillators powering biological organs.

Design of 3.1 to 10.6 GHz ultra‐wideband flat gain LNA

SummaryIn this paper, a new ultra‐wideband low‐noise amplifier (LNA) is proposed. The proposed LNA has flat gain and low noise figure (NF) in the frequency range of 3.1 to 10.6 GHz. To obtain higher gain, cascode architecture is used. In this design, to have a lower NF, the noise cancellation technique applies to the cascode architecture. In addition, to have better matching at the input and output, active feedback and matching transistors are used, which also leads to better NF. To have flat gain, RLC load is used. In the proposed LNA, only one inductor is used, which leads to the smaller chip area. The proposed circuit is designed in 90 nm CMOS technology. The simulation shows NF of between 1.62 and 2.1 dB, flat gain between 11.9 and 12 dB and power consumption of 11.72 mW in the frequency range of 3.1 to 10.6 GHz. The simulation results support the theoretical predictions. Copyright © 2017 John Wiley & Sons, Ltd.

Total Harmonic Distortion at Fault in RLC Load

<p>This paper focuses on the calculation of total harmonic distortion (THD) at various fault situations in case of RLC load. The faults are created by introducing heavy impedance of 1000 ohm, by blowing off the gate pulse at one of the terminals of the mosfet, and by introducing a line to ground fault. The Matlab based simulation has been done to show these effects.</p>

The influence of a mounting manner of power MOS transistors on characteristics of the Totem-Pole circuit with RLC load

Purpose The paper aims to consider the problem of the influence of mounting power metal-oxide semiconductor (MOS) transistors operating in the Totem–Pole circuit on energy losses in this circuit. Design/methodology/approach Using the computer simulation in SPICE software, the influence of such factors as on-state resistance of the channel of the MOS transistor, the self-heating phenomena in this transistor and resistance of wires connecting transistors with the other part of the circuit on characteristics of the considered circuit operating with resistor, inductor and capacitor (RLC) load is analyzed. The selected results of calculations are compared with the results of measurements. Findings On the basis of the obtained results of calculations, some recommendations concerning the manner of mounting the considered transistors, assuring a high value of watt-hour efficiency of the process of energy transfer to the load are formulated. Research limitations/implications The investigations were performed in the wide range of the frequency of the signal stimulating the considered circuit, but the results of calculations were presented for 2 selected values of this frequency only. Practical implications The considered analysis was performed for the circuit dedicated to power supplied of an elecrolyser. Originality/value Presented results of calculations prove that in some situations, the value of watt-hour efficiency of the considered circuit is determined by the length and the cross-section area of the applied wires bringing the signal to the connectors of the transistors and to load. On the other hand, self-heating phenomena in the power MOS transistors can lead to doubling power losses in these devices.

Islanding detection method based on system identification

Islanding detection is a crucial technique for distributed generation (DG) system. An islanding detection method based on system identification is proposed in this study. Regarding the grid as an RLC load, a recursive least square method is used to estimate the equivalent RLC parameters. Then a logistic regression classifier is applied to determine whether DG is disconnected from the grid or not by the data sets of the estimated parameters of the system. An experiment demonstrates that the algorithm is effective and fast for detecting an islanding event.

Synthesis of Low Sensitivity Broadband Matching Networks Using Clonal Selection Algorithm

This paper presents a new methodology for synthesis of broadband matching networks based on Clonal Selection Algorithms (CSA). This metaheuristic uses the hypermutation as only variation operator resulting in a gradual evolving of the network topology. A closed form expression for the transducer power gain (TPG) sensitivity with respect to the component values is employed, in such a way that the effects of the components tolerance on the matching network performance can easily be quantified. The evolvable function proposed is single-objective and eliminates the difficult task of assigning appropriate weights to parameters. The evaluation of the TPG sensitivity enables the designer to identify and remove irrelevant components of the circuit, simplifying it. The efficiency of the methodology is tested in two cases found in the literature: the traditional project of impedance matching for a simple RLC load proposed by Fano [1]; and a real synthesis of impedance matching network for a monopole whip antenna, proposed in [2]. The results are compared with other existing methods.