DC Voltage Source Research Articles

A Scalable High-Power Microwave Source Based on Coherent Stimulated Emission

Future moderate-band (MB) high-power microwave sources will take advantage of having a small size and a low cost. However, the output power of existing designs is limited by the dc voltage supply. To tackle this issue, this article proposes a novel scalable high-power microwave source based on the concept of coherent stimulated emission. The proposed microwave source consists of an antenna array, in which the two arms of each dipole antenna are connected with a fast-rise time switch and charged by a dc voltage source. Each antenna unit is triggered by the incoming wave radiated from the previous unit and then oscillates and correspondingly produces a new electromagnetic wave to trigger the next one. Both simulations and experiments show that the output waves of multiple antenna units are in phase, and the output power is accordingly enhanced. Compared with the existing MB high-power microwave sources, the proposed microwave source is able to significantly boost the maximum output power by applying more automatically triggered antenna units, featuring strong scalability and less limitation by the dc voltage supply.

Topology, Modeling and Control Scheme for a new Seven-Level Inverter With Reduced DC-Link Voltage

This paper presents a novel single-source three-phase multilevel converter with voltage boosting capability for medium-voltage photovoltaic applications. This converter consists of different switched-capacitor networks, formed by 1 capacitor and 3 active switches, as a basic switching cell to generate variable dc-link voltage that boosts the input dc-source voltage, producing 2n+1 (n2) voltage levels at the output. It can reduce the dc-link voltage requirements by 50% in comparison to the traditional neutral point clamped (NPC), flying capacitors, active NPC (ANPC), hybrid and hybrid clamped ANPC and cascaded H-bridge topologies, and 75% to advanced ANPC topologies. It can also reduce the number of required switches and capacitors as well as their voltage stresses compared to these state-of-the-art topologies reported in the literature so far. A finite control set model predictive control algorithm is derived to control the converter, which has the capability to control the active and reactive power without distorting the generated grid current quality. The capacitor voltage balancing is inherent in the proposed topology, and thus, there is no need for any additional voltage balancing circuit, which reduces the control complexity. As an example, a 7-level version of the proposed topology is compared to other existing 7-level inverter topologies.

Static Reactive Power Compensator Design, Based on Three-Phase Voltage Converter

At present, electrical network stability is of the utmost importance because of the increase in electric demand and the integration of distributed generation deriving from renewable energy. In this paper, we proposed a static reactive power compensator model with common direct current voltage sources. Converter parameters were calculated and designed to fulfill specifications. In order to ascertain the device response for different operating modes as reactive power consumer and generator, we developed the model’s power and control circuits in Matlab Simulink. Simulations were performed for different conditions, and as a result, the current and voltage waveforms and the circular power chart were obtained. This paper has theoretically proven it is possible to achieve the consumption or generation of purely active or reactive power by implementing a static reactive power compensator with common DC voltage sources.

A Dumbbell Type (D-Type) multilevel inverter based on switched capacitor concept

ABSTRACT In this paper, a new single-phase seven level inverter with reduced device count is introduced. The structure can boost the input voltage by synthesising the capacitors’ voltages in predetermined current paths. A single DC voltage source is utilised to generate the output AC staircase waveform, which is facilitated via Nearest Level Control. Self-voltage balancing ability, less number of semiconductor devices, high efficiency and control simplicity are the most significant inherent attributes of the proposed circuit. It is also noticeable that in this configuration neither bulky transformer/inductor nor filters are applied. Power loss calculation and required capacitance of the proposed inverter are investigated and theoretical efficiency of 93.31% was reached. Moreover, the proposed converter operates under various load conditions with lower Total Harmonic Distortion compared to recent topologies. Ultimately, operating principles of the proposed D-Type seven-level Inverter and simulation results in MATLAB SIMULINK environment are validated by experimental ones obtained from the laboratory prototype.

A New Switched-Ladder Multilevel Converter Structure with Reduced Power Electronic Components

This paper presents a new switched-ladder structure for multilevel converter which consists of several bidirectional and unidirectional switches along with DC voltage sources. The values of DC sources in the proposed topology are determined based on a new mathematical algorithm. The proposed multilevel converter is an extended structure, which can produce any levels at output voltage waveform. To prove the merits of the proposed structure, the proposed converter is compared with other similar structures. According to comparison results, it is shown that the presented structure requires the least numbers of DC sources, IGBTs, drivers and on-state switches. Also, the value of voltage rating of the switches is analyzed. The experimental results are provided for the proposed 17-level converter to prove the performance of suggested structure.

Step-up switched-capacitor multilevel inverter employing multiple inputs with reduced switches

A large device count, weak boosting capability, and DC voltage imbalance are common issues in conventional multilevel inverters. In this paper, a novel multilevel inverter is presented that can generate the desired number of output levels with reduced devices by using new switched-capacitor circuits (SCCs). The two input sources and capacitors in the SCC can be switched in parallel and series modes. In the parallel mode, the capacitor voltage of the SCC is charged to the DC source voltage, which inherently solves the capacitor voltage imbalance issue without any auxiliary circuits. In the series mode, the capacitor can be used as an alternative source, which helps achieve a high voltage gain. The multiple input sources of the SCC make the proposed topology suitable for application in renewable energy generation systems where several DC sources are available. Instead of an H-bridge module, a structure with two half-bridges and two switches is used as a polarity generation circuit at the load terminal. The input sources of two SCCs can be selected as symmetric and asymmetric patterns, which can result in a great number of output voltage levels. The circuit topology, operational principle, modulation strategy, capacitor analysis, and performance comparisons of the inverter are described in this paper. In addition, experimental results verify the feasibility and validity of the inverter.

A twice boost nine‐level switched‐capacitor multilevel (2B‐9L‐SCMLI) inverter with self‐voltage balancing capability

SummaryThe research on the multilevel inverter structures has been focused on reducing the number of voltage sources and the components while obtaining voltage boosting in the output voltage. A lesser number of components would ensure lesser cost while higher boosting ability increases its application potential. Based on these features, the paper presents a new topology for switched‐capacitor multi‐level inverter (SCMLI), which can produce an output voltage waveform of nine levels with a voltage boosting of twice the input voltage employing a single dc voltage source, three capacitors, and 11 power switches. The operation of switches, capacitors with a self‐charge balancing modulation scheme, and a voltage source for producing nine‐level boosted output voltage make this topology useful, and it is capable of supplying different types of load with efficiency above 97%. The simulation results and the hardware results are provided to verify the satisfactory operation of the proposed topology.

A streamlined 17-level cascaded H-bridge multilevel converter with solar PV integration

The quest for a green electrical power system has increased the use of renewable energy resources and power electronic converters in the existing power system. These power electronic converters, however, are a major cause of harmonics and result in the degradation of power quality. In the last two decades, researchers have proposed various designs of multilevel converters to minimize these harmonic distortions, however, a comprehensive solution for stand-alone solar photovoltaic (PV) systems with low total harmonic distortion (THD) is still missing in the present body of knowledge. This paper proposes a single-phase 17-level cascaded H-bridge multilevel converter (CHMC) model for a stand-alone system using solar PV arrays. The proposed model employs eight different flexible PV arrays that can be replaced with DC voltage sources when required to meet the load demand. The proposed model does not include any capacitor and filter thus saving a lot of cost in the overall system. The model has been implemented in the Simulink environment using a model-based design approach. The simulation results show that the proposed model has reduced the THD to almost 7% as compared to the existing models. The cost comparison of the proposed converter also proved its economic benefit over other types.

Liquid Metal Logic for Soft Robotics

While there are many soft matter sensing and actuation technologies, there is far less choice when it comes to soft material devices for control and computation. One solution is the Soft Matter Computer (SMC) which can perform both analogue and digital computations in soft materials. This computer processes a fluidic input pattern consisting of alternating regions of conducting and insulating fluids into an electronic output signal. However, the use of salt water as the conductive fluid means that the Soft Matter Computer has high electrical resistance and requires an AC voltage, making untethered operation impractical. In this letter, we introduce the liquid metal Soft Matter Computer (LM-SMC), which uses galinstan as an alternative conductive fluid. We show that by switching to a liquid metal-sodium hydroxide fluidic input, we reduce the electrical resistance of the SMC by three orders of magnitude, allowing operation at DC voltages of 2 Volts and under. We characterise the stability of the liquid metal input patterns and demonstrate the potential of the LM-SMC by using it to control bipolar ionic polymer metal composite and shape memory alloy actuators. By enabling fully soft computation and control of multiple actuators from a single low voltage DC source, the LM-SMC enables a new class of intelligent and untethered soft machines.

Design of Memristor with Hard-Switching Behavior Employing Only One CCCII and One Capacitor

In this paper, we present second generation current-controlled conveyor (CCCII)-based simple memristor circuit which exhibits a hard-switching voltage-current relationship. The proposed memristor circuit contains only single CCCII and single grounded capacitor that are attractive for the integrated circuit designers. The proposed memristor emulator has four main advantages: hard-switching behavior, not utilizing multiplier circuit, biasing current or voltage source (excluding DC current or voltage source), and being free of body effect for all transistors. Cadence Spectre Analog Environment with TSMC 0.18[Formula: see text][Formula: see text]m process parameters is used for all simulations. The memristive chip occupies only 81.85[Formula: see text][Formula: see text][Formula: see text][Formula: see text][Formula: see text]m area. All simulation results are presented to demonstrate the performance of the proposed circuit by changing some parameters such as frequency, temperature, DC power supply voltages and process variations. Also, the robust performance of the proposed memristor is confirmed via Monte Carlo simulations. The simulation results for designed memristor are in accordance with theoretical memristive behavior.

Kendali Tegangan Output Buck Converter Menggunakan Arduino Berbasis Simulink Matlab

The rapid development of technology to date has made many electrical and electronic equipment that require a direct current (dc) voltage source whose output voltage can be adjusted to the needs of the user. There are several direct voltage levels that are commonly used by electrical and electronic equipment. To get a direct voltage that can be used for various equipment, a direct voltage source that can be varied according to need is required. One way to convert a dc voltage source to a lower dc voltage source is by using a buck converter circuit. This study proposes a buck type direct current converter is porposed to use the Arduino uno as a PWM signal generator circuit to control to control the 24 volt input voltage. The converter output voltage regulation is implemented through a potentiometer and Arduino programming using the simulink Matlab. In this research, a buck converter is tested with output voltage feedback so that the output voltage remains stable. The result of the test that have been carried out show that the buck converter designed in this study has worked well in accordance with objectives. This can be seen from the buck converter output voltage that is in accordance with the reference voltage using a potentiometer that is included in the simulink Matlab program.

Filter Component Impact on EGS002-based Inverter Circuit Performances

This paper examines filter component impact on inverter output. The inverter prototype was designed by using pulse width modulation (PWM) signal generated by EGS002 module, combined with DC voltage source, voltage regulator, MOSFET bridge and low pass filter. As component assembled, the output voltage quality is determined by the choice of filter components. Experiment shows that the calculated values may not suitable as soldering and connection imperfection may change component values. As adjustments were performed, filter components of 12.63 H and 6.5uf generated the finest sinusoidal output of 30.8 Vpp with frequency of 50,05 Hz.

An Enhanced SVPWM Strategy Based on Vector Space Decomposition for Dual Three-Phase Machines Fed by Two DC-Source VSIs

This article presents an enhanced space vector pulse width modulation (SVPWM) strategy based on vector space decomposition (VSD) for the dual three-phase machines fed by two dc-source voltage source inverters (VSIs). Compared with existing methods that only account for balanced dc-link voltages, the proposed method considers unbalanced dc-link voltages in both the α-β and z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> -z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> planes. Two categories of medium voltage vectors are first defined in this article. An enhanced 12-sector SVPWM strategy that toggles two categories of medium voltage vectors in each fixed 30° sector is proposed. Moreover, the performance of the proposed method, including the modulation depth, the range of the dc-link voltage ratio, and the toggling point of the medium vector is analyzed. The proposed method can reduce the computational burden of the complicated sector classifications and it easily chooses suitable vectors to track the reference voltage with changes in the dc-link voltage ratio. The experimental results of the proposed SVPWM techniques are verified in a dual three-phase permanent magnet synchronous machine (PMSM) fed by two dc-source VSIs.

Cascaded H-Bridge Inverters for UPS Applications: Adaptive Backstepping Control and Formal Stability Analysis

In this letter, an advanced adaptive controller is designed for N-cascaded H-bridge multilevel inverters, each fed by a DC voltage source. The studied system provides an added-value to Uninterruptable Power Supply applications, and is able to generate a precise sinusoidal voltage using a low dimensional LC filter. The main objectives of this letter are: i. generating a low THD sinusoidal voltage, ii. developing adaptive control laws able to regulate the system even with the presence of parameters' variations, and iii. proving the stability of the designed system using some tools from Lyapunov stability, Lasalle's invariance principle and persistency of excitation. This latter proves that the closed-loop control system is uniformly exponentially stable. To achieve these objectives, the adaptive backstepping approach is used. The performance of the system is checked with the use of MATLAB/SIMULINK/ SimPowerSystems environment, where the synthesized regulator meets its objectives.

Non-Isolated n-Stage High Step-up DC-DC Converter for Low Voltage DC Source Integration

The dc-dc converters with high step-up DC-voltage gain play a vital role in integrating low voltage DC sources. Though several converter topologies are reported in the recent past, attempts have been made to reduce the components, especially the switching devices, passive elements, converter losses, etc., of the converter. A novel DC-DC converter topology, viz., single switched impedance network (SSIN)-based converter with n-stage is proposed in this paper. The operation of the SSIN based converter in continuous and discontinuous conduction modes are discussed. The effect of parasitic elements on DC-voltage gain and efficiency of the SSIN is carried out. The small-signal model of the SSIN converter is derived. The performance of the SSIN converter is compared with the similar converter topologies. The 500 W prototypes of the SSIN with n = 1 and n = 2 are fabricated, and the experimental results are presented in this paper. To improve the converter performance, SiC-based semiconductor devices are used. The SSIN converter with two-stage has low switch loss at 500 W load, improved efficiency during high power and high output voltage operation, the switch stress of V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> /2, etc.

A new cascaded asymmetrical multilevel inverter based on switched dc voltage sources

Multilevel inverters are now becoming an important element for medium-voltage high-power applications. A low switch count multilevel inverters are currently attracting more attention due to its high efficiency, low cost, and easy control. This paper proposes a new single-phase cascade asymmetrical multilevel inverter topology based on switched dc voltage sources which is capable of achieving a higher number of output levels using fewer number of switches, driver circuits, and dc voltage sources. Other advantages include the inherent generation of negative voltage levels and lower voltage stress across the switches. Three different approaches in selecting the magnitude of the sources for the cascade connection has been included to produce a higher number of voltage levels. Furthermore, the power loss and fault-tolerant analysis of the proposed basic module has also been discussed. To set the benchmark of the proposed multilevel inverter structure, a comparison with several recently proposed topologies is carried out. The comparison has been carried out for the basic module, generalized structure, and cascade connection. The proposed topology gave improved parameters for all three categories. Fundamental switching frequency modulation technique is used to achieve high-quality output voltage waveforms with lower harmonic contents and reduced switching losses. Finally, the operation and performance of the proposed basic module and its cascade connection for two modules are presented together with experimental results in several steady-state and dynamic operating conditions.

A generalized switched-capacitor step-up multilevel inverter employing single DC source

In this paper, a new generalized step-up multilevel DC-AC converter is proposed, which is suitable for applications with low-voltage input sources such as photovoltaic power generation and electric vehicles. This inverter can achieve a high voltage gain by controlling the series-parallel conversion of DC power supply and capacitors. Only one DC voltage source and a few power devices are employed. The maximum output voltage and the number of output levels can be further increased through the switched-capacitor unit's extension and the submodule cascaded extension. Moreover, the capacitor voltages are self-balanced without complicated voltage control circuits. The complementary operating mechanism between each pair of switches simplifies the modulation algorithm. The inductive-load ability is fully taken into account in the proposed inverter. Additionally, a remarkable characteristic of the inverter is that the charging and discharging states among different capacitors are synchronous, which reduces the voltage ripple of the frontend capacitors. The circuit structure, the working principle, the modulation strategy, the capacitors and losses analysis are presented in detail. Afterwards, the advantages of the proposed inverter are analyzed by comparing with other recently proposed inverters. Finally, the steady-state and dynamic performance of the proposed inverter is verified and validated by simulation and experiment. 1

Filter impact based on inverter circuit performances

This paper examines filter component impact on inverter output. The inverter prototype was designed by using pulse width modulation (PWM) signal generated by EGS002 module, combined with DC voltage source, voltage regulator, MOSFET Bridge and low pass filter. As component assembled, the output voltage quality is determined by the choice of filter components. Experiment shows that the calculated values may not suitable as soldering and connection imperfection may change component values. As adjustments were performed, filter components of 12.63 H and 6.5uf generated the finest sinusoidal output of 30.8 Vpp with frequency of 50.05 Hz.

Simple boost PWM controlled cascaded quasi Z-source inverter

In this paper cascaded quasi Z source inverter is used to give desired boosted output. It can derive from the quasi Z source inverter by adding one diode, one inductor, ant two capacitors. Power converters can be used for adjusting the parameters needed for synchronization of the source and load. This converter commonly used as an interface between the DC voltage source and load. The power converters are used to produce constant output by means of adjusting the firing pulses for switches to get variable output which helps in the protection of devices from high voltage or high current. The traditional Quasi Z-source Inverter (QZSI) is utilized for voltage Boost and voltage Buck operation. A QZSI be able to directly convert input dc voltage into buck or boosted AC output voltage based on applications. Further to improve the performance of QZSI, Cascaded QZSI (CQZSI) is presented in this paper with few additional components like capacitor, inductor and diode. The main aim of this paper is to give the efficient output to the load by using Cascaded Quasi Z-Source Inverter (CQZSI) as a result of voltage boost up ability, single stage power conversion, low voltage stress and high boost factor. The simulation result of cascaded quasi Z source inverter is presented with simple boost PWM in simulation part. In hardware part, the cascaded quasi Z source inverter can be analyzed with single phase inverter. The output voltage can be boosted upto two times of input voltage.

A Switched-DC Source Sub-Module Multilevel Inverter Topology for Renewable Energy Source Applications

This article presents a sub-module topology for switched DC source cascaded multilevel inverter configurations that require fewer switching devices and can generate a high number of voltage levels that are suitable for renewable energy sources. The proposed sub-module topology comprises eight semiconductor switches and four DC voltage sources that generate fifteen voltage levels. Furthermore, the cascaded topology is presented to increase the output voltage levels and to minimize the number of components. The proposed sub-module inverter and its cascaded topology are compared with several multilevel inverters to indicate the advantages and drawbacks of the proposal. The comparison studies show that the proposed topologies require fewer switching devices and gate drivers in comparison with other multilevel inverter topologies. In addition, the proposed cascaded topology reduces the cost of the inverter when compared to other multilevel inverter configurations. Furthermore, the power loss calculations and the implementation of the proposed topology in grid-connected photovoltaic applications are simulated and analyzed. Finally, the performance of the proposal is verified by simulation and experimental results for both symmetric and asymmetric sub-module topologies as well as for the proposed cascaded topology.