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The investigation and findings show that the H Bridge variable frequency drive is the optimum choice for resolving intrinsic motor problems and energy conservation. Variable frequency drives outperform other strategies like soft starters because they offer numerous benefits over other techniques, including greater versatility and control over the motor's starting and stopping capabilities. Dynamic torque control, overload protection, and power reduction during idle are other essential aspects of variable frequency drives. Conserving energy to the greatest extent possible is one strategy to avoid energy shortages. It has been reported that 75% of the electrical energy generated globally is used by motors. It has been noted that the main problem with motors is that they use a lot of current to start. As a result, high inrush current produces excessive heat, reducing the lifespan of electrical equipment and using more electricity. Reducing the initial inrush current to a manageable level is advised. By using an induction motor and the H Bridge, this current can be decreased. H Bridge uses a technique known as variable speed drive, which is often referred to as variable torque drive, to control the speed and torque of AC induction motors. Pulse width modulation is used to monitor the motor's voltage and torque in this occurrence. Although there are several methods to reduce the motor's current, such as by employing soft starts, variable torque drives are more advantageous. The strong starting torque and flexible speed control of DC motors make them useful in a range of applications. However, because of the cost and commutation, there are a few significant problems. As a result, the PWM-powered H bridge inverter extends the life of machinery and provides electricity to electrical appliances in response to demand. The fact that it is an energy-saving gadget, however, is by far its greatest advantage. This is especially important in a country like India, where the energy crisis has halted economic growth. [ABSTRACT FROM AUTHOR]

HASEL (Hydraulically Amplified Self-Healing Electrostatic) actuators have gathered momentum in recent years; they are made of very-low-cost materials, making it easy for anyone to develop their own actuators, and they are "soft" and can achieve tasks that are very difficult to complete with traditional rigid actuators, e.g., grasping soft objects. Unfortunately, HASEL actuators are driven by high-voltage (HV) power supplies, which are expensive to control accurately and difficult to scale up for multichannel applications, e.g., prostheses. This paper presents a low-cost HV power supply designed for HASEL applications that generates 2–10 kV DC at 5% of the cost of the existing HV power supplies used in HASEL actuators. At the core of our design, there is a new control strategy based on controlling the charging and discharging of the actuator from the supply's low-voltage (LV) side rather than switching the HV side with expensive HV optocouplers. Discharge is achieved via a secondary transformer and multiplier circuit, generating a negative HV output capable of discharging the HASEL effectively and safely up to 10 kV. [ABSTRACT FROM AUTHOR]

Multilevel inverters are becoming increasingly significant due to their ability to efficiently convert power in various applications such as renewable energy systems, electric vehicles (EVs), and industrial drives. The growing need for efficient power conversion in these areas has driven heightened interest in multilevel inverters. High inrush current is required for numerous applications, including variable frequency drives, single-phase or three-phase machine drives, locomotives, electric vehicles. However, managing this inrush current is crucial to prevent damage to the power source and other connected equipment, as well as to ensure smooth and reliable operation. The solution for this is to provide isolation between load and source. The proposed single phase switched capacitor multilevel inverter possess the feature of virtual isolation between the load and the source. This topology consists of a switched capacitor cell network and a multilevel inverter. In this work, a simplest architecture is used for the MLI section to reduce the number of switches. The MLI section consists of only eight switches. Although the switched capacitor network in this topology consists of a higher number of switches, the switches in the network carry only very low current, resulting in negligible losses. Additionally, the switched capacitor network is highly modular in nature. The proposed single-phase inverter can be converted to a three-phase multilevel inverter (MLI) by connecting identical units in each phase, with the reference sinewave signal for the pulse-width modulation technique derived from the corresponding phases. Consequently, this proposed topology is suitable for both low-power and high-power applications. This work demonstrates that self-voltage balancing of the level capacitors can be achieved without the need for auxiliary components.In this design, the level capacitors act as the source to the load and are charged through switched capacitors. The voltage THD in the suggested work is less than 5%, which is in accordance with IEEE 519 standards. High voltage gain, better load, and line regulation, are other significant advantages of this novel topology. Another feature of this work is simplicity in design and can be easily extended to higher voltage levels. Comprehensive simulation and experimental results are provided to validate the precise performance of the proposed multilevel inverter

HASEL (Hydraulically Amplified Self-Healing Electrostatic) actuators have gathered momentum in recent years; they are made of very-low-cost materials, making it easy for anyone to develop their own actuators, and they are “soft” and can achieve tasks that are very difficult to complete with traditional rigid actuators, e.g., grasping soft objects. Unfortunately, HASEL actuators are driven by high-voltage (HV) power supplies, which are expensive to control accurately and difficult to scale up for multichannel applications, e.g., prostheses. This paper presents a low-cost HV power supply designed for HASEL applications that generates 2–10 kV DC at 5% of the cost of the existing HV power supplies used in HASEL actuators. At the core of our design, there is a new control strategy based on controlling the charging and discharging of the actuator from the supply’s low-voltage (LV) side rather than switching the HV side with expensive HV optocouplers. Discharge is achieved via a secondary transformer and multiplier circuit, generating a negative HV output capable of discharging the HASEL effectively and safely up to 10 kV.

In this paper, we propose a method for calculating the DC source amplitude in an extended multilevel inverter (MLI) structure so that the maximum number of levels and the output voltage waveform are as close as possible to the sinusoidal wave with minimum total harmonic distortion (THD). For the developed structure, three algorithms are suggested to determine the amounts of DC voltage resources. The first important point about choosing the right amounts for the DC resources is that the number of levels should be as large as possible, and the second important point is that the intervals between the levels should be the same throughout the waveform. By observing these two points, the output voltage waveform can be as near as possible to the sinusoidal wave that we want. In this study, we used iteration-based methods to find suitable values for DC sources. Simulation results are offered to confirm the capability of the extended multilevel converter. After we solved the problem through calculation and analysis, a code was written in MATLAB with the aim that this time the code will tell us for what values of DC sources we will have the largest number of levels and as we expected, the output of the MATLAB code confirmed the correctness of the calculations. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes leaky least mean fourth (LLMF) algorithm for the control of five‐level series connected H‐bridge multilevel inverter (5L SCHB‐MLI). The SCHB multilevel inverter is a popular configuration due to its wide application for high‐power and medium‐voltage applications. The complete system comprising the grid, load, and compensator is modeled in MATLAB/SIMULINK. Prototype hardware is also developed in the laboratory for experimental validation. The 5L SCHB inverter is connected in a single‐phase power distribution system and controlled as a compensator. The voltage across both DC links of the H‐bridges is regulated to almost equal value by the proposed control algorithm. The closed loop system is designed to mitigate total harmonic distortion (THD) in the source current and improve the power quality of the proposed system. The system is analyzed under the steady state and dynamic state, and the results are also verified on the hardware prototype developed in the laboratory. The proposed algorithm is also compared with conventional least means square (LMS) algorithm and notch filter algorithm on several parameters. The paper discusses a detailed simulation and hardware analysis on the control of five‐level MLI topology. [ABSTRACT FROM AUTHOR]

Background and Objectives: The H-bridge (HB) driver design with high efficiency is one of the most challenging issues in power systems that drive AC/DC loads. HB driver circuit based upon complementary MOSFET type used as a driving system of DC motor, power converters, and battery charger for electrical vehicles. In Driving DC motors, dead-time (DT) generation has been considered a major factor such as preventive power line short-circuits (shoot-through) over high and low-side MOSFETs. In this paper, the HB driver is designed for linear actuators with consideration for the prevention of shoot-through. Methods: The propagation delay of logic gates are used to postpone the arrival gate drive signal for high/low side MOSFETs resulting in short circuit elimination on the DC source. Results: As mentioned, logic gates' propagation delay by their values causes interruption between the high and low-side power switches gate drive signal resulting in shoot-through elimination. Although the existence of DT influences the performance of the rotational speed and output torque of a DC motor by increasing the distortion and pulse interval, Linear actuators due to low-velocity linear motion do not require the PWM control, therefore DT has no substantial effect on driver performance. Conclusion: Simulation and experimental results validate the method proposed in this paper. According to the specifications of the circuit designed in this paper, for loads that do not need rotational speed control, logic gates with proper propagation delay can be chosen to eliminate short circuits in complementary MOS switches without requiring DT compensation methods. [ABSTRACT FROM AUTHOR]

Single Source Cross Connected Reduced Activated Switched-Capacitor Multilevel Inverter (S2C2RASCMLI) accompanied by fewer active switching components is appealing to nine-level of voltage with its simplicity and a solid network. In AC power distribution systems, multi-level inverters are used as DC-to-AC converter operations to achieve the desired output magnitude and frequency. It is employed for the smooth operation of electrical machines. The proposed S2C2RASCMIL cell yields a nine-level voltage with ten switches, nine driver signals, and two flying capacitors for dynamic load operation with reduced active switches. It has the capability of boosting the input voltage double the times. The proposed multilevel inverter operated on nine switching modes and in each mode, three switches have been conducted. It can be extended horizontal and/or vertical structure to produce more levels of output voltages. The hardware prototype was made and the results have been presented. To demonstrate the advantages of the new proposed multilevel inverter topology, a comprehensive comparison with a few other similar multilevel inverter configurations is done. Analysis and simulation output waveforms for a variety of load conditions were tested to check the feasibility of the proposed new multi-level inverter. The proposed MLI offers better performance than existing multilevel inverters.

The model predictive control (MPC) tries to find the best control output by optimizing among the predictions. In this context, determining the objective function of optimization is a critical process. This study discusses the velocity control of the mini brushed direct current (BDC) motor used in the actuator with MPC. Four different functions have been defined to design the most appropriate cost function for MPC by considering the parameters that may be effective in the motor dynamics such as velocity, current, power, and switching states. Software in the Loop (SIL), one of the modeling-based testing methods, was used within the scope of testing the algorithms. After the SIL tests, it has been observed that the mini BDC motor can be successfully controlled with simple adjustments to the cost function of the MPC. As a result of the analysis obtained the best results with the objective function consisting of velocity error, estimated current, and the difference between the two estimated velocity values. With this controller, the BDC motor can be controlled without overshoot and with a steady-state error of less than 2% under load.

This paper presents a method that enables a small car to reach its destination in an indoor environment using ultrawideband technology. For this purpose, we used four anchors and one tag. The tag can move because it is fixed on the car. The anchors and the tag are DWM1001 modules. The configuration of the five DW1001 modules is performed through a smartphone application provided by the manufacturer. The car has been built by us. The controller of the car is a Raspberry Pi microcomputer which controls the driver of the car DC motors by generating PWM signals. In addition, Raspberry Pi communicates with the tag by the UART interface. Thus, our goal was to control the car to reach a certain destination (xd, yd) requested by the user via Wi-Fi. Because the car hosts the tag, it continuously updates its position according to the information received from the four anchors. We implemented two scenarios, considering the initial (x, y) position of the car. In the first scenario, which is simpler, the car moved to its destination either along the x-axis or along the y-axis. In the second scenario, the car moves along one of the axes and then turns 90 degrees to reach its destination. Experimental results that show the precision of the positioning system are presented. [ABSTRACT FROM AUTHOR]

Single Source Cross Connected Reduced Activated Switched-Capacitor Multilevel Inverter (S²C²RASCMLI) accompanied by fewer active switching components is appealing to nine-level of voltage with its simplicity and a solid network. In AC power distribution systems, multi-level inverters are used as DC-to-AC converter operations to achieve the desired output magnitude and frequency. It is employed for the smooth operation of electrical machines. The proposed S²C²RASCMIL cell yields a nine-level voltage with ten switches, nine driver signals, and two flying capacitors for dynamic load operation with reduced active switches. It has the capability of boosting the input voltage double the times. The proposed multilevel inverter operated on nine switching modes and in each mode, three switches have been conducted. It can be extended horizontal and/or vertical structure to produce more levels of output voltages. The hardware prototype was made and the results have been presented. To demonstrate the advantages of the new proposed multilevel inverter topology, a comprehensive comparison with a few other similar multilevel inverter configurations is done. Analysis and simulation output waveforms for a variety of load conditions were tested to check the feasibility of the proposed new multi-level inverter. The proposed MLI offers better performance than existing multilevel inverters. [ABSTRACT FROM AUTHOR]

A new hybrid nine level multilevel inverter (H9MLI) topology is proposed and developed with the combination of switched capacitor (SC) and H-bridge structure. The main features of the proposed inverter are voltage boosting capability, reduced switch count, reduced switching control and extended vertical and horizontal topologies. In this paper, the operation modes, modulation strategy, power loss analysis and the simulation results for H9MLI and its extended topology (13 level and 17 level) are presented. The MATLAB/Simulink based simulation of the proposed inverter and its extended topologies for static and dynamic loads are analyzed and verified. The quantitative comparison indicating the merits of proposed topology over various prior-art multilevel inverter topologies were evaluated and tabulated in an inclusive way. The level shifted PWM technique is used for generating control pulses for the proposed inverter.

The model predictive control (MPC) tries to find the best control output by optimizing among the predictions. In this context, determining the objective function of optimization is a critical process. This study discusses the velocity control of the mini brushed direct current (BDC) motor used in the actuator with MPC. Four different functions have been defined to design the most appropriate cost function for MPC by considering the parameters that may be effective in the motor dynamics such as velocity, current, power, and switching states. Software in the Loop (SIL), one of the modeling-based testing methods, was used within the scope of testing the algorithms. After the SIL tests, it has been observed that the mini BDC motor can be successfully controlled with simple adjustments to the cost function of the MPC. As a result of the analysis obtained the best results with the objective function consisting of velocity error, estimated current, and the difference between the two estimated velocity values. With this controller, the BDC motor can be controlled without overshoot and with a steady-state error of less than 2% under load. [ABSTRACT FROM AUTHOR]

A new multilevel topology for an open-end winding motor drive is proposed in this article, presenting a similar structure to the cascaded H-bridge multilevel inverter. The proposed topology combines three-phase and single-phase conventional H-bridge voltage source inverters. The topology is flexible, allowing to increase the number of voltage levels through the simple integration of new single-phase H-bridge inverters connected in wye. Based on this topology, it is possible to obtain two different configurations. These modular multilevel topologies can be easily extended, both in terms of voltage level and the number of voltage levels. The topology is characterized by the capability to a supply higher voltage to the motor windings or use lower dc voltages when compared with classical solutions. Well-known modulation schemes, such as the multilevel sinusoidal pulsewidth modulation technique, can be easily adapted to the proposed topology. The operation and characteristics of the two configurations for the proposed multilevel topology are confirmed by several experimental tests realized through a laboratory prototype.

The paper presents a way of accomplishing a non-contact excita-tion by electromagnetic waves generated from a system that in-cludes WiFi microcontroller, H-Bridge and coil. The ESP 32 mi-crocontroller software achieves PWM signal, which follows’ a si-nusoidal shape of variable frequency. The PWM signal drives the H-bridge resulting in a more powerful electric signal that also drives the coil, accomplishing in this way the pseudo-sine electro-magnetic wave. The source code from microcontroller provides variable frequency and working period as well. The main features of the system are 0.5 to 3000 Hz, working periods between 0.1 and 10 seconds, the possibility to achieve more than one working peri-od with standby periods in between.

Simulation of SIMO based DC-DC Converter for multi level Solar PV Inverter is presented in this paper. In order to reduce the number of distinct DC supplies for an H-bridge inverter SIMO DCDC converter is applied which in turn allows the usage of single PV system for a multi level H-bridge inverter. Simulation model of three level and five level inverters is built and results are presented to validate the proposed ideas.

This article describes a modified structure 9-level inverter (MS9LI) with a dual dc link and eight switches. The dual dc links are different dc voltage sources with a 1:3 ratio. To generate high-quality nine-level output, the alternative phase opposition and disposition pulsewidth modulation (APODPWM) technique has been used. Most reported reduced device multilevel inverters (MLIs) include several underutilized dc sources and much more active switches. The designed MS9LI is more efficient since it uses fewer conducting switches. The proposed configuration furthermore does not need a backend H-bridge, and voltage stress is not more than the input dc voltage. A series connection of the proposed configuration can also be used to extend the topology. To prove the superior performance of the proposed MS9LI configuration, a detailed comparison with the foremost configurations in terms of the essential number of sources, switches, and drivers is made. In order to confirm the viability and functionality of the MS9LI configuration, various simulation and experimental findings are presented. [ABSTRACT FROM AUTHOR]

This paper presents a method that enables a small car to reach its destination in an indoor environment using ultrawideband technology. For this purpose, we used four anchors and one tag. The tag can move because it is fixed on the car. The anchors and the tag are DWM1001 modules. The configuration of the five DW1001 modules is performed through a smartphone application provided by the manufacturer. The car has been built by us. The controller of the car is a Raspberry Pi microcomputer which controls the driver of the car DC motors by generating PWM signals. In addition, Raspberry Pi communicates with the tag by the UART interface. Thus, our goal was to control the car to reach a certain destination (xd, yd) requested by the user via Wi-Fi. Because the car hosts the tag, it continuously updates its position according to the information received from the four anchors. We implemented two scenarios, considering the initial (x, y) position of the car. In the first scenario, which is simpler, the car moved to its destination either along the x-axis or along the y-axis. In the second scenario, the car moves along one of the axes and then turns 90 degrees to reach its destination. Experimental results that show the precision of the positioning system are presented.

This study analyzes a single-phase hybrid multilevel dc-link (MLDCL) inverter, in which a dc-link with two capacitors is integrated into a single dc source. When controlled under the conventional modulation scheme, the MLDCL inverter synthesizes a five-level output voltage. As the capacitor-voltage balancing depends on the fundamental period, the output voltage may contain unsolicited low-order harmonics. Moreover, in the conventional scheme, this inverter requires large dc-link capacitors. To avoid these problems, the present paper develops a simple phase-shifted pulse-width modulation scheme based on redundant switching states, which controls the MLDCL inverter and balances the capacitor voltage within each carrier period. The proposed modulation scheme also minimizes the dc-link capacitance by a factor of the frequency modulation ratio while reducing the total harmonic distortion of the output voltage and current. Unlike the conventional method, the proposed scheme considerably reduces the capacitor-voltage ripples and can be regulated by increasing the carrier frequency, thereby reducing the voltage stress on the switches and improving the reliability of the inverter. The feasibility of the proposed scheme over the conventional scheme is confirmed in a comparative study. Finally, the steady-state and dynamic performances of the proposed strategy are demonstrated in simulations and validated in experiments.

This research paper proposes a new switched-capacitor topology for the multilevel inverter. The structure has two isolated DC power supplies and a capacitor. Since the topology uses only one capacitor, it eliminates the problem of voltage balancing across the capacitors. This structure produces 13-level output voltage across the load terminals. The structure can be extended using derived generalized equations. A comparative analysis shows the number of components used with respect to other 13-level inverters existing in the literature. The power loss and efficiency of the topology are evaluated and experimentally verified. Moreover, the output voltage and current waveform for the topology is tested for pure resistive, inductive load, the impact of change in modulation index, and impact of the sudden change in load and is simulated and later verified experimentally using a dSPACE-1104 real-time controller. [ABSTRACT FROM AUTHOR]

The paper presents a way of accomplishing a non-contact excitation by electromagnetic waves generated from a system that includes WiFi microcontroller, H-Bridge and coil. The ESP 32 microcontroller software achieves PWM signal, which follows' a sinusoidal shape of variable frequency. The PWM signal drives the H-bridge resulting in a more powerful electric signal that also drives the coil, accomplishing in this way the pseudo-sine electromagnetic wave. The source code from microcontroller provides variable frequency and working period as well. The main features of the system are 0.5 to 3000 Hz, working periods between 0.1 and 10 seconds, the possibility to achieve more than one working period with standby periods in between. [ABSTRACT FROM AUTHOR]

A novel (N+1)-level multilevel inverter (MLI) using a modified solar panel (MSP) and newly proposed commutator coupled with slip rings, is presented in this paper. This multilevel inverter has only one H-bridge (HB) unit. The number of voltage levels of MLI depends on the number of the output terminal of MSP. The sinewave output is made possible by two-dimensional controls. The staircase sine wave has been converted into pure sinewave by using the filter capacitor at H-bridge. It is transformed to high voltage sinewave by using a step-up transformer. This proposed technique is verified by simulation and prototype.

In recent years, piezoelectric materials have been widely investigated for harvesting energy from ambient vibrations. A vibrating piezoelectric device (PD) generates alternating current (AC), which needs to be converted into direct current (DC) for powering electronic devices or for storage. A traditional full-wave bridge rectifier (FBR) interface circuit serves this purpose, but it suffers from high power loss due to the presence of high forward voltage across the diodes. In this article, an improved H-Bridge rectifier circuit is proposed as the AC-DC rectifier circuit to reduce power loss for high frequency and low amplitude application. The performance of the proposed rectifier circuit was experimentally studied, analysed and discussed. Two different testing scenarios for high frequency, namely, varying input power with fixed excitation frequency and varying excitation frequency with fixed input voltage were considered. Applicability of the circuit at low frequency range was also investigated. The outcome shows that the proposed circuit notably increases the voltage and the power produced from the PD when compared to traditional FBR circuits.

Multilevel Inverters (MLIs) are becoming more and more popular in medium and high power applications. This is due to several inherent advantages of MLI over two-level inverters such as high-quality output, lower device ratings, and several others. While the classical topologies are still having applications in most of the key areas, there is a growing interest in newer multilevel topologies with an objective of reducing power semiconductor device count, gate drivers and/or isolated DC sources. In this paper, a comprehensive review of some of the recently proposed newer multilevel inverter topologies with the abovementioned objectives is presented. In this article, a detailed investigation in terms of total power semiconductor switch count, number of DC sources, passive component requirement, highest switch voltage rating, total standing voltage etc. has been presented.

In this study, a novel current generator system was designed that can convert the basic signals used in engineering field into electrical current waves. The current generator system was realized by using Buck Converter and H-Bridge, which are Power Electronics circuit topologies. In order to produce the predicted current waveforms, the Artificial Neural Network (ANN), as a nonlinear control algorithm, has been adapted to the hybrid Power Electronics system. Then, Electrodeposition based coating experiments were carried out using the new generation current generator system. Copper (Cu) was used as a cathode and Nickel (Ni) as an anode in the coating process. Coating experiments were carried out for constant maximum current (Imax) conditions. The experiments were repeated with 3 different frequencies for each coating current wave. After coating, the surface morphology and sharp edge coating success of the covered areas were examined and the results were discussed by comparing to the DC's, PC's and PRC's.

This paper proposes a new topology of the switched-capacitor multilevel inverter (SCMLI) for photovoltaics system, which can eliminate the leakage current. In the proposed topology, the capacitors are employed as a virtual DC power supply to boost the input voltage. Here, all capacitors are charging equal to DC source, thus, just one DC source is needed to achieve the staircase waveform. In this structure in order to make the negative levels, the capacitors are connected to the output in reverse polarity. Thus, the H-bridge circuit which is used in traditional SCMLI to build zero and negative voltage levels and leads a variable common mode voltage is removed. Due to the direct connection of the neutral terminal of the grid to the negative polarity of the PV; then this topology can eliminate the leakage current. In addition, the topology has an excellent ability to path the reverse current as well as an acceptable output waveform spectrum. The operating states of all components and loss calculations are analyzed and formulated accurately as well as simulated by using MATLAB-SIMULINK software. To confirm the performance of the proposed topology; a 500 W prototype is built and experimental results are presented.

This study introduces an approach for converting the current from a sensor into controllable voltage. To this end, a switched-capacitor structure was integrated to provide efficient current-to-voltage conversion. The generated voltage was further regulated by an operational amplifier current source, enhancing stability and precision. An n-type metal oxide semiconductor field-effect transistor structure under an H-bridge was integrated into the system to achieve fine-tuned control over current stimulation. This component contributed to voltage regulation and enabled bi-directional control of current flow, offering versatility in adjusting current amplitudes using working and counter electrodes. This dynamic control mechanism was pivotal for effectively controlling the intensity of current stimulation. We applied Verilog-A modeling to simulate the optical characteristics of Si nanowires. The proposed system efficiently converted sensor-derived current into voltage using a switched-capacitor structure. Simultaneously, the precision was enhanced via operational amplifier regulation and n-type metal-oxide-semiconductor field-effect transistor-based H-bridge control. The simulation showed a current stimulus amplitude ranging from 2 to 13 μA for a variable photocurrent of Si nanowires (Rex: 10 kΩ, pulse: 100 Hz, 1 ms). The ability to finely control current stimulation intensity holds promise for diverse applications requiring accurate and adjustable current manipulation. This study contributes to the growing field of sensor technology by offering a unique perspective on the integration of nanostructures and electronic components for an enhanced control and functionality., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Dense networks are very pervasive in social analytics, biometrics, communication, architecture, etc. Analyzing and visualizing such large-scale networks are significant challenges, which are generally met by reducing the redundancy on the level of nodes or edges. Motifs, patterns of the higher order organization compared with nodes and edges, are recently found to be the novel fundamental unit structures of complex networks. In this work, we proposed a novel motif h-backbone (Motif-h) method to extract functional cores of directed networks based on both motif strength and h-bridge. Compared with the state-of-the-art method Motif-DF and Entropy, our method solves two main issues which are often found in existing methods: the Motif-h reconsiders weak ties into our candidate set, and those weak ties often have critical functions of bridges in networks; moreover, our method provides a trade-off between the motif size and the edge strength, which quantifies the core edges accordingly. In the simulations, we compare our method with Motif-DF in four real-world networks and found that Motif-h can streamline the extraction of crucial structures compared with the others with limited edges. [ABSTRACT FROM AUTHOR]

An Electrical and Computer Engineering Laboratory exercise has been included in the junior year fall term to partially bridge the theory to practice gap for multiple basic electrical and computer engineering topics. The laboratory investigates facets of power electronics and computer control for students who have recently been introduced to the theory of transistor bridge circuits for voltage polarity control in their electronics class, and digital pulse width modulation for DC motor speed control in their first computer logic class. After brief study of its specification, students follow a lab sequence to set up and instrument a commercial H-bridge to first record polarity and magnitude of output voltages under specified input conditions, and subsequently to observe DC motor response to the same inputs. DC power polarity and averaging through Pulse Width Modulation (PWM), as well as the collateral realities of brushed DC motor noise and logic versus power supply levels become clear to most student for the very first time. [ABSTRACT FROM AUTHOR]

Hybrid circuit breaker (HCB) has shown good performance for interrupting dc fault current. However, a massive number of IGBTs in series is needed. These will lead to high costs and significant difficulty in balancing IGBT dynamic voltage. This paper proposes a bidirectional hybrid circuit breaker based on a cascaded half-bridge submodule structure to reduce the overall costs and implementation difficulty of HCB. The number of IGBTs is reduced by 50%, and the operating speed is fast enough. A model of a four-terminal modular multilevel converter (MMC) system with a proposed hybrid circuit breaker in different stages is developed to describe the fault blocking process more clearly. The performance of the proposed HCB is validated and compared with other HCB structure through both theoretical derivation and time-domain simulation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

When compared with the three-level H-bridge inverter, the five-level active-neutral-point-clamped (5L-ANPC) H-bridge inverter has high output voltage level, high output power, and lower current harmonic content. Thus, it has the potential to be applied to the vessel integrated power systems. This paper proposes a method of space vector pulse width modulation (SVPWM) for the 5L-ANPC H-bridge inverter. First, the selection of the available switching vectors is based on an analysis of the switching constraints, switching times, and common-mode voltage. Then, according to the control requirements of the neutral-point potential and the floating capacitor voltage of the inverter, the action time of each switching vector is calculated. The sequence of the switching vectors in different intervals is determined based on the principle of reducing the switching times. Finally, a hardware-in-loop (HIL) real-time simulation experimental platform is established to verify the proposed method. [ABSTRACT FROM AUTHOR]

Large-scale grid integration of renewables and cross-country border energy exchange may be facilitated by multi-terminal high-voltage direct-current (MTDC) grids. However, as the number of terminals and dc lines increases, power flow management may become a major challenge. This paper addresses such a fundamental issue through the introduction of current flow controllers (CFCs) into the MTDC grid. A CFC is a low power rated controllable voltage source that can enhance system performance by suitably redirecting the power flow at the point of connection. This is achieved through the regulation of the dc line current by introducing a series voltage at the connection node. The characteristics, control, and operation for three configurations of series-connected CFCs are studied. These have been termed a dual-thyristor converter CFC, a cascaded voltage source converter-dc chopper-based CFC, and a dual H-bridge CFC (2B-CFC). A four-terminal MTDC grid has been modeled in Simulink/SimPowerSystems to analyze the dynamic performance of the devices. The simulation results show that all devices are capable of improving system performance. In addition, the CFCs are compared in terms of controllability and dc fault performance. For completeness, a 2B-CFC prototype has been developed to study the impact of a CFC on MTDC grid operation, with an MTDC test rig used to validate simulation results.

The paper presents a new generalized topology-based single-phase cascaded multilevel inverter with reduced power electronic switches, thereby reducing the driver circuits. A new basic unit is proposed in this paper. In order to generate required voltages at the output, an H-bridge is added in conjunction with the basic unit as the unit provides only positive voltage levels. Owing to the merits possessed by cascaded multilevel inverter such as reduction in switch count, driver circuits, low stresses in voltage and their power quality being high, a basic unit is developed. A comparison between the existing topologies and the proposed topology is presented. The developed cascaded 9-level multilevel inverter topology is validated with both simulations and experimentation. [ABSTRACT FROM AUTHOR]