Voltage Control Circuit Research Articles

Design and Implementation of an Event-Driven Smart Sensor Node for Wireless Monitoring Systems.

In this paper, an event-driven wireless sensor node is proposed and demonstrated. The primary design objective is to devise a wireless sensor node with miniaturization, integration, and high-accuracy recognition ability. The proposed wireless sensor node integrates two vibration-threshold-triggered energy harvesters that sense and power a threshold voltage control circuit for power management, a microcontroller unit (MCU) for system control, a one-dimensional convolutional neural network (1D-CNN) environment data analysis and vibration events distribution, and a radio frequency (RF) digital baseband transmitter with IEEE 802.15.4-/.6 protocols. The dimensions of the wireless sensor node are 4 × 2 × 1 cm3. Finally, the proposed wireless sensor node was fabricated and tested. The alarming time for detecting the vibration event is less than 6 s. The measured recognition accuracy of three events (knock, shake, and heat) is over 97.5%. The experimental results showed that the proposed integrated wireless sensor node is very suitable for wireless environmental monitoring systems.

Design and modeling of an all-solid-state high power bidirectional DC switch

In order to improve the reliability of the aircraft ring network power distribution system for the future development needs of advanced multi-power and all-power aircraft, a design scheme of an all-solid-state high-power bidirectional DC switch is proposed to upgrade the aircraft power distribution system originally composed of traditional mechanical switches and some low-power solid-state power controllers to an all-solid-state aircraft power distribution system. The solid-state high-power bi-directional DC switch uses SiC MOSFETs as switching elements is modeled and simulated by Saber simulation software and uses reverse time overcurrent protection and short circuit protection design to realize high voltage control distribution, circuit protection, and fault isolation functions. The simulation verifies that the designed all-solid-state high-power bidirectional DC switch has short-circuit protection and overcurrent protection intelligent protection functions. Applying the design to the aircraft distribution loop network greatly enhances the reliability of the aircraft distribution system drives the development of aircraft multi-electricity-all-electricity technology, and also promotes the application of digital solid-state series modular switches in civil transportation and high-voltage power supply fields.

Single-Port SRAM Cell with lower leakage current in standby mode

As is known in the art, it is relatively difficult to write a logic ‘1’ to the five-transistor (5T) static random access memory (SRAM) cell if the SRAM cell currently stores a logic ‘0’. In this paper, we proposed a 5T SRAM cell and a cell voltage control circuit coupled to provide power to the SRAM cell. The cell voltage control circuit supplies the SRAM cell with the HVDD supply voltage if the SRAM cell is in a read mode. If the SRAM cell is being written or during a standby mode, the cell voltage control circuit supplies the SRAM cell with the LVDD supply voltage that is less than the HVDD supply voltage. Several HSPICE simulations show that the proposed SRAM cell provides an improvement in SRAM cell topology by providing an efficient solution to the write ‘1’ issue.

ОБРАТНОХОДОВОЙ ПРЕОБРАЗОВАТЕЛЬ С БЫСТРОДЕЙСТВУЮЩЕЙ СХЕМОЙ УПРАВЛЕНИЯ

The relevance The converter with reverse power transmission (with locked power transistors) is one of the most popular topologies of DC voltage pulse converters. The topology of the reverse-pass converter is unique in terms of the effective interconnection of electromagnetic processes in it. The undoubted advantage of the converter is its extreme simplicity and cheapness, the scope of its widespread use is limited to devices of low and medium power, both standard and non-standard applications. However, some properties of the converter make it possible to effectively solve complex problems of building powerful converter devices. In general, the development and research of reverse-flow converters is an urgent task in improving the devices of modern conversion technology. Aim of research Simulation of a reverse-flow converter with a high-speed dual-circuit current and voltage control system. Research methods The research methods of pulsed power electronic devices, methods of studying digital devices on CMOS structures (metal-oxide-semiconductor) are used in the work. The computer simulation was performed in the Electronics Workbench software environment. Results Methods of constructing a high-speed control system for a reverse-flow converter based on the use of two current and voltage control circuits are proposed. Due to the proposed methods, the speed and stability of the converter increases, protection against short circuit and excess voltage at the output of the converter is provided. The results and conclusions are confirmed by modeling.

Reprogrammable Metasurface Controlled by 2D Thermal Fields.

The combination of thermal field sensing and microwave operation is an innovative topic in metamaterials. Although there exists research on modulating electromagnetic waves by controlling each column of the metasurface elements for programmable metasurfaces, the regulation is not flexible. In view of this, this paper proposes a metasurface based on distributed thermal sensing that can be independently modulated by each element. In this paper, the metasurface adopts a 1-bit coding metasurface, which is combined with PIN diodes to modulate the phase response. The voltage control circuit feeds back the change in the thermistors to the switching state of the PIN diode. Each metasurface unit contains thermistors, which are used to sense thermal stimulation and can be independently modulated. The metasurface composed of these elements can feel the field generated via heat energy. We can control electromagnetic waves by controlling this field. In order to prove the feasibility of this scheme, a metasurface sample of 8 × 8 elements was designed. Three patterns were used for the design, fabrication, and measurement of the samples. Meanwhile, printed circuit board (PCB) technology was applied. The results show that the simulated results are highly consistent with the experimental results, which verifies that this scheme is practicable.

OPTIMIZATION OF CHARGE / DISCHARGE TIME OF ACTIVE FILTER CAPACITORS DURING VOLTAGE FLUCTUATIONS

A voltage regulator on capacitors has been developed for the control circuit of a parallel active filter based on dq-theory with a block of sliding averaging current in the current control circuit i_d. It contains a delay unit, a digital low-pass filter of the first order FIR or IIR (depending on the variant of the considered scheme) and the unit “sgn”, which stabilizes the output signal. The voltage control circuit on the capacitor can be implemented entirely in digital signal processing and used instead of the analog PID controller, which is much more effective if you need to adapt the circuit to the load mode. Most analog filters suffer from phase distortion when signals at different frequencies are delayed by different amounts. Although it is still present in digital IIR filters. FIR filters are usually designed as a “linear phase”, which means that the filter has no phase distortion. Phase distortions occur due to the fact that signals of different frequencies are delayed differently when crossing the filter. For IIR filters, it is necessary to enter an additional factor that will regulate the group delay, during which the filter will delay the signal of a certain frequency. If you do the same for the FIR filter, you will see a straight horizontal line, which means that all signals are delayed by the same amount, which is good and will provide better signal quality. The unit “sgn” does not affect the process of maintaining the voltage on the capacitors and the speed of transients, its role is to enhance the compensatory capacity of the voltage regulator by filtering the digital signal. The selected filter, by automatically stabilizing the voltage on the capacitor provides a stable charge / discharge process of the capacitor and a high level of compensation of higher harmonics without significant additional generation of active power in the network. When used in the context of real-time analog systems, the digital filter sometimes has a problematic delay (input-output time difference) due to analog-to-digital and digital-to-analog conversion and smoothing. It is shown that by optimizing the charge / discharge time of the capacitor of the power active filter it is possible to achieve the minimum duration of the transient process with the minimum values of harmonic distortions.

Simulation of a double-circuit subordinated coordinate regulation system of the active po wer factor corrector for the electric locomotive auxiliary electric drive

Introduction. The object of this study is an auxiliary frequency-controlled electric drive of an AC locomotive, or more specifically, the structure and parameters of the system for regulating the coordinates of the active power factor corrector, which is a part of the electric drive and a unit that ensures the energy efficiency of the electric drive as well as its electromagnetic compatibility with other equipment on board the electric locomotive and the power network. The purpose of the study is to substantiate the structure of the system for regulating the coordinates of an active power factor corrector, the choice of types of regulators and the calculation of their parameters.Materials and methods. The author has chosen as the research method the calculation of transfer functions of regulators of the subordinated regulation system, followed by computer simulation of the processes in electrical circuits using the OrCAD computer-aided design system.Results. The author made a conclusion about the expediency of using a two-circuit system of subordinated coordinate regulation containing a voltage control circuit and a current control circuit. The researcher presented and analytically compares the results of modelling of a two-circuit coordinate regulation system for the active power factor corrector for various types of regulators. The models with an aperiodic current regulator and a proportional-integral voltage regulator showed the best results.Discussion and conclusion. The obtained data serve as the basis for further improvement of the active power factor corrector operation by improving and optimising the settings, structure and algorithms of the control system, which, with the selected hardware components of the power unit, will enable it to perform its functions with a high degree of reliability in the entire range of disturbing and controlling actions on board of an electric locomotive.

OPTIMIZATION OF CHARGE / DISCHARGE TIME OF ACTIVE FILTER CAPACITORS DURING VOLTAGE FLUCTUATIONS

A voltage regulator on capacitors has been developed for the control circuit of a parallel active filter based on dq-theory with a block of sliding averaging current in the current control circuit i_d. It contains a delay unit, a digital low-pass filter of the first order FIR or IIR (depending on the variant of the considered scheme) and the unit “sgn”, which stabilizes the output signal. The voltage control circuit on the capacitor can be implemented entirely in digital signal processing and used instead of the analog PID controller, which is much more effective if you need to adapt the circuit to the load mode. Most analog filters suffer from phase distortion when signals at different frequencies are delayed by different amounts. Although it is still present in digital IIR filters. FIR filters are usually designed as a “linear phase”, which means that the filter has no phase distortion. Phase distortions occur due to the fact that signals of different frequencies are delayed differently when crossing the filter. For IIR filters, it is necessary to enter an additional factor that will regulate the group delay, during which the filter will delay the signal of a certain frequency. If you do the same for the FIR filter, you will see a straight horizontal line, which means that all signals are delayed by the same amount, which is good and will provide better signal quality. The unit “sgn” does not affect the process of maintaining the voltage on the capacitors and the speed of transients, its role is to enhance the compensatory capacity of the voltage regulator by filtering the digital signal. The selected filter, by automatically stabilizing the voltage on the capacitor provides a stable charge / discharge process of the capacitor and a high level of compensation of higher harmonics without significant additional generation of active power in the network. When used in the context of real-time analog systems, the digital filter sometimes has a problematic delay (input-output time difference) due to analog-to-digital and digital-to-analog conversion and smoothing. It is shown that by optimizing the charge / discharge time of the capacitor of the power active filter it is possible to achieve the minimum duration of the transient process with the minimum values of harmonic distortions.

Improving the Reliability of DC-DC Power Supply by Reserving Feedback Signals

The paper deals with the problem of improving the reliability of DC-DC power supplies with pulse-width modulation. The topicality of the work is related to the importance of power supply issues in modern electronics, since the quality of operation of consumer electrical appliances, including critical ones, directly depends on the serviceability of sources. The object of the study is feedback circuits aimed at stabilization of the parameters of power supply of consumers. Failures of the mentioned feedback circuits most often occurs due to the electronic components degradation under harsh operating conditions as well as under severe mechanical overloads. Such failures are dangerous for uncontrolled increase of power supply output voltage and output current. To avoid this, a new method of reserving voltage feedback signals is presented in the paper which is implemented on the basis of flyback supply topology. Feedback signals are formed from the optocoupler located on the load side and from the auxiliary winding of the power transformer, together forming two independent output voltage control circuits. Only one circuit performs stabilization at any given moment of time. If one of these circuits fails, the second one can simply replace it in its operation. The proposed method does not require any digital signal processing algorithms or microprocessor control modules and can be implemented on the basis of cheap, widely available analog chips that perform pulse-width control of the output voltage. As a result, the problem of sudden feedback loop failure is solved and the reliability of electrical equipment is increased. The validity of the proposed method is confirmed by the results of computer simulation with the use of MatLab-Simulink environment. The obtained results can be used in design of fault-tolerant secondary power supplies that operate in harsh operating conditions.

Low Voltage Control of Micro-Ionic Thrusters Using the Electrostatic Induced Potential of the Collector

This work presents a low voltage (5 V) control method for micro-ionic thrusters with high operating voltage (>1 kV). When the collector of a micro-ionic thruster is connected to the negative electrode through a 5V switch circuit, and a high DC voltage (1-10 kV) is applied to the emitter, we can get a suitable control voltage (0-4 kV) based on the electrostatic induced potential characteristics of the collector. This voltage control method allows multiple emitters to share one boost circuit of high DC voltage without using multiple high voltage control circuits. Theoretical analysis, simulations, and experiments are conducted to validate our low voltage control method, and the attitude control of a lever device with two ion thrusters in different conditions is realized with a small steady error within 2 seconds.

Optimal Design Analysis with Simulation and Experimental Performance Investigation of High-Power Density Telecom PFC Converters

The spread of the 5G technology in the telecom power applications increased the need to supply high power density with higher efficiency and higher power factor. Thus, in this paper, the performance of the different power factor correction ( PFC ) topologies implemented to work with high power density telecom power applications are investigated. Two topologies, namely the conventional and the bridge interleaved continues-current-conduction mode (CCM) PFC boost converters are designed. Selection methodology of the switching elements, the manufacturing of the boost inductors, and the optimal design for the voltage and current control circuits based on the proposed small signal stability modeling are presented. The printed circuit board (PCB) for the two different PFC topologies with a power rating of 2 kW were designed. PSIM simulation and the experiments are used to show the supply current total harmonic distortions (THD), voltage ripples, power efficiency, and the power factor for the different topologies with different loading conditions.

Improving the torque direct control method of the asynchronous motor in the converter using the active rectifier

The frequency converter study has shown that controlled rectifiers, also known as active rectifiers, have many advantages over uncontrolled rectifiers (diode bridges). The frequency converter with an active rectifier ensures that the input current is sinusoidal, the power factor is 1, the DC voltage constant at the output, the energy exchange according to bidirectional is between the load and grid. The voltage oriented control for the active rectifier will measure the grid voltage and use current control circuits or instantaneous power control circuits. The paper analyses the advantages of using the method of controlling the current in the rectifier circuit when working with the three-phase motor load. The torque direct control method of the motor is enhanced by selecting a new switch table of the voltage vector. The combining power, an active rectifier circuit, inverter, motor, and load create a complete electric drive system with improved working efficiency. The research results were verified by Matlab&Simulink software.

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

Three-level buck converter utilizing a DAC-based flying capacitor voltage control technique

This paper proposes a three-level buck converter utilizing a Digital-to-Analog Converter (DAC)-based flying capacitor voltage control technique, which controls the voltage on a flying capacitor with a differential difference amplifier and common mode feedback circuit for stable operation. Employment of the DAC-based flying capacitor voltage control circuit allows the proposed circuit to compensate for the inductor voltage error as the load current varies. The proposed three-level buck converter was implemented with a CMOS 180 nm standard process. The measurement results demonstrate the wide range of the input and output voltage from 2.7 V to 3.6 V and 0.7 V to 2.4 V, respectively. The proposed three-level buck converter achieved the peak power efficiency of 91% and output ripple voltage of 32.5 mV at the switching frequency of 2 MHz and load current range of 10 mA to 400 mA.

A 65nm CMOS Process Li-Ion Battery Charging Cascode SIDO Boost Converter with 89% Maximum Efficiency for RF Wireless Power Transfer Receiver

This paper proposes a 65nm CMOS process cascode single-inductor-dual-output (SIDO) boost converter for RF wireless power transfer (WPT) receiver. In order to withstand 4.2V Li-ion battery output, cascode 2.5V I/O PFETs are used at the power stage while 2.5V cascode NFETs are used for 1V output to supply low voltage control circuit. By using NFETs, 1V output with 5V tolerance can be achieved. Measurement results show conversion efficiency of 89% at P IN =7.9mW and V BAT =3.4V.

Thermal sensing metasurface with programmable wave-front manipulation

Combining thermal field sensing with microwave manipulation has always been a widely pursued topic for metamaterials for some time. However, most temperature-sensitive designs for metamaterials and metasurfaces are still limited in the single absorption manipulation. In this paper, we present a metasurface with programmable wave-front modulation for distributed thermal sensing. An element integrated with a Positive-Intrinsic-Negative (PIN) diode was designed for 1-bit phase response control, while a column of thermistors was applied for the distributed thermal stimulus. When the thermistors in distinct positions sensed the heat, a voltage control circuit directly changed the on–off states of diodes, to generate specific scattering fields. To demonstrate this behavior, a metasurface sample with 25 × 27 elements was designed, fabricated, and measured using four patterns. The results show great consistency with the simulation data, thereby validating the design.

A Magnetic-Field Regulation and Stabilization System

An inexpensive system for controlling and stabilizing the magnetic-flux density of an electromagnet on the basis of a monolithic Hall sensor is described. The main functional unit of the system is a precision controllable stable-current source with digital control and a regulating unit based on a power MOSFET transistor, which operates in the saturation region. A signal from a magnetic-field sensor is used to control the magnetic-field flux density, while a negative electromagnet-current feedback stabilizes the flux density. In this method, the 1/f noise of a Hall-effect sensor does not affect stability of the electromagnet flux density, while the drift and noise characteristics of the system are determined by the parameters of the used reference-voltage source. The position of the working point of the transistor in the saturation region is stabilized in the entire range of operating currents using a drain–source voltage control circuit. The developed system is used to control the magnetic-field flux density of the mass analyzer of the MI1201IG mass spectrometer and provides the following characteristics of the magnetic-field flux density control: the operating frequency band is 0–10 Hz, the flux-density control range is 0–0.4 T with a step of 1.5 µT, and the overall drift and noise instability do not exceed ±2 × 10–6 T within 20 min in the operating temperature range of 20–50°С.

Tunable AC/DC converter using graphene-germanium barristor based half-wave rectifier

Tunable DC voltage control circuit based on a half-wave rectifier was developed using a graphene–germanium barristor. The output DC voltage level could be modulated at 30–100% of the peak voltage by controlling the Schottky barrier height between graphene and germanium using a gate bias. Owing to the simple and low-temperature integration process, this device can be used for a variable DC power supply in monolithically integrated circuits or flexible devices.

A 100 kV, 20 A, 1 ms long pulse solid-state Marx modulator for klystron

Due to difficulties associated with the conventional gas tube based modulators, solid-state switch based klystron modulators are gaining popularity in the scientific community. Research, design, and development of high voltage solid-state modulators for electron and proton accelerators are in progress at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. A prototype of 100 kV, 20 A, 1 ms pulse duration Marx modulator has been designed and developed. The modulator has been constructed using 34 numbers of Insulated Gate Bipolar Transistors (IGBT), based 3 kV main modules for generation of a 100 kV base pulse. A droop correction scheme, consisting of 24 numbers of 1 kV corrector modules, has been adopted to compensate the droop in the output pulse. Before incorporating the droop compensation technique, the modulator had droop of 16% in the output voltage pulse. A microcontroller based control unit is used for the programmed staggered triggering of all the main modules and corrector modules. Fiber optic based control signal transmission was done to realize electrical isolation between high voltage circuits and control circuits. The modulator has been tested for 100 kV, 20 A, 1 ms pulse duration at 1 Hz, initially without droop compensation and later with the activation of the correction scheme for droop compensation. With the droop compensation scheme, less than 1% droop could be achieved in the output voltage pulse. Output voltage pulses of 1 ms pulse width, 1.4 μs rise time and 9.7 μs fall time at 100 kV have been achieved successfully. The present effort forms a strong basis for further development of this technology for higher average power as well as for replacing the earlier thyratron based modulators.

On Optimization of Manufacturing of a Voltage-Controlled Circuit Based on Heterostructures to Increase Density of Their Elements. Influence of Miss-Match Induced Stress on Technological Process

On Optimization of Manufacturing of a Voltage-Controlled Circuit Based on Heterostructures to Increase Density of Their Elements. Influence of Miss-Match Induced Stress on Technological Process