Hysteretic Control Research Articles

Enabling High-Power Conditioning and High-Voltage Bus Integration Using Series-Connected DC Transformers in Spacecrafts

This article proposes a photovoltaic power processor for high-voltage and high-power distribution bus, between 300 V and 900 V, to be used in future space platforms like large space stations or lunar bases. Solar arrays with voltages higher than 100 V are not available for space application, being necessary to apply power conversion techniques. The idea behind this is to use series-connected zero-voltage and zero-current unregulated and isolated DC converters to achieve high bus voltage from the existing solar arrays. Bus regulation is then achieved through low-frequency hysteretic control. Topology description, semiconductor selection, design procedure, simulation and experimental validation, including tests in vacuum and partial pressures, are presented.

Decentralized Implicit Inverse Control for Large-Scale Hysteretic Nonlinear Time-Delay Systems and Its Application on Triple-Axis Giant Magnetostrictive Actuators.

This article proposes fuzzy-logic systems (FLSs)-based decentralized adaptive implicit inverse control scheme for a class of large-scale nonlinear systems with time delays and multihysteretic loops. Our novel algorithms feature hysteretic implicit inverse compensators designed to effectively mitigate multihysteretic loops in large-scale systems. In this article, hysteretic implicit inverse compensators can replace the traditional hysteretic inverse models, which are exceedingly difficult to construct, and no longer necessary. The authors provide three contributions: 1) a searching mechanism to obtain the approximate value of the practical input signal from the so-called hysteretic temporary control law; 2) the arbitrarily small L∞ norm of the tracking error attained by utilizing the proposed initializing technique, which applies the combination of FLSs and a finite covering lemma to deal with time delays; and 3) the construction of a triple-axis giant magnetostrictive motion control platform, which validates the effectiveness of the proposed control scheme and algorithms.

CONTROL OF ELECTRIC DRIVES WITH HIGH SWITCHING FREQUENCY OPERATION CAPABILITIES: ENVISIONING FUTURE PROSPECTS

Industrial drives are currently of great relevance considering the technological challenges associated with climate change mitigation. Current technologies use silicon devices with switching frequencies around 10 kHz. However, new wide bandgap (WBG) devices are expected to replace these technologies and allow operation at switching frequencies of 100 kHz or higher. This may have implications for how control algorithms for electrical drives are implemented. In this perspective paper the authors analyse and discuss the implications of high frequency operation on control, and predict the possible widespread use of hysteretic controllers suitable for operating in such switching regimes.

On Single-Input Dual-Output (SIDO) DC/DC Multi-Port Converters for DC Microgrid Applications

This paper proposes the use of linear-assisted switching power converters in the context of single-inductor dual-output (SIDO) for microgrids (MG) applications. By combining a DC/DC ripple-controlled switching power converter with the respective voltage linear regulators at each output, improved performance in terms of load and line regulations is obtained. To achieve that aim, a current-steering switching policy is proposed, together with a resource-aware circuit implementation. The ripple-based hysteretic control results in variable switching frequency to guarantee critical conduction mode (boundary of CCM and DCM).

A Fast SIMO Converter for Command-Directed IoT Nodes With State-Driven Priority Sequencing and Delay-Adjusted Fixed Window Hysteretic Control Using Constant Current-Peak Sequential DCM-CCM Operation

A Fast SIMO Converter for Command-Directed IoT Nodes With State-Driven Priority Sequencing and Delay-Adjusted Fixed Window Hysteretic Control Using Constant Current-Peak Sequential DCM-CCM Operation

Strategic Behavior and Optimization of an M/M/1 Queue with N-Policy and Hysteretic Control

Strategic Behavior and Optimization of an M/M/1 Queue with N-Policy and Hysteretic Control

An efficient controller design of a PV integrated single inductor multiple output DC-DC converter for dynamic voltage and low power applications.

In this article, a Single Inductor Multiple Output (SIMO) DC-DC boost converter for driving independent three outputs of dynamic voltage and low power is proposed. Compared with the traditional SIMO DC-DC converter, the proposed work accomplishes (i) independent control of power at each output, (ii) small switch count, (iii) relatively better scalability with increasing output channel, (iv) fast response time, and (v) relatively better efficiency. The core aim of the current article is to implement an efficient controller design of the SIMO DC converter circuit operating in continuous conduction mode for dynamic voltage applications. The SIMO circuit comprises a photovoltaic (PV) array as a renewable energy harvesting source at the input. A hysteretic controller based on direct control with seamless transition control topology is implemented in this model for SIMO operation. This scheme is popular due to its less cost, simple, easy-to-use design architecture, and fast speed of close loop control. The configuration of the solar array is designed to deliver maximum power on the input of the SIMO DC-DC converter. For tracking the maximum power point, incremental conductance with integral control configuration is applied on the PV array with fast speed and efficiency. The MATLAB/Simulink environment is utilized for model configuration. The simulation results show that the proposed SIMO configuration with the PV array provided 100.5 W and 21.7 W for 1000 W/m2 and 250 W/m2, respectively.

Fast Energy-Harvesting TEG-Supplied Charging Regulator Microsystem

This paper presents a fast hysteretic switched-inductor charging regulator (SLCR) microsystem. It is powered by on-chip thermoelectric generators (TEGs) to supply Internet-of-Things (IoT) wireless microsensors. On-chip TEGs are appealing because they are 12–1400× smaller than off-chip ones. IoT sensors mostly idle in low-power mode and transmit data wirelessly only in high-power mode on demand. This requires CMOS SLCRs to respond quickly to abrupt load dumps caused by IoT sensors. State-of-the-art (SoA) SLCRs respond to load dumps in 100 μs–2.5 ms. This time duration amounts to a significant portion of the IoT sensor's data transmission time (500 μs–7 ms). This slow response time jeopardizes the quality of data transmission. This paper presents a fast hysteretic control that responds in 9.6 μs. This control adopts nested hysteretic architecture and requires only three comparators and simple combinational logics, which is appealing, considering the low power budget limited by on-chip TEGs. Moreover, this paper contributes detailed stability analysis, derives response time and accuracy and provides intuitive and accurate system design equations. Measured results of a 180-nm CMOS prototype validate that the proposed system shortens response time by 10–260× compared to the SoA.

A Regulated 400-mV CMOS DC-DC Converter with On-the-Fly Equivalent Output Resistance Tuning

Energy harvesting is a technology that can be applied to IoT systems to eliminate the need for batteries. Many types of energy sources are available for energy harvesting, such as light, thermal, vibration, and electromagnetic energy. Indoors, where most IoT devices are located, artificial light, such as from LED lamps, can be used for energy harvesting in circuits with very ultra-low power consumption. Integrated switch-capacitor DC-DC converters are required for this type of system to convert the harvested energy into a constant output voltage suitable for powering an electronic circuit. The idea of this work is to use a hysteretic feedback control consisting of comparators and a logic system to adjust the switching frequency and the voltage conversion ratio (VCR) of the converter. With this, the equivalent output resistance is tuned to a value that results in a constant output voltage. A new method for modeling the equivalent output resistance based on charge flow analysis is proposed, which also considers the effects of source resistance. An integrated energy-harvesting system consisting of a switched-capacitor DC-DC converter is implemented to obtain an output voltage of 400 mV using a small photovoltaic cell for energy harvesting from indoor light. The proposed system can power an ultra-low-power device between 20 μW and 40 μW with a minimum input voltage of 230 mV. Electrical simulation results show that the implemented converter can achieve a peak efficiency of 81.24% at an input voltage of 260 mV for a 20 μW load.

A Wireless Hysteretic Controlled Wireless Power Transfer System With Enhanced Efficiency and Dynamic Response for Bioimplants

This article presents a 6.78-MHz wireless power transfer (WPT) system with system-level wireless hysteretic control technique and circuit-level designs for both the receiver (RX) and transmitter (TX) chips. The proposed system achieves RX local voltage regulation and TX global power regulation without using any off-chip components (e.g., MCU, DAC, or various controllers and decoders) nor TX current sensing coils, which were required in previous works. A higher light-load efficiency and instant load-transient response are also achieved with the proposed wireless hysteretic control because of its operation principle. To further improve the efficiency, dynamic switch timing calibrations in the active rectifier in the RX are also designed, with resolved dual steady-state operation issues during the transitions between on-/off-delay compensations. Both the RX and TX chips have been fabricated in 180-nm standard CMOS. Measurement results show a 68.9% peak end-to-end (E2E) efficiency, with an up-to-20% enhancement at light-load conditions over a previous non-linearly controlled WPT system design. When compared to the other state-of-the-art designs, this work achieves an overall higher E2E efficiency, unnoticeable under-/over-shoots with instant recovery in load transients, and a lower system complexity with a higher level of integration without using any extra components other than the LCs to close the wireless loop.

Spatially Explicit Linkages Between Redox Potential Cycles and Soil Moisture Fluctuations

AbstractReduction‐oxidation cycles measured through soil redox potential (Eh) are associated with dynamic soil microbial activity. Understanding changes in the composition of, and resource use by, soil microbial communities requires Eh predictability under shifting hydrologic drivers. Here, 50‐cm soil column installations are manipulated to vary hydrologic and geochemical conditions, and are extensively monitored by a dense instrumental deployment to record the depth‐time variation of physical and biogeochemical conditions. We contrast measurements of Eh, soil saturation and key compounds in water samples (probing the majority of soil microbial metabolisms) with computations of the relevant state variables, to investigate the interplay between soil moisture and redox potential dynamics. Our results highlight the importance of joint spatially resolved hydrologic flow/transport and redox processes, the worth of contrasting experiments and computations for a sufficient understanding of the Eh dynamics, and the minimum amount of biogeochemistry needed to characterize the dynamics of electron donors/acceptors that are responsible for the patterns of Eh not directly explained by physical oxic/anoxic transitions. As an example, measured concentrations of sulfate, ammonium and iron II suggest coexistence of both oxic and anoxic conditions. We find that the local saturation velocity (a threshold value of the time derivative of soil saturation) exerts a significant hysteretic control on oxygen intrusion and on the cycling of redox potentials, in contrast with approaches using a single threshold saturation level as the determinant of anoxic conditions. Our findings improve our ability to target how and where hotspots of activity develop within soil microbial communities.

Efficiency Analysis and Design Considerations of a Hysteretic Current Controlled Parallel Hybrid Envelope Tracking Power Supply

This paper presents the realization of an Envelope Tracking Power Supply (ETPS), for a sinusoidal envelope input signal. A parallel hybrid topology is chosen for the implementation. In this topology, a voltage-controlled Class-AB linear amplifier stage and a current-controlled switching converter stage operate in parallel. A hysteretic current control scheme is employed to control the operation of the switching converter. Block-level implementation of the ETPS is done using Simulink 2017b, continuous mode simulation. Simulations are performed using a sinewave input envelope signal = 1.94+ 1.2 sin(ω∙t). The input frequency varied from 1MHz to 60MHz. As the input frequency is increased, the ETPS moves from the linear to the non-linear region of operation. During the transition, the slew rates of the load current and the switching current match at a particular input frequency of 2MHz while the efficiency peaks. The maximum obtained efficiency while tracking the sinewave input signal is 82.3%. The way the efficiency can be optimized by focusing on the matching of the slew rates of load and switching currents is explained. Also, an insight into the study of various circuit parameters and the trade-offs that the designer needs to consider while designing an ETPS, is provided.

A 95.1% Efficiency Hybrid Hysteretic Reconfigurable 3-Level Buck Converter With Improved Load Transient Response

This article presents a hybrid hysteretic reconfigurable 3-level buck converter for improving load transient response. A reconfigurable 3-level mode operation is proposed to improve the load transient response without the voltage rating issue. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> feedback network of the hybrid hysteretic control can be adjusted for the optimized transient response. Furthermore, a hysteresis-based quasi-self-balancing scheme, keeping the voltage across the flying capacitor at half the input voltage, is proposed to guarantee stable operation of the proposed converter. Implemented in a 55 nm CMOS, the proposed converter achieves maximum efficiency of 95.1% at an input voltage of 4.2 V, an output voltage of 3.3 V, and a load current of 200 mA. For a load current step of 750 mA, the under/overshoot voltage and settling times are 62/60 mV and 2.48/2.32 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> s, respectively. Compared to the conventional 3-level mode operation, the proposed technique improves the under/overshoot voltage and settling time by 2.21/2.22 and 1.78/1.69 times, respectively.

A Design Methodology for the Seismic Retrofitting of Existing Frame Structures Post-Earthquake Incident Using Nonlinear Control Systems

A structural design methodology for retrofitting weakened frame systems following earthquakes is developed and presented. The design procedure refers to frame systems in their degraded strength and stiffness states and restores their dynamic performance using nonlinear control systems. The control law associated with the employed systems regards the gains between the negative state feedback and the control force, which consists of linear, nonlinear, and hysteretic portions. Structural optimization is introduced in designing the nonlinear control systems, and the controller gains are optimized using the fixed-point iteration to improve the frame system’s dynamic performance. The fixed-point iteration method relates to first-order PDE equations; hence, a new state-space formulation for weakened inelastic frame systems is developed and presented using the frame system’s lateral force equilibrium equation. The design scheme and optimization strategy differ from designing passive control systems, given that the nonlinear control system’s force consists of linear, nonlinear, and hysteretic portions. The utilization of the fixed-point iteration in the structural design area is by itself a novel application due to its robustness in addressing the gains of any type of nonlinear control system. This paper’s nonlinear control system chosen to exhibit the application is Buckling Restrained Braces (BRBs) since force consists of linear and hysteretic portions. The implementation of hysteretic control force is rare in structural control applications. In the case of BRBs, the fixed-point iteration optimizes the cross-sectional areas. Two system optimization examples of 3-story and 15-story inelastic frames are provided and described. The examples demonstrate the fixed-point iteration’s applicability and robustness in optimizing control gains of nonlinear systems and regulating the dynamic response of weakened frame structures.

AlScN-Based SAW Magnetic Field Sensor for Isolated Closed-Loop Hysteretic Current Control of Switched-Mode Power Converters

This letter uses a surface acoustic wave magnetic field sensor for measurement and closed-loop current control of the inductor current in a GaN-based dc-dc power converter. The sensor is based on aluminium scandium nitride thin films with relatively high Sc concentration of 32% and fabricated on low-cost 8-in silicon substrate, with a magnetostrictive FeCoSiB film on top of a SAW delay line. The device has dc and bidirectional current measurement capability (derived from the magnetic flux density around a current trace) and is operated electrically isolated above the current trace. With permanent magnets as magnetic bias, the setup has a usable bidirectional current range of ±5 A. A phase detector IC measures the phase shift between the 296 MHz, 19 dBm input, and 35 dB attenuated output signal of the delay line sensor. The active sensor area has a distance of 2.5 mm from the current trace. In a 1.2 mT bias, the sensor is operated with a sensitivity of 18.28°/mT and bipolar current range of up to ±5 A. The sensor signal is enhanced by an analog filter to compensate the over 1 µs delay from the delay line and readout circuit. Finally, the sensor is used as the input of an analog hysteretic current control loop. The closed-loop current control operation is demonstrated using a 48 V GaN-based half-bridge dc-dc converter with 16 kHz triangular inductor current.

A Wide-Input-Range Low-Profile Adaptive Delay Compensated Hysteretic LED Driver With Enhanced Current Accuracy

This article presents a wide-input-range low-profile dc–dc-based LED driver. An adaptive delay compensated hysteretic control (ADCHC) is proposed to adaptively modulate both peak and valley inductor currents for minimizing their current deviations, thereby enhancing the accuracy of the average LED current under different input and output voltages. A high-voltage current sensor with passive ripple filtering scheme is also developed to ensure fast and accurate inductor current sensing in the megahertz (MHz) range. The proposed LED driver was realized using two 100-V e-mode GaN FETs as power switches together with on-chip gate drivers and controller implemented in a 0.5- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> , 120-V process. This driver supports an input voltage range from 5 to 100 V and delivers a maximum output power of 25 W. The LED current error is minimized to within ±3.2% of the nominal 350-mA LED current under different input voltages and numbers of output LEDs. Compared with the prior art, the proposed LED driver has the smallest LED current error, operates 2 times higher frequency, and uses <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\times $ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.5\times $ </tex-math></inline-formula> smaller inductance and inductor volume. The proposed LED driver also features competitive peak power efficiency of 91.7% at 1.8-MHz frequency and 90-V input.

A switched‐capacitor‐assisted wireless power transfer system with regulating TX power and fast global loop

Wireless power transfer systems demand a regulating transmitter (TX) for global loop control and also a regulating receiver (RX) for its local loop. This design broadens the TX output power range, by merging a switched capacitor (SC) circuit with only 3 switches and 1 flying capacitor to boost the output power of the Class-D power amplifier. In addition, the transmitting power can be regulated by the duty ratio of the SC, improving the end-to-end power transfer efficiency under different load conditions. Moreover, the system obtains fast load transient response, with the help of a light-to-heavy load transient enhancement scheme in the TX and the hysteretic control in the RX. Designed in a 0.18-μm BCD process, this work achieves 3.1 W maximum RX output power, 67.6% peak total efficiency, and 50 μs response time during the light-to-heavy load transient simulation.

Implementation of Single-Phase Differential Mode Inverter with Constant Input Power for PV System

Abstract: A buck-boost ac-ac converter with inverting and non-inverting operations is proposed. The non-inverting operation activity can be utilized to remunerate voltage hang, and altering activity can be utilized to repay voltage swell. Along these lines, the proposed converter as a unique voltage restorer is equipped for making up for both voltage hang and swell in a wide range. It’s essential exchanging cell is a unidirectional buck circuit, inferable from which it has no shoot-through concerns. It accomplishes safe substitution without utilizing RC snubbers or delicate recompense techniques. Further, it tends to be actualized with power MOSFETs without their body diodes directing, and for current freewheeling outside diodes of good converse recuperation highlights can be utilized to limit the opposite recuperation issues and significant. Keywords: Buck-Boost Converter, CCM, DCM, SM Controller Photovoltaic, Hysteretic Controller, MATLAB.

Pulse Bursting Phenomenon in Constant On-time Controlled Boost Converter

Constant on-time (COT) is a pulse frequency modulation based control method, which is widely used for the controller of switching mode power supplies due to the advantages of simple implementation, low cost and good performances. In fact, like hysteretic control, COT is also a ripple-based control, and its loop stability is very dependent on the output voltage ripple characteristic. COT controlled buck converter is mainly concerned in nowadays. For boost converter, the output voltage ripple characteristic is quite different with that of buck converter. Thus, the stability of COT controlled boost converter is necessary to be investigated. In this paper, with particular theoretical analysis, the unique pulse bursting phenomenon in COT controlled boost converter appears when the time constant of the output capacitor is relatively small, which results in large inductor current and output voltage swing. The quantitative relationship between the time constant and the other circuit parameters such as input voltage, output current and inductance is deduced, which is very different with that of COT controlled buck converter. Simulation and ex-perimental results are provided to verify the theoretical analysis results. The investigation presented in this paper gives an im-portant guideline for the circuit parameter design of COT con-trolled boost converter.

All state constrained decentralized adaptive implicit inversion control for a class of large scale nonlinear hysteretic systems with time-delays

This paper proposes an all state constrained decentralized adaptive implicit inversion control scheme for a class of large scale nonlinear systems with unknown time delays and asymmetric saturated hysteresis. First, to address the states constrained problem, the asymmetric barrier Lyapunov function is introduced to keep the error surface within an appropriate range from the view of engineering practice to ensure the performance and safety, such as for attitude tracking of rigid spacecraft, for spacecraft approach and intersection. Second, the transmission delays between different subsystems are considered and approximated through the incorporation of the neural-network approximators and the finite coverage lemma. Third, a new hysteresis implicit inverse algorithm is designed to effectively mitigate asymmetric and saturated hysteresis nonlinearities. It should be noted that the implicit inverse implies that the analytical inverse of the asymmetric and saturated hysteresis is not required. Instead, the decoupling algorithms are designed to extract the actual control signal from the temporarily hysteretic control signal , which reduces the preliminary work of the control algorithm. Finally, all of the signals in the closed-loop system are proved to be semi-globally ultimately uniformly bounded and the tracking errors converge to an arbitrarily small residual set. The experimental results on two-machine excitation power systems in the hardware-in-loop system are presented to illustrate the effectiveness of the proposed scheme.