Input Voltage Changes Research Articles

State Feedback with Integral Control Circuit Design of DC-DC Buck-Boost Converter

The pulse-with modulated (PWM) dc-dc buck-boost converter is a non-minimum phase system, which requires a proper control scheme to improve the transient response and provide constant output voltage during line and load variations. The pole placement technique has been proposed in the literature to control this type of power converter and achieve the desired response. However, the systematic design procedure of such control law using a low-cost electronic circuit has not been discussed. In this paper, the pole placement via state-feedback with an integral control scheme of inverting the PWM dc-dc buck-boost converter is introduced. The control law is developed based on the linearized power converter model in continuous conduction mode. A detailed design procedure is given to represent the control equation using a simple electronic circuit that is suitable for low-cost commercial applications. The mathematical model of the closed-loop power converter circuit is built and simulated using SIMULINK and Simscape Electrical in MATLAB. The closed-loop dc-dc buck-boost converter is tested under various operating conditions. It is confirmed that the proposed control scheme improves the power converter dynamics, tracks the reference signal, and maintains regulated output voltage during abrupt changes in input voltage and load current. The simulation results show that the line variation of 5 V and load variation of 2 A around the nominal operating point are rejected with a maximum percentage overshoot of 3.5% and a settling time of 5.5 ms.

Adaptive Dynamic Surface Control of Buck Converter Based on Energy Storage System

To enhance the stability of the Buck converter and the capacity of resisting disturbance of the controller and converter, come up with an adaptive dynamic surface control strategy based on voltage mode control, which improves the ability of the energy storage system to stabilize the output voltage when the input voltage or load changes. The Radial Basis Function (RBF) neural network is combined with the finite covering lemma to approximate the unknown nonlinear functions with time-delay in the system. The error conversion and performance functions are adopted to ensure the tracking performance index. The adaptive dynamic surface controller is applied to ensure the stability of the output voltage of the system when the external conditions change. The proposed control method is tested on the hardware-in-the-loop (HIL) experimental platform. The consequence illustrate that the designed controller is feasible and has good voltage stability performance.

Interval Type-2 Fuzzy-Logic-Based Constant Switching Frequency Control of a Sliding-Mode-Controlled DC–DC Boost Converter

The inherent unlimited high switching frequency of the sliding mode controller (SMC) is limited by practical constraints of the hysteresis modulation (HM) technique. The inductor current and output voltage of a converter can be regulated using a combination of HM-SMC. However, HM-SMC results in a variable switching frequency operation, which is not preferred due to Electromagnetic Interference (EMI) issues. In this paper, an interval fuzzy controller is designed and developed as a solution to enable HM-SMC. In addition, a robust sliding surface is proposed, which provides an improved dynamic response. The two proposed controllers’ compatibility with one another has been tested via experiments such as a step change in input voltage, load resistance variation, and finally, a step change in output voltage reference value. The test results validate that while the interval type-2 fuzzy maintains a constant switching frequency with acceptable dynamic responses, it successfully regulates the state variables of the system. A comparison of the performance of the proposed control method with existing techniques in the literature is presented.

Robust Discrete-Time Hybrid Controller for Non-Inverting Buck-Boost DC-DC Converter

Petro-Processors of Louisiana, Inc. (PPI) site, located North of the city of Baton Rouge Parish, used two sites as depositories for various petrochemical wastes from mainly the 1960s until the 1980s. The main problem was the potential for leachate migration and for exposure of toxic materials, which had been released into local waterways. Therefore, the site is considered a public health hazard area because of risks to human health from past, present, and future exposure to hazardous substances. This study focuses on investigating selected chlorinated organic liquids, which are the predominant contaminants among all wastes: Hexachlorobenzene (HCB) and Hexachlorobutadiene (HCBD) with possible health effects using a risk assessment study. The results show that even though the petrochemical waste disposal has completely shut down since1980, it will still take an average of the HCB and HCBD to reach the domestic well with groundwater is 68 years and 57 years, respectively via slow migration, which will increase the cancer risks for the people who live near PPI site. Our results indicated that the cancer risks of exposure to HCB and HCBD are 4.6x10-6 and 2.6x10-3, respectively, which are more than the 10-6 goal. In addition, this study can be used at similar sites and for different compounds to investigate the potential impacts of pollutants on human health.

Passive Backstepping Control of Dual Active Bridge Converter in Modular Three-Port DC Converter

A dual active bridge (DAB) converter in a modular three-port DC converter is the key equipment to connect distributed energy and energy storage units and realize its efficient and large-scale utilization. When a DAB converter with traditional control is disturbed by the input voltage of distributed energy sources, some problems occur, such as large fluctuation of load voltage and slow dynamic response. In order to address such problems, this paper firstly starts with the single-phase shift control of the DAB converter, establishes the dynamic mathematical model of the DAB converter according to the nonlinear characteristics of the converter, transforms it into the passive form of Euler–Lagrange (E-L) model and designs the passive controller based on the analysis of the passive nature and stability of the converter, in order to improve the energy dissipation rate and ensure the global stability of the system. Secondly, in conjunction with the backstepping control, a passive backstepping controller is designed with the goal of shifting the comparison to eliminate errors caused by input disturbances and achieve fast-tracking of the reference voltage. Finally, a DAB simulation model based on passive backstepping control is established in Matlab/Simulink. By selecting the appropriate injection damping value, it is compared with traditional PI control and passivity-based control strategy, and the effectiveness of forward and reverse power transmission modes of the DAB converter under passive backstepping control is verified. The results show that the DAB converter with passive backstepping control has better dynamic performance and stronger robustness after sudden changes in input voltage.

Simplified Nonlinear Current-Mode Control of DC-DC Cuk Converter for Low-Cost Industrial Applications.

This paper presents a robust nonlinear current-mode control approach for a pulse-width modulated DC-DC Cuk converter in a simple analog form. The control scheme is developed based on the reduced-state sliding-mode current control technique, in which a simplified equivalent control equation is derived using an averaged power converter model in continuous conduction mode. The proposed controller does not require an output capacitor current sensor and double proportional-integral compensators as in conventional sliding-mode current controllers; thus, the cost and complexity of the practical implementation is minimized without degrading the control performance. The simplified nonlinear controller rejects large disturbances, provides fast transient response, and maintains a constant switching frequency. The nonlinear control scheme is developed using an analog circuit with minimal added components, which is suitable for low-cost industrial applications. The control law derivation, control circuit design, controller gains selection, and stability analysis are provided. The proposed control methodology is verified via simulating the closed-loop nonlinear power converter model in MATLAB/SIMULINK under abrupt changes in load current and input voltage. The simulation results show that the proposed control scheme provides robust tracking performance, a low percentage overshoot, fast transient response, and a wide operating range. The maximum percentage overshoot and settling time of the closed-loop power converter response during line disturbance are 5.6% and 20 ms, respectively, whereas the percentage overshoot and settling time during load disturbance are 2.8% and 15 ms, respectively.

Model Predictive Controlled Quasi Z Source Inverter Fed Induction Motor Drive System

Ongoing advancements in inverters have offered pathway to high gain quasi Z source inverter Circuit (QZSIC). High gain QZSIC can be found between Semi Converter (SC) and three phase Induction Motor Loads (TPIML). This paper proposes suitable controller for closed loop controlled QZSIC-TPIML. This strive deals within improvement in time- response of QZSIC fed induction motor system. The objective of this effort tis to design a closed loop controlled QZSI*fed-induction motor framework that provides a stable-rotor-speed. The QZSIC is settled to switch it to “3phase AC”. The yield of 3phase inverter is sieved before it’s applied to a‘3phase-Induction-motor’. Closed loop control of QZSIC-TPIML using SMC and MPC is simulated &their rejoinders are compared. The ‘Model Predictive controller (MPC)’ is acclaimed to retain persistent significance of-speed. The result obtained via MP-controlled QZS-IIMD-method is compared with Sliding mode-controlled SMC) QZS-IIMD systems for change in input voltage. The wished-for MP controlled-QZS-IIMD method has benefits like fast settling-time and less steady state speed error.PIC16F84basedhardware for 0.5HP, QZSIC-IMDS is implemented.

Identification of converter for Gamma ZSI fed induction motor drive system

Photovoltaic (PV) Renewable energy is frequently encountering major changes in input voltage of inverter because of oscillations in PV energy. The initial cost of drive system gets increased if a PV with higher voltage is selected. The objective of the work is to reduce the voltage rating of PV by using high gain boost converter. Three converters namely (KY Boost Converter (KYBC)/Single Boost Converter (SBC)/Quadratic Boost Converter (QBC) are considered. By comparing the (KY Boost Converter (KYBC)/Single Boost Converter (SBC)/Quadratic Boost Converter (QBC) fed Gamma Z-Source Inverter (GZSI) systems, suitable converter is chosen. Here the GZSI is placed between converter and three phase induction motor. This work compares the various combinations of converter fed GZSIS between PV and three phase induction motor. The open loop simulation for KYBC/SBC/QBC fed GZSI with three induction motor is presented here. Using MATLAB/Simulink the simulation for three converters fed GZSI with three phase induction motor are presented. By comparing the output voltage, motor speed, motor torque, voltage ripple and mechanical power for the KYBC/SBC/QBC fed GZSI, converter is selected. The results show that QBC fed GZSI with three phase induction motor gives enhanced performance compared to KYBC-GZSI and SBC/GZSI. The comparison of KYBC/SBC/QBC fed GZSI systems is done for similar input voltage and load conditions.

Antlion-based sliding mode control of vienna rectifier for internet of electric vehicle

Electric car charging infrastructure has recently grown to be a crucial component of the electrified powertrain. A single-phase Vienna rectifier is the most commonly used rectifier in electric vehicles because of its high efficiency and low cost. Vienna rectifiers have unusually high values for system parameters including peak overshoot values and settling time relative to changing input voltage. Increasing system parameters reduced the stability and effectiveness of the system. In this research work, a novel Antlion optimization algorithm (ALO) based sliding mode controller (ALO-SMC) of the single-phase Vienna rectifier has been suggested. The planned ALO-SM controller enhances the system's constraints and lowers fault values to increase stability so that the battery can be charged with the least amount of overshoot and settling time. The Simulink model of the proposed single-phase Vienna rectifier with ALO-SM controller is developed with the MATLAB software tool. The resulting assessment confirms that the proposed ALO-SM controller-based EV charging station yields better output performance with improved stability in a shorter computation time. Finally, the result shows the proposed ALO-SM controller improves the system stability with a minimum overshoot of 1.22% with a settling time of 0.01s for the given 48V battery bank and steady-state error than the existing PSO and PSO-PI controllers respectively.

A virtual adaptive RC damper control method to suppress voltage oscillation in DC microgrid

In DC Microgrid tightly regulated load converters operate as a constant power load (CPL). CPLs have negative incremental resistance characteristics, which leads to voltage oscillations and instability in DC microgrid systems. As a result, a virtual adaptive resistance–capacitance (VARC) damper control mechanism has been developed in this study to overcome the instability impact generated by the CPL. To satisfy the need for system stability, a technique to insert a virtual R-C connected in parallel with the capacitor (located on the feeder-side converter) is proposed. The proposed active damping control is self-adaptive for variations in load current. The proposed method allows for a straightforward setting of the control parameters, in which the dynamic performance of the load converter was unaltered. Stability is provided by an inherent and accurate adaptive control technique, as well as by strong resilience during sudden changes in input voltage and CPL plug-and-play. Both of these factors contribute to high levels of robustness. Therefore, practical restrictions such as weight reduction and low power dissipation, which are essential for onboard DC MGs, are maintained. The simulation results are carried out and the effectiveness of the proposed technique is tested by considering various operating conditions. Furthermore, the proposed technique is compared with the existing methods and it is found to be superior under various operating conditions.

Control strategies and experimental validation for high-gain non-isolated double inductor boost converter

In this paper, a control design methodology for a high-gain non-isolated double-inductor boost converter is proposed. The studied topology of the converter is based on a traditional boost converter operating under the inductor-switched method to obtain a high-voltage gain with a low-duty cycle. Based on the proposed methodology, three control laws are obtained. The proposed control strategies consist of two decoupled control loops: an inner loop aimed to track the input current to a desired current reference and an outer loop addressed to regulate the converter output voltage to a constant reference value. For the inner control loop, first a proportional action is proposed in order to provide damping to the system. In addition, the proportional controller is enhanced using an estimation scheme, based on immersion and invariance theory to deal with the effect of inductor parasitic resistances on the system. The third controller is a proportional-integral action in order to guarantee the current tracking objective. On the other hand, the control design of the output voltage loop results in a PI controller for the three cases which is aimed to regulate the output voltage of the converter. The performance of the proposed control laws is validated in three experimental scenarios: steady-state, input voltage changes and output resistance changes. Output voltage regulation and input current tracking are the main results obtained in each case.

Multi-stage switched-inductor switched-capacitor high gain DC-DC converter

ABSTRACT This paper presents a Multi-stage Switch Inductor Switch Capacitor High Gain DC-DC Converter for microgrid application designed with integrated Active Switch Capacitor (ASC) and Active Passive Inductor Cell (APIC). The closed loop control of a proposed voltage lift DC-DC converter is performed to ensure the constant output voltage disregarding the change in input voltage. The new high gain extendable DC-DC boost converter topology is capable of providing high-gain voltage with low duty cycle and it is extendable by increasing the number of APIC network. Analytical modelling of the proposed converter is carried out to obtain the technical specifications. The open loop and closed loop simulation model of the proposed converter is developed in the MATLAB/Simulink environment to analyse the performance of the converter. The microcontroller-based hardware model of the proposed converter of power rated 200 W (18/200 V at 50% duty ratio) is developed and tested in open loop to validate the simulation results and experimental set-up results are reported.

Double-integral sliding mode control of the switched-inductor quasi-Z source boost converter

Compared with the traditional converter, the switching inductance quasi-Z source DC-DC boost converter has the characteristics of wide output voltage, small capacitor size and more reliable circuit. However, in the process of DC voltage boost, the system is prone to high startup impulse voltage, output voltage fluctuation, and other problems. Therefore, a double integral sliding mode control (DISMC) method is proposed. The control method takes the capacitance voltage error, the inductance current error and their sum of single integral and double integral as state variables, and derives the equivalent control law from the sliding mode surface. A Lyapunov function is constructed to analyze the existence conditions of DISMC method. And the effects of abrupt changes of input voltage, negative reference voltage and load power on transient oscillation, steady state error and overshoot of the system are analyzed. This control method solves the non-minimum phase problem of capacitor voltage, so as to improve the start-up performance of the controller and speed up the response of the system. Finally, the superiority and effectiveness of the control method are verified by simulation.

Dynamic behavior analysis of cascaded buck converter and boost converter system

PurposeCascaded DC-DC converters system is the main structure of distributed power system, and it has complex nonlinear phenomena during operation, which affect the power quality. Therefore, the dynamic behavior of the cascaded buck converter and boost converter system, as one of the typical cascaded DC-DC converters systems is analyzed.Design/methodology/approachFirstly, the studied cascaded system of the buck converter with peak current control and the boost converter with PI current control is introduced and its discrete modeling is built. Then, the Jacobian matrix of the cascaded system is calculated to research the stability when the parameter change. Finally, simulation by PSIM and experiments are carried out to verify the theoretical analysis.FindingsThe coexistence of fast and slow time scale bifurcations with the changes of reference current and input voltage are studied in the cascaded system, and using simulation analysis to further study the sensitivity of the inductor current of the front-stage converter and back-stage converter to different parameters.Originality/valueA discrete model of the cascaded buck converter and boost converter system is established, and its dynamic behavior is analyzed in detail for the first time.

Real time hardware implementation of discrete sliding mode fuzzy controlled buck converter using digital signal processor

This paper deals with the real time hardware implementation of discrete sliding mode fuzzy control (DSMFC) for buck converter using digital signal processor (DSP). Applications like electric vehicle suspension control, flight dynamic control, robot position control and engine throttle position control; sliding mode control (SMC) plays a major role. Hardware realization is difficult with SMC strategy due to the continuous gain change results in chattering problem and actuator or contact may break. To resolve this problem the fuzzy logic (FL) approach has combined with the robust technique discrete sliding mode control (DSMC) to develop a new strategy for DSMFC. The mathematical modeling of the controller is done using MATLAB/Simulink software and practical design of the converter is also realized. The robustness of the controller is proved by introducing sudden change in input voltage as well as load with the help of switching circuit in hardware realization. The obtained practical results are verified by comparing with the simulation output and reference value.

An Analog Multiplier Controlled Buck-Boost Converter

This brief presents an analog multiplier based controller for a noninverting buck-boost (NIBB) converter, in which the controller can work for both buck and boost modes of the NIBB converter, thus simplifying the design and saving the power and area for the controller. Moreover, it can obtain good line regulation and load regulation performances. The analog multiplier based controller can automatically change over between the buck and boost modes according to the input and output voltages. This brief, fabricated in 65-nm CMOS process, exhibits a core area of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1}.{67}{\times }{0}.{64}{mm}^{2}$ </tex-math></inline-formula> . It outputs a stable 0.9 V when the input voltage changes from 0.7-1.4 V, with a maximum output load current of 200 mA.

The Influence of the Transformer Core Material on the Characteristics of a Full-Bridge DC-DC Converter

The paper analyzes the influence of the material from which the ferromagnetic core of a transformer is made on the characteristics of a full-bridge converter. Experimental investigations were carried out for three bridge converters containing transformers with ring cores made of various materials: iron powder, ferrite, and nanocrystalline material. The properties of the aforementioned converters were considered in a wide range of changes of input voltage, load resistance, as well as frequency and the duty cycle of the control signal. Based on the obtained measurements results of the relationship between the parameters of the used transformer core and the obtained values of the output voltage, the energy efficiency of the full bridge converter was discussed. The method of transformer modeling in the SPICE program for the analysis of the considered converter in this program was proposed. The correctness of this model was demonstrated for a converter containing a transformer with a powdered iron core.

Implementation of sliding mode backstepping controller for boost converter in real‐time for LED application

AbstractThis paper describes the real‐time implementation of a sliding mode backstepping controller for boost converters for LED lighting applications. The sliding surface is used to calculate the first error value in the backstepping control procedure, which ensures the system's robustness over a wide range of disturbances by achieving an asymptotically stable system based on the Lyapunov function. Due to the non‐minimum phase nature of boost converter, the system will become unstable. Hence the output voltage is indirectly controlled by controlling the sliding surface in the proposed sliding mode backstepping controller in order to achieve the asymptotically stable system. The detailed simulation is carried out on the MATLAB/Simulink platform, and the results are compared to that of a conventional proportional‐integral‐derivative (PID) controller and a traditional sliding mode controller, which ensures system robustness across a wide range of load resistance and input voltage changes, resulting in enhanced transient and, steady‐state responses. In the laboratory, a prototype of proposed controller is designed to ensure its accuracy in real‐time. By comparing the proposed control technique to the conventional sliding mode controller and PID controller, the flexibility of the proposed control method is validated for any variation at the input and output sides. From the experimental results, it is apparent that the proposed controller responds accurately and rapidly regardless of the disturbances caused to the system.

EXPERIMENTAL STUDIES OF INFORMATION SIGNAL-TO-RESISTANCE CONVERTER FOR AUTOMATIC CONTROL SYSTEM

Potentiometric sensors are widely used in the construction of automatic and automated process control systems. In potentiometric sensors, resistance is the output signal and its magnitudes depend on the magnitude of the input signal. voltage, current, digital code, angle of rotation, displacement or other signal is usually used as the input signal. In practice, the task of simulating of the signal which coming from the built-in potentiometric sensor is often appeared. An additional potentiometric sensor can be used to simulate the signal of the built-in sensor that allows setting the required resistance magnitude by changing any external parameter.&#x0D; The model of the voltage-to-resistance converter is made. This model allows simulating the potentiometric state sensor of the controlled system. The experimental determination of its transfer characteristic at different ambient temperatures is carried out. This model is based on a two-channel conversion circuit, which includes a source of optical radiation and two photoresistors optically connected to it. One of photoresistors is connected to a current stabilizer, while the voltage on it is analyzed by a tracking circuit that changes the brightness of the optical radiation source according to the magnitude of the control voltage. The transfer characteristic of the converter in the initial section has an insensitivity zone, following by a rectilinear section. Within the insensitivity zone, a change in input voltage does not change the output resistance. The magnitude of the insensitivity zone is determined by the maximum voltage on the incandescent lamp that determines its brightness, as well as the minimum possible resistance of the using illuminated photoresistor. Within the rectilinear section, the output resistance of the converter is linearly related to the magnitude of the input voltage. The conversion error does not exceed 0.6 % at an ambient temperature of 20° C. When the temperature decreases to -20° С, the conversion error increases to 7 %, which is due to differences in temperature errors of the photoresistors using in the model.

Compact Quadratic Boost Switched-Capacitor Inverter

This article presents a new topology for a single-stage nine-level (9L) switched-capacitor inverter. The structure of the proposed topology is not only simple but also compact. The proposed topology is developed with self-voltage balancing and a low number of power components. The output voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v_o</i> ) gain is four times higher than the input voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</sub> ). Each mode of operation is discussed with a detailed current path. The conventional sinusoidal pulsewidth modulation technique is used to generate the gate pulses. Next, the experimental results are obtained from a 1 kW prototype setup. The proposed topology is tested under different scenarios such as load change, input voltage changes, and modulation variations. Both simulation and experimental results have good agreement in terms of efficiency. Finally, a detailed comparative study is performed with other recent 9L inverters to prove the merits of the proposed topology.