Converter Supplies Research Articles

LDO-Free Power Management System: A 10-bit Pipelined ADC Directly Powered by Inductor-Based Boost Converter With Ripple Calibration

This article presents a compact power management solution for a pipeline analog-to-digital converter (ADC), employing only a switching-mode power converter. By directly powering the ADC using a boost DC-DC converter, the power delivery network (PDN) exhibits an overall-high power efficiency. The proposed foreground ADC calibration calibrates the ripple error induced from the power converter, which obviates the need for well-regulated supply and reference voltage offered by low-efficiency linear low-dropout regulators (LDOs). A chip integrates the boost DC-DC converter and the pipelined ADC with an external power inductor. The prototype, implemented in 65-nm CMOS, occupies 2.34-mm2 of total active area (9.4% - ADC, 2.6% - power controller and switches, and 88% - output capacitance). In the measurement, the boost converter, switching at 31.25MHz, converts a 0.5V input to 1.2V and delivers 22.8mW of power to the pipeline ADC. The boost DC-DC converter supplies all voltage domains, including analog/digital power supply and reference. The resulting overall system power efficiency is 78.6%. Sampled at 500MS/s, the ADC achieves a signal-to-noise and distortion ratio (SNDR) of 34.7/39.9dB without/with the ripple calibration for an input frequency of 177MHz, respectively.

Single Inductor Multiple Output Auto-Buck-Boost DC–DC Converter with Error-Driven Randomized Control

We propose a single inductor multiple output (SIMO) auto-buck-boost DC–DC converter with error-driven randomized control (EDRC). The conventional controls in a SIMO DC–DC converter supply power to outputs that have been selected in a sequential order. Furthermore, they control the inductor current levels at either edge of a switching period in a steady state to be at the same level to alleviate cross-regulation. However, this limits the flexibility of the converter to respond to changes in load requirements. A sequential selection of light loads results in these loads being selected more often than a load demand, degrading the efficiency for light loads. In addition, limited flexibility leads to delayed responses. This paper introduces an auto-buck-boost topology that selects outputs based on output errors, and instantaneously adjusts the inductor current level. Moreover, we propose a technique for allowing any output to avoid selection when all outputs are fully supplied. The proposed EDRC scheme achieves improvements in efficiency in regards to light loads, cross-regulation, and output driving capability.

39‐4: A Method of Panel‐Current Limitation for Automotive OLED Displays

This paper presents a method of limiting the panel current to a safe level to improve the reliability of automotive OLEDs. The proposed circuit consisting of the buck converter and the inverting buck‐boost converter supplies the positive and negative voltage (ELVSS) to the OLED panel, respectively. The load current is limited by adjusting the ELVSS voltage when abnormal situations such as panel damage or partial short circuit occur while driving. Thus, OLED displays can keep providing safety‐related information to the driver without being turned off. A prototype of the proposed circuit demonstrates limiting the load current to 1A despite the sudden change in load resistance.

Influence of Asymmetrical Stator Axes on the Performance and Multi-Physical Field of Canned Permanent Magnet Machine for Vacuum Dry Pump With Vector Converter Supply

Limitation in manufacturing tolerances and assembly imperfections are the source of asymmetrical stator axes (ASA) defect, in particular, in a vacuum dry pumps (VDP) where the canned permanent magnet machines (CPMMs) are with fractional slot concentrated winding (FSCW). The performance and multi-physical field of CPMM in the vacuum environment is vulnerable to ASA. This work provides comprehensive research on the influence of ASA on the performance and multi-physical field of CPMM for VDP. This article establishes a mathematical model and Park transformation of a 1.6kW 6-pole/9-slot CPMM under the ASA condition. With the universality of ASA and not so strictly symmetrical stator axes as commonly expected, the experimental results demonstrated the significant impacts of ASA on the drive performance and multi-physical field, especially the inductance characteristics, the symmetry degree of stator current and flux linkage, rotor electromagnetic force and stator electromagnetic vibration of CPMM. The obtained conclusions can act as a significant reference for robust design and analysis of electric machines and drives.

Design considerations of local controller for ITER coil power supply with high availability and reliability

Abstract The local controller of an AC/DC converter for ITER coil power supply comprises a conventional system, an interlock system, and a safety system, which exhibit high reliability and availability through optimized designs for each system feature. The conventional system is made of three controllers according to each function, such as an interface controller (INTFC), an alpha controller (ALPC), and an analog-to-digital converting controller (ADC). They are configured with a 1 kHz UDP for real-time communication and 10 Hz TCP for transient recorder and with the digital fault recorder function to help facilitate data analysis and to easily troubleshoot problems in the fault event to improve the availability. Further, it is designed for accurate diagnosis by delivering time-stamped data to the parent system using the precision time protocol following the specification of IEEE 1588-2008 v2. The interlock system comprises a slow/fast local interlock controller (S-LIC/F-LIC). The S-LIC is configured with a redundant power supply and redundant Profinet communications for system availability, as well as a highly reliable programmable logic controller (PLC) for system reliability. The F-LIC is designed with an analog circuit board for protection and is evaluated for reliability. The safety system comprises highly reliable PLCs with a redundant power supply to monitor the safety-relevant signals and to transmit them to the parent system for occupational safety. In this study, the local controller of an AC/DC converter is introduced with designs applied to each system to satisfy the requirement and improve its reliability and availability.

Comparative performance analysis of bridgeless boost and bridgeless buck converter for UPS application

In this paper, a comparative performance analysis of bridgeless boost and bridgeless buck converter for Uninterruptable Power Supply (UPS) is presented. The performance of UPS application in terms of their efficiency is compared between the conventional diode bridge converter and both bridgeless converters. The input supply power quality is also been analysed by applying open and closed loop control techniques to the converter. The results show that the efficiency and the input supply quality of the bridgeless converters are significantly improved. UPS using bridgeless boost converter has better performance in all aspect compared to bridgeless buck converter. Aligned with that, the closed loop controller for the converter has also improved the efficiency and PF more than the open loop controller in performing the UPS system. All the analytical work was performed using PSIM software.

Eco Friendly CFC Less Refrigerating/Air Conditioning System

Normally, We are using refrigerating system to store the foods, Medicines..etc to extend the lives of the products. But in the existing refrigerating system which causes cooling effect with the help of refrigerants like CFC’s,HCFC’s. They are the harmful components which causes environmental Degradation. In order to overcome this we are using peltier concepts for refrigeration and protecting the environment. In this project to introduce a portable refrigeration using peltier Element. In peltier element when given DC supply produces cooling effect on one closed surface and heating effect on another surface. The cooling effect on one surface is circulated using a fan. The heat from the hotter side is sink in the heat exchanger is removed using circulating coolant or using fan. A 230V AC supply is step down using a Transformer and Rectified using a Bridge rectifier and given as a Input to the Buck converter. The Buck Converter supplies variable DC supply to the Thermo Electric Generator. The main advantage of this system is eco friendly and simplified system with reliable control.

A fault-tolerant grid-forming converter applied to AC microgrids

A crucial converter for the islanded operation of AC microgrids is the grid-forming converter. This central converter supplies electrical loads, and assures the distributed generators operation, since the malfunctioning of grid-forming converter can jeopardize the whole microgrid. This paper proposes a bidirectional grid-forming converter with a fault-tolerant functionality applied to islanded AC microgrids using a centralized control architecture. The converter is based on a delta connection of three single-phase voltage source inverters (VSIs) using an H-bridge topology for three-phase three- or four-wire systems. For this latter case, a zigzag transformer is used to provide the neutral conductor for the system. In addition to establishing voltage and frequency references for the microgrid, the converter is capable of changing its configuration from delta to open-delta, and vice-versa, in a smooth mode and without interrupting the microgrid operation. Thus, in case of failure of one of the grid-forming VSIs, the system can keep supplying the microgrid. A control strategy is developed to allow a stable operation in all operating modes. Experimental results are presented with a converter prototype to validate the proposed topology, control and mode of connection.

Preliminary design of high power magnet converter for CRAFT

In order to test the superconducting magnet performance for the Comprehensive Research Facility for Fusion Technology (CRAFT) project of China, a power supply converter needs to be designed. In this paper, short circuits upstream and downstream of the direct current (DC) reactor are analyzed, and the thyristor style and the parallel number are determined by the limit analysis of junction temperature and fault current I2t. On this basis, the over current and voltage verification of fast fuse are finished to protect the thyristor at fault cases by considering the short circuit of the bridge arm. Then, the resistor and capacitor parameters of thyristor snubber are committed to decreasing the reverse over voltage. These analysis results will be used as the preliminary design of high power magnet converter for CRAFT.

Adaptived-Axis Current Control of RSyM for Photovoltaic Water Pumping Incorporating Cross Saturation

In this article, an adaptive d -axis current control of a reluctance synchronous motor (RSyM) drive for a photovoltaic (PV) water pumping system has been presented, which incorporates impacts of the cross saturation in realtime to compensate the errors in the speed estimation. The response of the RSyM drive is optimized by adaptive d -axis current estimation. A real-time assessment of the d -axis inductance is carried out to include the cross magnetization into consideration for improving the efficiency of the motor. The d -axis current is varied for minimum value to provide the maximum output torque. Here, a two-stage solar energy conversion system is used to drive the centrifugal pump coupled to an RSyM drive. A boost converter is used to optimize the PV power using an incremental conductance based maximum power point tracking technique. The boost converter supplies power to a dc–ac, an insulated gate bipolar transistor based inverter through a capacitor connected across the dc link. The control of RSyM is implemented using the adaptive id -based vector control algorithm. An adaptive d -axis current is fed to the controller corresponding to the available solar irradiation, which aids in the maximization of drive efficiency and the minimization of stator copper losses. Moreover, this control improves the motor input terminal power factor. A speed/position sensorless control technique is utilized to reduce the complexity and to enhance the reliability of a water pumping system. The suitability of an implemented controller is verified through the experimental results taken on a 3.7 kW RSyM-driven PV energized water pumping system.

Closed Loop Control of a Series Class-E Voltage-Clamped Resonant Converter for LED Supply with Dimming Capability

In this work, a new closed-loop control system is applied to a class-E resonant DC–DC converter with voltage clamp used for light-emitting diode (LED) supply. The proposed power topology was first described by Ribas et al. in a recent work. In the present paper, the LED current is sensed and used to implement a feedback control loop instead of the simplified feedforward scheme used in this previous reference. To design the control, a novel, simplified small-signal model is presented. This model is used to analyze the converter behavior as a function of the output power. The proposed approximation is significantly simpler than the multifrequency averaging technique normally used to analyze resonant converters. The feedback control loop is designed to reduce the LED low frequency current ripple while providing dimming control. Both the model and the control are verified by simulation and laboratory experimentation and the results obtained are in good accordance with the expected values.

Semiresonant Half-Bridge Zeta Converter With Reduced Turn-OFF Currents for High-Efficiency Power Supply

This article presents a semiresonant half-bridge zeta (HBZ) converter for high-efficiency power supply. Since the proposed converter utilizes a primary inductor and secondary capacitor as a resonant tank, it can make a resonant operation during the on-state of a low-side primary switch. Therefore, the proposed converter can effectively reduce turn-off currents of the low-side primary switch and the secondary diode without any additional component and control scheme, which decreases turn-off switching loss and reverse-recovery loss. Moreover, the proposed converter can maintain advantages of the conventional HBZ converter such as high input/output (I/O) voltage gain and wide zero-voltage-switching (ZVS) range with the proposed design procedure. As a result, the proposed converter can improve its efficiency over the entire load conditions compared to the conventional HBZ converter. A 250 W, 300-400 V input, and 56 V output prototype has been built and tested to verify the effectiveness of the proposed converter.

PERANCANGAN FLYBACK CONVERTER UNTUK CATU DAYA DRIVER MOTOR BLDC ( BRUSHLESS DIRECT CURRENT )

Flyback Converter is an electronic circuit that can increase the output voltage value, the voltage value can be adjusted by changing the value of the duty cycle. This Flyback Converter will be controlled by the Pulse Width Modulation method as the output voltage setting and this research is equipped with a feedback function as monitoring and control of Input Pulse Width Modulation.
 This designed flyback converter aims to provide an isolated power supply as a power source for Brushless Direct Current Motor drivers, and this research was conducted to analyze how much power the flyback converter can produce to be able to supply Brushless Direct Current Motor drivers.
 The results of the analysis obtained in the research Design of flyback converter for power supply of BLDC (Brushless Direct Current) motor driver that is flyback converter is given an input voltage of 31 VDC and output voltage of 15 VDC, rheostat load with a capacity of 39 Ohm, a frequency of 31 KHz in the form of a box wave duty cycle reaches 70%. Flyback converter designed to produce maximum power of 49.6 watts on 70% duty cycle testing.

DESIGN AND SIMULATION OF PHASE SHIFTED DC-DC FULL BRIDGE CONVERTER

Electric and hybrid electric vehicle (EV/HEV) architectures require a small DC-DC converter to replace any conventional vehicle’s alternator. The DC-DC converter, also described as the vehicle Auxiliary Power Module (APM), provides power flow between the vehicle high voltage (HV) and low voltage (LV) DC bus. This abstract represents the phase shifted full bridge DC-DC converter scheme to design, simulate DC/DC Converter for a power rating of 80W intended for low power/auxiliary applications in electric vehicles The proposed converter is very beneficial as it can be used for 4 quadrant operation much adaptive to the unknown parameters in the PV system and these unknown parameters are estimated through the adaptation laws in the algorithm which guarantees maximum power extraction possible from the power converter for a PV system. The converter supplies AC current as per requirement. The overall stability of the converter output is analyzed by simulation. The results are compared with other existing converter results for improving power quality even further. The proposed results indicate the robustness of the proposed scheme.

Performance Measure of LCC Resonant Converter for High Voltage Power Supply

This Work presents the Design and Analysis of LCC Resonant Converter for Power Supplies which are used for high Voltages. LCC Resonant Converter was designed and simulated in both Open loop and closed loop in Matlab Simulink. The Closed loop was found to have a lesser steady state error as compared with that of the open loop. The Stress across the Switches was measured for different input voltages and found that it is linearly proportional to the input voltage. Also the Output Voltage was plotted against different load conditions.

Loss and Thermal Analysis of a High-Speed Surface-Mounted PMSM With Amorphous Metal Stator Core and Titanium Alloy Rotor Sleeve

This paper investigates the no-load iron loss, on-load loss, and thermal performance of a high-speed surface-mounted permanent-magnet synchronous machine with an amorphous metal stator core (AMSC) and a titanium alloy retaining sleeve by numerical methods. The electromagnetic properties of the AMSC are tested by an experimental platform. The distributions of no-load iron loss, rated-load loss, and the thermal behavior of the motor are investigated under converter supply conditions. Finally, the loss and thermal performances of the prototype are tested and compared with the corresponding simulation results to verify the accuracy of the calculation results and the superiority of the prototype.

A Study on Control Algorithm of Thyristor Dual Converter System for DC Electricity Supply of Urban Railway

Most of systems that supplying electric power to operate an electric train of an urban railway to supply power by converting AC into DC through trolly wire, there are two rectification methods to converting AC into DC, with diodes or thyristor. Rectification method using thyristor is composed by 12 pulse thyristor converter with forward and reverse connection. Forward connection thyristor converter supplies electric power to trolly wire as forward mode operation, Reverse connection thyristor converter returns surplus trolly wire voltage to AC top main when regenerative electric power occurs according to regenerative braking, which reduces 20% operating power of an electric train. Rectification method using thyristor is appropriate for an electric train of an urban railway for improving operation efficiency and reducing greenhouse gases. In this paper, propose a dual converter using thyristor system for an urban railway substations and a control algorithm, and the validity of the proposed control technique is verified by the fabrication and experiment of 10 kW scale reduction model.

A Modular Multilevel Voltage-Boosting Marx Pulse-Waveform Generator for Electroporation Applications

In order to overcome the limitations of the existing classical and solid-state Marx pulse generators, this paper proposes a new modular multilevel voltage-boosting Marx pulse generator (BMPG). The proposed BMPG has hardware features that allow modularity, redundancy, and scalability as well as operational features that alleviate the need of series-connected switches and allows generation of a wide range of pulse waveforms. In the BMPG, a controllable, low-voltage input boost converter supplies, via directing/blocking (D/B) diodes, two arms of a series modular multilevel converter half-bridge sub-modules (HB-SMs). At start up, all the arm's SM capacitors are resonantly charged in parallel from 0 V, simultaneously via directing diodes, to a voltage in excess of the source voltage. After the first pulse delivery, the energy of the SM capacitors decreases due to the generated pulse. Then, for continuous operation without fully discharging the SM capacitors or having a large voltage droop as in the available Marx generators, the SM capacitors are continuously recharged in parallel, to the desired boosted voltage level. Because all SMs are parallelly connected, the boost converter duty ratio is controlled by a single voltage measurement at the output terminals of the boost converter. Due to the proposed SMs structure and the utilization of D/B diodes, each SM capacitor is effectively controlled individually without requiring a voltage sensor across each SM capacitor. Generation of the commonly used pulse waveforms in electroporation applications is possible, while assuring balanced capacitors, hence SM voltages. The proposed BMPG has several topological variations such as utilizing a buck–boost converter at the input stage and replacing the HB-SM with full-bridge SMs. The proposed BMPG topology is assessed by simulation and scaled-down proof-of-concept experimentation to explore its viability for electroporation applications.

Isolated Buck‐Boost converters with AC‐TLR and dual‐transformer structure for wide output voltage range applications

A novel isolated buck-boost (IBB) converter with a dual-transformer (DT) and an active-controlled three-level rectifier (AC-TLR) is proposed in this study. A new family of IBB converters is derived with different implementations of the AC-TLR. The two transformers in the converter supply power to the output alternatively through the phase-shift control of the active switch in the AC-TLR. A voltage-doubler configuration is built and three voltage levels are generated with the DT and AC-TLR structure. Therefore, the diodes and switches in the rectifier sustain only half of the high-output voltage and turns ratios of the transformers are reduced. In addition, the zero-voltage-switching operation of all the active switches on both the primary and secondary sides is achieved and the reverse-recovery problem of all the diodes is alleviated in the wide operation range. Furthermore, the output voltage of the converter is regulated in a wide range due to the buck and boost voltage conversion characteristics of the converter. The operational principles, modulation and characteristics of the converter are presented. Finally, a 400 V input and 350-750 V output prototype is built and tested to verify the effectiveness of the proposed converters.

Delay-Dependent Stability Analysis of Modular Microgrid With Distributed Battery Power and SoC Consensus Tracking

The modular microgrid based on distributed battery storages is a simple and reliable power supply way for the islands. Modules are interconnected to the transmission network through the three-port converter. The three-port converter supplies the local ac bus voltage within the module and realizes the power exchange between the module and the transmission network. Distributed battery power and SoC consensus tracking model considering communication time delay is established on the leader-following multi-agent consensus tracking theory. By using the delay decomposition method, where the delay interval is discretized into two segmentations with an equal width, a modified Lyapunov-Krasovskii functional is constructed. A delay-dependent sufficient condition for the absolute stability of the battery power and SoC consensus tracking is derived in terms of linear matrix inequalities (LMIs) by using the free-weighting matrix method. The maximum delay margin corresponding to different controller parameters is calculated with the LMI toolbox of MATLAB. The case study is carried out based on the DongAo Island microgrid demonstration project. Simulations of battery power and SoC consensus tracking with constant time or time-varying delays verifies the effectiveness of the maximum delay margin determined by the stability criteria. Experiments reveal that the three-port converter can meet the requirements of the modular microgrid networking and operation control. The distributed battery power and SoC consensus tracking of the modular microgrid can be achieved when the communication time delay is less than the maximum delay margin.