Switching Power Supply Research Articles

Incorporating home appliances into a DC home nanogrid.

The possibility to incorporate home appliances of high efficiency into a home Direct Current (DC) nanogrid is presented. Switching power supplies made possible this fact. We present in this work an advance of the mathematical model for the switching power supplies as a part of the nanogrid, as well as preliminary results of measurements of currents in some home appliances used at home that will be used to elaborate a thorough model of DC nanogrids. We measured the consumption of meaningful loads on both Alternating Current (AC) and DC. For instance, we used an induction stove for cooking giving a loss of the 16.66% of the maximum wattage level while in the medium wattage the loss is of the 32.72 % (on AC) while for a laptop adapter, the loss is 3.33%. Their respective losses operating on DC are zero.

A power management circuit based on autonomous control

Based on the concept of external triggering and internal autonomous control, by using the semiconductor device with switching characteristics, using the function of capacitor voltage regulation and energy storage, and fully utilizing the charge and discharge function of the capacitor, the author introduces a new type of power management circuit. The circuit realizes the function of the device to independently control the power supply that is turned off when the storage, standby, etc. do not need to work. When the device needs to work, the power supply switch of the circuit is triggered by the external condition, and the power supply automatically supplies power to the device through the circuit. Therefore, the function of energy saving and energy saving of the device is realized, the battery life capability of the battery is improved, the loss of the power supply of the device is greatly reduced, and the technical problem that the battery of the current device is largely lost during idle and standby periods is solved, and the environmental protection and energy saving has Certain meaning.

Research on Drive Control of Piezoelectric Injector

This article is based on PWM switching power supply technology, using high-performance SoC SCM ADμC841 as the main control unit and through the IGBT on-off control, the drive circuit of the piezoelectric injector is designed. The simulation model of the drive circuit is established by Matlab/Simulink. According to different current trends during charging and discharging, three current driving modes were simulated and analyzed. The test results show that the variable duty cycle based on current feedback uses an approximate trapezoidal current charging method, which not only has a faster charge-discharge speed, but also can effectively limit the maximum current, and has a stable charge and discharge process. Therefore, the variable duty ratio is the best driving method among the three driving methods.

Design of Digital Control Phase-Shifting Full-Bridge Switching Power Supply

With the development of switching power supply towards miniaturization and high efficiency, digital and soft switching technology has become the research focus of switching power supply. Phase-shifted full-bridge DC/DC converter is commonly used in medium and high power applications due to its advantages of low switching loss, high efficiency and low output current ripple. Based on the existing switching power supply and digital control technology, a digital control phase-shifting full-bridge switching power supply is designed. Its output voltage ranges from 0 to 12 V.The output current ranges from 0 to 50 A. The voltage and current level can be adjusted according to the user’s power demand, and the output mode of steady voltage or steady current can be set. The parallel operation of multiple power supply is realized by RS485 communication protocol.

The Analysis and Design of High-power Intrinsic Safe Forward Converter Based on Power-i Technology

The existing anti explosion measures and the intrinsic safety evaluation methods have become the bottleneck factors that restrict the further improvement of the output power of the native security. Therefore, This article is based on the latest anti explosion standard, the principle of realizing high power output by Power-i technology to suppress the spark discharge energy of switching power supply is analyzed, as well as the composition of the power supply system and its evaluation method. The forward converter is selected as the topology of the high-power local security power supply, according to the technical index of Power-i system, the circuit structure of high power intrinsic safe converter is put forward, and the double protection circuit of overcurrent, overvoltage and short circuit when the output is short circuited and open fault is designed. It has been tested that the output 24V/2A high power intrinsically safe positive converter based on Power-i standard can meet the requirements of explosion protection under type I environment. The experimental results verify the intrinsic safety of the designed high power intrinsic positive shock converter, and reflect the correctness of the theoretical analysis and design method.

An Embedded Sensor Node for the Surveillance of Power Quality

The energy supply of office buildings and smart homes is a key issue in the global energy system. The growing use of microelectronics-based technology achieves new devices for a more comfortable life and wider use of electronic office equipment. On the one hand, these applications incorporate more and more sensitive electronic devices which are potentially affected by any external electrical transient. On the other hand, the existing electrical loads, which generally use electronic power systems (such as different types of battery chargers, ballasts, inverters, switching power supplies, etc.), generate different kinds of transients in their own electrical internal network. Moreover, improvements in the information of the state of the mains alternating current (AC) power line allows risk evaluation of any disturbance caused to permanently connected electronic equipment, such as computers, appliances, home security systems, phones, TVs, etc. For this reason, it is nowadays more important to introduce monitoring solutions into the electrical network to measure the level of power quality so that it can protect itself when necessary. This article describes a small and compact detector using a low-cost microcontroller and a very simple direct acquiring circuit. In addition; it analyzes different methods to implement various power quality (PQ) surveillance algorithms that can be implemented in this proposed minimum hardware platform. Hence; it is possible to achieve cheap and low-power monitoring devices that can become nodes of a wireless sensor network (WSN). The work shows that using a small computational effort; reasonable execution speed; and acceptable reliability; this solution can be used to detect a variety of large disturbance phenomena and spread the respective failure report through a 433 MHz or 2.4 GHz radio transmitter. Therefore, this work can easily be extended to the Internet of Things (IoT) paradigm. Simultaneously, a software application (PulsAC) has been developed to monitor the microcontroller’s real-time progress and detection capability. Moreover, this high-level code (C++ language), allows us to test and debug the different utilized algorithms that will be later run by the microcontroller unit. These tests have been performed with real signals introduced by a function generator and superimposed on the true AC sine wave

Construction of the UC2845 Simulation Model Based on Matlab/Sumlink

MATLAB/Simulink has some gaps in the simulation of the internal structure of the integrated chip. The article analyzes the internal structure of the UC2845 peak current control integrated chip and divides its internal parts into four parts: startup section, oscillation section, feedback section and current sampling section. The working principle and working process of each part of the chip are analyzed. The simulation model of each part is built based on MATLAB/Simulink platform, and the UC2845 chip simulation model is completed. Based on the chip model, a simulation circuit of DC24V/15V switching power supply was built. Based on UC2845 chip, an experimental circuit of DC24V/15V switching power supply was built. The simulation waveform and experimental waveform were compared, and the accuracy and practicability of the chip simulation model were verified. The chip simulation model has reference and guidance value for the simulation of UC18, UC28, UC38 series integrated chips in MATLAB/Simulink.

Leakage Inductance Calculation of the Transformers With Disordered Windings

In switching power supplies, the transformer leakage inductance (TLI) is of considerable practical significance. Ordered winding is the certain assumption in previously reported works for the calculation of the TLI value. However, disordered windings are usually unavoidable in practice and their effect on the value of the TLI is considerable. The problem becomes more complex when the number of winding turns increases. In this paper, the effect of winding disorder on the TLI value is investigated. In disordered wrapping, the winding turns arrangement (WTA) of each produced transformer is different from the others. Thus, each produced transformer has an exclusive TLI value in a disordered wrapping. Moreover, the number of possible WTAs is high, especially in transformers with a large number of winding turns. The proposed method utilizes an analytical tool for estimating the distribution of the TLI values for all of the possible WTAs. This estimation is carried out based on the limited number of the WTAs. The required number of WTAs is calculated and the validity of the proposed method is checked with Kolmogorov–Smirnov theorem. The TLI value is calculated by means of the stored magnetic energy in different parts of the transformer using the magnetomotive force variation method. Finite element simulation and experimental results are presented to show the effects of disorder on the TLI value and the validity of the proposed analytical method.

밀리미터파(Ka 밴드) 복합모드 탐색기용 고출력 펄스형 진행파관 증폭기(TWTA) 설계 및 제작

The traveling wave tube amplifier (TWTA), which can be applied to the Ka-band millimeter-wave multi-mode seeker, consists of an high voltage power supply(HVPS), a grid modulator, a command and control, and an RF assembly. We designed a power supply that generates a −17.9 kV high voltage by synchronizing the pulse repetition frequency(PRF) and power supply switching frequency(i.e. synchronization frequency), and a high-speed grid-switching modulator for RF pulse modulation. The TWTA, which is fabricated through miniaturization with a volume of 3.18 L, has high pulse switching characteristics of up to 18.5 ns. The maximum rise/fall time of the grid on/bias signal and peak power is more than 564.9 W. Moreover, an excellent spurious performance of −68.4 dBc or less was confirmed within the range of PRF and PRF/2.

New topology of a switched‐capacitor‐based multilevel inverter with a single DC power supply

The utilisation and importance of multilevel inverters, as one of the key component of new electrical systems, are ever-increasing. As a result, many works and evolutions have been carried out, which lead to improvements of topologies and control strategies. Newly introduced topologies can generate output voltage with maximum level number, minimum switching components and power supplies. This study introduces a multilevel inverter with minimum number of DC power supply and optimum number of semiconductors based on the switched-capacitor method. One of the best features of the proposed topology is its voltage generation with boost capability without any need for H-bridge. Moreover, the proposed topology has modular extension capability in order to increase the number of output levels. The comparison between the proposed converter and some previous topologies shows that it has better conditions with respect to the used semiconductor count, switches and capacitors losses. The operation and performance of the proposed multilevel converter have been ascertained through simulations and verified experimentally for a single-phase 17-level inverter. All results are illustrated to show the proposed converter's ability in smooth sinusoidal output voltage generation with boosting the input voltage without any transformer.

Suppression of EMI radiation noise by inductor current recoil on boost PFC

As the development of switching power and power factor correction (PFC) technology in electronic devices, there is strong transient current rate and electromagnetic interference (EMI) noise caused by switching power supply MOSFET, IGBT, and other semiconductor, which can seriously affect the normal operation of electronic devices and the electromagnetic environment. This paper established a radiation EMI model of Boost PFC circuit under critical conduction mode (CRM); extracted the high-frequency noise current caused by Boost PFC switching device; proposed EMI radiation noise suppression technology by inductor current recoil; discussed the influence of the boost inductor and the parasitic capacitance, the transient current change rate, and the radiation EMI noise; built a Boost PFC hardware circuit; examined on EMI standardisation based on RE 101 (magnetic field radiation) and RE 102 (electric field radiation). It is proved that the boost inductor current recoil method can effectively suppress the radiation EMI noise of the Boost PFC circuit under CRM. Results show that the magnetic field radiation noise can be reduced to 2 dBpT in frequency 25 Hz–100 kHz, the radiation noise can be reduced to 20 dB V/m in frequency 100 kHz–5 MHz.

Study on Conduction EMI Noise for EMC Filter Mounted on Switching Power Supply

Study on Conduction EMI Noise for EMC Filter Mounted on Switching Power Supply

Highly Thermally Conductive Yet Electrically Insulating Polymer/Boron Nitride Nanosheets Nanocomposite Films for Improved Thermal Management Capability.

Thermally conductive yet electrically insulating polymer composites are urgently required for thermal management applications of modern electrical systems and electronic devices because of their multifunctionality and ease of processing. However, the thermal conductivity enhancement of polymer composites is usually at the price of the loss of lightweight, the deterioration of flexibility, and electrical insulation. Here we report advanced polymer nanocomposites containing orientated boron nitride nanosheets (BNNSs), which simultaneously exhibit high thermal conductivity enhancement, excellent electrical insulation, and outstanding flexibility. These nanocomposite films can be easily constructed by electrospinning polymer/BNNSs nanocomposite fibers, vertically folding the electrospun nanocomposite fibers and the subsequent pressing. The nanocomposite films exhibit thickness-dependent in-plane thermal conductivity, which can reach 16.3 W/(m·K) in the 18 μm thick nanocomposite film with 33 wt % BNNSs. In addition, the nanocomposite films have superior electrically insulating properties compared with the pristine polymer, such as reduced dielectric loss, increased electrical resistivity, and enhanced breakdown strength. The strong thermal management capability of the nanocomposite film was demonstrated in switching power supply, which showed the importance of high in-plane thermal conductivity in thermal management of high-power density electronic devices.

In-situ formation of Fe3O4 and ZrO2 coated Fe-based soft magnetic composites by hydrothermal method

In this paper, the soft magnetic composite was prepared using a powder metallurgy method with the Fe3O4 and ZrO2 co-coated iron powder which was synthesized though the in-situ hydrothermal method. Energy dispersive spectroscopy (EDS) coupled with X-ray photoelectron spectroscopy (XPS) revealed that the Fe3O4 and ZrO2 were uniformly coated on the surface of iron powders. The addition of ZrO2 in the coating effectively improves the properties of the soft magnetic composite. ZrO2 can further improve the insulating properties, and enhance the thermostability of the coating simultaneously which will lead to resistivity increase and eddy current loss decrease. By controlling the additive amount of zirconium cation and annealing temperature, high magnetic induction of 1.002 T (measured at 8000 A/m), relatively high permeability of 83 (measured at 100 kHz), and low total core loss of 255.2 W/kg (measured at 100 kHz and 50 mT) were achieved. The Fe@ZrO2&Fe3O4 SMCs show high electrical resistivity and saturation induction, which may be widely used in high speed electric motor, transformer, inductance and switching power supply.

4T Analog MOS Control-High Voltage High Frequency (HVHF) Plasma Switching Power Supply for Water Purification in Industrial Applications

High-power plasma power supply is very useful for many industrial and medical applications. Plasma is generated artificially in the laboratory or industry by applying the electric or magnetic field. In this manuscript, we presented the simple 4T analog MOS control high voltage high frequency inverter circuit as a plasma power supply using modulation index technique. The presented plasma power supply operated at 25 kHz frequency and 10 kV peak to peak voltage. It generates a 0 V to 10 kV controllable electric field. The generated electric field is applied and produces plasma, which can be used for many industrial applications. A 10 kV to 5 kW plasma power supply has been practically developed based on the proposed topology and experimentally tested and, additionally, excellent output power conversion efficiency is achieved. From these results, the 4T analog MOS control high voltage high frequency (HVHF) plasma switching power supply is verified.

Thermosets containing benzoxazole units: Liquid‐crystalline behavior and thermal conductivity

A series of liquid‐crystalline (LC) thermosetting monomers containing benzoxazole (BO) units were synthesized to evaluate the thermal conductivities (λ) of their cured resins. A BO‐containing bisnadiimide system showed LC behavior during the heating process. However, the thermal cure of the bisnadiimide provided a film without optical anisotropy; consequently, the cured film exhibited normal levels of thermal diffusivity (α) and thermal conductivity (λ). The disappearance of the optically anisotropic ordered structures during thermal curing is likely related to the temperature gaps between the cure reaction ranges and LC ranges (Tcure‐TLC gap). In addition, epoxy resins consisting of bisepoxides and BO‐containing diamines were investigated because of their high flexibility in terms of molecular design that can be used to reduce the Tcure‐TLC gap. The combination of a terephthalylidene‐type bisepoxide and BO‐containing diamine with a controlled flexible chain length resulted in the smallest Tcure‐TLC gap among the epoxy resin systems examined herein. The cured epoxy resin film exhibited an appreciably increased λ value (0.257 W m−1 K−1) in the Z direction. This indicated the importance of the Tcure‐TLC gap for enhancing the α and λ values of the cured films. This epoxy resin system was cured under a continuous DC electric field during polarizing optical microscopy. A prompt response with deformation of the LC domains was observed in harmony with temporal ON/OFF switching of the DC power supply. As expected, the cured film exhibited a significantly enhanced λ value (0.488 W m−1 K−1) in the Z direction.

Adaptive DC-Link Voltage Control of LLC Resonant Converter

In this study, an adaptive DC-link voltage control of a two-stage switching power supply with LLC resonant converter is proposed. With this control method, the frequency variation range can be reduced and the conversion efficiency under different load conditions can be improved compared with the conventional variable frequency control technique. By operating the LLC resonant converter near its resonant frequency, circulating loss as well as the conduction loss can be reduced and optimal design of LLC resonant converter can be made possible. Moreover, no additional auxiliary circuits are required for the proposed method. The operational principle of the proposed control scheme is verified with a 350 W prototyping circuit. The switching-frequency-variation range is reduced from 12 to 4 kHz and the efficiency is improved from 89.4 % to 90.2 % at full load.

All-Passive Optical Fiber Sensor Network With Self-Healing Functionality

An all-passive optical fiber sensor network is proposed based on a novel single-line bidirectional optical add-drop multiplexer (SBOADM). By reasonably employing fiber Bragg gratings and optical circulators to compose the self-developed SBOADM, single-line bidirectional transmission can be easily achieved by the SBOADM without the assistance of a power supply or optical switch. Experimental results prove that when optical signals are fed into the proposed SBOADM in clockwise or counterclockwise direction, the insertion loss of the dropped optical signals is roughly 3.7 dB or 4.5 dB, respectively, and the attenuation of each added signal is about 3.6 dB. When the SBOADM is employed to bridge a hybrid tree-based and ring-based optical fiber sensor network, self-healing functionality can be easily embedded into the network. Once an interruption occurs in the network, the only thing that the system maintainer needs to do is to adjust one optical switch pre-installed in the remote node of the sensor network. Simulation results show that the maximum power penalty caused by the self-healing function is roughly 6 dB. That is to say, the proposal can easily overcome any one fiber-link failure without adjusting the network deploying setting or employing complex control management.

A Co-Simulation Analysis Method for Improving PCB EMC Performance

Based on the principle of the combination of field and circuit, the co-simulation method of the PCB EMC for switching power supply is carried out in this paper. We used the frequency variable source as the simulation excitation, which is closer to the actual work situation of PCB than the traditional sweep source. According to the distribution of the E and H near field, the EMC performance of PCB can be predicted, and we improved the structure of PCB by reducing the number of vias and increasing the trace width. The EMC performance of the switching power supply PCB is improved, and this method also has the advantages of reducing design costs and shortening the development cycle.

Research on Three-Phase Electronic Multifunctional Energy Meter

A three-phase electronic multi-function smart meter is designed to improve performance, cost performance, accuracy, overload capacity, and electromagnetic compatibility. A measuring meter with conventional power parameters was developed based on the switching power supply and energy metering chip MCU. Users can meet the requirements of anti-theft, power grid harmonic content measurement. This paper provides solutions, implementation schemes and test methods for multi-function power meters. Designing a three-phase electronic multi-function energy meter with high reliability, low cost, high accuracy, and advanced performance.