This article proposes a new auxiliary power supply (APS), which is used to feed the controllers, drivers, and sensors of the submodules for medium-/high-voltage and high-power solid-state transformer. In medium-/high-voltage and high-power applications, the APS is usually connected to the dc bus of the submodule to obtain electric energy. The voltage of the submodule's dc bus is often as high as several thousand volts so that the APS must have the ability to handle such high input voltage. An input-series capacitor structure, which makes the voltage stress of the power semiconductor devices reduced, is adopted in the proposed APS. Therefore, the high input voltage can be handled by the low-voltage power semiconductor devices. Furthermore, the input voltage sharing can be achieved without any special control strategy, which makes the control system simplified and the stability improved. Meanwhile, zero-current switching is guaranteed for all the switches, so that the power density and efficiency can be improved. Finally, the simulation model and prototype are built, by which the feasibility and effectiveness of the proposed APS are verified.

Auxiliary Power Supply for Medium-/High-Voltage and High-Power Solid-State Transformers

In this paper, the design and control of Photovoltaic/battery system using a flyback converter for stand-alone applications is presented. A flyback converter is used to get DC output along with an AC output for high frequency applications without employing an inverter. The PV/battery system uses photovoltaic array as the main source of power and a battery as the storage device. The energy input of the PV system is effectively utilized by adopting an MPPT technique and the storage battery is controlled to balance the load requirements using a bi-directional dc-dc converter. This system ensures that the load demand is satisfied under varying solar irradiance conditions and a constant voltage is maintained for different load conditions. The modelling and control strategy of the implemented system is realized in MATLAB/Simulink environment.

Design and Analysis of Dual Output Flyback Converter for Standalone PV/Battery System

This paper represents a comparative study of three different types of DC-DC converter that can be used for reduction of total harmonic distortion (THD) in stator current, back electromotive force (EMF) and torque of brush less DC motor. In addition, the topologies of these converters are analysed, and the THD of the output characteristics have also been studied. In this work, SEPIC, Zeta and Flyback converters are considered and their outputs are fed to the BLDCM with the help of universal bridge or six step inverter. Moreover the THD of the output voltages are not only measured for three converters but also reduced by tuning the parameters. At first these three converters are modeled in MATLAB/ Simulink based simulation platform and studied the performance individually and further executed with hardware circuitry. Finally the output parameters from both software simulation and real time hardware are compared for these three converters separately and got satisfactory similar results. Again we studied the performance with these converters in terms of efficiency while fed in the commutation drive circuitry of BLDCM by considering minimum THD. From this comparative simulation results, it has been observed that Zeta converter showed maximum efficiency. Therefore, in real time hardware implementation, the commutation drive circuitry of BLDCM is studied with Zeta converter. With this configuration, a comparatively low THD of stator current, back EMF and electromagnetic torque have been achieved in BLDCM with PID controller.

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Comparative study of three different bridge-less converters for reduction of harmonic distortion in brushless DC motor

Indonesia is a large archipelago country with various characteristic areas. Based on a report from the Ministry of Energy and Mineral Resources, Indonesia's electrification ratio has reached 98.86%. Even though Indonesia's electrification ratio is close to 100%, it cannot be denied that there are still many remote areas that still do not have electricity supply. This can be caused by areas that are difficult to reach, thus hampering the construction of the electricity network. To meet electricity needs in remote areas and with not too many population, a Diesel Power Plant (PLTD) is usually built, but this type of plant requires fuel oil which of course also requires replenishment every certain time after the fuel runs out. To solve the above problems, a portable solar power plant (PLTS) is proposed which can be easily mobilized to facilitate delivery to remote areas. PLTS portable can also be used as an emergency power source in areas where electricity facilities have been cut off due to natural disasters. To adjust the output voltage of the solar panels, a single input multi output (SIMO) converter topology is proposed. This converter consists of a flyback converter that can increase and decrease the voltage and has isolation between the input and output sides. In addition, this converter also has several outputs so that it can supply two loads (battery and communication equipment) at the same time. To maximize the conversion of solar energy in this system, it is also proposed to use the MPPT control with the PSO method.

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Desain dan Implementasi MPPT PSO pada Sistem Pembangkit Listrik Tenaga

This paper presents an active clamped two-switch flyback Zeta converter. The disadvantage of conventional flyback converters is the ringing caused by the transformer leakage inductance and the main switch parasitic capacitance resonance, resulting in high voltage stress on the switch. In the proposed converter, by using the active clamping technique, The voltage spike on the main switch is absorbed by the clamp capacitor, the voltage stress of the two main switches is clamped to V in , and the switch operates in zero voltage switching, which can reduce the switching loss and improve the overall effectiveness. The converter proposed in this paper can reduce two diodes on the primary side of the converter compared with the traditional two-switch flyback converter. Finally, the simulation results of the 240W DC/DC prototype are presented to verify the feasibility.

An active clamped two switch flyback Zeta converter with reduced switch voltage stress

Flyback converters have been quite used for DC-DC conversion and electrical isolation since they are simple to operate, minimum component count and small size. Flyback converter like any other switch mode power supply (SMPS) has two modes of conduction, the best mode for the design is selected and implemented. Due to its operation in relatively high frequency in range of 100 KHz compared to 50 Hz transformer with hard switching, some noises appeared from parasitic and leakage elements in the converter. The sources of noises have been tracked to minimize its effect on performance. The practical results obtained from the design implement actions are shown in this paper.

Flyback converter design for low power application

Operational amplifiers have been used for interfacing analog signals to microcontrollers units. Due to its random nature, analog signals vary very much, perhaps then exceed the voltage ranges of operation. Chip manufacturers protect their chips by using diode circuits, but those diodes are not intended to normal use. To overcome the signals which may exceed the limit, clamping circuit have been used in this research. The best solution was achieved using a multiplexing circuit implemented using simple switches.

Ashraf A. Mohammed

Papers

Flyback converter design for low power application

Practical considerations for interfacing operational amplifiers with analog to digital converters in microcontrollers