INRUSH CURRENT LIMITATION BY UTILIZATION OF LINEAR MODE OF IGBT TRANSISTOR

Input filter is essential part of each switched mode power supply design. Important issue that must be solved in the design process is control of the high inrush current due to rapid rise of the voltage during initial connection of the power to the power supply. In the paper a single IGBT or MOSFET transistor is applied to control dv/dt in order to limit the high current spikes during initial power turn on or to limit overcurrent in microarc oxidation process. This inrush current limiting technique is beneficial because dv/dt control reduces the electromagnetic interference due to current and voltage spikes. As inrush current limiting device has minimal parts count the design is cost effective and reliable

Standby Power Reduction of Auxiliary Power Supply for Digitally Controlled SMPS

This paper presents a method how to reduce the standby power consumption of auxiliary power supply of a digitally controlled SMPS in sleep status. This design features simple flyback power supply which charges an ultracapacitor in short time and then is turned off via relay. The microcontroller controls on/off circuit to ensure that the voltage on the ultracapacitor does not rises below the critical value

Digital Control of Variable Frequency Interleaved DC-DC Converter

This paper represents a design and implementation of a digital control of variable frequency interleaved DC-DC converter using a digital signal processor (DSP)

System for Start of Internal Combustion Engine with Hybrid Battery-Supercapacitor Source

The supercapacitors are electrical energy storage devices with high power density, low series resistance and they can be charged and discharged millions of times. That makes supercapacitors as promising solution for application in the starting process of the internal combustion engines (ICE). In the paper application of the small capacity ultracapacitor bank with DC-DC converter is analyzed for the ICE starting. The starting process of the ICE is analyzed more delicate to understand starting time and energy. A prototype is designed and tested under real conditions. Experimental results ar

BLDC Motor Speed Control with Digital Adaptive PID-Fuzzy Controller and Reduced Harmonic Content

Low power brushless direct current (BLDC) motors are used in many consumer appliances. These motors have a relatively high winding resistance and therefore current control loop can be avoided in some cases, but fast and accurate speed regulation can be still needed. To minimize harmonics and generated sound noise, improved sinusoidal pulse width modulation (PWM) has been tested in the paper. As the most suitable commutation type, the sine wave with the third harmonic component has been selected. This type of communication reduced the torque ripple of the motor. This paper analyses the possibility to improve traditional proportional-integral-derivative (PID) speed regulator with Fuzzy logic block. A simulation model of BLDC motor, inverter, speed detection circuit and controller have been created. Simulation results showed that by applying the Fuzzy-based PID controller, the transient time can be reduced from 0.2 s to 0.05 s and overshoot can be avoided in comparison with traditional PID controller. Experimental results show a significant improvement in the motor dynamics—the overshoot and transient time were reduced twice. The difference with simulation results and experimental ones can be explained by delays introduced by the microcontroller

Digitally Controlled Synchronous Buck-Boost Converter for Ultracapacitor Based Energy Storage Application

This paper presents a synchronous buck-boost DC-DC converter which connects the ultracapacitor pack and a DC bus of an electric vehicle. In order to control this kind of DC-DC converter the digital signal processor (DSP) is used. The proposed power converter charges ultracapacitor pack to store the kinetic energy during vehicle braking and regenerate this stored energy during next speed up. In the paper the software algorithm of the control loop of the converter is presented. The experimental test of the DC-DC converter was performed using the test platform for DC electric motor of traction vehicle. The presented switched converter can be used for electric vehicle with low-power DC electric motor

Bidirectional Interleaved DC–DC Converter for Supercapacitor Energy Storage Integration with Reduced Capacitance

This paper analyzes the control method of a multiphase interleaved DC–DC converter for supercapacitor energy storage system integration in a DC bus with reduced input and output filter size. A reduction in filter size is achieved by operating only in modes with duty cycles that correspond to smaller output current ripples. This leads to limited control of the charging and discharging process of the supercapacitor energy storage system. Therefore, a detailed analysis of the optimal charging strategy is provided in this paper for interleaved converters with different numbers of phases. The results show that such control can be used, albeit with some percentage loss in efficiency. Experimental results are presented in this paper to verify the theoretical results

A Digitally Controlled Test Bench for DC Electrical Drives

This paper presents a test platform for low-power DC electric motor of traction vehicle or high-power motor scaled analog in the traction and braking modes. The load simulator of the traction drive is made by applying the induction motor controlled by a frequency converter. A microcontroller controls bi-directional DC/DC converter and sends speed reference signal to the frequency converter. The test bench is useful to determine power consumption of motor in various speed cycles, as demonstration bench to show operation of electric vehicle to students and to investigate the strategies of energy sources charge and discharge

Response time reduction of DC–DC converter in voltage mode with application of GaN transistors and digital control

This paper discusses the potential to decrease the response time of a DC–DC converter through the substitution of Si transistors with GaN transistors and the implementation of digital control techniques. This paper introduces an improved methodology for designing digital voltage controllers by analyzing discretization delays and subsequently implementing a modified analog controller design method. The theoretical analysis was verified using an experimental prototype of a 100 W 48 V to 12 V GaN-based DC–DC converter. A digital controller that allows a 50 kHz bandwidth to be achieved based on an STM32G4 microcontroller was developed, and the design of the controller is discussed in detail. The converter was operated with a 500 kHz switching frequency using a 6 µH inductor and a 20 µF ceramic capacitor output filter. Although the digital control introduced a 1.2 µs delay, a converter response time equal to 40 µs was achieved. Simulation models were created and their results were verified via comparisons with experimental results obtained with an AP310 frequency response analyzer.<br/

Digitally Controlled Synchronous Buck-Boost Converter with Coupled Inductor for Ultracapacitor Based Energy Storage Application

This paper presents a synchronous buck-boost DC-DC converter with coupled inductor which connects the ultracapacitor pack and a DC bus of an electric vehicle. In order to control this kind of DC-DC converter the digital signal processor (DSP) is used. The coupled inductor is used to reduce current ripples in each phase, thus allowing to measure currents in a simple way and improves transient response. The proposed power converter charges ultracapacitor pack to store the kinetic energy during vehicle braking and regenerate this stored energy during next speed up. In the paper the software algorithm of the control loop of the converter is presented. The experimental test of the DC-DC converter was performed using the test platform for DC electric motor of traction vehicle. The presented switched converter can be used for electric vehicle with low-power DC electric motor