The paper deals with an application-specific integrated circuit (ASIC) facilitating voltage conversion in thermoelectric energy harvesters. The chip is intended to be used to boost up the voltage coming from a thermoelectric module to a level that is required by electronic circuits constituting wireless sensor nodes. The designed charge pump does not need any external parts for its proper operation because all the capacitors, switches and oscillator are integrated on the common silicon die. The topography of the main functional blocks and post-layout simulations of the designed integrated circuit are shown in the article.

AC and DC input characteristics of the flyback converter are analysed and investigated via Spice simulations and measurements. The influence of parasitic effects in converter components on input characteristics is studied in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The results of the calculations based on analytical formulas and averaged models are in a good accordance with Spice simulations and measurements.

In the hybrid multiple H-bridge topology of beam supply, the load change of a DC/DC full-bridge converter can greatly affect the output voltage during onsite operation. An improved sliding mode control (SMC) strategy is thus proposed in this paper, where the rate of switching control is added to the law of system equivalent control to create a law that can realize a complete sliding mode control. Considering the special operating conditions of the load can have an influence on the performance of the controller, the impact of uncertainty existing in onsite conditions is suppressed with the proposed strategy utilized. The validity of the proposed strategy, finally, is verified by simulation, which proves the outperformance of the system in both robustness and dynamics.

In this fast-changing environmental condition, the effect of fossil fuel in vehicle is a significant concern. Many sustainable sources are being studied to replace the exhausting fossil fuel in most of the countries. This paper surveys the types of electric vehicle’s energy sources and current scenario of the onroad electric vehicle and its technical challenges. It summarizes the number of state-of-the-art research progresses in bidirectional dcdc converters and its control strategies reported in last two decades. The performance of the various topologies of bidirectional dc-dc converters is also tabulated along with their references. Hence, this work will present a clear view on the development of state-of-the-art topologies in bidirectional dc-dc converters. This review paper will be a guide for the researchers for selecting suitable bidirectional traction dc-dc converters for electric vehicle and it gives the clear picture of this research field.

The measurement of frequency characteristics, like magnitude and phase, related to a specific transfer function of DC–DC converters, can be a difficult task – especially when the measured signal approaches the boundary of a small-signal model validity (i:e. 1/3 of the switching frequency fS). It is hard to find a paper where authors mention the measurement techniques they use to draw frequency characteristics. Meanwhile the presence of noise in the output signal does not enable to directly measure the gain and the phase shift between the input and output signals. In such situations additional analysis is required in order to achieve a reliable result. This paper contains a description of a few methods that can be used to analyse measured signals in order to determine the gain and the phase shift of a specific transfer function. They enable to verify mathematical models in a wide range of frequencies (up to 1/3 fS). The methods use signals measured in the time domain and can be implemented in mathematical software such as Matlab or Scilab.

The purpose of this paper is to propose a model of a novel quasi-resonant boost converter with a tapped inductor. This converter combines the advantages of zero voltage quasi-resonant techniques and different conduction modes with the possibility of obtaining a high voltage conversion ratio by using a tapped inductor, which results in high converter efficiency and soft switching in the whole output power range. The paper contains an analysis of converter operation, a determination of voltage conversion ratio and the maximum voltage across power semiconductor switches as well as a discussion of control methods in discontinuous, critical, and continuous conduction modes. In order to verify the novelty of the proposed converter, a laboratory prototype of 300 W power was built. The highest efficiency η  = 94.7% was measured with the output power P_o =  260 W and the input voltage V_in = 50 V. The lowest efficiency of 90.7% was obtained for the input voltage V_in  = 30 V and the output power P_o = 75 W. The model was tested at input voltages (30–50) V, output voltage 380 V and maximum switching frequency 100 kHz.

Large-signal input characteristics of three DC–DC converter types: buck, boost and flyback working in the discontinuous conduction mode (DCM), obtained by precise large signal PSpice simulations, calculations based on averaged models and measurements are presented. The parasitic resistances of the converter components are included in the simulations. The specific features of the input characteristics in theDCMand the differences between the continuous conduction mode (CCM) and DCM are discussed.

Large-signal input characteristics of three DC–DC converter types: buck, boost and flyback working in the continuous conduction mode (CCM), obtained by simulations and measurements are investigated. The results of investigations are presented in the form of the analytical formulas and the exemplary results of the measurements and two forms of simulations: based on the full description of the converter components and on the averaged models. The parasitic resistances of the converter components are included in the simulations and their influence on the simulation results is discussed.

The paper presents the problem of position control of DC motor with rated voltage 24 V loaded by flywheel. The fractional order PD controller implemented in National Instruments NI ELVIS II programmed in LabView is used for controlling. The simple method for determining stability regions in the controller parameters space is given. Knowledge of these regions permits tuning of the controller and ensures required the phase margin of the system.

In this article results of diagnostic investigations of separately excited DC motor were presented. In diagnostics were applied a Fourier analysis method based on the fast Fourier transform (FFT) and a recognition method using Bayes classifier. In training process a set of the most important frequencies has been determined for which differences of corresponding signals in two states are the largest. Three categories of signals have been recognized in identification process: faultless state, state of the rotor broken one coil and state of the rotor shorted three coils

An early fault diagnostic method of Direct Current motors was presented in this article. The proposed method used acoustic signals of a motor. A method of feature extraction called MSAF-RATIO30-EXPANDED (method of selection of amplitudes of frequencies – ratio 30% of maximum of amplitude – expanded) was presented and implemented. An analysis of proposed method was carried out for early fault states of a real DC motor. Four following states of the DC motor were measured and analyzed: the healthy DC motor, DC motor with 3 shorted rotor coils, DC motor with 6 shorted rotor coils, DC motor with a broken coil. Measured states were caused by natural degradation of the DC motor. The obtained results of analysis were good. The presented early fault diagnostic method can be used for protection of DC motors.

The paper deals with circuits, composed of bipolar transistors, diodes, resistors and independent voltage sources, having multiple DC solutions. An algorithm for tracing temperature characteristics, expressing the output signal in terms of the chip temperature, is developed. It is based on the efficient method for finding all the DC solutions sketched in this paper. The algorithm gives complete characteristics which are multivalued and usually composed of disconnected branches. On the other hand the characteristics provided by SPICE are fragmentary, lose some branches or exhibit apparent hysteresis.

This paper presents a concept and the results of an investigation of a DC–DC boost converter with high voltage gain and a reduced number of switches. The novel concept assumes that the converter operates in a topology composed of series connection switched- capacitor-based multiplier (SCVM) sections. Furthermore, the structure of the sections has significant impact on parameters of the converter which is discussed in this paper. The paper demonstrates the basic benefit such a multisection SCVM idea in the converter, which is the significant reduction in the number of switches and diodes for high voltage gain in comparison to an SCVM converter. Aside from the number of switches and diodes, such parameters as efficiency and volume of passive components in the multisection converter are analyzed in this paper. In figures, the analysis is demonstrated using the example of 100 kW thyristor-based converters. All the characteristics of the converter are compared between various configurations of switching cells in the particular sections, thus the paper can be useful for a design approach for a high voltage gain multicell converter.

In the description of small-signal transmittances of switch-mode power converters several characteristic frequencies are usually used, corresponding to poles and zeros of transmittances. The knowledge of these frequencies is important in the design of control circuits for converters and usually are assumed to be constant for a given power stage of a converter. The aim of the paper is to evaluate the influence of converter primary parameters and load conductance on characteristic frequencies. Analytical derivations and numerical calculations are performed for an ideal and non-ideal BUCK converter working in continuous or discontinuous conduction mode.

The aim of this study is to design a control strategy for the angular rate (speed) of a DC motor by varying the terminal voltage. This paper describes various designs for the control of direct current (DC) motors. We derive a transfer function for the system and connect it to a controller as feedback, taking the applied voltage as the system input and the angular velocity as the output. Different strategies combining proportional, integral, and derivative controllers along with phase lag compensators and lead integral compensators are investigated alongside the linear quadratic regulator. For each controller transfer function, the step response, root locus, and Bode plot are analysed to ascertain the behaviour of the system, and the results are compared to identify the optimal strategy. It is found that the linear quadratic controller provides the best overall performance in terms of steady-state error, response time, and system stability. The purpose of the study that took place was to design the most appropriate controller for the steadiness of DC motors. Throughout this study, analytical means like tuning methods, loop control, and stability criteria were adopted. The reason for this was to suffice the preconditions and obligations. Furthermore, for the sake of verifying the legitimacy of the controller results, modelling by MATLAB and Simulink was practiced on every controller.