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Generally speaking, in order to effectively keep the output power of the solar array at the maximum output power, a DC-DC converter is indispensable for achieving the maximum power point tracking (MPPT). In addition, the output power created from the solar array is varied, and hence the DC-DC converter with a high voltage conversion ratio is needed to meet the load requirements. Therefore, a high step-up converter is presented herein, which is derived from the traditional boost converter and hence possesses simple structure, continuous input current and easiness of control. The effectiveness of this converter is demonstrated by some experimental results. After this, the maximum power point tracking (MPPT) method with shading conditions considered is presented, which is realized by the proposed converter and the field programmable gate array (FPGA). Finally, the PV simulator, named PVS01203 made by Nippon Kernel System Co., Ltd., is used to verify the effectiveness of the proposed MPPT method under shading conditions. [ABSTRACT FROM AUTHOR]

In this study, a control technique combining the pulse amplitude modulation (PAM) and the pulse width modulation (PWM) is presented to minimize the output voltage ripple of the proposed converter. The proposed converter is a two-stage structure. The first stage, used to adjust the input voltage of the second stage, is an active clamp buck-boost converter, and the second stage, used to reduce the output voltage ripple, is a two-phase interleaved buck converter with an active clamp based on only one resonant circuit. Furthermore, the output voltage ripple can be cancelled when the two-phase interleaved buck converter operates under the condition of individual duty cycles of 50% with a phase shift of 180o. Moreover, both the first stage and second stage converters can achieve zero voltage switching (ZVS). Therefore, compared with hard switching control, the efficiency can be improved. Above all, the number of phases can be extended. Finally, the operating principles and experimental results are provided to verify the performance of the proposed converter. [ABSTRACT FROM AUTHOR]

In this paper, detection of inductor saturation, together with anti-saturation control, is presented, which is applied to a synchronously-rectified (SR) buck converter. Since the inductor maybe sometimes work in a saturation situation, such as overload. In theory, as the inductor is saturated, the corresponding current slope in the inductor will be increased, and such a phenomenon can be used to judge whether the inductor is saturated or not. However, as this phenomenon occurs, variations in current are not easy to obtain because of limitations of slope detection speed and effects of noise interruption. Therefore, the detection of the inductor current ripple amplitude and the load current, together with the input voltage information, is used to judge whether the inductor is saturated or not. Afterwards, once the inductor is saturated, the proposed anti-saturation control strategy is applied to make the inductor work far from saturation. In this paper, some experimental results are provided to verify the proposed detection and compensation of inductor saturation. [ABSTRACT FROM AUTHOR]

In this paper, an isolated asymmetrical half-bridge LCC resonant inverter is presented, which is the kernel of the proposed lighting ballast that is used to drive an external electrode fluorescent lamp (EEFL). This lighting ballast contains three power stages if dimming is necessary; otherwise it contains two power stages only. The first power stage is constructed by a traditional boost converter with power factor correction (PFC), and such a converter operates in the critical mode (CRM). The second power stage is built up by a buck converter is used to control the duty cycle such that the corresponding output voltage can be changed and hence dimming of the EEFL can be achieved. The third power stage is established by an isolated asymmetrical half-bridge LCC resonant inverter operating under a fixed switching frequency with a fixed duty cycle. Via LCC resonance, not only the power switches of this inverter work in zero voltage switching (ZVS) so as to reduce the switching loss, but also the voltage gain is larger than one such that the turns ratio of transformer can be reduced. Most importantly, as the EEFL operates on the rated conditions, i.e., without dimming, the second power stage is to be bypassed, thereby causing the corresponding efficiency to be upgraded. The basic operating principles and corresponding mathematical deductions of the proposed inverter are described, and applied to the constructed EEFL lighting ballast that is verified by some experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a novel step-up converter is presented, whose operating principles are mainly based on charge pump capacitors and dual boost inductors. Furthermore, although three switches are used, no isolated gate driver is needed instead of one half-bridge gate driver and one low-side gate driver. Accordingly, the proposed converter is easy in analysis and simple in implementation. In addition, some experimental results are provided to verify the effectiveness of the proposed converter. [ABSTRACT FROM AUTHOR]

A high voltage-boosting converter is proposed herein, which combines one coupled inductor and one charge pump. Under a low input voltage with a high input current, the proposed converter has high voltage conversion ratio, and possesses an active voltage clamping circuit which pumps some portion of the leakage inductance energy to the output so as to increase the efficiency at light load, thereby causing the efficiency at light load to be very high. Hence, it is very suitable for the burn-in test of the buck-type converter. In this paper, the basic operating principles of the proposed converter are provided, together with some experimental results to verify its feasibility and effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, counter-based pulse-width-modulated (PWM) control according to the output voltage ripple using a one-comparator scheme without any analog-to-digital converter (ADC) utilized is presented herein, which is implemented based on the field programmable gate arrays (FPGA) and applied to DC-DC converters. However, too small or distorted output ripple limits its performance. Consequently, a sawtoothed wave injection method is proposed to overcome this problem and enhance its application capability greatly. In the paper, the one-comparator counter-based pulse-width-modulated (PWM) control strategy and the sawtoothed wave injection method are firstly described in details. And finally, some simulation and experimental results are provided to demonstrate the effectiveness of the proposed control scheme. [ABSTRACT FROM AUTHOR]

Two simple voltage-boosting converters, based on charge pumps with one inductor inserted, are presented herein. Above all, by only changing the turn-on types for switches, without changing the circuit structure, there are two voltage conversion ratios to be generated easily. The proposed converters have individual simple operating analyses--if each converter operates in the continuous conduction mode (CCM), only two operating modes exist. Furthermore, the power switches used in each converter are easy to drive--only two half-bridge gate drivers and one low-side gate driver are needed and the voltage stress on the output diode can be reduced as compared to the traditional boost converter. In this paper, a brief illustration of basic operating principles of the proposed converters is firstly given, and secondly some experimental results are provided to demonstrate their effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, a one-comparator counter-based sampling strategy, together with the proposed primary-side post regulator and the proposed pulse width modulation (PWM) type, is applied to a forward converter with a single isolation stage and multiple outputs having synchronous rectification (SR). With only the required comparators and without any analog-to-digital converter (ADC), the information on feedback output voltage is entirely obtained according to the counter. To upgrade the load transient response, the proposed nonlinear control technique is applied. Therefore, the proposed control topology can improve the cross regulation and load transient response of the SR forward converter. In this paper, the proposed sampling and control schemes are described and some experimental results are provided to verify its feasibility. [ABSTRACT FROM AUTHOR]

Two types of high step-up DC-DC converters based on the concept of the charge pump and coupling inductor, together with a passive voltage clamping circuit which pumps part of the leakage inductance energy to the output, are presented herein. Moreover, the implementation of the passive voltage clamping circuit for this converter with multiphase is very easy. Above all, there are two types of high step-up converters in this paper, depending on gate driving signals without changing any circuit structure. In this paper, the basic operating principles of the proposed converter are firstly described, and secondly some experimental results are provided to verify the effectiveness of the proposed converter topologies. [ABSTRACT FROM AUTHOR]

A negative KY buck converter is presented herein along with its soft switching operation. This converter can transfer the positive input voltage to the negative output voltage. Above all, zero voltage switching (ZVS) and zero current switching (ZCS) are used to achieve soft switching operation. Moreover, the input current is limited to some extent. In this paper, the behavior of the proposed circuit is firstly described in detail, and secondly some simulated and experimental results are provide to demonstrate the effectiveness of the proposed topology. [ABSTRACT FROM AUTHOR]

In this paper, novel dual-output boost and buck-boost converters with positive and negative output voltages under a given single positive voltage source fed. Due to its dual output with positive and negative output voltages, these converters are very suitable for driving the half-bridge class-D amplifier, so as to remove a DC blocking capacitor required in the half-bridge class-D amplifier. In this paper, firstly the basic operating principles of this converter are illustrated along with a simple mathematical deduction, and eventually some experimental results are provided to demonstrate its effectiveness. [ABSTRACT FROM AUTHOR]

Design and implementation of a simple current sharing control technique, based on the concept of the differential-mode choke, is presented herein, which is applied to two-phase synchronously-rectified (SR) buck converter. This current-sharing structure is quite simple. In this circuit, a synchronously-rectified (SR) switch is used to upgrade the efficiency, two phases with phase shift of 180° is employed to reduce the inductor current ripples, and coupling output inductors is utilized to further decrease the inductor current ripples. In this paper, the detailed basic operating principles, together with mathematical derivations, are firstly described, and secondly some simulated and experimental results are offered to demonstrate the proposed control strategy. [ABSTRACT FROM AUTHOR]

In this paper, topology exchange between the KY converter and its derivative is presented so as to tackle the wide input voltage range and hence to increase system control reliability. Since the KY converter, named 1-plus-D converter, is a non-isolated voltage-boosting converter with buck-type behavior, its derivative, named 1-plus-2D converter, also possesses fast transient responses. And hence, the proposed topology exchange control strategy can make each other transferred smoothly. Some experimental results are provided to demonstrate the effectiveness of the proposed control scheme. [ABSTRACT FROM AUTHOR]

In this paper, a simple soft switching technique, together with input current spike suppressed, is applied to the KY converter, also named 1-pluse-D converter, to upgrade the efficiency in the vicinity of the rated load and hence enhance its capability in industrial applications. The basic operating principles of the proposed soft switching scheme for the KY converter are illustrated and verified by some simulated and experimental results. [ABSTRACT FROM AUTHOR]

An inverse KY converter, derived from the KY converter, is proposed herein. And such converter can be used as a bidirectional converter, whose operating modes are classified into two odes. One is the buck mode and the other is the boost mode. This converter can operate stably between these two modes. In this paper, the detailed illustration and mathematical deduction for the basic operating principles of the proposed topology are given, along with some measured results to verify its effectiveness. [ABSTRACT FROM AUTHOR]

An active load for the burn-in test of the DC-DC converter, possessing multiple inputs with a wide range of input voltages, is proposed herein, whose controller is realized by a digital signal processor (DSP). By means of DSP, data monitoring and command setting are easy to realize. First of all, the details of the proposed circuit topology and the corresponding control strategy are presented. Finally, some experimental results are provided to demonstrate the proposed burn-in test plant. [ABSTRACT FROM AUTHOR]

In this paper, a simple method to design the current sharing loop, together with the voltage feedback loop, is presented for two DC-DC converter modules paralleled. First of all, the proposed current sharing loop is described in detail. Next, in order to design the parameters of the voltage controller based on the given crossover frequency and phase margin, the corresponding small-signal model is introduced. According to the proposed current sharing loop, such a small-signal model can be easily figured out. Finally, some experimental results, together with some simulated results, are provided to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, a novel approach for designing soft switching for synchronously rectified (SR) buck converters is presented, which contains one resonant MOSFET switch, one resonant inductor, one resonant capacitor, one diode. In such a circuit, the resonant MOSFET switch can be driven by one half-bridge driver, without the problem in float driving. Besides, the resonant inductor is not connected in series with the output input, and hence there is no problem in duty cycle loss. Also, the resonant capacitor is connected in parallel with the parasitic, capacitance of the MOSFET switch and hence there is a slight effect of such parasitic capacitance on the resonant behavior. Eventually, the detailed illustration of the basic operation of the proposed resonant circuit, together with some simulated and experimental results, is provided to demonstrate its effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, an input inductor current injection technique, together with the one-comparator counter-based pulse-width-modulation (PWM) control strategy, is presented herein and applied to the boost converter to upgrade its stability and transient upload response. This is easy to realize based on the field programmable gate arrays (FPGA). The detailed illustration of the proposed control strategy is provided, along with some experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a novel control scheme based on the field programmable gate array (FPGA) is proposed herein, which is utilized to improve the upload response for the zero-voltage-switching (ZVS) buck converter. Without changing controller parameters and system topology and only with modifying pulse-width-modulation (PWM) control signals, the upload response can be upgraded. In order to verify the proposed control scheme, there are some simulation and experimental results provided in addition to detailed description of the corresponding basic operating principles. [ABSTRACT FROM AUTHOR]

Although PSPICE is a powerful tool to simulate the circuits, it is a tough job to simulate the electromagnetic behavior of a converter-fed motor drive, particularly the switched reluctance motor (SRM) with highly-nonlinear property. Therefore, a simulation environment of the SRM drive combining the features of POWERSYS and SIMULINK is developed in this paper. In the establishment of SRM drive simulation environment, the nonlinear inductance-current-position characteristics are experimentally obtained first. Accordingly, the variation of the phase inductance with rotor position is approximately represented by Fourier series with the first three terms considered. The coefficients of the Fourier series are determined by the values of the inductance at the aligned position, the unaligned position and the position midway between the two. On the other hand, the variation of phase inductance with winding current for a given rotor position is fitted by a third-order polynomial whose coefficients are derived from experimental results. The construction of other components is also described in detail. Some experimental and simulated winding current and rotor speed dynamic responses are compared to validate the effectiveness of the developed simulation environment. [ABSTRACT FROM AUTHOR]

In this paper, based on a field programmable gate array (FPGA) technique is presented to design the PID controller and applied to the forward converter. The on-line tuning of controller parameters is used to reduce the effect of input voltage variations on the transient load response. Besides, the improvement in the transient load response is considered further, especially for the maximum input voltage. The validity of the proposed control topology is demonstrated via some experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a simple power control scheme for a constant frequency self-oscillating inverter with a variable duty cycle is proposed. The proposed topology, based on the half-bridge series resonant inverter, can achieve a stable and efficient Zero-Voltage-Switching (ZVS). As a consequence, the converter efficiency is significantly improved. This novel technique consists in injecting a DC control current through a saturable core providing a variable asymmetric control as a function of the injected current; we can therefore control and regulate the output power while maintaining the switching frequency close to the resonant one. The control principles of the proposed method are described in detail and its validity is verified through simulated and experimental results on 750 W with constant frequency variable power. [ABSTRACT FROM AUTHOR]

This paper presents a new non-isolated, single-inductor, dual-output resonant step down/up converter. The outputs are fed power from the same supply one after another. The output voltages could be more than or less than the supply voltage and both buck or boost outputs are possible. Soft switching is achieved and losses are reduced. Steady state analysis of the converter is done. The primary output is closely regulated by common-mode frequency control and the auxiliary output is controlled by differential mode PWM control. A comprehensive simulation of the converter with line and load variations is done and the results are in agreement with the analysis. Some typical hardware results are also presented as a validation. The topology is scalable to additional outputs as well. [ABSTRACT FROM AUTHOR]

In the next future, hybrid electric vehicles and electric vehicles will be more and more hybridized using different electrical storage devices. Traditionally in a vehicle having many energy storage systems, several independent power electronic converters were utilized. Due to their reduced part count, control simplicity and better efficiency, multi-input dc-dc converters seem to be a promising choice in hybridizing energy systems, therefore in literature many solutions have been proposed. In the paper, a new bidirectional soft-switching multi-input dc-dc converter for automotive applications is proposed. Such configuration is obtained as combination of two individual half-bridge dc-dc converters feeding a common dc bus. The soft-switch capability is achieved adding a simple auxiliary active clamping circuit for each leg. Such auxiliary circuit is operational regardless of boost or buck mode operation. The configuration guarantees fixed switching frequency, active clamped zero voltage switching operations of the main switches and bidirectional power flow. ZVS operations are guaranteed with wide load range. Reverse recovery effects are minimized and the drop voltage occurred over the switches is significantly reduced. In the paper the operating principle, soft-switching conditions and steady state analysis are presented. A 500 W prototype has been built and experimental results to verify the theoretical analysis are provided. [ABSTRACT FROM AUTHOR]