Multiple Charge Pump for High Output Voltage

Analysis and minimization of input current and voltage ripples of five-phase PWM inverters are presented in this paper. The analytical expressions for the RMS value of input current and voltage ripples as a function of the PWM reference signal are derived. Different to three-phase PWM inverters, it is shown that pure sinusoidal is the optimum reference signal that produces minimum input voltage ripple. Input current ripple does not depend on the employed reference signal so the ripple canpsilat be minimized by changing reference signal. Simulation and experimental results verify the analysis.

This paper presents an analysis of input and output ripples of PWM AC choppers. Expressions of input and output current and voltage ripples of single-phase PWM AC choppers are first derived. The derived expressions are then extended to three-phase PWM AC choppers. As input current and output voltage ripples specification alone cannot be used to determine the unique values of inductance and capacitance of the LC filters, an additional criterion based on the minimum reactive power is proposed. Experimental results are included in this paper to show the validity of the proposed analysis method.

The Weinberg converter is a suitable choice for the battery discharge regulator of a geostationary satellite due to its high efficiency, continuous input and output current, and soft switching of switches and diodes. Nevertheless, this converter has high output current ripple during the commutation period of its output diodes. Therefore, the output RMS current and output voltage ripple are high, which may directly affect the lifetime and total capacitance of bus capacitors and hence, the lifetime and volume of the geostationary satellite. Thus, reducing the output current ripple is important to the design of the geostationary satellite. An improved Weinberg converter with an additional inductor and capacitor is proposed in this paper to reduce the output current and voltage ripple. It features soft switching of all switches, no reverse recovery problems of the diodes, and reduced magnetizing offset current in the coupled inductor. The proposed converter is verified with experimental results from a 750W, 100kHz, 36-50Vdc prototype.

This paper presents a multi-cell single-phase high power factor boost rectifier in interleave connection, operating in critical conduction mode, employing a soft-switching technique, and controlled by field programmable gate array (FPGA). The soft-switching technique is based on zero-current-switching (ZCS) cells, providing ZC (zero-current) turn-on and ZCZV (zero-current-zero-voltage) turn-off for the active switches, and ZV (zero-voltage) turn-on and ZC (zero-current) turn-off for the boost diodes. The disadvantages related to reverse recovery effects of boost diodes operated in continuous conduction mode (additional losses, and electromagnetic interference (EMI) problems) are minimized, due to the operation in critical conduction mode. In addition, due to the interleaving technique, the rectifier's features include the reduction in the input current ripple, the reduction in the output voltage ripple, the use of low stress devices, low volume for the EMI input filter, high input power factor (PF), and low total harmonic distortion (THD) in the input current, in compliance with the IEC61000-3-2 standards. The digital controller has been developed using a hardware description language (VHDL) and implemented using a XC2S200E-SpartanII-E/Xilinx FPGA device, performing a true critical conduction operation mode for all interleaved cells, and a closed-loop to provide the output voltage regulation, like as a pre-regulator rectifier. Experimental results are presented for a implemented prototype with two and with four interleaved cells, 400 V nominal output voltage and 220 Vrms nominal input voltage, in order to verify the feasibility and performance of the proposed digital control through the use of a FPGA device

Eight-poles of various designs, including an eight-terminal network with three input and five output terminals, are needed to replace some power objects. Especially when only the input and output characteristics of electrical energy are of interest. The paper presents the eightterminal network equations with three input and five output terminals, establishing a connection between these characteristics. Equations of the A-form establish a connection between the input and output voltages and currents; the B-form equations establish a connection between the output and input voltages and currents; G-form equations establish a connection between the input current, output voltages and output voltage, output currents; H-form equations establish the relationship between the input voltage, output currents and output current, output voltages; the Yform equations establish a connection between the input and output currents and the input and output voltages; The Z-form equations establish the relationship between the input and output voltages and the input and output currents. When implementing these equations, attention should be paid to the difference in the directions of the currents in each individual case.

This paper discusses applying various switching strategies such as conventional complementary and proportional methods on a specific converter. This converter was recently presented and it can provide high voltage gain and has current ripple cancelation ability at a preselected duty-cycle. The input current ripple is zero when the converter works at a special duty-cycle. But load disturbance leads to output voltage changes that maybe cause the duty-cycle to deviate from its preselected value. In this situation, the input current ripple cannot be completely canceled. The proposed proportional strategy is an optimized method for minimizing input current ripple at other operating duty-cycles and also it provides a voltage gain lower than conventional complementary strategy. Here, the converter's performance is analyzed under two switching strategies and the effect of various strategies has been investigated on converter parameters including output voltage and input current ripple. These considerations are verified by implementing a 100-W prototype of the proposed converter in laboratory.

This paper presents the analysin ,design and implementation of a high voltage ratio topology of DC-DC converter. The DC-DC converter has high voltage ratio with reduced input current, output voltage and output current ripple, and also reduces the voltage and current rating of power electronics components and compared with conventional boost converter. The voltage stress on the switches are reduced in this topology. Analysis, design and converter operating waveforms in the continuous conduction mode are provided along with design guidelines. The converter has been designed for rated power of 50W, input voltage of 24V, output voltage of 72V and switching frequency of 25 kHz. The floating output interleaved input high voltage gain converter is compared with conventional boost converter, hardware and simulation results are verified.

In order to use dc to dc boost converter in combination with a fuel cell, for modern aircraft APU, it is important that the input current ripples to be very small. This paper presents a comparative analysis of a dc to dc boost converter with variable duty cycle and one with constant duty cycle. The Dc to dc boost converter proposed was modeled in Multisim, with a PID controller. After numerical simulations it was found that input current ripples have a maximum output current of approximately 20A. The variation is more flat when operating with constant duty cycle. The use of this controller that changes the duty cycle also leads to a greater variation of ripples in relation with the output current. Thus, to make a comparison with theoretical results, which were achieved in the bibliography, numerical simulations were made with the PWM pulse at a constant value, with 50% duty cycle. Based on simulation results there were plotted the boost converter output characteristics for the two cases. Graphs were performed in Matlab. Besides these output characteristics, there were also plotted the output and input current variation, the current through the transistor, the ripples for the output voltage and for the input current in relation with the output current.

DC-DC converters are used to convert and regulate voltages depending on the requirement of the specific load. There are two types of DC-DC converter: (1) linear regulators and (2) switching regulators. A linear regulator has a small output voltage ripple but its power efficiency degrades when the difference between the input voltage and output voltage increases. On the other hand, the switching regulator has better power efficiency compared to the linear regulator. The switching regulator can convert wide range of input voltages while maintaining high power efficiency and it can also step-up voltages which a linear regulator cannot. The drawback for switching regulator is the need for control circuit that controls the switches and regulation. The switching regulator has also the problem of relatively larger output voltage ripple, which is not suitable for sensitive circuits. In this paper, a hybrid topology was proposed to combine the advantages of the two DC-DC converters. From the simulation of the three converters, the linear regulator only has an efficiency of 28.058% while the switching regulator and hybrid power converter have efficiencies of 49.0881% and 45.6753%, respectively. In addition, input voltages from 0.5V to 5V were tested on the three regulators that would result in a regulated output voltage of 1V. The linear regulator can only regulate voltages above 1V and the PMOS transistor used has a operating voltage of 2.5V which limits the upper voltage boundary of the linear regulator to 3.5V. The switching regulator can regulate wider range of input voltages but due to power loss across the converter, the switching regulator cannot produce a constant output voltage of 1V when the input voltage ranges from 0.5V to 0.7V. The three converters were designed and implemented in a 65nm CMOS process.

This paper presents a new soft switching (SS) multiphase interleaved boost converter (MIBC) consisting of three boost converters (BCs) that operate rapidly and efficiently to charge a lithium-ion battery for photovoltaic (PV) power system applications. This suggested converter can operate both active power switches at zero current switching (ZCS), and when switched off, it works at zero voltage switching (ZVS), which reduces switching losses and increases switching efficiency (SF). An interleaving structure is employed to decrease the conduction losses and reduce the input current ripple (ICR) and output voltage ripple (OVR) to increase the power rating. The suggested converter regulates the input and output power by modulating the phase shift in the pulse width modulation (PWM) technique using the maximum power point tracking (MPPT) algorithm via two closed feedback loops, one for a slower external loop and the other for a faster PWM control internal loop, similar to current mode control. The suggested converter has high voltage (HV) gain due to the coupled inductors (CIs), which act as a transformer. This magnetic design structure in both the steady-state and transient states also decreases the size and enhances the converter’s performance. Finally, the suggested converter was experimentally verified on a 285W prototype, and the maximum efficiency was found to be 98%, based on modeling and experimental data.

Input ripple analysis of five-phase pulse width modulated (PWM) inverters is presented. The analytical expressions for the rms value of the input current and voltage ripples as a function of the PWM reference signal are derived. Similar to three-phase PWM inverters, the input current ripple does not depend on the employed reference signal, so the ripple cannot be minimised by changing the shape of reference signal. On the other hand, different from three-phase PWM inverters, it is shown that a pure sinusoidal signal is the optimum reference signal that produces a minimum input voltage ripple in five-phase PWM inverters. Input voltage ripples under several modulation techniques are compared. Experimental results are included to verify the proposed analysis method.

In this paper, a novel non-isolated interleaved DC/DC boost converter is presented in which coupled inductors and a passive clamp circuit are employed. ZCS turn-on condition for main switches is provided, and the stored energy in leakage inductance is recycled by means of a passive clamp circuit. Therefore, the voltage stress across switches is reduced resulting in circuit efficiency improvement. Due to interleaved structure and cross-coupled inductors, the input current ripple is reduced and the input current is continuous. To achieve ZCS turn-on condition, the intrinsic leakage inductance of the coupled inductors is used which leads to improving the power density and reducing the switching losses. In order to confirm the theoretical analysis, a prototype with 30 V input voltage, 300 V output voltage, and 300 W is implemented and tested.

An integrated switched-capacitor (SC) DC-DC converter with a digital interleaving regulation scheme is presented. By interleaving the newly-structured charge pump (CP) sub-cells in multiple phases, the input current ripple and output voltage ripple of the converter are reduced significantly. The converter exhibits excellent robustness, even when one CP sub-cell fails to operate due to unexpected device failure. A fully digital controller is employed with hysteretic control, featuring deadbeat stability and fast transient response. With a 1.5-V input power supply, the SC power converter precisely provides an adaptable regulated power output from 1.6 to 2.7 V. A maximum output ripple of plusmn20 mV is observed at the full load of 540 mW. The load transient response is around 1.8 mus, when the load current switches from half to full load (from 100 to 200 mA). The design provides a fast-response, low-noise, and fault-tolerant solution to new-generation on-chip power supplies.

Ultra-stability high-voltage triboelectric nanogenerator designed by ternary dielectric triboelectrification with partial soft-contact and non-contact mode

A step-up/step-down DC-DC converter with high efficiency and small output voltage ripple is proposed in this paper. To reduce the switching loss and improve the efficiency, the converter operates in buck or boost mode when the input voltage is much higher or lower than the output voltage. However, a large output voltage ripple appears at the boundary of buck mode and boost mode due to the speed limitation of standard analog circuit. A transition mode using a digital dither technique is adopted and the output voltage ripple is reduced when the input voltage is close to the output voltage. Furthermore, the average inductor current is also reduced in the proposed transition mode. The converter has been designed with a standard a 0.5 μm CMOS process. The peak efficiency is 96% and the output voltage ripple is reduced to less than 10 mV in the transition mode.