Non-isolated High Gain Research Articles

Non isolated coupled converter tied voltage source inverter drive

<span>The voltage source inverters (VSI) are ever required section in the AC motor drive and power system interface. The electrical drive segment, the VSI based drives are unavoidable and they are closely operated with induction motor, permanent magnate synchronous motor and BLDC motor. These drives are normally needed high torque-power characters. Hence, the input DC-link side voltage is increased with help of increasing input AC in the rectifier input. However, this causes the power quality disturbance in the AC main and DC-link. In order to go for a increasing the AC voltage, the rectifier out is connected with DC to DC boost converter and they are increasing the DC voltage to meet out the drive DC-link voltage demand. With this aim, the paper proposes the idea to connect high step non-isolated high gain coupled DC to DC converter with three phase VSI for drives applications. The proposed converter has an ability to increase the voltage five times and the counter winding arrangement ratio of the converter is help for the further increase of gain. Inn this interface the front end DC to DC converters inductors are charged by making the short circuit with inverter switching. The converter voltage gain is controlled by shoot through of the VSI switch (converter gain directly proportional to inverter shoot through). The proposed converter has a higher degree of freedom in their values of winding and output voltage. Hence, the DC-link voltage of the inverter can be extended in any level. The operation principle and modes of the proposed DC to DC Source tied VSI is analyzed and simulated using MATLAB-Simulink software simulation. The laboratory based small scale power circuit is developed with help of control algorithm. The entire implementation is done through PIC microcontroller platform. The deign Investigation, system simulation and experimentation confirming the proposed DC to DC converter tied VSI drive system.</span>

Ripple-Free Input Current High Voltage Gain DC–DC Converters With Coupled Inductors

This paper presents three nonisolated high voltage gain dc–dc converters with ripple-free input current. The proposed converters combine coupled inductors and voltage-doubler structure (VDS) to achieve high step-up of input voltage. An active clamp circuit is used to suppress voltage spike of the switch caused by of the leakage inductor of the coupled inductor. VDS is placed in the secondary winding of the coupled inductor that clamps the diodes voltage stress. Working principle and design methodology of the proposed converters are presented in detail. Experimental results for a 300 W laboratory prototype, 48 V input voltage, and regulated output voltage of 400 V, are shown to validate the operation of proposed converters.

Three Topologies of a Non-Isolated High Gain Switched-Inductor Switched-Capacitor Step-Up Cuk Converter for Renewable Energy Applications

This paper introduces three topologies of a non-isolated high gain step-up Cuk converter based on a switched-inductor (SL) and switched-capacitor (SC) techniques for renewable energy applications, such as photovoltaic and fuel cells. These kinds of Cuk converters provide a negative-to-positive step-up dc–dc voltage conversion. The proposed three topologies SLSC Cuk converters increase the voltage boost ability significantly using the switched-inductor and switched-capacitor techniques compared with the classical Cuk and boost converters. The proposed Cuk converters are derived from the classical Cuk converter by replacing the single inductor at the input and output sides with a SL and the transferring energy capacitor by a SC. The main advantages of the proposed SLSC Cuk converters are achieving a high voltage conversion ratio and reducing the voltage stress across the main switch. Therefore, a switch with low voltage rating and thus, of low RDS-ON can be used, and that leads to a higher efficiency. For example, the third topology have the ability to boost the input voltage up to 13 times when D = 0.75, D is the duty cycle. The voltage gain and the voltage stress across the main switch in the three topologies have been compared with the classical Cuk and boost converter. The proposed three topologies avoid using a transformer, coupled inductors, or extreme duty cycles leading to less volume, loss, and cost. The proposed SLSC Cuk converters are analyzed in continuous conduction mode (CCM), and they have been designed for 12 V input supply voltage, 100 W rated power, 50 kHz switching frequency, and 75% duty cycle. A detailed theoretical analysis of the CCM is represented and all the equations have been derived and matched with the results. The proposed three topologies SLSC Cuk converters have been simulated in MATLAB/SIMULINK and results are discussed.

Analysis, Design, and Implementation of a High Gain Soft-Switching Bidirectional DC–DC Converter With PPS Control

This paper proposes a pulse width modulation plus phase-shift (PPS) control for nonisolated high gain soft-switching bidirectional dc–dc converter (HSBDC). The phase-shift angle is used to control the direction and amount of power flow of the bidirectional dc–dc converter, while the duty cycle is used to balance the voltage between two high voltage side (HVS) capacitors. The HSBDC with PPS control has the advantages of simple control structure and symmetrical switching patterns, ensured soft-switching in both forward and backward modes at all load under wide voltage range, and reduced voltage ratings of the HVS capacitors and switches. The operation principle of the HSBDC with PPS control is analyzed in detail. Based on the analysis the passive component is designed to achieve higher efficiency. A 3-kW prototype is implemented and tested to verify the validity of the proposed method.

Non-isolated high gain DC-DC converter for smart grid- A review

Smart grids are becoming the most interesting and promising alternative for an electric grid system. Power conditioning units and control over the distribution of power is the essential feature for the smart grid system. In this paper, we reviewed several non-isolated high gain topologies derived from boost converter for providing required voltage to the grid tie inverter from renewable energy sources. Steady state analysis of all the topologies is analyzed to compare the performance of the topologies. Simulation is carried out in nL5 simulator and the results are compared and validated with the theoretical results. This paper is a guide to the researchers to choose the best topology for the smart grid application.

Nonisolated High Gain DC–DC Converter for DC Microgrids

DC microgrids are popular due to the integration of renewable energy sources such as solar photovoltaics and fuel cells. Owing to the low output voltage of these dc power generators, high efficient high gain dc–dc converters are in need to connect the dc microgrid. In this paper, a nonisolated high gain dc–dc converter is proposed without using the voltage multiplier cell and/or hybrid switched-capacitor technique. The proposed topology utilizes two nonisolated inductors that are connected in series/parallel during discharging/charging mode. The operation of switches with two different duty ratios is the main advantage of the converter to achieve high voltage gain without using extreme duty ratio. The steady-state analysis of the proposed converter using two different duty ratios is discussed in detail. In addition, a 100 W, 20/200 V prototype circuit of the high gain dc–dc converter is developed, and the performance is validated using experimental results.

Analysis and implementation of high‐gain non‐isolated DC–DC boost converter

High step-up DC-DC converters are increasingly required in many industrial applications. Conventional topologies operate at extreme duty cycle, high-semiconductor voltage stress, switching loss, and diode reverse recovery problems. This study presents a new non-isolated high gain, boost converter operating with a modest duty cycle by integrating a coupled inductor and switched capacitor technique. Importantly, the structure of the high-voltage side, together with the switched capacitor, reduces the voltage stress of the power switch to less than one third of the output voltage, which in turn helps to reduce the conduction loss by using a low on-resistance (R ds-on ) switch. The diode voltage stress is less than the output voltage which facilitates faster recovery. Furthermore, the converter employs a passive clamp circuit to recycle the leakage energy. The main switch achieves zero current switching (ZCS) turn-on performance and all diodes achieve (ZCS) turn off reducing reverse recovery related losses. As a result, the circuit exhibits high efficiency performance; which is essential for most modern power electronic applications. In this study, the operational principle and performance characteristics of the proposed converter is presented and validated experimentally with a 250 W, 20V input voltage/190V output voltage prototype circuit.

A modified high step-up non-isolated DC-DC converter for PV application

A non-isolated high voltage gain DC-DC converter has been presented in this paper. The boost, SEPIC and modified SEPIC converters were analyzed and their performance was compared with the proposed converter. The proposed converter has been designed for the input voltage of 15 V and an output voltage of 150 V with 100 W output power. The efficiency of the converter obtained was 92.5%, which is higher than that of the other converter models which were analyzed. Also, the proposed converter utilizes reduced input current and shows low switching voltage stress. The time response analysis conveys that the proposed converter settles to the steady state voltage and current faster than the other compared converters.

Single Switched Non-isolated High Gain Converter

<p>This paper presents a new single switched inductor- capacitor coupled transformer-less high gain DC-DC converter which can be used in renewable energy sources like PV, fuel cell in which the low DC output voltage is to be converted into high dc output voltage. With the varying low input voltages, the output of DC-DC converter remains same and does not change. A state space model of the converter is also presented in the paper. This constant output voltage is obtained by close loop control of converter using PID controller. High voltage gain of 10 is obtained without use of transformer. All the simulations are done in MATLAB-SIMULINK environment.</p>

Non-isolated high gain DC-DC converter by quadratic boost converter and voltage multiplier cell

Abstract A novel non-isolated DC-DC converter is proposed by combining quadratic boost converter with voltage multiplier cell. The proposed converter has low semiconductor device voltage stress and switch utilization factor is high. The superiority of the converter is voltage stress of the semiconductor devices depends on voltage multiplier (VM) cell. By increasing the VM cell the stresses across the devices reduce drastically. The proposed converter has same number of components compared to certain voltage lift converters taken for comparison. A detailed comparative study is made on the proposed converter with few voltage lift converters in the literature, conventional boost with VM cell and quadratic boost converter. A 40 W prototype is constructed with 12 V input voltage and 96 V output voltage to verify the performance and validate the theoretical analysis of the proposed converter.