Regenerative Clamping Circuit Research Articles

A novel soft‐switching quadratic high voltage gain trans‐inverse DC/DC converter

AbstractThis paper suggests a new non‐isolated high step‐up DC/DC converter with soft‐switching performance and low input current ripple for renewable energy generation systems. In this introduced circuit, a three‐winding coupled‐inductor combined with a quadratic boost circuit and voltage multiplier cell to obtain high voltage gains. The advanced features of the proposed topology are its ultra‐high voltage gain, soft‐switching performance, low voltage stress across the switching components, continuous input current with low ripple, and the existence of a common ground between the input source and output load. Due to the partial trans‐inverse property in the suggested topology, higher voltage gains can be achieved under smaller turns ratios of the coupled in comparison to the other typical topologies, which leads to efficiency improvement. Moreover, in this introduced circuit, the voltage stress on the single power switch is mitigated using a regenerative clamp circuit. The theory and operating principle of the suggested converter, along with the steady‐state analysis and efficiency interpretation of the proposed converter are discussed in detail. Finally, to verify the theoretical analysis, a 200 W (25 V/400 V) sample prototype is established.

An Isolated High-Frequency Link Microinverter Operated with Secondary-Side Modulation for Efficiency Improvement

This paper discusses the operation of a single-stage, isolated, high-frequency ac-link-based single-phase dc–ac converter, suitable for photovoltaic microinverter applications, controlled using phase modulation of the secondary-side cycloconverter devices. A detailed analysis is presented explaining the impact of prominent circuit nonidealities such as device capacitance and transformer leakage inductance on circuit behavior. The proposed extended-dead-time based modulation scheme helps in achieving zero-voltage-switching of the primary devices over the entire line cycle of the ac output and also offers the benefit of reduced transformer rms current due to absence of circulating current in the zero state. A flyback-based regenerative clamp circuit is used for mitigating voltage spikes on the secondary devices arising due to leakage inductance induced oscillations. A generic commutation strategy is also discussed, which makes operation with nonunity power factor loads also possible. Experimental results on a 260-W laboratory prototype under different load conditions are presented to illustrate the discussed principles and highlight the performance improvements.

A High Voltage Gain DC–DC Converter Integrating Coupled-Inductor and Diode–Capacitor Techniques

The high-voltage gain converter is widely employed in many industry applications, such as photovoltaic systems, fuel cell systems, electric vehicles, and high-intensity discharge lamps. This paper presents a novel single-switch high step-up nonisolated dc-dc converter integrating coupled inductor with extended voltage doubler cell and diode-capacitor techniques. The proposed converter achieves extremely large voltage conversion ratio with appropriate duty cycle and reduction of voltage stress on the power devices. Moreover, the energy stored in leakage inductance of coupled inductor is efficiently recycled to the output, and the voltage doubler cell also operates as a regenerative clamping circuit, alleviating the problem of potential resonance between the leakage inductance and the junction capacitor of output diode. These characteristics make it possible to design a compact circuit with high static gain and high efficiency for industry applications. In addition, the unexpected high-pulsed input current in the converter with coupled inductor is decreased. The operating principles and the steady-state analyses of the proposed converter are discussed in detail. Finally, a prototype circuit is implemented in the laboratory to verify the performance of the proposed converter.

Voltage Multiplier Cells Applied to Non-Isolated DC–DC Converters

This paper introduces the use of the voltage multiplier technique applied to the classical non-isolated dc-dc converters in order to obtain high step-up static gain, reduction of the maximum switch voltage, zero current switching turn-on. The diodes reverse recovery current problem is minimized and the voltage multiplier also operates as a regenerative clamping circuit, reducing the problems with layout and the EMI generation. These characteristics allows the operation with high static again and high efficiency, making possible to design a compact circuit for applications where the isolation is not required. The operation principle, the design procedure and practical results obtained from the implemented prototypes are presented for the single-phase and multiphase dc-dc converters. A boost converter was tested with the single-phase technique, for an application requiring an output power of 100 W, operating with 12 V input voltage and 100 V output voltage, obtaining efficiency equal to 93%. The multiphase technique was tested with a boost interleaved converter operating with an output power equal to 400 W, 24 V input voltage and 400 V output voltage, obtaining efficiency equal to 95%.

A novel high-efficiency flyback power-factor-correction circuit with regenerative clamping and soft switching

Although most power factor correction (PFC) circuits use the boost topology, the flyback topology does have the advantages of input-output isolation, inrush current limiting and voltage step-down capability. In this paper, the problems associated with flyback PFC circuits are identified. These problems are solved by using a novel regenerative clamping circuit. The circuit topology, analysis, design considerations and experimental results of the new flyback PFC circuit are presented.

Novel single-stage isolated power-factor-corrected power supplies with regenerative clamping

Single-stage isolated power-factor-corrected power supplies (SSIPPs) have the attractive features of fast regulation and a single control loop. In this paper, we further propose to add a very simple regenerative clamping circuit to an SSIPP to reduce the voltage stress and to recycle the energy trapped in the leakage inductance of the isolation transformer, thus eliminating the need for a lossy snubber circuit. In addition, the proposed clamping circuit also improves the power factor of the SSIPP, employing a boost converter as the input stage. Analysis and experimental results are reported to verify the operation and performance of the SSIPP with regenerative clamping.