Duty‐cycle‐controlled resonant dual‐half‐bridge converter with multifunctional capacitors for distributed generation applications

Abstract

This study describes a duty-cycle-controlled resonant dual-half-bridge converter with multifunctional capacitors for enhancing the voltage level of fuel cell and photovoltaic sources to 380 V. Owing to the incorporation of dc-link capacitors and leakage inductance into two various resonant circuits, both switches turn-on under the zero-voltageswitching circumstance and turn-off with low current because of quasi-resonant operation. Since the currents of diodes are controlled by the leakage inductances of transformers, it is not obligatory for a designer to employ the diodes with reverse-recovery current specification; consequently, less expensive diodes can be adopted. The complementary effects of series-connected secondary windings of transformers and switched-capacitor circuits result in forming the balanced voltage multiplier stage, augmenting the voltage conversion ratio substantially without the need for utilising a transformer having higher turns ratio; so, one of the magnificent factors of growth of the conduction losses has been avoided. Ultimately, the results of the laboratory prototype operating with 58 kHz switching frequency, 18 V input voltage, 380 V output voltage, and 500 W output power prove that the proposed topology would be proficient to fulfil its function in systems using distributed generation resources.

State space modeling of inverter based microgrids considering distributed secondary voltage control

“…2) Low pass filter: due to the high switching impact of the inverter-based MGs on voltage and currents, a low pass filter is used in (6,7) to filter the high frequency distortion of MGs: ( / ( )) ( In order to construct the complete model of a whole MG, everything should be transformed to a common reference frame. Here the angle of inverter 1 is assumed to be the reference, hence all other DGs' angles will be calculated from (13) and then can be used to transform the system to its common reference frame.…”

“…2) Low pass filter: due to the high switching impact of the inverter-based MGs on voltage and currents, a low pass filter is used in (6,7) to filter the high frequency distortion of MGs:…”

“…icrogrids (MGs) are a smaller scale of power systems that integrate high penetration of renewable energies and energy storage systems (ESSs) into the grid [1][2][3][4][5][6]. Power electronic converters are used as the interface between renewable energies such as solar power, wind power and fuel cells and the grid [7][8][9]. Utilizing renewable energies in MGs as well as the flexibility of MGs in connecting and disconnecting to/from the grid is counted as two main advantages of MGs over the conventional power systems.…”

Robust Nonlinear Fuzzy Formation Control of Unmanned Quadrotors

“…In order to define the objectives of the optimization problem, a cost function is defined as follows [51,52]  …”

Back-to-back converter control of grid-connected wind turbine to mitigate voltage drop caused by faults

“…In addition to frequency and active power, voltage and reactive power must be bounded and controlled in predefined ranges [10][11]. To achieve the goal, the generators must be controlled in a properly, so that the voltage drop and voltage rising are avoided at peak time or low demand, respectively [12][13][14][15].…”