Self-oscillating DC-to-DC switching converters with transformer characteristics
ABSTRACT Fourth-order converters with both input and output filters are analyzed in self-oscillating sliding mode. The boost converter with output filter and the Cuk converter are shown to have stable dynamics and an equilibrium point with transformer characteristics. The analytical predictions are verified by experimental results.
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- "are the steady-state averaged values of the instantaneous input and output port variables shown in Fig. 4(a) and n is the transformation ratio. In this regard, it has been demonstrated in  and  that the boost converter with output filter (BOF) and´Cuk converter have stable dc-transformer characteristics. Similarly, the synthesis of a power gyrator requires a switching structure leading to the following set of relations between the steady-state input and output variables ,  g-gyrator type I 2 = gV 1 , "
ABSTRACT: Switched power converters are used to interface the dc output in modern distributed power generation systems, which are usually aggregated to the main grid to yield the necessary power using interconnected modules. Synthesis, modeling, and stability analysis of interconnected systems using cascaded converters working under sliding-mode control are considered in this paper. A systematic procedure to synthesize cascaded connection of dc-dc boost converters is introduced. The approach is based on making each module to behave as a suitable canonical element for power processing. Three different elements are considered, which are the dc power gyrator, the dc transformer, and the dc loss-free resistor. These canonical elements are designed by means of a sliding-mode control theory and then their dynamic behavior is studied in detail. The sliding-mode conditions for each case are derived in closed form to obtain design-oriented criteria for selecting the parameters of the system. The aforementioned canonical elements are compared to select the most suitable one for a distributed power system. Simulation results ensure the correctness of the proposed approach. Experimental measurements corroborate the theoretical predictions and the numerical simulations.IEEE Transactions on Power Electronics 03/2014; 29(3):1366-1381. DOI:10.1109/TPEL.2013.2261093 · 6.01 Impact Factor
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- "This feature increases the system efficiency and capability. Based on this power system, our contribution proposes some improvement, these are: 1) the STATCOM including a block to compensate the current in the neutral wire of an induction generator and voltage asymmetries on the dc bus of the converter and 2) the battery bank is connected to a self-oscillating dc–dc converter  based in a relay feedback control . This choice provides certain advantages over other options of bidirectional dc–dc converters , such as simplicity of design, good performance over a wide operating range, robustness, and lower cost. "
ABSTRACT: This paper presents a STATCOM with a self-oscillating bidirectional dc-dc converter for interfacing battery energy storage in a stand-alone induction generator system. The self-oscillation mode is based on relay feedback control with hysteresis. To reduce the output current ripple, an LCL filter is connected between the half bridge of this dc-dc converter and the energy storage system. The other side of bidirectional converter is coupled with a voltage-source converter. The proposed control allows that the previous electronic converters, with an additional resistive dump load, compensate all disturbances in a self-excited induction generator due to three-phase four-wire loads and an improvement of system efficiency. The simulated results show good performance of the stand-alone power system under different loading conditions.IEEE Transactions on Power Delivery 11/2010; 25(4-25):2734 - 2741. DOI:10.1109/TPWRD.2010.2051565 · 1.73 Impact Factor