Control Strategy Of DC-DC Converter Research Articles

Fuzzy PI control strategy for DC-DC converter of DC charging pile based on improved Gray Wolf optimization algorithm

Fuzzy PI control strategy for DC-DC converter of DC charging pile based on improved Gray Wolf optimization algorithm

A Nonlinear Control Strategy for DC-DC Converter with Unknown Constant Power Load Using Damping and Interconnection Injecting

DC-DC converters with constant power loads are mostly used in DC microgrids. Negative impedance and large disturbances of constant power loads may lead to the instability of DC-DC converters. To address this issue, a nonlinear control strategy consisting of an improved passivity-based controller and nonlinear power observer is proposed in this paper. First, an improved passivity-based controller is designed based on the port-controlled Hamiltonian with dissipation model. By proper damping and interconnection injecting, the fast dynamic response of output voltage and stability of the DC-DC converter is achieved. Second, the constant power load is observed by a nonlinear power observer, which is adopted to estimate the power variation of the constant power load within a small settling time and improve the adaptability of the DC-DC converter under power disturbance. Finally, the simulation and experimental results are presented, which illustrate the proposed control strategy not only ensures the stability of the DC-DC converter under large disturbances, but also can track the desired operating point with low voltage overshoot in no more than 10 milliseconds.

A Data-Driven Based Voltage Control Strategy for DC-DC Converters: Application to DC Microgrid

This paper develops a data-driven strategy for identification and voltage control for DC-DC power converters. The proposed strategy does not require a pre-defined standard model of the power converters and only relies on power converter measurement data, including sampled output voltage and the duty ratio to identify a valid dynamic model for them over their operating regime. To derive the power converter model from the measurements, a local model network (LMN) is used, which is able to describe converter dynamics through some locally active linear sub-models, individually responsible for representing a particular operating regime of the power converters. Later, a local linear controller is established considering the identified LMN to generate the control signal (i.e., duty ratio) for the power converters. Simulation results for a stand-alone boost converter as well as a bidirectional converter in a test DC microgrid demonstrate merit and satisfactory performance of the proposed data-driven identification and control strategy. Moreover, comparisons to a conventional proportional-integral (PI) controllers demonstrate the merits of the proposed approach.

Operation and Control of Hybrid Fuel Cell/ Energy Storage Distributed Power Generation System during voltage Sag Conditions

This paper presents a control strategy for fuel cell/energy storage power generation system during voltage sag conditions. The hybrid DC power sources are connected to grid using power electronic converters include DC-DC converter and grid connected voltage source inverter. The power from hybrid power sources is controlled during voltage sag by designing of control strategy for DC-DC converter. Moreover, a robust control strategy of voltage source converter for both positive and negative symmetrical components is presented to control of inverter current under unbalanced voltage sag. Simulation results for 25 KW PEM fuel cell of TALEGHAN site are given to show the response of system under voltage sag and illustrate the performance including active power control and voltage sag ride-through capability of the proposed control strategy.

A Digital Parallel Current-Mode Control Algorithm for DC–DC Converters

This paper presents a novel digital current-mode control strategy for dc-dc converters. In the proposed algorithm, the required duty cycle is calculated directly by two parallel terms. With some simple operations in digital implementation, the resultant control system achieves rapid and precise output voltage regulation under the input voltage and output load change. Moreover, the implementation of the proposed algorithm with a digital controller is discussed in detail. Analysis shows that the parallel current-mode control does not exhibit subharmonic oscillation. A 400-kHz switching frequency buck converter based on field-programmable gate array implementation is built to verify the feasibility and advantages of the parallel current-mode control.