| CPC G05F 1/67 (2013.01) [G05F 1/70 (2013.01)] | 20 Claims |
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1. A finite-time sliding mode maximum power point tracking (MPPT) control system for a photovoltaic (PV) array, comprising:
a PV array having a positive terminal and a negative terminal, wherein the photovoltaic array is configured to generate a current Ipv at the positive terminal;
a boost converter including a first capacitor in parallel with the PV array and an inductor having a first end connected to the positive terminal;
a metal oxide silicon field effect transistor (MOSFET) having a source terminal connected to a second end of the inductor and a drain terminal connected to the negative terminal, wherein a body terminal of the MOSFET is configured to generate a DC voltage Vdc when the MOSFET is switched ON;
a pulse width modulator (PWM) connected to receive the current IPV and a voltage across the first capacitor at a set of PWM input terminals, wherein the PWM includes a PWM processor configured to execute a perturb and observe (P&O) algorithm and generate a maximum power point signal at a PWM output terminal, wherein the PWM output terminal is connected to a gate of the MOSFET, wherein the a maximum power point signal is configured to modulate the DC voltage Vdc according to a duty cycle D defined by the P&O algorithm;
a second capacitor in parallel with the MOSFET, wherein the second capacitor is configured to charge during a positive phase of the duty cycle D to the voltage Vdc and discharge during a negative phase of the duty cycle D;
an inverter in parallel with the second capacitor, wherein the inverter is configured to generate three phase voltage signals;
a point of common coupling (PCC) connected to the inverter to receive the three phase voltage signals;
an electrical grid connected to the PCC, wherein the electrical grid is configured to convert the three phase voltage signals to three phase current signals and calculate three phase voltage error signals by subtracting a grid voltage at each phase from a reference voltage signal;
a first direct to quadrature transformer configured to receive the three phase current signals and convert the three phase current signals to direct current signals and quadrature current signals;
a second direct to quadrature transformer configured to receive the three phase voltage error signals and convert the three phase voltage error signals to direct voltage error signals and quadrature voltage error signals;
a DC voltage controller configured to receive the direct current signals, the quadrature current signals, the direct voltage error signals and the quadrature voltage error signals and generate a direct power control signal Ud;
a finite time sliding mode controller (FTSMC) having at a set of FTSMC input terminals configured to receive the current IPV and a voltage across the second capacitor and generate a reactive power control signal Uq, wherein the FTSMC includes a memory having program instructions for performing a particle swarm optimization and at least one FTSMC processor configured to execute the particle swarm optimization to determine optimum gain parameters of the FTSMC during an offline mode of the FTSMC and to apply the optimum gain parameters to the FTSMC to generate the reactive power control signal Uq during an online mode; and
a voltage source controller configured to receive the reactive power control signal Uq and the direct power control signal Ud and generate a set of timing signals configured to operate the inverter,
wherein the finite-time sliding mode MPPT control system is configured to minimize the voltage error signals for each phase.
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