Methods and systems for solar photovoltaic automatic voltage regulation under extreme weather conditions

A finite-time sliding mode maximum power point tracking (MPPT) control method for a photovoltaic (PV) array, comprising:

• generating, by a PV array having a positive terminal and a negative terminal, a current Ipv at the positive terminal;
• connecting a first capacitor in parallel with the PV array;
• connecting an inductor having a first end to the positive terminal;
• generating, by a body terminal of 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, a DC voltage Vdc when the MOSFET is switched ON;
• receiving, at a set of PWM input terminals of a pulse width modulator (PWM), the current IPV and a voltage across the first capacitor;
• executing, by a PWM processor of the PWM, a perturb and observe (P&O) algorithm and generating a maximum power point signal at a PWM output terminal;
• connecting the PWM output terminal to a gate of the MOSFET;
• modulating, by the maximum power point signal, the DC voltage Vdc according to a duty cycle D defined by the P&O algorithm;
• connecting 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;
• generating three phase voltage signals by connecting an inverter in parallel with the second capacitor;
• receiving, at a point of common coupling (PCC) connected to the inverter, the three phase voltage signals;
• converting, by an electrical grid connected to the PCC, the three phase voltage signals to three phase current signals;
• calculating, by the electrical grid, three phase voltage error signals by subtracting a grid voltage at each phase from a reference voltage signal;
• converting, by a first direct to quadrature transformer configured to receive the three phase current signals, the three phase current signals to direct current signals and the quadrature current signals;
• converting, by a second direct to quadrature transformer configured to receive the three phase voltage error signals, the three phase voltage error signals to direct voltage error signals and quadrature voltage error signals;
• generating, by 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, a direct power control signal Ud;
• receiving, by a finite time sliding mode controller (FTSMC), the current IPV and a voltage across the second capacitor, the FTSMC including a memory having program instructions for performing a particle swarm optimization and at least one FTSMC processor configured to execute the particle swarm optimization;
• determining, by executing the particle swarm optimization, optimum gain parameters of the FTSMC during an offline mode of the FTSMC and applying the optimum gain parameters to the FTSMC to generate the reactive power control signal Uq during an online mode;
• generating, by the FTSMC, a reactive power control signal Uq;
• and
• receiving, by a voltage source controller, the reactive power control signal Uq and the direct power control signal Ud;
• generating, by the voltage source controller, a set of timing signals configured to operate the inverter;
• and
• minimizing, by the finite-time sliding mode MPPT control system the voltage error signals for each phase.

A non-transitory computer readable medium having instructions stored therein that, when executed by one or more processors, cause the one or more processors to perform a method for controlling an output of a photovoltaic (PV) array, comprising:

• generating, by the PV array having a positive terminal and a negative terminal, a current Ipv at the positive terminal;
• connecting a first capacitor in parallel with the PV array;
• connecting an inductor having a first end to the positive terminal;
• generating, by a body terminal of 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, a DC voltage Vdc when the MOSFET is switched ON;
• receiving, at a set of PWM input terminals of a pulse width modulator (PWM), the current IPV and a voltage across the first capacitor;
• executing a perturb and observe (P&O) algorithm and generating a maximum power point signal at a PWM output terminal;
• connecting the PWM output terminal to a gate of the MOSFET;
• modulating, by the maximum power point signal, the DC voltage Vdc according to a duty cycle D defined by the P&O algorithm;
• connecting 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;
• generating three phase voltage signals by connecting an inverter in parallel with the second capacitor;
• receiving, at a point of common coupling (PCC) connected to the inverter, the three phase voltage signals;
• converting, by an electrical grid connected to the PCC, the three phase voltage signals to three phase current signals;
• calculating, by the electrical grid, three phase voltage error signals by subtracting a grid voltage at each phase from a reference voltage signal;
• converting, by a first direct to quadrature transformer configured to receive the three phase current signals, the three phase current signals to direct current signals and the quadrature current signals;
• converting, by a second direct to quadrature transformer configured to receive the three phase voltage error signals, the three phase voltage error signals to direct voltage error signals and quadrature voltage error signals;
• generating, by 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, a direct power control signal Ud;
• receiving, by a finite time sliding mode controller (FTSMC), the current IPV and a voltage across the second capacitor;
• performing a particle swarm optimization;
• determining, by executing the particle swarm optimization, optimum gain parameters of the FTSMC during an offline mode of the FTSMC and applying the optimum gain parameters to the FTSMC to generate the reactive power control signal Uq during an online mode;
• generating, by the FTSMC, a reactive power control signal Uq;
• and
• receiving, by a voltage source controller, the reactive power control signal Uq and the direct power control signal Ud;
• generating, by the voltage source controller, a set of timing signals configured to operate the inverter;
• and
• minimizing, by the finite-time sliding mode MPPT control system the voltage error signals for each phase.