Current-based Maximum Power Point Tracking Research Articles

Predictive Control with Current-Based Maximum Power Point-Tracking for On-Grid Photovoltaic Applications

The high increase of renewable energy sources and the increment of distributed generation in the electrical grid has made them complex and of variable parameters, causing potential stability problems to the PI controllers. In this document, a control strategy for power injection to the electrical system from photovoltaic plants through a voltage source inverter two-level-type (VSI-2L) converter is proposed. The algorithm combines a current-based maximum power point-tracking (Current-Based MPPT) with model predictive control (MPC) strategy, allowing avoidance of the use of PI controllers and lowering of the dependence of high-capacitive value condensers. The sections of this paper describe the parts of the system, control algorithms, and simulated and experimental results that allow observation of the behavior of the proposed strategy.

A current-based fuzzy controller for MPPT of grid-connected PV systems

The output voltage oscillations of a photovoltaic (PV) system in parallel with other challenging voltage sources such as batteries result in drastic power oscillations. So, it is much more attractive to employ a PV system as a current source rather than as a source of voltage alongside a battery. To this aim, the inductance current of the PV's DC–DC converter is controlled and forced to track the maximum power point (MPP) reference, acting as a source of current. Then, the load voltage, and the DC–DC converter output voltage would be the same as the battery voltage. For this purpose, the paper proposes a two-level current-based maximum power point tracking (MPPT) algorithm. The proposed high-level algorithm contains two loops, namely, a set-point calculation loop and a fine-tuning loop. Based on an offline calculation using the PV's short circuit current, the set-point loop first estimates the PV's maximum power point. Second, the fine-tuning loop tracks the exact value of the PV's maximum power point, using the perturbation and observation (P&O) method. Further, a low-level fuzzy-based controller is proposed to force the continuous current (i.e., inductance current) of PV's DC–DC converter to track the generated reference of the high-level controller with no oscillation. The low-level fuzzy-based controller is proposed instead of the conventional proportional integral (PI) controller that does not work with minimal errors, since inserting one unstable pole into the PV system's transfer function. Matlab/Simulink simulations validate the effectiveness of the proposed MPPT algorithm.

A power conversion system for PMSG-based WECS operating with fully-controlled current-source converters

We propose a new power conversion system for a permanent magnet synchronous generator (PMSG) based grid-connected wind energy conversion system (WECS) operating with fully-controlled back-to-back current-source converters. On the generator side, two independent current-source rectifiers (CSRs) with space-vector pulse width modulation (SVPWM) are employed to regulate and stabilize DC-link currents. Between DC-link and the electrical grid, a direct-type three-phase five-level current-source inverter (CSI) is inserted as a buffer to regulate real and reactive power fed to the grid and thus adjusts the grid side power-factor. We also present a current-based maximum power point tracking (MPPT) scheme, which helps the generator extract the maximum power through closed-loop regulation of the generator speed. By applying the multilevel modulation and control strategies to the grid-side five-level CSI, a multilevel output current waveform with less distortion is produced, and the bulk requirement of the output capacitor filter to eliminate the harmonic current is reduced. All the proposed concepts are verified by simulation models built in a PSIM environment.

Design and Implementation of Photovoltaic Power Conditioning System using a Current-based Maximum Power Point Tracking

This paper proposes a novel current-based maximum power point tracking (CMPPT) method for a single-phase photovoltaic power conditioning system (PV PCS) by using a modified incremental conductance method. The CMPPT method simplifies the entire control structure of the power conditioning system and uses an inherent current source characteristic of solar cell arrays. Therefore, it exhibits robust and fast response under a rapidly changing environmental condition. Digital phase locked loop technique using an all-pass filter is also introduced to detect the phase of grid voltage, as well as the peak voltage. Controllers of dc/dc boost converter, dc-link voltage, and dc/ac inverter are designed for coordinated operation. Furthermore, a current control using a pseudo synchronous d-q transformation is employed for grid current control with unity power factor. A 3 kW prototype PV PCS is built, and its experimental results are given to verify the effectiveness of the proposed control schemes.

Closure on “Theoretical and Experimental Analyses of Photovoltaic Systems With Voltage and Current-Based Maximum Power Point Tracking”

Closure on “Theoretical and Experimental Analyses of Photovoltaic Systems With Voltage and Current-Based Maximum Power Point Tracking”

Discussion of “Theoretical and Experimental Analyses of Photovoltaic Systems With Voltage and Current-Based Maximum Power Point Tracking”

For original paper see Masoum et al. (IEEE Trans. Energy Conversion, vol.17, p.514-22, December 2002).

Discussion of “Theoretical and Experimental Analyses of Photovoltaic Systems With Voltage and Current-Based Maximum Power Point Tracking”

For original paper see Masoum et al. (IEEE Trans. Energy Convergence, vol.17, p.514-22, December 2002).

Theoretical and experimental analyses of photovoltaic systems with voltageand current-based maximum power-point tracking

Detailed theoretical and experimental analyses are presented for the comparison of two simple fast and reliable maximum power point tracking (MPPT) techniques for photovoltaic systems (PV): the voltage-based (VMPPT) and the current-based (CMPPT) approaches. A microprocessor-controlled tracker capable of online voltage and current measurements and programmed with both VMPPT and CMPPT algorithms is constructed. The load of the solar system is either a water pump or a resistance. Simulink facilities are used for simulation and modeling of the novel trackers. The main advantage of this new MPPT, as compared with present trackers, is the elimination of reference (dummy) cells, which results in a more efficient, less expensive, and more reliable PV system.

Theoretical and Experimental Analyses of Photovoltaic Systems with Voltage and Current-Based Maximum Power Point Tracking

Detailed theoretical and experimental analyses are presented for the comparison of two simple fast and reliable maximum power point tracking (MPPT) techniques for photovoltaic systems (PV): the voltage-based (VMPPT) and the current-based (CMPPT) approaches. A microprocessor-controlled tracker capable of online voltage and current measurements and programmed with both VMPPT and CMPPT algorithms is constructed. The load of the solar system is either a water pump or a resistance. Simulink facilities are used for simulation and modeling of the novel trackers. The main advantage of this new MPPT, as compared with present trackers, is the elimination of reference (dummy) cells, which results in a more efficient, less expensive, and more reliable PV system.