Modelling of Solar PV under Varying Condition with an Improved Incremental Conductance and Integral Regulator

Abstract

The introduction of solar photovoltaic (PV) systems would provide electricity accessibility to rural areas that are far from or have no access to the grid system. Various countries are planning to reduce their emissions from fossil fuel, due to its negative effects, by substituting with renewable energy resources. The use of solar PV systems is expanding globally because of growing energy demands and depleting fossil fuel reserves. Grid integration of the solar system is expected to increase further in the near future. However, the power output of solar PV systems is inherently intermittent, and depends on the irradiance and the temperature operation of the solar cell, resulting in a wide range of defects. Hence, it is vital to extract peak power from the solar panel in all conditions to provide constant power to the load. This paper presents a tracking control method of the peak output power of a solar PV system connected to a DC-DC boost converter using an improved incremental conductance and integral regulator (IC + IR). The research was carried out because the solar PV output is dependent on environmental parameters, such as solar insolation and temperature. Therefore, it is pertinent to forecast the peak power point in outdoor conditions and to operate at that point, so that solar PV can produce the highest output each time it is used. A peak power point strategy that maximizes the output of a solar PV array is proposed. This method establishes the maximum output operation point under the effects of the solar insolation and the module temperature. An automatic converter restoration scheme with block/de-block signal control is proposed to protect the converters from the higher phase current, total capacitor voltage deviation, grid disturbance, and fault current. The proposed scheme also tracks the peak power point (PPP) of the solar array with stable output voltage under varying operating conditions. It reduces the error signal and ripples at the PPP during instantaneous and incremental conductance to zero. In addition, it controls the solar PV system under constantly changing climatic conditions, and thus improves the system efficiency.

Sliding Mode Control based MPPT and Output Voltage Regulation of a Two-stage Stand-alone PV System

“…The reference voltage is assumed to be 32 V [1]. The output voltage responses of the boost and buck converters are illustrated in Figures (9) and (10). The results show that although the input voltage of the buck converter varies due to changes in solar irradiation, its output voltage remains regulated.…”

“…The idea is to produce attractive forces so that the output voltages of the PV module remain in the attraction zone, which is the zone where the maximum power points are located. The attractive potential field can be defined according to Equation (10), where U att (V P V ) denotes the attractive potential field, K att is a positive design constant, V P V is the output voltage of the PV module, V lb and V rb are the left and right boundary voltages of the attraction zone, respectively.…”

“…2 , V P V < V lb (10) Applying the negative gradient to the attractive field expression, the corresponding attractive force is obtained, as shown in Equation (11).…”

“…The Owl search algorithm is used together with the InC method to reduce the convergence time to the maximum power point and mitigate the inherent limitations of the conventional InC method in [9]. An improved version of the InC and integral regulator (IR) is used to track the peak output power of a PV system interfaced by a DC-DC boost converter in [10]. In [11], the Roach Infestation (RI) algorithm is presented for the MPPT of a photovoltaic system, and fuzzy logic is used to generate variable step sizes for the InC method in [12].…”

Embedded electronic system for evaluation of photovoltaic modules based on a current-voltage curve tracer

“…In the process of assembling photovoltaic systems, to avoid damaging them, it is necessary to carry out a visual inspection, start-up tests, performance evaluation and subsequent periodic maintenance of the photovoltaic system (mainly in the case of large or complex installations) [6], [7]. Photovoltaic systems go through performance tests related to irradiance values and temperature, which are carried out under certain climatic conditions so as not to affect current and voltage measurements [8], [9]. Such a requirement creates obstacles in the start-up process, since the adequate conditions are only reached in hours close to noon and due to clouds, the irradiance incident on the modules can vary very quickly [10], [11].…”