Different Maximum Power Point Tracking Methods and their study for different ambient conditions

Abstract

Abstract-This article brings together a study of important maximum peak power tracking (MPPT) practices used for photovoltaic systems. Different techniques were taken from various articles on MPPT and are contemplated and compared. This paper offers the Simulink PV system model using P&O (Perturb and Observe) method of MPPT and its characteristics for different varying ambient conditions. Keyword-MPPT, PV, P&O, PV array I. INTRODUCTION Chasing the maximum power point (MPP) on the P-V curve of a photovoltaic (PV) array is typically an indispensable part of a PV system. The two main problems with PV source is its meager efficiency (almost less than 19%) and its output power variation due to change in atmospheric conditions like insolation and temperature. Apart from this, its nonlinear I-V characteristic compels the user to use something to chase the MPP. MPP is an exceptional point on the P-V curve with the associated power (at a particular temperature and insolation) having maximum value. This MPP also varies with the atmospheric condition. To elicit maximum power, MPPT is done so as to track the MPP. Until now different MPPT schemes have been used but most of them are derived from P&O method [1,3,5,6]. II. MAXIMUM POWER POINT (MPP)A PV array or generator will have one point on its current/voltage characteristic that corresponds to maximum power output. This is referred to as the maximum power point or maximum power tip or MPP. Figure 1.1 shows a maximum power tip for certain values of temperature and irradiation. It can be observed from the figure that the maximum power tip lies near the knee-point of the I-V curve. III.DIRECT COUPLING When a PV unit is coupled to a load directly, the PV module's operating point will be at the intersection of its I-V curve and load line, which is the I-V relationship of load. For example, a resistive load gives a straight line slope of 1/R as presented in Figure 1 In other hand, the load impedance orders the operation state of PV unit. In common, this operating state lies rarely at the MPP, consequently not producing the maximum power. A review demonstrates that majority of direct-coupled framework uses a mere31% of the peak PV capability [2,4,7,16]. A PV set is commonly oversized to pay off for low power delivered during winter season. This incongruousness of PV set and load necessitates added over-sizing of the PV set and accordingly upsurges the whole arrangement cost. For exploiting the PV set, the incoming sun's energy must be converted to electricity with the highest efficiency, done when the photovoltaic module operates on the maximum power point. Nevertheless, since this working point is sturdily affected due to solar fallout and temperature intensities, it may arbitrarily fluctuate on the I-V curl (illustrated Figure 1.4). Thus, to dynamically set the MPP as an action point for a extensive range of solar radiation and temperature, specific circuits, known in the literature by Maximum Power Point Trackers (MPPT),are employed. If properly adapted, MPPT can quote exc...