Table of Contents
What is the solar power?
How to define the solar power ? Basic solar power systems include solar panel, charge controller, batteries and inverter that supply to ac loads. Here the main focus parts are the charge controllers and the batteries. The photovoltaic cell and an essential sunlight based force framework were presented. The square graph is indicated again in Figure below. You discovered that the essential parts of a sunlight based fueled framework were the sun powered board, the charge regulator, the batteries, and the inverter. Presently we will proceed with the sun oriented force inclusion by centering on the charge regulator and batteries.
Profound cycle (profound release) fixed lead-corrosive batteries are the most well-known batteries in sun oriented force frameworks on the grounds that their underlying expense is lower and they are promptly accessible. Not at all like vehicle batteries, which are shallow-cycle, profound cycle batteries can be consistently released by as much as 80% of their ability, despite the fact that they will have a longer life if the cycles are shallower. Profound cycle batteries are needed in sun based force frameworks essentially in light of the fact that the daylight is not at its most extreme constantly—it is a discontinuous fuel source. At the point when the light force from the sun diminishes on account of mists or disappears totally around evening time, the yield from a sun based board drops definitely or goes to zero. During the times of low light or no light, the batteries will release essentially when a heap is associated. Normally, the voltage yield of a sun powered board should be in any event 13.6 V to charge a 12 V battery. Sunlight based boards are typically appraised at voltages higher than the ostensible yield. For instance, most 12 V sun oriented boards produce 16 V to 20 V at ideal light conditions. The higher voltage yields are fundamental so the sun powered board will in any case deliver an adequate charging voltage during some nonoptimal conditions.
Batteries can be associated in arrangement to build the yield voltage also, in corresponding to expand the ampere-hour limit, as delineated in Figure below for any number of batteries. A few arrangement associations of batteries can be associated in corresponding to accomplish both an expansion in amp-hrs and yield voltage. For instance, expect a framework employments 12 V, 200 Ah batteries. In the event that the framework requires 12 V and 600 Ah, three equal associated batteries are utilized. In the event that the framework requires 24 V and 200 Ah, two arrangement associated batteries are utilized. In the event that 24 V and 600 Ah are required, three sets of arrangement batteries are associated in equal.
The Charge Controller
A sun based charge regulator is required in sun based force frameworks that utilization batteries to store the energy, except for low-power frameworks. The sun powered charge regulator manages the force from the sunlight based boards basically to forestall cheating the batteries. Cheating batteries diminish battery life and may harm the batteries. By and large, there is no requirement for an accuse regulator of stream charge sun oriented boards, for example, those that produce five watts or less. A decent dependable guideline is that if the sun oriented board produces around two watts or less for every 50 battery amp-hrs (Ah), at that point you needn’t bother with one. A charge regulator is required if the sun based board delivers multiple watts for every 50 Ah of battery rating. For instance, a 12 V battery evaluated at 120 Ah won’t need a charge regulator, as the accompanying computation shows, on the grounds that the sunlight based force is under 5 W.
For this situation, the charging circuit is appeared in Figure shown below. The diode forestalls the battery from releasing back through the sun oriented board when the board voltage dips under the battery voltage. For instance, when the sun powered board is creating 16 V, the diode is forward-one-sided and the battery is charging. At the point when the battery voltage is 12 V and the board yield drops to under 12.7 V, the diode is converse one-sided and the battery can’t release back through the sun oriented cells.
For heavenly bodies of more than around 5 W, a charge regulator is fundamental. Fundamentally, charge regulators control the 16–20 V yield of the commonplace 12 V sunlight based board down to what the battery needs relying upon the measure of battery charge, the sort of battery, what’s more, the temperature. Sun oriented boards produce more voltage at cooler temperatures.
Types of Charge Controllers
Three fundamental sorts of charge regulators are on/off, PWM, also, MPPT. The most fundamental regulator is the on/off sort, which basically screens the battery voltage and stops the charging when the battery voltage arrives at a predefined level to forestall cheating. It at that point restarts the charging once the battery voltage dips under a foreordained esteem. Figure below shows the essential idea. The switch demonstrated speaks to a semiconductor that is turned here and there. The voltage of the battery is taken care of back to the control circuit. At the point when the voltage is under a set low esteem, the control circuit turns the switch on to charge the battery. At the point when the battery charges to a set high worth, the control circuit kills the switch. The diode forestalls release back through the control circuit when the yield of the board is lower than the battery.
PWM (pulse width modulation) charge regulators continuously decrease the measure of intensity applied to the batteries as the batteries draw nearer to full charge. This kind of regulator permits the batteries to be all the more completely energized with less weight on the batteries. This broadens the life of the batteries and continually keeps up the batteries in a completely energized state (called “drift”) during daylight hours. The PWM regulator delivers a progression of heartbeats to charge the batteries rather than a steady charge. The battery voltage is continually checked to decide how to change the recurrence of the beats and the beat widths. When the batteries are completely energized and there is no heap to deplete them, the regulator produces short heartbeats at a low rate or no heartbeats by any stretch of the imagination. At the point when the batteries are released, long beats at a high rate are sent or the regulator may go into a steady charging mode, depending on the measure of release. Following figure shows the fundamental idea of a PWM charge regulator. To some extent (a), the PWM furthermore, control circuit produces beats dependent on the contribution from the inspecting circuit. The examining circuit decides the real battery voltage by inspecting the voltage between beats. The diode goes about as a rectifier and furthermore impedes release of the battery back through the charger around evening time. Part (b) exhibits how the battery charges during each heartbeat and how the width and the time between beats change as the battery charges.
As you have taken in, the yield voltage of a sun based board shifts incredibly with the measure of daylight and with the air temperature. Consequently, sunlight based boards with voltage evaluations higher than the battery voltage should be utilized to give adequate charging voltage to the battery under not exactly ideal conditions. As referenced before, a 12 V sun based board may deliver 20 V under ideal conditions however can create just a certain measure of current. For instance, if a sun oriented board can create 8 An at 20 V, it is appraised at 160 W. Batteries like to be charged at a voltage somewhat higher than their appraised voltage. On the off chance that a 12 V battery is being charged at 14 V, and it is drawing the most extreme 8 A from the sun oriented board, the force conveyed to the battery is 8 A 14 V 112 W rather than the 160 W delivered by the sun based board at 20 V. The batteries just put away 70% of the accessible energy since the 12 V battery can’t work at 20 V. MPPT (greatest force point tracker) charge regulators dispose of a large part of the energy misfortune found in different kinds of regulators and produce a lot higher efficiencies. The MPPT ceaselessly tracks the info voltage and current from the sun oriented board to decide at the point when the pinnacle input power happens and afterward changes the voltage to the battery to upgrade the charging. This outcomes in a greatest force move from the sun based board to the battery. In Figure below, the blue bend is the voltage-current trademark for a certain sun based board under a predetermined state of occurrence light. The green bend is the force demonstrating where the pinnacle happens, which is in the knee of the V-I bend. On the off chance that the occurrence light diminishes, the bends will move down.
The MPPT is essentially a DC-to-DC converter. A rearranged block chart indicating the essential practical idea is appeared in Figure GA2–7. In spite of the fact that there are a few different ways in which the MPPT can be actualized, the figure outlines the essential capacities. The DC/AC converter, the transformer, and the AC/DC converter seclude the dc contribution from the dc yield, so the yield can be adapted to most extreme force. For instance, if a 160 W sunlight based board produces 20 V at 8 A, it should be diminished to roughly 13.6 V to charge a 12 V battery. A typical charger won’t have the option to give in excess of 8 An at 13.6 V (or 109 W), which implies the board isn’t being utilized effectively and just 76% of the accessible force from the sunlight based board is utilized. A MPPT charge regulator can supply around 11 An at 13.6 V (150 W), subsequently diminishing the charging time and creating a superior coordinate between the board and the battery. For this situation, the board is being utilized all the more productively since it can convey about 94% of the accessible capacity to the battery.
Also read here: