【正文】 ing a discharged battery, it simply connects the modules directly to the battery. This forces the modules to operate at battery voltage, typically not the ideal operating voltage at which the modules are able to produce their maximum available power. The PV Module Power/Voltage/Current graph shows the traditional Current/Voltage curve for a typical 75W module at standard test conditions of 25176。 VBATTERY x IMODULE, or 17V 247。C VMP rating higher than 17V will also tend to produce more charge current increase because the difference between actual VMP and battery voltage will be greater. A highly discharged battery will also increase charge current since battery voltage is lower, and output to the battery during MPPT could be thought of as being “constant power”. What most people see in cool fortable temperatures with typical battery conditions is a charge current increase of between 10 – 25%. Cooler temperatures and highly discharged batteries can produce increases in excess of 30%. Customers in cold climates have reported charge current increases in excess of 40%. What this means is that current increase tends to be greatest when it is needed most。s called maximum power point tracking (MPPT). It extracts additional power from your PV array, under certain conditions. This article explains the process by a mechanical analogy, for people who do not understand basic function of a MPPT is analogous to the transmission in a car. When the transmission is in the wrong gear, the wheels do not receive maximum power. That39。s pare a PV module to a car engine. Its voltage is analogous to engine speed. Its ideal voltage is that at which it can put out maximum power. This is called its maximum power point. (It39。s wheels. It varies with battery state of charge, and with the loads on the system (any appliances and lights that may be on). For a 12V system, it varies from about 11 to . In order to charge a battery (increase its voltage), the PV module must apply a voltage that is higher than that of the battery. If the PV module39。 C. They do that because it will drop to around 15V on a very hot day. However, on a very cold day, it can rise to 18V! What happens when the Vpp is much higher than the voltage of the battery? The module voltage is dragged down to a lowerthanideal voltage. Traditional charge controllers transfer the PV current directly to the battery, giving you NO benefit from this added potential. Now, let39。s transmission varies the ratio between speed and torque. At low gear, the speed of the wheels is reduced and the torque is increased, right? Likewise, the MPPT varies the ratio between the voltage and current delivered to the battery, in order to deliver maximum power. If there is excess voltage available from the PV, then it converts that to additional current to the battery. Furthermore, it is like an automatic transmission. As the Vpp of the PV array varies with temperature and other conditions, it tracks this variance and adjusts the ratio accordingly. Thus it is called a Maximum Power Point Tracker. What advantage does MPPT give in the real world? That depends on your array, your climate, and your seasonal load pattern. It gives you an effective current boost only when the Vpp is more than about 1V higher than the battery voltage. In hot weather, this may not be the case unless the batteries are low in charge. In cold weather however, the Vpp can rise to 18V. If your energy use is greatest in the winter (typical in most homes) and you have cold winter weather, then you can gain a substantial boost in energy when you need it the most! 中文翻譯 什么是最大功率點(diǎn)跟蹤 (MPPT),它是又如何工作的 ? 光伏發(fā)電作為可再生能源變得日益重要，它有許多有點(diǎn)，如不需燃料、沒(méi)有污染、需要很少的維護(hù)費(fèi)用、沒(méi)有噪聲等等。 光伏系統(tǒng)產(chǎn)生的能量取決于陣列的開(kāi)路電壓。它的 VI 和 VP 特性曲線表示了一個(gè)特定的工作點(diǎn)，在這個(gè)點(diǎn)上可以提供最大功率。所以許多方法被用來(lái)確定最大功率跟蹤。 MPPT 不是一種移動(dòng)模組本身來(lái)使它們更直接面對(duì)太陽(yáng)的機(jī)械跟蹤系統(tǒng)。從模塊得到的額外電力將以電池充電電流的形式得到利用。 為了了解 MPPT 使如何工作的，我們先了解一下常規(guī)的 (非 MPPT)充電控制器是如何工作的。這就促使模組工作在蓄電池的電壓上，而這個(gè)電壓通常