Sulfation is the formation or deposit of lead sulfate on thesurface and in the pores of the active material of the batteries'lead plates. If the sulfation becomes excessive and forms largecrystals on the plates, the battery will not operate efficientlyand may not work at all. Common causes of battery sulfation arestanding a long time in a discharged condition, operating atexcessive temperatures, and prolonged under or overcharging.
300kVAA品牌UPS采用6脉冲整流,无输入隔离变压器,配置了有源滤波器和无源滤波器的混合滤波器(THM)作为抑制谐波的措施,有源滤波器的基本原理是:通过检测补偿对象的电流il,经补偿电流检算电路计算出补偿电流的指令信号ic*,该信号作为补偿电流参考值经补偿电流发生电路得到补偿电流实际值ic,补偿电流与负载电流中要补偿的谐波及无功电流抵消(ic=ih),Zui终得到期望的电源电流(is=if)。300kVAA品牌UPS采用了混合滤波器(THM),当谐波含量较大时,有源滤波自动投入,当谐波含量较小时,采用LC无源滤波。图6和7分别为混合滤波器的原理示意图和300kVAA品牌UPS的THM示意图,图8和9分别为在混合滤波器THM后端和前端检测到的电能质量分析图,将两图分析比较可知:在混合滤波器后端测量的效果等同于直接测量6脉冲SCR整流器产生的谐波,观察其波形发现它与250kVAA品牌UPS输入波形极其类似。另外,其总输入谐波电流畸变很大,Zui高的一相达到47.6%,尤以5次谐波为主(43.6%),7次谐波次之(17.2%)且输入功率因数很低,仅为0.77。对比混合滤波器前端的检测数据可知:输入电流波形呈现光滑完好的正弦波,输入总谐波畸变在4.4%以内,3次谐波含量相比略大(3.6%),其余各次谐波含量都很小。有源滤波器对谐波的抑制过程可以理解为:由有源滤波器产生以下这种波形的电流,即整流器所需波形的电流减去电网波形电流,总而言之,由有源滤波器提供谐波电流,而非电网提供。但是,由于有源滤波器自身无法产生任何电能,必须以消耗电网电能的方式来进行谐波补偿,所以,有源滤波与UPS配合使用时具有效率不高的缺点。
What are some of the major types of lead acid batteries?
Batteries are divided in two ways, by application (what they areused for) and construction (how they are built). The majorapplications are automotive, marine, and deep-cycle. Deep-cycleincludes solar electric (PV), backup power, and RV and boat "house"batteries. The major construction types are flooded (wet), gelled,and AGM (Absorbed Glass Mat). AGM batteries are also sometimescalled "starved electrolyte" or "dry", because the fiberglass matis only 95% saturated with Sulfuric acid and there is no excessliquid. Flooded may be standard, with removable caps, or theso-called "maintenance free" (that means they are designed to dieone week after the warranty runs out). All gelled are sealed and afew are "valve regulated", which means that a tiny valve keeps aslight positive pressure. Nearly all AGM batteries are sealed valveregulated (commonly referred to as "VRLA" - Valve RegulatedLead-Acid). Most valve regulated are under some pressure - 1 to 4psi at sea level.