一、电压暂降跌落问题

现代电网的电网故障的不可避免性和用电负荷抗扰能力的脆弱性，增加了对高质量高可靠性供电的需求。对于电力用户来讲，电压暂降（也是国际公认）严重的问题之一。因闪电、暴雨、大风、施工和人员误操作等，引起的短路导致的电压暂降现象，足以影响敏感设备的正常运行。

二、电压暂降常见的电压跌落和电压过高的原因有以下五种：

1） 故障电流引起电压凹陷：当输电网或者配电网中发生短路故障时，电流急剧增大，在公共电压连接点产生电压跌落，同时电压跌落沿着电网扩散而给大量用户造成干扰；

2） 感应电机启动引起电压凹陷：感应电机全压启动时，需要从系统汲取的电压值是满负荷运行时的5-10倍,这一大电流流经系统阻抗时会引起电压跌落。

3） 雷击，闪电导致的电压凹陷，雷击引起的绝缘子闪络和线路对地放电是造成系统线路电压跌落的主要原因。在雨季或多雷地区，暴露在露天的运行设备很容易受到雷电干扰。

4）功率因数过低或过高引起的电压波动，无功功率在系统可以造成线路上的电压损耗，这就是容性无功抬高供电电压的原因。

5）不可预知的偶然事件：建筑道路施工，交通事故，人为误操作等等。

三、电压暂降跌落行业标准要求

电压暂降   

IEEE标准及[敏感词]标准《电能质量电压暂降和短时中断》（GB/T30137-2013）规定了电压暂降定义：电力系统中某点工频电压均方根值突然降低至0.1p.u.~0.9p.u.，并在短暂持续10ms~1min后恢复正常的现象。

短时中断

电力系统中某点工频电压方均根值突然降低至0.1p.u.，并在短暂持续10ms~1min后恢复正常的现象。

四、DNVV产品性能特点

DSP全数字化控制，整流、逆变、充电、放电各个功率变换环节全部数字化控制;

系统级+单板级+器件级全面防护，[敏感词]可靠，环境适应性更强;

超大10英寸LCD触摸显示屏，彩色图形显示，操作方便，人机界面友好;

智能化系统自诊断方案，丰富的故障记录，大容量的历史记录存储空间;

。[敏感词]容量支持2MW，超大型数据中心不间断供电的[敏感词]选择

五、DNVV产品应用场合

1、半导体行业（芯片制造，测试和封装）

2、新能源行业（太阳能多晶硅，单晶硅拉硅，电池测试，老化及封装等）

3、医疗器械行业（医疗检测仪器，放射化疗仪器，液相分析仪等等）

4、汽车制造行业（自动焊接，涂装，油漆烘烤等等）

5、食品饮料行业（食品烘焙，包装，罐装，制瓶机等等）

6、石油化工行业（加油机，炼油机，磕头机，化工厂等等）

7、纺织行业（丝印机，缠绕机，卷扬机等等）

8、智能工厂行业

六、DNVV产品工作原理图

DNVV产品工作原理图

七、DNVV技术特点

1、 Voltage sag and drop problem

The inevitability of power grid failures in modern power grids and the vulnerability of power load immunity have increased the demand for high-quality and reliable power supply. For power users, voltage sag (also internationally recognized) is one of the most serious problems. The voltage sag caused by short circuit due to lightning, rainstorm, strong wind, construction and personnel misoperation is enough to affect the normal operation of sensitive equipment.

2、 The most common reasons for voltage sag and high voltage are as follows:

1) Voltage sag caused by fault current: When a short circuit fault occurs in the transmission or distribution network, the current increases sharply, resulting in a voltage drop at the common voltage connection point. At the same time, the voltage drop spreads along the power grid, causing interference to a large number of users;

2) Induction motor startup causes voltage sag: When an induction motor starts at full voltage, the voltage value that needs to be drawn from the system is 5-10 times that of full load operation. This large current flowing through the system impedance can cause voltage drop.

3) Lightning strikes, voltage dips caused by lightning strikes, insulator flashover caused by lightning strikes, and line to ground discharge are the main causes of voltage drops in system lines. In rainy seasons or areas with frequent thunderstorms, equipment exposed to the open air is easily affected by lightning interference.

4) Voltage fluctuations caused by low or high power factor can result in voltage losses on the line due to reactive power in the system, which is the reason why capacitive reactive power raises the supply voltage.

5) Unpredictable accidental events: road construction, traffic accidents, human error, etc.

3、 Industry standard requirements for voltage sag and drop

Voltage sag  

The IEEE standard and national standard "Voltage sag and short interruption of power quality" (GB/T30137-2013) define voltage sag as the phenomenon in which the root mean square value of the power frequency voltage at a certain point in the power system suddenly drops to 0.1p.u.~0.9p.u. and returns to normal after a brief duration of 10ms~1min.

Short term interruption

The phenomenon where the root mean square value of the power frequency voltage at a certain point in the power system suddenly drops to 0.1 p.u. and returns to normal after a brief duration of 10 ms to 1 min.

4、 Performance characteristics of DNVV products

DSP fully digital control, all power conversion links including rectification, inversion, charging, and discharging are digitally controlled;

System level single board level device level comprehensive protection, ultimate reliability, and stronger environmental adaptability;

Large 10 inch LCD touch screen display, color graphic display, easy to operate, user-friendly human-machine interface;

Intelligent system self diagnosis solution, rich fault records, and large capacity historical record storage space;

The maximum capacity supports 2MW, making it the best choice for uninterrupted power supply in ultra large data centers

5、 Application scenarios of DNVV products

1. Semiconductor industry (chip manufacturing, testing, and packaging)

2. New energy industry (solar polycrystalline silicon, monocrystalline silicon pulling silicon, battery testing, aging and packaging, etc.)

3. Medical device industry (medical testing equipment, radiotherapy and chemotherapy equipment, liquid phase analyzer, etc.)

4. Automotive manufacturing industry (automatic welding, painting, paint baking, etc.)

5. Food and beverage industry (food baking, packaging, canning, bottle making machines, etc.)

6. Petrochemical industry (refueling machines, refineries, kowtow machines, chemical plants, etc.)

7. Textile industry (screen printing machines, winding machines, winches, etc.)

8. Intelligent factory industry

6、 DNVV product working principle diagram

DNVV product working principle diagram

7、 Characteristics of DNVV technology