DNSVG动态功率因数补偿装置技术概述

1、DNSVG用于补偿无功

图2.2 带有DNSVG无功补偿装置的系统
假设负荷消耗感性无功（一般工业用户都是如此）Q_L，此时控制SVG使其产生容性无功功率，并取Q_SVG=Q_L，这样在负荷波动过程中，就可以保证：Q_S=Q_SVG-Q_L=0。
如果对电网等比较复杂的补偿对象而言，当需要向电网提供感性无功时，可以通过对SVG的控制，使其产生感性无功功率，并取Q_SVG=Q_C，这样在负荷波动过程中，仍然可以保证：Q_S=Q_SVG-Q_C=0。
此外，SVG在补偿系统无功功率达同时，几乎不产生谐波。更重要的是，SVG还可以对系统的谐波、不平衡等电能质量问题进行多功能综合补偿，实现部分有源滤波（APF）的功能。

2、DNSVG的设计目标

1）功率因数维持在 0.95及以上（可设定）；
2）稳定系统电压（可设定）；
3）谐波电流满足国标；
4）动态补偿额定输出电流THD≤3%；
5）补偿无功容量自动跟踪电网变化；
6）动态补偿响应时间≤5ms；
7）允许短时过载能力1.2倍；
8）完善的保护功能；
9）友好的人机界面；
10）灵活的通讯接口，可远程监控设备运行，并记录运行数据；

 

Overview of DNSVG Dynamic Power Factor Compensation Device Technology

1. DNSVG is used to compensate for reactive power

Figure 2.2 System with DNSVG reactive power compensation device
Assuming that the load consumes inductive reactive power (which is generally the case for industrial users) Q_LAt this point, control the SVG to generate capacitive reactive power and take Q_SVG=Q_LIn this way, during the process of load fluctuations, Q can be guaranteed_S=Q_SVG-Q_L0
If for complex compensation objects such as the power grid, when it is necessary to provide inductive reactive power to the grid, the SVG can be controlled to generate inductive reactive power and Q can be taken_SVG=Q_CIn this way, during load fluctuations, Q can still be guaranteed_S=Q_SVG-Q_C0
In addition, SVG generates almost no harmonics while compensating for reactive power in the system. More importantly, SVG can also provide multifunctional comprehensive compensation for power quality issues such as harmonics and imbalances in the system, achieving partial active filtering (APF) functionality.

2. Design Objectives of DNSVG

1) Maintain power factor at 0.95 or above (adjustable);
2) Stable system voltage (adjustable);
3) Harmonic current meets national standards;
4) Dynamic compensation rated output current THD ≤ 3%;
5) Compensate for reactive power capacity and automatically track changes in the power grid;
6) Dynamic compensation response time ≤ 5ms;
7) Allow a short-term overload capacity of 1.2 times;
8) Complete protection functions;
9) Friendly human-machine interface;
10) Flexible communication interface, capable of remotely monitoring device operation and recording operational data;