在了解电压互感器消中性点谐器的作用之前,我们不妨先探讨一下电力系统的中性点运行方式。在三相交流电力系统中，作为供电电源的发电机和变压器的中性点，有三种运行方式：一种是电源中性点不接地;一种是电源中性点经消弧线圈接地;一种是电源中性点直接接地。前两种合称为中性点非有效接地，或小电流接地系统，后一种中性点直接接地称为中性点有效接地，或大电流接地。

In understanding of voltage transformer neutral point elimination harmonic function before, we might as well first explore the neutral point of power system operation mode. In a three-phase ac power system, as the power supply of the generator and transformer neutral point, there are three operation modes: power is a kind of neutral point grounding; Is a kind of power supply neutral point via arc suppression coil grounding; Is a kind of power supply neutral directly grounded. The first two collectively known as neutral point is not effective grounding, or the small current grounding system, a kind of neutral point grounding directly after called the neutral point grounding effectively, or large current grounding. 

1 电力系统为中性点经消弧线圈接地，此系统已考虑到消弧接地(如上述第二条所述)，在系统的电压互感器中，Yo接线可不考虑加装一次消谐器。

1 for neutral point via arc suppression coil grounding power system, this system has been given arc suppression grounding (as mentioned in the above article 2), in system of voltage transformer, yukio okamoto, wiring is not consider adding a harmonic elimination. 

2 我们一般指PT柜加装消谐器，是指安装在6-35kV电磁式电压互感器(简称压变)一次绕阻Yo结线中性点与地之间的非线性电阻器，起阻尼与限流的作用。在6-35kV发电、变电站，我们经常碰到的是电网中性点不接地，其母线上的Yo接线的电磁式压变一次绕组，成为中性点不接地电网对地的唯一金属通道，电网相对地电容的充、放电途径 必然通过压变一次绕组。这种慢变过程使压变铁芯深度饱和，当电网接地消失时，压变一次绕组中会出现数安培幅值的涌流，将压变0.5A高压熔丝熔断。即使这种涌流尚未达到熔断器的熔断值，但仍超过电压互感器额定电流，长时间处于过电流状态下运行的电压互感器会被烧毁，继而引发其他事故。选用一次消谐器，这种现象就不会发生。当单相接地电容电流小于一定的值时，不会在压变一次绕组中出线较大的涌流，对压变和高压熔丝无任何影响，从经济和产品成本的角度考虑，可以不装消谐器。如果顾客提出要求，在电压互感器一次侧加装消谐器会给设备运行增加一层防护。

2 we generally refers to PT ark with harmonic elimination device, is refers to the installation in 6 to 35 kv electromagnetic voltage transformer (hereinafter referred to as pressure change) a winding yukio okamoto, connection between neutral and ground nonlinear resistor, damping and current limiting effect. In 6-35 kv power generation, substation, we often encounter the neutral point grounding grid is, its parent online yukio okamoto, wiring of electromagnetic pressure becomes a winding, become a neutral point grounding grid, the only metal channel to the ground, the grid relatively capacitor charge and discharge way Must become a winding through pressing. The slowly varying process make depth of iron core saturation pressure, when the grounding grid disappears, pressure changes will appear in A winding several amperes amplitude of flow, the pressure change 0.5 A high-voltage fuse fusing. Even if the flow has yet to reach fuse fusing value, but still more than rated current, voltage transformer run over current conditions for a long time of voltage transformer will be destroyed, which in turn cause other accidents. Choose a harmonic elimination device, this phenomenon will happen. When single phase grounding capacitive current is less than a certain value, not the pressure change in the primary winding wire larger flow, the pressure change and high-voltage fuse without any impact, considering from the Angle of economy and the product cost, can not install harmonic elimination. If the customer request, the voltage transformer primary side mounted to the harmonic elimination will add a layer of protection to equipment operation. 

3 提到压变加装一次消谐器，不要误认为只要是PT柜就加装，因为在2PT柜中，电压互感器为V-V接线，主要用于计量、测量、绝缘监测，这里不存在中性点接地的问题(不可能有电网相对地电容的 充、放电途径)，不需要加装消谐器。

3 mentioned compression with a harmonic elimination device, don't be deceived into thinking that as long as it is ark of PT is equipped with, because in 2 PT ark, V - V voltage transformer connection, mainly used for measuring, measuring, insulation monitoring, there is no neutral grounding problem (there can be no grid relatively capacitor charge and discharge way), do not need to install harmonic elimination. 

4在有些工程设计中，用户根据现场电网的实际情况，在母线侧已接入一定大小的电容器，使线路的容性阻抗(Xc)与感性阻抗(XL)的比值小于0.01,可避免谐振,在此配电系统中,电压互感器中性点也无需加装消谐器。

4 in some engineering design, the user according to the actual situation of the power grid, the bus side has access to a certain size of capacitor, the circuit of the capacitive impedance (Xc) and sensibility impedance (XL) is the ratio of less than 0.01, can avoid resonance, in the distribution system, voltage transformer neutral point also need not add harmonic elimination. 

总之，在PT中性点加装消谐器,要根据电力网的具体情况和运行方式区分对待,不要盲目地增加,设计增加一次消谐器注意区分半绝缘电压互感器和全绝缘电压互感器所选用的一次消谐器型号不同。

In brief, on PT neutral harmonic elimination device, according to the specific conditions and operation mode of the power grid to distinguish treatment, don't blindly increase, designed to increase a harmonic elimination distinguish half insulation voltage transformer and fully insulated voltage transformer chooses different number of a harmonic elimination ware.