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http:/www.zhongshangwang.com/ http:/www.sdxinzhi.com/探讨变压器励磁涌流产生机理及抑制措施探讨变压器励磁涌流产生机理及抑制措施Mechanism and suppression measures of transformer magnetizing inrush current generation摘要:变压器作为交流电力系统重要的电气设备,其正常运行直接关系着系统的安全。差动保护作为变压器主保护,励磁涌流是影响其正确动作与否的关键因素之一。文章分析了变压器励磁涌流及其特点,以单相变压器为例,分析了励磁涌流产生的机理,并给出了常见的抑制措施。Abstract: transformer as AC power system electrical equipment important, its normal operation is directly related to the safety of the system. Differential protection as the main protection of transformer, inrush current is one of the key factors and its action is right or not. This paper analyzes the inrush current and its characteristics, taking single-phase transformer as an example, the mechanism of inrush current generated by the analysis, and gives the measures to suppress the common.关键词:变压器 励磁涌流 二次谐波 间断角Keywords: transformer inrush current harmonic two interval angle1、变压器励磁涌流及特点1, transformer inrush current and the characteristics of变压器是一种依据电磁感应原理制造而成的静止元件,是交流输电系统中用于电压变换的重要电气设备。当合上断路器给变压器充电时,有时候,能够观察到变压器电流表的指针有很大摆动,随后,很快又返回到正常的空载电流值,这个冲击电流通常就被称为励磁涌流。The static components of transformer is a basis of electromagnetic induction principle, manufacture, is an important electrical equipment voltage converter for AC transmission system. When the circuit breaker to the transformer when charging, sometimes, can observe the pointer to the transformer current meter has a great swing, then, quickly returned to normal values of no-load current, the current impact is often referred to as the inrush current.总的来说,变压器励磁涌流有以下几个特点:第一,波形呈现尖顶形状,表明其中含有相当成分的非周期分量和高次谐波分量,其中高次谐波以二次和三次为主,并且,随着http:/www.tahxhb.com/ http:/www.sdyrtggs.com/时间推移,某一相二次谐波含量可能超过基波分量的一半以上。第二,励磁涌流幅值与变压器空载投入的电压初相角直接相关。对于单相变压器来说,当电压过零点投入时,励磁涌流幅值最大。由于三相变压器各相间有 120 度相位差,所以涌流也不尽相同。第三,在最初几个波形中,涌流将出现间断角。第四,涌流衰减的时间常数与变压器阻抗、容量和铁心材料等都相关。In general, the transformer magnetizing inrush current has the following characteristics: first, waveform showing spire shape, show that the aperiodic component and harmonic component which contains a component, wherein the harmonic in two and three, and, with time, a phase two harmonic content may exceed the fundamental component more than half. Second, excitation inrush current amplitude and the initial phase angle of no-load transformer is directly related to. For single-phase transformer, when the voltage over zero input, inrush current maximum amplitude. Because each phase of three-phase transformer with 120 phase difference, so the inrush current are not the same. Third, in the first few waveform, current will appear discontinuous angle. Fourth, the current decay time constant and impedance of transformer, capacity and core materials are related.2、励磁涌流产生机理2, the generation mechanism of inrush current变压器励磁涌流是由变压器铁心饱和引起的。在铁心不饱和时,铁心磁化曲线的斜率很大,励磁电流近似为零;一旦铁心出现饱和,磁化曲线斜率变小,电流随着磁通线性增长,最终演变为励磁涌流。Transformer inrush current is caused by the transformer core saturation. In the core is not saturated, core magnetization curve slope is large, the excitation current is approximately zero; once the core saturation magnetization curve slope, smaller, current with flux linear growth, eventually evolved into the inrush current.下面以单相变压器空载合闸为例分析励磁涌流产生机理。设变压器在时间 t=0 时合闸,则施加于变压器上的电压为:The following to single-phase transformer no-load closing to the producing mechanism of inrush current cases. The transformer is provided on at time t=0, the voltage applied to the transformer for:(1)http:/www.zhongshangwang.com/ http:/www.sdxinzhi.com/1.又,变压器电压与磁通间的关系为: (2)Also, the relationship between the transformer voltage and flux for: ( 2 )故: (3)Therefore: ( 3 )式(3)中第一式为稳态磁通,后两式为暂态磁通,为铁心剩磁,与合闸时刻的电压相关。Type (3 ) in the first type is a steady-state flux, two for the transient flux, as the core remanence, voltage associated with closing time.计及成本和工艺,现代常用的电力变压器饱和磁通一般设为 1.151.4,而变压器运行电压一般不应超过额定电压的 10%。因此,变压器稳态正常运行时,磁通不会超过饱和磁通,铁心也不会饱和。但在暂态过程中,如变压器空载合闸时,由于剩磁的作用,运行磁通就有可能大于饱和磁通,从而造成变压器饱和。例如,最严重的是电压过零时刻,合闸,假若此时铁心的剩磁,非周期磁通为经过半个周期后,磁通达到,将远大于饱和磁通,造成变压器严重饱和。Considering cost and process, commonly used in modern power transformer saturation flux is generally set to 1.15 1.4, and the transformer voltage generally should not exceed 10% of rated voltage. Therefore, the 3D steady during normal operation, the magnetic flux does not exceed the saturation magnetic flux, the core is not saturated. But in the transient process, such as the transformer no-load closing, the remanence effect, there may be greater than the operating flux saturation flux, resulting in transformer saturation. For example, the most serious is the voltage zero-crossing moment, closing, remanence if core, aperiodic flux after half a cycle, the flux reached, will be greater than the saturation magnetic flux, the transformer saturation.3、抑制措施3, control measures对于现场中常用的三相电力变压器,防止变压器励磁涌流引起差动保护的措施主要有以下几类。For three-phase power transformer used in the field, to prevent the differential protection of transformer magnetizing inrush current caused by the measures mainly in the following categories.3.1 采用速饱和中间变流器http:/
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