基于功率量的电力变压器保护新原理及高速算法研究

发布时间：2018-01-04 23:27

本文关键词：基于功率量的电力变压器保护新原理及高速算法研究　出处：《广西大学》2014年博士论文　论文类型：学位论文

【摘要】：随着大容量及超大容量变压器的广泛使用,变压器主保护性能的重要性也更加凸现出来。因此,研究性能更优良的变压器保护新原理和新算法具有重要的理论价值和实际意义。论文着重基于提升电力变压器电流纵联差动保护的整体性能水平及研究与变压器差动保护无关的主保护新原理展开工作,论文研究的主要内容和成果有： (1)基于瞬时无功功率理论,提出了基于差有功及差无功直流分量绝对值比值的变压器涌流辨识新方法。该方法基于变压器不同状态时有功和无功的内在关系,摆脱了传统的基于差流波形特征的涌流识别方法的种种限制,揭示了变压器励磁涌流和故障状态的本质不同。 (2)变压器处于励磁涌流状态时,其铁芯随励磁电压的变化周期性地在饱和状态及非饱和状态之间摆动,相应地其瞬时励磁电感值也周期性地变化(铁芯饱和时较小,退出饱和时很大),此时其励磁电感或电抗值含有较丰富的基频分量值；基于励磁电感或电抗的涌流辨识方法把握了涌流与内部故障的本质差异,但其缺陷是需要测量变压器绕组的电流值,因而对现场TA(电流互感器)配置有特殊要求,要求能测各侧各相绕组电流。本文提出了基于零序过滤的变压器励磁电感计算方法及涌流识别方法,适合于TA按典型方案配置的Y/△接线变压器,使得励磁电感涌流辨识方法的应用范围得以扩展。 (3)提出了三种高速功率方向保护算法或原理并应用于变压器保护。方法一是基于瞬时值对称分量变换的变压器快速方向保护算法。方法二是基波正序突变量高速方向保护新算法。方法三是滤除高频暂态量的突变量高速方向保护原理。方法一采用了特殊设计的滤波器及快速滤序算法,并根据新型方向判据来快速判别故障方向。相比于方法一,方法二、三无需特殊设计的滤波器,只需采用十分成熟的低通滤波器来滤除高频暂态分量,方法二再采用差分滤波来抑制电流非周期分量,然后采用基于帕克变换的新方法来快速计算基波正序故障分量相量,以实现快速的故障方向判别。不同于方法二的快速相量算法,方法三是时域的高速算法,且无需对短路电流非周期分量进行额外处理,并采用了新型相序变换方法以使保护原理能适应不同的故障类型。这三种新型快速方向保护算法或原理,对于一般内部故障可在故障后极短时间内出口跳闸,可极大提高切除各种情况下变压器内部故障的速度。当选用P级电流互感器时,保护可在互感器进入饱和前可靠出口跳闸。 (4)提出了电力变压器故障分量无功功率方向保护原理。该方案基于故障分量保护原理,只需采集变压器端口电压、电流数据,无需任何先验参数,摆脱了传统变压器差动保护中励磁涌流识别的束缚,体现了变压器主保护原理新的研究思路,可应用于不同接线组别的变压器保护,可有效区分外部近区故障切除电压恢复产生涌流、带载合闸等各种变压器状态。 (5)提出一种有效区分空投涌流与空投于故障的变压器保护新原理。该原理利用帕克变换或瞬时有功、无功电流分量法,可计算变压器在各种暂态过程中的基波正序有功、视在电流比值或基波正序功率因数,并根据这些计算结果的大小来判断变压器是否发生内部故障。该原理与前述的功率方向保护算法相结合,可构成较为完善的变压器保护方案。
[Abstract]:With the widespread use of large capacity and ultra large capacity transformer, the importance of transformer protection performance is more prominent. Therefore, it has important theoretical value and practical significance to study the performance protection principle and the new algorithm is more excellent. The new principle of transformer main protection paper to enhance power transformer longitudinal differential protection of the overall level of performance and with the research of transformer differential protection based on related work, the research contents and results are:
(1) based on the instantaneous reactive power theory, put forward the difference and difference of active reactive DC component of transformer inrush current identification method based on the absolute value of the ratio. The method is based on the inherent relationship between the different states of transformer active power and reactive power, get rid of the limitations of the traditional based on differential current waveform characteristics of inrush current identification method, reveal the essence of transformer inrush current and fault condition is different.
(2) in transformer inrush current state, its core changes with periodic excitation voltage in saturation and non saturation condition between the swing, the instantaneous excitation inductance value of the periodic changes (core saturation when small, large, this time out of saturation) the excitation inductance or reactance value contains the fundamental component rich value; inrush current identification method of magnetizing inductance or reactance based on the grasp of the essential differences between inrush and internal fault, but its defect is that you need to measure the current of the transformer winding, thus the TA (current transformer) configuration has special requirements, requirements can be measured on each side of each phase winding current is presented in this paper. Method and transformer excitation inrush current identification method based on zero sequence inductance filter, suitable for Y/ transformer in TA delta according to the typical configuration of the inductor in the inrush current identification method of the excitation should be used to expand the scope of Show.
(3) put forward three kinds of high speed power direction protection algorithm or principle and applied to transformer protection. A transformer is fast direction protection algorithm based on instantaneous symmetricalcomponents. Method two is the fundamental positive sequence of variable speed directional protection algorithm. The new method is three variable speed directional protection principle of high frequency transient filtering a method of using a filter. The special design and rapid sequence filter algorithm, and according to the new criterion to judge the direction of fault direction quickly. Compared to the method, the method of two three filters with special design, only need to filter out the high frequency transient components using ten mature low-pass filter method using differential filter two to suppress the current non periodic component, and then the fast calculation of fundamental positive sequence fault component phasor method based on Parke transform, to achieve rapid discrimination of the fault direction is different from the party. The fast phasor algorithm of algorithm two, three is the high-speed algorithm in time domain, and does not need additional processing for the non periodic components of short-circuit current. A new phase sequence transformation method is adopted to make the protection principle adapt to different fault types.
The three new algorithms or fast direction protection principle, for internal fault in the fault in a short time to trip, can greatly improve the rate of resection of the internal fault of transformer under various conditions. When the P current transformer, the transformer protection can saturate before reliable trip.
(4) the power transformer fault component of the reactive power direction protection principle. The scheme of fault component protection principle based on the transformer only collection port voltage, current data, without any prior parameters, get rid of the shackles of traditional identification of inrush current in transformer differential protection, reflects the research ideas of transformer protection principle. Can be used in different transformer wiring group, which can effectively distinguish external near fault recovery voltage surge current, transformer load or other state.
(5) put forward a new principle of transformer to distinguish inrush current and fault to drop drop protection. The principle of using Parke transform or instantaneous active and reactive current component method, the fundamental positive sequence can be calculated in a variety of transformer in transient process of power, as in the current ratio or fundamental positive sequence power factor, and based on these calculation results the size of the judges whether the transformer internal fault. The principle and power direction protection algorithm the combination, may constitute a transformer protection scheme more perfect.

【学位授予单位】：广西大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM774

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