电气专业外文翻译3

1 Power Quality Monitoring

Patrick Coleman

Many power quality problems are caused by inadequate wiring or improper grounding. These problems can be detected by simple examination of the wiring and grounding systems. Another large population of power quality problems can be solved by spotchecks of voltage, current, or harmonics using hand held meters. Some problems, however, are intermittent and require longer-term monitoring for solution.

Long-term power quality monitoring is largely a problem of data management. If an RMS value of voltage and current is recorded each electrical cycle, for a three-phase system, about 6 gigabytes of data will be produced each day. Some equipment is disrupted by changes in the voltage waveshape that may not affect the rms value of the waveform. Recording the voltage and current waveforms will result in about 132 gigabytes of data per day. While modern data storage technologies may make it feasible to record every electrical cycle, the task of detecting power quality problems within this mass of data is daunting indeed.

Most commercially available power quality monitoring equipment attempts to reduce the recorded data to manageable levels. Each manufacturer has a generally proprietary data reduction algorithm. It is critical that the user understand the algorithm used in order to properly interpret the results.

1.1 Selecting a Monitoring Point

Power quality monitoring is usually done to either solve an existing power quality problem, or to determine the electrical environment prior to installing new sensitive equipment. For new equipment, it is easy to argue that the monitoring equipment should be installed at the point nearest the point of connection of the new equipment. For power quality problems affecting existing equipment, there is frequently pressure to determine if the problem is being caused by some external source, i.e., the utility. This leads to the installation of monitoring equipment at the service point to try to detect the source of the problem. This is usually not the optimum location for monitoring equipment. Most studies suggest that 80% of power quality problems originate within the facility. A monitor installed on the equipment being affected will detect problems originating within the facility, as well as problems originating on the utility. Each type of event has distinguishing characteristics to assist the engineer in correctly identifying the source of the disturbance.

1.1.1 What to Monitor

At minimum, the input voltage to the affected equipment should be monitored. If the equipment is single phase, the monitored voltage should include at least the line-to-neutral voltage and the neutral to-ground voltages. If possible, the line-to-ground voltage should also be monitored. For three-phase equipment, the voltages may either be monitored line to neutral, or line to line. Line-to-neutral voltages

are easier to understand, but most three-phase equipment operates on line-to-line voltages. Usually, it is preferable to monitor the voltage line to line for three-phase equipment.

If the monitoring equipment has voltage thresholds which can be adjusted, the thresholds should be set to match the sensitive equipment voltage requirements. If the requirements are not known, a good starting point is usually the nominal equipment voltage plus or minus 10%.

In most sensitive equipment, the connection to the source is a rectifier, and the critical voltages are DC. In some cases, it may be necessary to monitor the critical DC voltages. Some commercial power quality monitors are capable of monitoring AC and DC simultaneously, while others are AC only.

It is frequently useful to monitor current as well as voltage. For example, if the problem is being caused by voltage sags, the reaction of the current during the sag can help determine the source of the sag. If the current doubles when the voltage sags 10%, then the cause of the sag is on the load side of the current monitor point. If the current increases or decreases 10–20% during a 10% voltage sag, then the cause of the sag is on the source side of the current monitoring point.

Sensitive equipment can also be affected by other environmental factors such as temperature, humidity, static, harmonics, magnetic fields, radio frequency interference (RFI), and operator error or sabotage. Some commercial monitors can record some of these factors, but it may be necessary to install more than one monitor to cover every possible source of disturbance.

It can also be useful to record power quantity data while searching for power quality problems. For example, the author found a shortcut to the source of a disturbance affecting a wide area by using the power quantity data. The recordings revealed an increase in demand of 2500 KW immediately after the disturbance. Asking a few questions quickly led to a nearby plant with a 2500 KW switched load that was found to be malfunctioning.

1.2 Selecting a Monitor

Commercially available monitors fall into two basic categories: line disturbance analyzers and voltage recorders. The line between the categories is becoming blurred as new models are developed. V oltage recorders are primarily designed to record voltage and current strip chart data, but some models are able to capture waveforms under certain circumstances. Line disturbance analyzers are designed to capture voltage events that may affect sensitive equipment. Generally, line disturbance analyzers are not good voltage recorders, but newer models are better than previous designs at recording voltage strip charts.

In order to select the best monitor for the job, it is necessary to have an idea of the type of disturbance to be recorded, and an idea of the operating characteristics of the available disturbance analyzers. For example, a common power quality problem is nuisance tripping of variable speed drives. Variable speed drives may trip due to the waveform disturbance created by power factor correction capacitor switching, or due to high or low steady state voltage, or, in some cases, due to excessive voltage imbalance. If the drive trips due to high voltage or waveform disturbances, the drive diagnostics will usually indicate an over voltage code as the cause of the trip. If the voltage is not balanced, the drive will draw significantly unbalanced currents. The current imbalance may reach a level that causes the drive to trip for input over current. Selecting a monitor for variable speed drive tripping can be a challenge. Most line disturbance analyzers can easily capture the waveshape disturbance of capacitor switching, but they are not good voltage recorders, and may not do a good job of reporting high steady state voltage. Many line disturbance analyzers cannot capture voltage unbalance at all, nor will they respond to current events unless there is a corresponding voltage event. Most voltage and current recorders can easily capture the high steady state voltage that leads to a drive trip, but they may not capture the capacitor switching waveshape disturbance. Many voltage recorders can capture voltage imbalance, current imbalance, and some of them will trigger a capture of voltage and current during a current event, such as the drive tripping off.

To select the best monitor for the job, it is necessary to understand the characteristics of the available monitors. The following sections will discuss the various types of data that may be needed for a power quality investigation, and the characteristics of some commercially available monitors.

1.3 Voltage

The most commonly recorded parameter in power quality investigations is the RMS voltage delivered to the equipment. Manufacturers of recording equipment use a variety of techniques to reduce the volume of the data recorded. The most common

method of data reduction is to record Min/Max/Average data over some interval. Figure 1.1 shows a strip chart of rms voltages recorded on a cycle-by-cycle basis. Figure 1.2 shows a Min/Max/Average chart for the same time period. A common recording period is 1 week. Typical recorders will use a recording interval of 2–5 minutes. Each recording interval will produce three numbers: the rms voltage of the highest 1 cycle, the lowest 1 cycle, and the average of every cycle during the interval. This is a simple, easily understood recording method, and it is easily implemented by the manufacturer. There are several drawbacks to this method. If there are several events during a recording interval, only the event with the largest deviation is recorded. Unless the recorder records the event in some other manner, there is no time-stamp associated with the events, and no duration available. The most critical deficiency is the lack of a voltage profile during the event. The voltage profile provides significant clues to the source of the event. For example, if the event is a voltage sag, the minimum voltage may be the same for an event caused by a distant fault on the utility system, and for a nearby large motor start. For the distant fault, however, the voltage will sag nearly instantaneously, stay at a fairly constant level for 3–10 cycles, and almost instantly recover to full voltage, or possibly a slightly higher voltage if the faulted section of the utility system is separated. For a nearby motor start, the voltage will drop nearly instantaneously, and almost immediately begin a gradual recovery over 30–180 cycles to a voltage somewhat lower than before. Figure

1.3 shows a cycle-by-cycle recording of a simulated adjacent feeder fault, followed by

a simulation of a voltage sag caused by a large motor start. Figure 1.4 shows a Min/Max/Average recording of the same two events. The events look quite similar when captured by the Min/Max/Average recorder, while the cycle-by-cycle recorder reveals the difference in the voltage recovery profile.

FIGURE 1.1 RMS voltage strip chart, taken cycle by cycle.

FIGURE 1.2 Min/Max/Average strip chart, showing the minimum single cycle voltage, the maximum single cycle voltage, and the average of every cycle in a recording interval. Compare to the Fig. 1.1 strip chart data.

Some line disturbance analyzers allow the user to set thresholds for voltage events. If the voltage exceeds these thresholds, a short duration strip chart is captured showing the voltage profile during the event. This short duration strip chart is in addition to the long duration recordings, meaning that the engineer must look at several different charts to find the needed information.

Some voltage recorders have user-programmable thresholds, and record deviations at a higher resolution than voltages that fall within the thresholds. These deviations are incorporated into the stripchart, so the user need only open the stripchart to determine, at a glance, if there are any significant events. If there are events to be examined, the engineer can immediately ―zoom in‖ on the portion of th e stripchart with the event.

Some voltage recorders do not have user-settable thresholds, but rather choose to capture events based either on fixed default thresholds or on some type of significant change. For some users, fixed thresholds are an advantage, while others are uncomfortable with the lack of control over the meter function. In units with fixed thresholds, if the environment is normally somewhat disturbed, such as on a welder circuit at a motor control center, the meter memory may fill up with insignificant events and the monitor may not be able to record a significant event when it occurs. For this reason, monitors with fixed thresholds should not be used in electrically noisy environments.

FIGURE 1.3 Cycle-by-cycle rms strip chart showing two voltage sags. The sag on the left is due to an adjacent feeder fault on the supply substation, and the sag on the right is due to a large motor start. Note the difference in the voltage profile during recovery

FIGURE 1.4 Min/Max/Average strip chart of the same voltage sags as Fig. 1.3. Note that both sags look almost identical. Without the recovery detail found in Fig. 1.3, it is difficult to determine a cause for the voltage sags

FIGURE 1.5 Typical voltage waveform disturbance caused by power factor correction capacitor energization

1.3.1 Voltage Waveform Disturbances.

Some equipment can be disturbed by changes in the voltage waveform. These waveform changes may not significantly affect the rms voltage, yet may still cause equipment to malfunction. An rms-only recorder may not detect the cause of the malfunction. Most line disturbance analyzers have some mechanism to detect and record changes in voltage waveforms. Some machines compare portions of successive waveforms, and capture the waveform if there is a significant deviation in any portion of the waveform. Others capture waveforms if there is a significant change in the rms value of successive waveforms. Another method is to capture waveforms if there is a significant change in the voltage total harmonic distortion (THD) between successive cycles.

The most common voltage waveform change that may cause equipment malfunction is the disturbance created by power factor correction capacitor switching. When capacitors are energized, a disturbance is created that lasts about 1 cycle, but does not result in a significant change in the rms voltage. Figure 1.5 shows a typical power factor correction capacitor switching event.

FIGURE 1.6 RMS stripcharts of voltage and current during a large current increase due to a motor start downstream of the monitor point.

1.4 Current Waveshape Disturbances

Very few monitors are capable of capturing changes in current waveshape. It is usually not necessary to capture changes in current waveshape, but in some special cases this can be useful data. For example,inrush current waveforms can provide more useful information than inrush current rms data. Figure 1.7 shows a significant change in the current waveform when the current changes from zero to nearly 100 amps peak. The shape of the waveform, and the phase shift with respect to the voltage waveform, confirm that this current increase was due to an induction motor start.

Figure 1.7 shows the first few cycles of the event shown in Fig.1.6.

1.5 Harmonics

Harmonic distortion is a growing area of concern. Many commercially available monitors are capable of capturing harmonic snapshots. Some monitors have the ability to capture harmonic strip chart data. In this area, it is critical that the monitor produce accurate data. Some commercially available monitors have deficiencies in measuring harmonics. Monitors generally capture a sample of the voltage and current waveforms, and perform a Fast Fourier Transform to produce a harmonic spectrum. According to the Nyquist Sampling Theorem, the input waveform must be sampled at least twice the highest frequency that is present in the waveform. Some manufacturers interpret this to mean the highest frequency of interest, and adjust their sample rates accordingly. If the input signal contains a frequency that is above the maximum frequency that can be correctly sampled, the high frequency signal may be ―aliased,‖ that is, it may be incorrectly identified as a lower frequency harmonic. This may lead the engineer to search for a solution to a harmonic problem that does not exist. The aliasing problem can be alleviated by sampling at higher sample rates, and by filtering out frequencies above the highest frequency of interest. The sample rate is usually found in the manufactur er’s literature, but the presence of an antialiasing filter is not usually mentioned in the literature.

1.6 Summary

Most power quality problems can be solved with simple hand-tools and attention to detail. Some problems, however, are not so easily identified, and it may be necessary to monitor to correctly identify the problem. Successful monitoring involves several steps. First, determine if it is really necessary to monitor. Second,

decide on a location for the monitor. Generally, the monitor should be installed close

to the affected equipment. Third, decide what quantities need to be monitored, such as voltage, current, harmonics, and power data. Try to determine the types of events that can disturb the equipment, and select a meter that is capable of detecting those types of events. Fourth, decide on a monitoring period.

Usually, a good first choice is at least one business cycle, or at least 1 day, and more commonly, 1 week. It may be necessary to monitor until the problem recurs. Some monitors can record indefinitely by discarding older data to make space for new data. These monitors can be installed and left until the problem recurs. When the problem recurs, the monitoring should be stopped before the event data is discarded.

After the monitoring period ends, the most difficult task begins — interpreting the data. Modern power quality monitors produce reams of data during a disturbance. Data interpretation is largely a matter of experience, and Ohm’s law. There are many examples of disturbance data in books such as The BMI Handbook of Power Signatures, Second Edition, and the Dranetz Field Handbook for Power Quality Analysis.

1 电能质量监测

帕特里克·科尔曼

许多电能质量问题所造成的布线不足或不当的接地。这些问题可以由简单的检查接线和接地系统的检测。另一个人口众多的电能质量问题是可以解决的抽查，电压，电流或谐波使用手持米。然而，一些问题，间歇性和需要长期监测解决方案。

长期的电能质量监测主要是数据管理中存在的问题。如果电压的RMS值和当前记录每个电周期为三相系统，将每天生产约6个字节的数据。一些设备被破坏的电压波形的变化，可能不会影响波形的RMS值。记录电压和电流波形将导致约132千兆字节数据的每一天。虽然现代数据存储技术是可行的，记录每一个电周期，在这个数据的质量检测电能质量问题的任务确实是艰巨的。

大部分市售的电能质量监测设备，试图减少记录的数据管理的水平。每个制造商有一个普遍的专有的数据缩减算法。关键是了解用户所使用的算法，以便正确地解释结果。

1.1 选择一个监测点

电能质量监测通常是可以解决现有的电能质量问题，或事先确定的电气环境，安装新的敏感设备。对于新的设备，很容易认为监控设备应在安装新设备的连接点最近的点。影响现有设备的电能质量问题，频频施压，以确定如果问题正在引起一些外部来源，即实用。这导致监测设备的安装服务点尝试检测问题的根源。这通常是没有监测设备的最佳位置。大多数研究表明，电能质量问题， 80 ％来自设施内。受影响的设备上安装一个监视器将检测设施内的问题，以及存在的问题，在始发实用工具。每种类型的事件已显着特点，以协助工程师正确识别干扰源。

1.1.1 监测

至少，向受影响的设备的输入电压进行监测。如果设备是单相，监视电压应包括至少线到中性点电压和中性的对地电压。如果可能的话，线对地电压也应监测。对于三相设备，电压可能被监视线中性，或线到线。线到中性的电压更容易理解，但最三相设备上线到线电压运作。通常情况下，最好是监视线到线电压为三相设备。

如果监控设备有可调节的电压阈值，阈值应设置相匹配的敏感设备的电压要求。如果要求不知道，一个很好的起点通常是设备的额定电压加上或减去10％。

在最敏感的设备，连接到源是一个整流器，临界电压是直流。在某些情况下，它可能是必要的监控关键的直流电压。一些商业的电能质量监测仪能够监测交流和直流同时，而另一些则仅交流。

它常常是有用的监测电流以及电压。例如，如果问题正在引起电压骤降，目前在凹陷的反应，可以帮助确定凹陷源。如果目前的双打时的电压骤降10％，那么下垂的原因是负载侧电流监测点。如果电流增加或减少10-20％， 10％的电压骤降期间，凹陷的原因是对源端的电流监测点。

敏感的设备，也可以受到其他环境因素，如温度，湿度，静态，谐波磁场，无线电频率干扰（RFI），操作错误或破坏。一些商业显示器，可以记录一些这些因素，但它可能需要安装多台监视器，以涵盖所有可能的干扰源。

它也可以是有用的发电量数据，同时记录电能质量问题。例如，笔者发现一个快捷方式的影响发电量数据采用大面积的干扰源。录音显示，增加2500千瓦的需求后，立即干扰。要求迅速导致附近一个2500千瓦的电厂的几个问题，发现故障切换负载。

1.2 选择显示器

市售显示器分为两个基本类别：线干扰分析仪和电压记录。类别之间的界线变得模糊，作为新车型的开发。电压记录仪主要是用来记录电压和电流的带状图数据，但一些模型能够捕捉到在某些情况下的波形。线干扰分析仪是用来捕捉电压事件可能会影响敏感设备。一般来说，行干扰分析仪是没有良好的电压录像机，但新的模式比以往的设计在录音电压带图表。

为了选择最好的显示器工作，这是必要的干扰类型有一个想法，要记录，并提供干扰分析仪的经营特色的想法。例如，一个共同的电能质量问题是跳闸滋扰变速驱动器。变速驱动器的行程由于功率因数校正电容切换，或高或低的稳态电压，由于创建的波形干扰，或在某些情况下，由于过度的电压不平衡。如果驱动器的行程，由于高电压或波形干扰，驱动器的诊断通常会显示过电压跳闸原因代码。如果电压不均衡，驱动器将提请显着的不平衡电流。目前的不平衡可能达到的水平，导致过电流的驱动器输入的行程。选择变速驱动器跳闸的显示器可以是一个挑战。最线干扰分析仪可以轻松地捕获波形干扰电容器切换，但他们没有良好的电压录像机，可能不会做报告稳态高电压做好。许多线干扰分析仪无法捕捉所有的电压不平衡，也不会对他们应对当前的事件，除非有一个相应的电压事件。大多数的电压和电流的录像机可以轻松地捕获稳态高电压驱动器跳闸，导致，但他们可能无法捕捉到的电容开关波形干扰。许多电压录像机可以捕捉电压不平衡，电流不平衡，其中一些将触发捕获的电压和电流在当前的事件，如关闭驱动

器跳闸。

要选择这个职位的最佳显示器，它是必要的，以了解可用的显示器的特点。以下各节将讨论的各类电能质量调查，和一些市售显示器的特点，可为需要的数据。

1.3 电压

电能质量调查记录最常用的参数是RMS电压传递到设备。录音设备的制造商使用了多种技术，以减少记录的数据量。最常用的方法是减少的数据记录超过一定间隔的最小/最大/平均数据。图1.1显示了一个循环周期的基础上记录的RMS 电压的条状图。图1.2显示了一个最小/最大/同一时期的平均图表。一个常见的记录期限为1个星期。典型的录像机使用的记录间隔2-5分钟。每个记录间隔会产生三个数字：最高的1个周期，最低的1个周期，每个周期的时间间隔内的平均电压有效值。这是一个简单，容易理解的记录方法，并很容易实现由生产商。这种方法有几个缺点。如果有几个事件记录间隔期间，只有最大偏差的事件被记录下来。除非记录仪的记录的事件在一些其他的方式，有没有时间戳记与事件有关，并没有可用的时间。最关键的缺陷是缺乏活动期间的电压档。电压档事件源提供了重要的线索。例如，如果该事件是一个电压骤降，最低的电压可能是相同的一个遥远的公用工程系统故障引起的事件，并为附近的一个大型电机启动。然而，对于遥远的故障，电压将下垂几乎瞬间，留在3-10个周期相对稳定的水平，几乎立即恢复到全电压，也可能是稍高的电压如果公用系统故障的部分分离。附近的电机启动，电压会下降近瞬间，几乎立即开始逐步复苏比30-180周期电压比以前有所回落。图1.3显示了一个模拟的相邻馈线故障逐周期的记录，其次是大型电机启动引起的电压骤降模拟。图1.4显示了一个最小/最大/平均记录相同的两个事件。事件看上去非常相似，当俘虏的最小值/最大值/平均值记录，而循环周期记录揭示了在电压恢复配置文件的差异。

图1.1电压有效值带状图，采取循环周期

图1.2最小/最大/平均带图表，显示单周期的最低电压，最大的单周期电压，平均每个记录间隔周期。比较的图。 1.1带状图数据

一些线路干扰分析仪允许用户设置阈值电压事件。如果电压超过这些阈值，持续时间短条状图表显示电压档在事件捕获。在这短短的时间带图表除了持续时间长的录音，这意味着工程师必须在几个不同的图表看，找到所需要的信息。

一些电压录像机有用户可编程的阈值，并记录偏差，在更高的分辨率比内阈值的电压。这些偏差纳入带状图，使用户只需要打开带图表来确定，一目了然，如果有任何重大的事件。如果有被检查的事件，工程师可以立即带状图的一部分，与事件“放大”。

一些电压录像机不具备用户设定的阈值，而是选择捕捉固定的默认阈值或某些类型的显着变化的事件。对于某些用户，固定阈值的优势，而另一些不舒服，缺乏控制仪表功能。与固定阈值的单位，如果通常是有点不安的环境，如在电机控制中心的焊工电路，仪表内存可能填补了微不足道的事件和显示器可能无法记录一个重要的事件发生时。出于这个原因，不应该被用来固定阈值的显示器，在电气噪声环境。

图1.3逐周期有效值带状图显示两个电压骤降。左侧凹陷是由于供应变电站相邻馈线故障，右侧的凹陷是由于大电机启动。注意在恢复过程中的电压档的差异

图1.4最小/最大/平均带状图如图相同的电压骤降。1.3。请注意，这两个凹陷看起来几乎相同。如果没有恢复细节图。 1.3 ，这是难以确定的电压骤降的一个原因

图1.5典型电压波形的功率因数校正电容器通电造成的干扰

1.3.1 电压波形干扰

一些设备可以干扰电压波形的变化。这些波形的变化可能不会显着影响的rms电压，但仍可能导致设备故障。只有一个RMS录音机可能无法检测到的故障原因。大多数线干扰分析仪有某种机制来检测和记录电压波形的变化。有些机器比较连续波形的部分，并捕获波形的波形的任何部分，如果有一个显着偏离。其他捕获的波形在连续波形的有效值，如果有一个显着的变化。另一种方法是捕捉波形电压总谐波失真（THD），连续循环之间，如果有一个显着的变化。

最常见的电压波形的变化可能导致设备故障是由功率因数校正电容器切换干扰。当通电时，电容干扰创建，持续约1个周期，但不会导致电压有效值的一个显着的变化。图1.5显示了一个典型的功率因数校正电容切换事件。

图1.6 RMS的条状图表的电压和大电流的增加，由于下游电机启动时电流监测点

1.4 电流波形扰动

极少数显示器能够捕获电流波形的变化。捕捉电流波形的变化，它通常是没有必要的，但在某些特殊情况下，这可能是有用的数据。例如，浪涌电流波形可以提供更多有用的信息比浪涌电流有效值数据。图1.7显示了显着的变化时，在电流波形从零到近100安培的峰值电流的变化。波形和电压波形相移的形状，确认该电流的增加是由于感应电机启动。图1.7显示在图1.6所示的事件前几个周期。

图1.7电压和电流波形在图1.6所示的电流增加的前几个周期

1.5 谐波

谐波失真是一个令人关注的种植面积。许多市售的显示器能够捕获谐波快照。有些显示器有能力捕捉谐波条状图表数据。在这方面，关键是显示器生产准确的数据。一些市售的显示器具有测量谐波的缺陷。显示器一般捕获的电压和电流波形样本，并进行快速傅立叶变换产生的谐波频谱。根据奈奎斯特采样定理，必须输入波形采样至少两次的频率最高，是目前在波形。一些制造商解释这意味着感兴趣的最高频率，并相应地调整其采样率。如果输入信号中包含以上的最高频率可以正确采样频率，高频信号可能会被“别名”，也就是说，它可能会被错误地认定为一个较低的频率谐波。这可能导致工程师寻找一个不存在的谐波问题的解决方案。通过采样混叠问题可以得到缓解，在更高的采样率，并筛选出感兴趣的最高频率以上的频率。采样率通常被发现在制造商的文学，但存在一个抗混叠滤波器通常不是在文献中提到的。

1.6总结

大部分的电能质量问题可以解决简单的手工工具和注意细节。然而，有些问题，不是那么容易确定，它可能是必要的监测，正确识别的问题。成功地监测涉及几个步骤。首先，确定如果真的是必要的监控。第二，决定了显示器的位置。一般而言，显示器的受影响的设备应安装在靠近。第三，决定需要进行监测，如电压，电流，谐波，功率数据，什么数量。尝试，以确定事件的类型，可以干扰设备，并选择一米，是能够检测这些类型的事件。四，决定上一个监测期。通常，一个良好的第一选择是至少一个营业周期，或至少1天，而更常见的， 1个星期。这可能是必要的监督，直到问题再次出现。有些显示器可以无限期地丢弃旧的数据记录，使新的数据空间。这些监视器可以安装和离开，直到问题再次出现。当问题再次出现，监控事件数据将被丢弃之前，应该停止。

监测期结束后，最艰巨的任务开始 - 解释数据。现代电能质量监测过程中产生大量的数据扰动。数据的解释主要是一个经验的问题，欧姆定律。有许多书籍，如BMI电力签名手册（第二版），电能质量分析Dranetz场手册中的扰动数据的例子。

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