How to connect the power analyzer_Power analyzer wiring diagram

　　Power Analyzer Principle

　　Traditional active power meters are usually designed for industrial frequency or medium frequency sine wave measurement, so they can only meet the active power measurement of sine wave circuits. When the waveform distortion is small, the nominal measurement accuracy can be obtained. When the waveform distortion increases, the measurement error increases, and even the normal measurement function is lost.

　　The power analyzer is a functional upgrade product of the active power meter and generally has the following functions:

　　1. It has the basic functions of a power meter: measurement of voltage, current true effective value and total active power;

　　2. Expand the applicability of the basic functions of the power meter so that it can measure the voltage, current true RMS and total active power of sinusoidal and non-sinusoidal circuits. Generally, it is required to adapt to a wider bandwidth and a wider fundamental frequency range;

　　3. Ability to conduct qualitative and quantitative analysis on detailed information of non-sinusoidal voltage, current and power.

　　Qualitative analysis is usually done through intuitive time domain analysis, which is mainly based on real-time waveforms. Quantitative analysis is usually done through abstract but accurate frequency domain analysis, which is mainly based on Fourier transform.

　　Figure 1 is a general power analyzer block diagram.

　　Power Analyzer Wiring Diagram

　　When using a PA power analyzer for measurement, wiring is the first and most basic operation. It is difficult for many engineers to explain the wiring method of a power analyzer clearly. Here, we will use the PA power analyzer as a basis to help you understand the basic wiring skills.

　　As we all know, any circuit needs to form a loop to work. The circuit working loop is shown in Figure 1, and the current flows from the high end to the low end.

Figure 1 Circuit operation diagram

　　The power analyzer is actually the same. We can understand the wiring method of the power analyzer based on this idea.

　　1. 3P4W wiring

Figure 2 3P4W wiring diagram

　　As shown in Figure 2, the power supply points from the high end to the low end, and the current is measured at the high end. Therefore, the wiring is: AN, BN, CN, and the current is measured at A, B, and C respectively. This is easy to understand.

　　2. 3V3A wiring

Figure 3 3V3A wiring diagram

　　We can assume that Figure 3 "takes phase C as the reference point, which can be regarded as the low end", then the power supply goes from the high end to the low end, the current measures the high end current, the voltage connection method is AC, BC, AB, and the current measures A, B, and C respectively, which is very simple.

　　The above is the wiring method of 3V3A.

　　3. 3P3W wiring

　　Some engineers may ask, why do you need to connect the last line? Since you have "specified the low end", why do you need to connect the two high ends at the end, for example, the last AB phase, the current is measured at C. In fact, you can not connect the last phase, not connecting it will not affect the measurement results. This is the 3P3W connection method, that is, the "two-meter method". After connecting, you can complete the phase sequence relationship and you can see the vector diagram.

　　The above understanding may not be official, but it can help understand the wiring method. Finally, we need to remind you that this understanding is only suitable for power analyzers.