Energy Consumption Test Scheme of Power Meter for Household Appliances

Influence of energy consumption level on the use of electrical appliances

When we buy air conditioners, the best way to judge the cooling capacity of an air conditioner is to look at its output power.

In an ideal state, the output power of one horse is about 2400W, and the energy efficiency ratio of air conditioner = air conditioner output power / air conditioner input power. Therefore, according to the formula, under the same refrigeration effect, the higher the energy efficiency ratio, the lower the power consumption. Figure 1 shows the three-level energy efficiency standard set for air conditioning in the new energy consumption national standard.

Figure 1 new energy efficiency standards

Therefore, if the cooling effect of your own air conditioner is general, but the power consumption is large, it is likely that the energy efficiency grade of the air conditioner is low, resulting in excessive energy consumption.

Significance of more advanced energy consumption level

Figure 2 energy efficiency identification

With the rapid economic growth of various countries, the demand and ownership of household appliances have increased by leaps and bounds, which has brought huge energy consumption and serious pollution to the environment. As shown in Figure 2, in order to reduce the environmental pollution caused by these household appliances, countries all over the world improve the energy efficiency of energy consuming products by formulating and implementing energy efficiency standards and promoting energy efficiency labeling system, promote the progress of energy-saving technology, so as to reduce the emission of harmful substances and protect the environment.

Energy consumption test scheme of power meter for household appliances

More and more household appliances adopt frequency conversion technology, which not only saves energy consumption, but also distorts the waveform signal of the product. Moreover, due to the application of frequency conversion, the working state is frequently changed during the operation of household appliances, resulting in a wide range of changes in the working current, which can be reduced from tens of amps to a few milliamps. So, what kind of instrument can meet the test and measurement requirements of variable frequency household appliances such as air conditioners?

Fig. 3 test diagram of household and office appliances

As shown in Figure 3, the test diagram of household and office appliances is shown. Here, we take air conditioning as an example to share with you the difficulties in the test of down conversion appliances?

Test difficulties

1. Frequency conversion appliances not only save energy consumption, but also make the waveform signal of the product prone to distortion. These distorted waveforms are non sinusoidal signals, such as pulse wave, triangular wave, rectangular wave, trapezoidal wave and pulse wave, which contain rich high-frequency harmonic components. Due to the limitation of sampling rate and bandwidth, ordinary power meter can not accurately measure the high-frequency components, so there is a huge gap between its measured value and the real value.

2. General power measuring instruments only allow power measurement in the same range in the integration mode, which can not meet the correct measurement of the power of variable frequency household appliances.

Solution

Fig. 4 Relationship between frequency conversion home appliance signal and power meter bandwidth

As shown in Figure 4, we can see that for the power meter with low bandwidth, the high-frequency components in the signal are filtered by the analog front-end circuit, resulting in energy loss. The 300kHz bandwidth of Zhiyuan electronic power meter fully meets the power consumption measurement of frequency conversion household appliances and other new technology products.

Fig. 5 Comparison between automatic range switching and fixed range mode

Pa300 series digital power meter adopts a brand-new design architecture, carries out many optimizations in low power consumption measurement, has higher power factor accuracy, and is very suitable for standby power consumption measurement. Moreover, the harmonic analysis function of up to 50 times can analyze the waveform quality more accurately. As shown in Figure 5, this series of power meters can automatically switch the range in the integration mode, which provides a guarantee for the accurate measurement of the power of variable frequency household appliances.

summary

Pa300 series digital power meter has the highest sampling rate of 500Ks / s and 300kHz bandwidth. It can automatically switch the range under the integration mode adopted by frequency conversion appliances, and supports the characteristics of wide current input. It provides a reliable power measurement solution for the test of working power consumption.