**First, the Relationship Between Home Energy Efficiency Labels and Standby Power Consumption Testing**
Undeniably, various household appliances have greatly enhanced our daily lives. In recent years, when purchasing home appliances, people have increasingly focused on their energy consumption. Among the numerous energy efficiency labels, how can we select more energy-efficient and eco-friendly products?
Which appliances come with Chinese energy efficiency labels? As early as 2005, relevant departments began researching and promoting energy efficiency labeling. This means the earliest China energy efficiency label was implemented on March 1, 2005. Initially, the products covered were only refrigerators and air conditioners. Over time, products such as washing machines, electric water heaters, induction cookers, rice cookers, tablets, and microwave ovens were added. However, the energy efficiency labels of certain products, like refrigerators, have undergone several revisions, with increasing demands placed on energy efficiency levels, leading to the current energy efficiency label format we see today. Some products have energy efficiency ratings of level 3, while others are rated at level 5. What do these numbers signify, and how should consumers choose?
1. What is an energy efficiency label, and how can we choose the right appliance based on it?
An energy efficiency label is an attachment to energy-consuming products, indicating the energy efficiency rating performance index of the product, as shown in Figure 3.1. Its purpose is to provide users and consumers with essential information to aid in purchase decisions. It helps guide and assist consumers in selecting energy-efficient and environmentally friendly products.
Figure 3.1 China Energy Efficiency Label
From Figure 3.1, it's clear that China’s energy efficiency label is divided into five levels. How are these levels differentiated?
· Level 1 indicates the product has reached an internationally advanced level, being the most energy-efficient, i.e., having the lowest energy consumption, with an energy efficiency ratio of 3.40 or more;
· Level 2 indicates comparative energy savings, with an energy efficiency ratio of 3.20~3.39;
· Level 3 represents the average energy efficiency level of the Chinese market, with an energy efficiency ratio of 3.00~3.19;
· Level 4 signifies lower energy efficiency than the market average, with an energy efficiency ratio of 2.80~2.99;
· Level 5 is the market access indicator, meaning products below this level are not permitted for production or sale, with an energy efficiency ratio of 2.50~2.79.
The energy efficiency ratio primarily refers to the ratio of the actual cooling capacity to the actual input power when an air conditioner performs cooling operations under rated working conditions and specified conditions. Specifically, this includes the cooling energy efficiency ratio EER and the heating energy efficiency ratio COP.
Cooling Capacity: The actual cooling capacity of the air conditioner.
Input Power: The actual input power (power consumption) of the air conditioner.
Cooling Capacity = C × M × ΔT = 4.2 × 10³ J/kg°C × M × (Tback - Tsupply)
M = Q × h = D × 1h = 1000Ckg
ΔT = (Tback - Tsupply) = (BA)°C
This value reflects the energy savings of different air conditioner products. The higher the energy efficiency ratio value, the less power consumed per unit time, as shown in Figure 3.2.
Figure 3.2 Description of Energy Efficiency Levels
In the process of calculating the energy efficiency ratio, testing the actual input power of the air conditioner is particularly crucial. Currently, many manufacturers prefer to use power meters from the home appliance industry to test basic functions such as voltage, current, power, and energy consumption. These power meters can also conduct preliminary analysis and detection of input terminal voltage and current.
Among the testing and certification organizations for home appliances, high-precision power meters have become an indispensable tool. ZLG Zhiyuan Electronics' PA310 power meter achieves a basic power accuracy of 0.1%. The three-channel capability allows testing of three-phase AC, with a maximum sampling rate of 500KS/s, a bandwidth of 300KHz, standard synchronous harmonic measurement (up to 50 times) for Total Harmonic Distortion (THD), and compliance with the IEC61000-4-7 harmonic measurement standard. This solves the current inaccurate testing caused by harmonics in the inverter household appliance industry. Additionally, its own test functions for power consumption and harmonics, along with a fast data update cycle of up to 100ms, are perfect for the power testing of current home appliance inputs.
**Second, Testing Programs for Inverter Air Conditioners and Other Variable Frequency Appliances**
More and more home appliances are adopting frequency conversion technology. What are the challenges in testing inverter home appliances?
Global warming has become a topic of increasing concern, not only sparking public interest but also prompting the industry to take action toward energy conservation and the use of alternative energy sources. Measures such as the Energy Conservation Law and Energy Star have imposed requirements on the operating modes of home appliances.
Let us take air conditioners as an example to share with you the difficulties in testing inverter home appliances.
As more home appliances adopt frequency conversion technology, they not only save energy but also distort the waveform signals of the products. Furthermore, due to the application of frequency conversion technology, the operational state of home appliances frequently changes, causing significant fluctuations in working current, ranging from tens of amps to just a few milliamps. So, what kind of instrument can meet the testing and measurement requirements for inverter home appliances like air conditioners?
1. Testing Difficulties
Frequency conversion appliances save energy by distorting the waveform signals of the product. These distorted waveforms are non-sinusoidal signals, including pulse waves, triangular waves, rectangular waves, trapezoidal waves, and pulse waves, rich in high-frequency harmonic components. Ordinary power meters cannot accurately measure high-frequency components due to limitations in sampling rate and bandwidth, resulting in a significant discrepancy between their measured values and real values.
General power measuring instruments only allow power measurement within the same range in integration mode and cannot correctly measure the power of inverter home appliances.
Figure 3.3 Example of Distorted Waveforms
2. Solution
How should we address these measurement challenges? Zhiyuan Electronics’ PA300 series power meter has the following features:
· Sampling rate of up to 500KS/s, bandwidth of 300KHz;
· Standard simultaneous measurement of harmonics (up to 50 times) and total harmonic distortion (THD) according to IEC61000-4-7 harmonic measurement standards;
· Automatic range switching in integration mode, supporting a wide current range: 50μA~20A range measurement;
· Power measurement accuracy up to 0.1%;
· Rich communication interfaces, including USB Host, USB Device, GPIB, RS-232, and Ethernet.
500KS/s Sampling Rate: According to Nyquist’s sampling law, the sampling rate of the instrument should be higher than twice the highest frequency of the input signal. The Zhiyuan electronic power meter has a sampling rate of 500KS/s and can measure the rich harmonics in distorted waveforms.
300KHz Bandwidth: A low-bandwidth power meter filters out high-frequency components in the signal via analog front-end circuits, causing energy loss. The bandwidth of Zhiyuan Electronic Power Meter at 300KHz fully meets the power consumption measurement of new technology products like inverter home appliances.
How do you measure reproducible harmonic measurements for voltage and current fluctuations in the grid? According to the strict regulations of IEC61000-4-7, the spectrum analysis time window for harmonic measurement is 10 cycles, so the measuring instrument must be able to prevent the frequency aliasing phenomenon occurring during harmonic analysis. At the same time, the sampling frequency needs to synchronously track the fundamental frequency of the input signal and eliminate the phenomenon of spectrum leakage at its root. The PA300 series power meter uses pure hardware analog filtering and phase-locked loop technology to avoid frequency aliasing and spectrum leakage, ensuring the reproducibility of harmonic measurements.
Figure 3.4 Reproducible Harmonic Measurements
The PA300 series power meter features a new design architecture, multiple optimizations for low-power measurement, and higher power factor accuracy, making it ideal for standby power measurement. And up to 50 harmonic analysis functions provide more accurate waveform quality analysis. At the same time, the series of power meters can automatically switch the range function in the integration mode to ensure the accurate measurement of the frequency conversion appliance power.
Figure 3.5 PA300 Series Power Meter Features
The PA300 series power meter has a sampling rate of up to 500KS/s and a bandwidth of 300KHz. It can automatically switch the range function for the integral mode adopted by inverter home appliances and supports the input of wide current to provide a reliable power measurement solution for testing the working power consumption.
**3. Measurement Solutions for Large Current Devices Such as Induction Cookers**
As market demand has grown, IH (Induction Heating) induction cookers have gradually replaced gas cookers due to their safer performance. IH induction cookers use large currents to generate powerful thermal energy and convert it into heat. What are the requirements for measuring instruments in such high-current devices?
“Electrification†has seamlessly integrated into our lives, from kitchen appliances to water heaters and other household equipment, all driven by electricity. As market demand has grown, IH (Induction Heating) induction cookers have gradually replaced gas cookers because of their safer performance. IH induction cookers use large currents to generate powerful thermal energy and convert it into heat.
What are the requirements for measuring instruments in such high-current devices?
1. Test Requirements
A. Does it support the function of direct input of a wide current range?
B. Is the accuracy of the measurement items reliable? Can I monitor and record data for all test items to understand the working status of the equipment?
With the gradual improvement of household equipment, the development of measuring instruments is also closely followed. The design of Guangzhou Zhiyuan Electronics’ PA310 power meter fully considers the trends in modern household appliances, providing a suitable solution for high-current equipment like IH induction cookers.
2. The Solution
The large current flowing through the IH induction cooker can be directly input into the PA310, allowing voltage, current, power, harmonic distortion (THD), and other parameters to be measured without a current sensor or other device.
· Direct Input of Large Current: 20Arms;
· Power meters designed with single shunts tend to have low accuracy and very large temperature drift. The PA310 power meter uses dual shunt technology. The current can be directly input from 5mA-20A. It can be directly connected to the IH induction cooker and power meter without a current sensor.
· High-Precision Power Consumption Measurement: 0.1%;
· The power meter's power measurement accuracy can reach 0.1%. Due to the application of dual shunt technology, the steady-state temperature change of the shunt resistor can be maintained, reducing temperature drift, ensuring 0.1% power measurement precision from small current to large current measurements.
Up to four measurement items can be displayed simultaneously, and simultaneous measurement of harmonics (up to 50 times) and total harmonic distortion is supported. Additionally, there is a special PAM PC analysis software as standard, monitoring and recording the data of all test items.
The unique design of the PA310 power meter not only enables direct measurement of high current devices but also guarantees a basic accuracy of up to 0.1% for high current measurements.
Wuxi Ark Technology Electronic Co.,Ltd. , https://www.arkledcn.com