1. Overview of the implementation of certification
The major event plaguing many power supply factories in the first half of 2023 is the promulgation and implementation of new 3C certification standards. The certification EMC standard GB/T 17743-2021 has just been implemented on July 1, 2022 (requiring that the conversion work should be completed before July 1, 2023); however, the harmonic standard update GB/T was released on December 29, 2022 17625.1-2022 (hereinafter referred to as the "new version of the standard"), both national standards require certificate renewal at the same time.
Compared with GB/T 17743-2021, the new version of the standard GB/T 17625.1-2022 was released later. Although the mandatory implementation date is still some time away, if the product needs to update its certificate, the author recommends that the new version of the standard be directly used for certification. This can not only reduce the cost of repeated certification caused by multiple updates (products require double the manpower and material resources to be invested in the repeated certification process), but more importantly, it can save the time of multiple certifications and seize the first advantage of product release.
Based on the above factors, I would like to share 2 parts of the content:
1. Focus on sharing the updated content of harmonic standards to facilitate partners’ evaluation and selection during design;
2. Advantages of Reasunos Semiconductor LLC solution under the new version of standards;
2. Changes in harmonic requirements of the new version of the standard
The harmonic standards have been updated in five points. The main changes are as follows:
1. Update the emission limits for lighting equipment with rated power ≤25W to cover new lighting equipment;
2. A threshold of 5W is added to lighting equipment, and lighting equipment above 5W needs to be tested for harmonics;
3. Only in emergency mode, illuminated emergency lamps are not lighting equipment;
4. Independent phase control dimmers, stage lighting and studio professional lighting fixtures are classified as Class A;
5. If the effective input power of the lighting equipment control module is ≤2W, the harmonic test of the lighting equipment does not meet the limits in standards 7.4.2 and 7.4.3. Therefore, the impact of the control module on the harmonic current does not need to be considered and must be The control module is tested separately from the rest of the functionality.
As a first step, each power control level is tested for a few seconds. If it is continuous power level control, it should be divided into 10 equal intervals and record at which power level the measured total harmonic current (THD) is high.
In the second step, the final test is done using the power level that produces the maximum total harmonic current (THD).
3. Changes in lighting equipment test limits
Test limits for lighting equipment with effective input power >25W:
For other lighting equipment with a rated power >25W, the harmonics of the input current should not exceed the relative limits given in Table 1. For those types that include means of control (for incandescent lamps with a rated power greater than 25 W and luminaires with built-in phase control dimming, the harmonics of the input current should not exceed e.g. dimming, color). The harmonics of the input current should not exceed the harmonic current values derived from the percentage limits for the maximum active input power (Pmax) conditions given in Table 1 when tested under the following two conditions:
If Pmax≤50w, Pmin=5w
If 50w<Pmax≤250w, Pmin=10%×Pmax
If Pmax>250w, Pmin=25w (5w≥ P ≤25w)
■Lighting products with 5W ≤ rated power ≤ 25W should meet one of the following three requirements
■Requirement 1: The harmonic current does not exceed the power-related limit in the second column of Table 3 (5w≥ P ≤25w)
■Expressed as a percentage of the fundamental current, the 3rd harmonic current shall not exceed 86%, and the 5th harmonic current shall not exceed 61%
■The input current waveform should meet the following requirements: reach 5% of the peak current (threshold current) at or before 60° relative to the zero-crossing point of the fundamental voltage.
■ Peaks at or before 65°
■Current threshold not less than 5% before 90°
■The phase angle test is also measured within the period containing the absolute value peak
■The current threshold is equal to 5% of the maximum absolute value of the peak current appearing in the measurement window, the measurement window is 2.5 minutes
■Total harmonic current distortion (THD) does not exceed 70%
■The second harmonic current shall not exceed 5% of the fundamental current
■The third harmonic current shall not exceed 35% of the fundamental current
■The 5th harmonic current shall not exceed 25% of the fundamental current
■The 7th harmonic current shall not exceed 30% of the fundamental current
■The 9th harmonic current shall not exceed 20% of the fundamental current
■The 11th harmonic current shall not exceed 20% of the fundamental current
4. Reasunos Semiconductor LLC’s solution assists in the certification of new harmonic standards
Rayson Semiconductor's independently innovative constant current CSCP-LLC architecture cleverly uses LLC signals to form a power factor correction loop, eliminating the need for APFC-specific chips and corresponding power devices, effectively reducing the number of components by 20-30%, making the circuit simple and reliable, and improving the product The production throughput rate is improved, and the product volume is reduced at the same time, and it can be applied to more small-volume products.
1. For products that require an input AC single voltage and a power range of 5W-24W/25W-400W, they need to meet the new standard of low THD and make full use of the simple circuit features of Reasunos Semiconductor's overall solution, that is, it can achieve THD standards. It can also achieve a small volume of space, and is an ideal and priority solution for the implementation of new standard solutions;
2. For products with input AC full voltage and power range of 5W-24W/25W-400W, Reasunos Semiconductor LLC solution front-end cooperates with APFC solution to achieve excellent THD effect; in the AC100-240V/50-60HZ range Achieving less than 5% of the industry's top standards within 10 days; helping you easily achieve the smooth implementation of new standard certification.
5. Introduction to Reasunos Semiconductor LLC’s constant current solution
Continuous mass production of LLC constant current solution product series
Typical application schematic diagram
Introduction and product features of Reasunos Semiconductor LLC’s constant current resonance solution
■Adopts a patented technology of charge pump and LLC cascade to solve the complexity of APFC circuit;
■Achieved high PF value>0.96, low THD<5%, high efficiency>94%, and no flicker;
■Achieved the purpose of improving product reliability.
In compliance with the new national standard policy, the Reasunos Semiconductor LLC solution is the first choice. The Reasunos Semiconductor CSCP-LLC solution perfectly achieves high PF (>0.96), low THD (<5%), high efficiency (>94%), no flicker and large Pentathlon solutions covering small and medium-sized full power segments will also continue to innovate towards energy-saving and healthy lighting concepts to help customers achieve product upgrades and enhance product competitiveness!