Abstract

A power adapter commonly introduces power factor correction at higher power to improve grid utilization. The power adapter raises power factor above 0.95 through active or passive PFC. This power adapter covers power factor, harmonic current and PFC topology parameters, helping high-power products meet EN61000-3-2 harmonic rules and export smoothly.

1. Power Factor and Harmonic Background

Without PFC, a power adapter has power factor about 0.6-0.7 with high harmonic current. With PFC, the power adapter greatly improves power factor and lowers harmonics. Power factor of the power adapter directly affects grid utilization and metering.

2. Passive PFC Parameters

The power adapter often uses valley-fill passive PFC at low and medium power for simple, low-cost circuits. Passive PFC of the power adapter raises power factor to about 0.9. Harmonic improvement of the power adapter passive solution is limited, fitting less demanding applications.

3. Active PFC Parameters

At higher power, the power adapter uses active PFC reaching power factor 0.99. Active PFC of the power adapter adopts Boost circuit to actively shape input current. Harmonic suppression of active solution is thorough and meets strictest rules.

4. PFC and Main Circuit Coordination

Active PFC of the power adapter must coordinate with the main switching supply to avoid interference. PFC stage of the power adapter outputs stable bus voltage for the following stage. Matching PFC switching frequency of the power adapter improves EMC.

5. Value of Harmonic Compliance

Meeting harmonic standards is essential for high-power power adapter in EU and US markets. Non-compliant power adapter may be banned or require rectification. Good PFC design lowers certification cost.

Conclusion

PFC design of the power adapter decides power factor and harmonic compliance. For a high-power power adapter with PFC, contact Simsukian for harmonic test reports and samples.

Authoritative References

1. IEC 62368-1 Audio/video, information and communication technology equipment safety standard

2. DOE Level VI External Power Supply Standard (US)

3. IEC 63002 Interoperability specifications for external power supplies