Conducted emissions are common on electrical equipment. There are voltage transients, surges and harmonic distortion on mains too. In this video I will offer 5 personal tricks that I use all the time to prevent issues with conducted EMC and immunity.
A quick note about PFC: as it provides AC rectification itself, when you add a PFC into an existing circuit, the VFD input stage will have a fixed DC input (~380V). This means that the rectifying diode bridge in VFD will simply pass the current with a slight voltage drop, without doing any rectification. In the video, I made it sound slightly abmbiguous, I think.
You can read about PFC and its improvements on harmonic distortion here:
www.ti.com/seclit/ml/slup390/...
Standards mentioned in this video:
EN61000-3-2 (Voltage Harmonics):
webstore.iec.ch/publication/2...
EN61000-3-3 (Voltage Flicker)
webstore.iec.ch/publication/6...
EN61000-3-11 (Voltage Interruptions)
webstore.iec.ch/publication/2...
EN61000-4-2 (Elecrtostatic Discharge)
webstore.iec.ch/publication/4189
EN61000-4-4 (Burst Testing)
webstore.iec.ch/publication/4222
EN61000-4-5 (Surge Testing)
webstore.iec.ch/publication/4223
EN61000-6-3 (Residential Emissions)
webstore.iec.ch/publication/2...
EN61000-6-4 (Industrial Emissions)
webstore.iec.ch/publication/2...
TIMELINE:
00:00 - Start
01:00 - 1. Differential and Common Mode Noise
01:57 - 1.1 EMI Filter
02:41 - 1.2 DM and CM Noise Filtering
03:55 - 2. Ground Loops
04:55 - 2.1 Galvanic Isolation
05:57 - 2.2 PCB Scissor Rule
07:19 - 2.3 Isolation Components
07:42 - 3. Inrush Current
08:52 - 3.1 Thermistors
10:13 - 3.2 Inrush Current Management
11:03 - 4. Voltage Surges and Transients
12:51 - 4.1 Varistors
13:39 - 4.2 Crowbar Clamping Circuit
14:16 - 4.3 Voltage Harmonics
15:17 - 4.4 Power Factor Correction
16:45 - 5. Electrostatic Discharge
18:15 - 5.1 TVS Diode Placement
18:57 - 5.2 Metalwork Connection
21:09 - Video Summary
23 июн 2024
