3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012

1. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 • The sound of power supplies • Elimimate Supply voltage influence: Prefilter design • Self-learning Regulation Digital Regulation by Emulating Analogue Controllers: Implementation Niels Heidbrook DESY

2. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 AC load ISCR ~ constant filter U1 Iload L SCR bridge 12 pulse Power supply USCR f0=600Hz U2 C U3

3. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 AC load (Iload Delta-Sigma ADC delay = 1ms) Iload L Power supply U=4Vpp f0=600Hz ~ C delay

4. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 AC load filter Iload L U=4Vpp f0=600Hz reaction ~ ~ C delay

5. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 AC load filter Iload L U=4Vpp f0=600Hz U=4Vpp f0=600Hz pre-action ~ ~ C action pre-delay

6. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 AC load 600Hz @ 4Vpp => High internal filter current Iload Power supply = Frequency generator U=4Vpp f0=600Hz U=4Vpp f0=600Hz ~ ~

7. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Usupply Iload Regulator Duty cycle D0 Power supply Uload=D*Usupply D0 D Uload Iload change Frequency generator (Ram Curve) Iload = constant? Only hardware: 50Hz Mains trigger

8. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Iload Ram curve Uout f0=600Hz Power supply = Frequency generator USCR f0=600Hz delay Iload ~ ~ ~ Average Iload Uout Only hardware: 50Hz Mains trigger Ram curve t pre-delay

9. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Iload Ram curve Uout f0=600Hz Power supply = Frequency generator USCR f0=600Hz delay Iload ~ ~ ~ Average Iload Uout Only hardware: 50Hz Mains trigger Ram curve t pre-delay

10. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Iload Ram curve Uout f0=600Hz Power supply = Frequency generator USCR f0=600Hz delay Instability at wrong learning delay Iload ~ ~ ~ Average Iload Uout Only hardware: Too long Too short 50Hz Mains trigger Ram curve t pre-delay Linear approximation between the points

11. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Instability at wrong learning delay Solution 1: Take less resolution of the Ram curve Iload Average Iload Uout Only hardware: 50Hz Mains trigger Ram curve t pre-delay Inaccurate at high frequencies Linear approximation between the points

12. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Instability at wrong learning delay Solution 2: Mix in 1st derivation of Ram curve Iload is not constant Iload + K*d/dt(Ram curve)= constant Average Iload Uout Mix in 1st derivation of Ram curve Only hardware: Too long Too short 50Hz Mains trigger Ram curve t pre-delay

13. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Self-learning Regulation Test circuit Rectifier Iload Disturbance Power supply = Load Mains ~

14. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Elimimate Supply voltage influence: Prefilter design Usupply Regulator Duty cycle D Power supply Uload=D*Usupply D Uload

15. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Elimimate Supply voltage influence: Prefilter design Usupply Regulator Duty cycle D Prefilter D1=D/Usupply Power supply Uload=D1*Usupply D D1 Uload Prefilter Uload=D1*Usupply Uload=(D/Usupply)*Usupply Uload=D

16. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 The sound of power supplies

17. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 The sound of power supplies 1. Unique WAV file Header Size (don’t care) ‘RIFF’ Always: LSB is first ‘WAVE’ ‘fmt ’

18. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 The sound of power supplies 1. Unique WAV file Header Number of interleaved channels=1 Sampling Rate 22050Bit/s Data Rate 44100Bit/s Always: LSB is first Chunk size (don’t care) Format code Hex:2078 Dez:8312 (complement on two) =>invert MSB bit Dez:8312=> ADC value was 41080 Speaker position mask (don’t care) Size of extension (don’t care) Data block size (don’t care) Number of valid bits (don’t care) Bits per sample=16 First 16 bit data value

19. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 The sound of power supplies 2. Append test data (Saw tooth signal) 1. Take the Header 2. Append ADC data in 2’s complement. (inverted MSB bit) Append LSB first. LSB byte is always the same (example) MSB byte counts downwards

20. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 The sound of power supplies 3. Wave analysis Audacity (freeware) Mono, 22050 bit/s The data has to be long enough to be played in Winamp.

21. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 The sound of power supplies 4. Frequency analysis Audacity (freeware) 1351Hz

22. 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Java applet for continuous wave analysis

23. Conclusion 3rd Workshop on Power Converters for Particle Accelerators (POCPA)2012 Digital regulation is needless Have fun listening to your power supplies 