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

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 AC load Power supply I load filter C L SCR bridge 12 pulse U SCR f 0 =600Hz I SCR ~ constant U1U1 U2U2 U3U3

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 Power supply I load C L delay U=4V pp f 0 =600Hz ~ (I load Delta-Sigma ADC delay = 1ms) AC load

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 filter C L U=4V pp f 0 =600Hz delay ~ reaction ~ I load AC load

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 I load filter C L U=4V pp f 0 =600Hz pre-delay ~ pre-action ~ U=4V pp f 0 =600Hz action AC load

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 I load U=4V pp f 0 =600Hz ~~ U=4V pp f 0 =600Hz Power supply = Frequency generator 4V pp => High internal filter current AC load

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 Self-learning Regulation Power supply Uload=D*Usupply D Uload Regulator Duty cycle D 0 Usupply Frequency generator (Ram Curve) 50Hz Mains trigger Only hardware: I load I load = constant? change D0D0

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 Self-learning Regulation I load U SCR f 0 =600Hz ~~ U out f 0 =600Hz Power supply = Frequency generator t U out ~ Ram curve delay Ram curve Average I load I load pre-delay 50Hz Mains trigger Only hardware:

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 Self-learning Regulation I load U SCR f 0 =600Hz ~~ U out f 0 =600Hz Power supply = Frequency generator t U out ~ Ram curve delay Ram curve Average I load I load pre-delay 50Hz Mains trigger Only hardware:

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 Self-learning Regulation I load U SCR f 0 =600Hz ~~ U out f 0 =600Hz Power supply = Frequency generator t U out ~ Ram curve delay Ram curve Average I load I load pre-delay 50Hz Mains trigger Only hardware: Instability at wrong learning delay Too long Too short Linear approximation between the points

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

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

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

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

3rd Workshop on Power Converters for Particle Accelerators (POCPA) 2012 Elimimate Supply voltage influence: Prefilter design Power supply Uload=D 1 *Usupply D Prefilter D 1 =D/Usupply Uload Regulator Duty cycle D D1D1 Usupply Prefilter Uload=D 1 *Usupply Uload=(D/Usupply)*Usupply Uload=D

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

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

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

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

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

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

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

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