UI Parameters (FRM)
This section contains all of the parameters and keys that PyFresco uses to measure the frequency response of a power converter system. These parameters are UI inputs that should be stored as class attributes.
FRM Keys
The PRBS and Sine-fit methods both require three main parameters that the user must select: Regulation Mode, Input, and Output. The details of these parameters are outline below. Note that the Sine-fit algorithm does not require other input parameters to obtain a frequency response.
Regulation Mode:
- keyword
reg_modeDesired mode to be in when performing the measurement experiments.
V: Control system is in open-loop mode. (in the FGC, this is set with REG.MODE V)
I: RST for the current-loop is enabled (in the FGC, this is set with REG.MODE I)
B: RST for the field-loop is enabled (in the FGC, this is set with REG.MODE B)- Type
str- Default
V- Recommended
If the purpose of the measurement is to synthesize an RST and ILC controller, use
V. For synthesizing controllers for the voltage loop, useV.IorBare generally used for analysis purposes (i.e., confirming the closed-loop behavior).- Feasible values
[
I,B,V]
Input:
- keyword
ref_modeThe input signal name of the measurement (i.e., signal name from FGC log).
- Type
str- Default
V_REF- Recommended
Not applicable.
- Feasible values
If Regulation Mode is
V: [V_REF,F_REF_LIMITED,V_MEAS]If Regulation Mode is
I: [I_REF_ADV]If Regulation Mode is
B: [B_REF_ADV]
Output:
- keyword
meas_modeThe output signal name of the measurement (i.e., signal name from FGC log).
- Type
str- Default
I_MEAS- Recommended
Not applicable.
- Feasible values
If Regulation Mode is
V: [V_MEAS,I_CAPA,V_MEAS_REG,I_MEAS,B_MEAS]If Regulation Mode is
I: [I_MEAS_REG]If Regulation Mode is
B: [B_MEAS_REG]
Sine-Fit Keys
Frequency Array:
- keyword
num_freqNumber of frequencies points to measure within the user defined frequencies \([f_{min},f_{max}]\).
- Type
int- Default
\(200\)
- Recommended
For controller synthesis purposes, values between 150 and 300 should suffice.
- Feasible values
\([2, 10^4]\)
PRBS Keys
Period Iters:
- keyword
period_itersThe number of samples in the shortest PRBS step. the highest frequency point in the Bode plot will be \(F_s / (2 \times\)
period_iters\()\)If Regulation Mode is
V, \(F_s = (\text{FGC.ITER_PERIOD})^{-1}\).If Regulation Mode is
I/B, \(F_s\) is given in (8).- Type
int- Default
1
- Recommended
1
- Feasible values
\([1, 10]\)
Peak-to-Peak Amplitude:
- keyword
amplitude_ppThe peak-to-peak amplitude of the PRBS step.
- Type
float- Default
1
- Recommended
Application dependent. The user should abide by the limits set within the FGC: LIMITS.V.POS / LIMITS.V.NEG , LIMITS.I.POS / LIMITS.I.NEG , LIMITS.B.POS / LIMITS.B.NEG .
- Feasible values
\((0, 10^6]\)
Num. of Sequences:
- keyword
num_sequencesThe number of PRBS periods. One PRBS period has a length of \(2^{\text{k_order}} - 1\).
- Type
int- Default
15
- Recommended
Application dependent. The value should be selected such that the drift is elimiated several periods before the end of the PRBS sequence. In general, any value between 10 and 20 should suffice.
- Feasible values
\([6, 50]\)
K order:
- keyword
k_orderIndicates the size of a unique word of data in the a PRBS sequence.
- Type
int- Default
12
- Recommended
Application dependent. The larger the value, the better the resolution at lower frequencies. However, a larger value will require more PRBS samples (and thus more memory).
- Feasible values
\([8, 20]\)