Controller for a four-phase current-fed push-pull topology. Based on a TMDSCNCD280039C control card.
| Card pin | Function |
|---|---|
| 49, 51 | PWM1A, PWM1B |
| 53, 55 | PWM2A, PWM2B |
| 50, 52 | PWM3A, PWM3B |
| 54, 56 | PWM4A, PWM4B |
| 57, 59 | PWM5A, PWM5B |
| 61, 63 | PWM6A, PWM6B |
| 58, 60 | PWM7A, PWM7B |
| 62, 64 | PWM8A, PWM8B |
| Card pin | ADC channel | Function |
|---|---|---|
| 9 | A0 | Vin |
| 11 | A1 | Vout |
| 15 | A2 | Vclamp |
| 17 | A4 | Iout |
| Card pin | GPIO | Net | Function |
|---|---|---|---|
| 89 | GPIO-40 | SW1 | Reference decrease |
| 99 | GPIO-49 | SW2 | Reference zero |
| 101 | GPIO-51 | SW3 | Reference increase |
| 103 | GPIO-48 | SW4 | Off |
| 105 | GPIO-50 | SW5 | Reset |
| 107 | GPIO-52 | SW6 | On |
| Card pin | GPIO | LED indication |
|---|---|---|
| 72 | GPIO-22 | Overvoltage: Vclamp |
| 74 | GPIO-23 | Overvoltage: Vout |
| 76 | GPIO-28 | Overvoltage: Vin |
| 78 | GPIO-29 | Overcurrent |
| 80 | GPIO-30 | PI regulator OK: Io |
| 82 | GPIO-31 | PI regulator OK: Vclamp |
All hardware ADC channels are bandwidth limited. The exact frequency needs to be investigated.
Sampling instance needs to be investigated. Four channels need to be sampled: Vin, Vout, Vclamp and Iout.
Voltage inputs are isolated with an ACPL-C87B isolation amplifier. Nominal voltage for this amplifier is 2V. Voltage dividers are tuned for nominal voltage magnitudes. Maximum input voltage for the amplifier is 2.46.
Voltage divider with an isolation amplifier. R1 = 6×665k. R2 = 10k. Attenuation = 400. 800V ➞ 2.0V. 984V ➞ 2.46V (max).
Voltage divider with an isolation amplifier. R1 = 6×665k. R2 = 10k. Attenuation = 400. 200V ➞ 0.5V. 920V ➞ 2.3V. 984V ➞ 2.46V (max).
Current sensor with an isolation amplifier. R1 = 9×665k + 2×10k. R2 = 10k. Attenuation = 601.5. 1200V ➞ 1.995V. 1480V ➞ 2.46V (max).
LES XX-NP current transducer. 0A = 2.5V±0.625·I/Inom. There is a voltage divider on the output of the current transducer. R1 = 3.3k, R2 = 6.8k. Attenuation = 0.6733. ADC should see 1.68±0.4208·I/Inom volts.
Undervoltage and overvoltage setpoints still need to be confirmed in simulations. Output current limits need to be verified experimentally. Ideally there should also be a protection if the controllers are not steady-state within some time period.
Nominal voltage Uin = 800V.
Overvoltage protection set at 105%·Uin = 840V.
Undervoltage protection set at 90%·Uin = 720V.
Nominal voltage range Uout = 200-920V.
Overvoltage protection set at Uin−10V = 190V.
Undervoltage protection set at Uout+10V = 930V.
Nominal volatge Uclamp = Uin·n2/n1 = 1200V.
Overvoltage protection set at 105%·Uin = 1260V. This needs to be tested and controller needs to be tuned not to have an overshoot.
TBD, depends on the hardware limits.