LBDS RTS transformers matching MKD RTB validation in

LBDS RTS transformers matching, MKD RTB validation in JU 3 Janusz Rodziewicz

Outline • MKD RTB prototype integration and validation Introduction • Transformer model development and validation • Simulation prediction for the diagnostic pulse propagation • Conclusions •

MKD RTB JU 3 integration 10/6/2020 - Blue cable length OK CA 50 pickups cables OK Line cable VH 4 screwing OK - Measurement link with the PTC in validation 3

JU 3 RTL Signal 7. 5 Te. V all pickups • • At the measurements a noise can observed at around 6µs (freewheel commutation) Old VRD (clamping level ~27 V)

Diagnostic with the RTD 120 us pulse RTD 120 us (delay in discussion) In case of the MKB erratic RTD 120 us has to retrig the MKDs (as fast as possible to avoid no dilution conditions) In addition, the pulse issued by the RTD 120 us has to propagate down to the IPOC at both ends of the LBDS for the diagnostic purpose • The amplitude of the diagnostic pulse received by IPOC shall be higher than 6 V The topology of the RTB assumes output, pulse transformers linking RTBs outputs and PTMs inputs. Practical pulse transformers are constrained in their performance by the magnetic flux limitations. When the LBDS is operating at high energy pulses are delivered to the RTL from multiple generators and theirs pickups. Saturated or semi-saturated transformer will load the line with its ‘low’ impedance and prevent the ‘RTD 120 us’ pulse to reach IPOC Simulation models of the RTL transformers are required in order to perform a valid simulation of the earliest (after the main pulse at the RTL) diagnostic pulse propagation 10/6/2020 Document reference 5

Transformers simulation models Processing B(t) ∝ int(EMF) H(t) ∝ Iwinding Hysteresis measurement C 1 – Vwinding C 2 – Iwinding Math – int (Vwinding) Validation of the model through comparison with test results of basic characteristics: • saturation • desaturation • impedance New core part with the hysteresis curve as per measurement Default, Pspice automatic fit based on Jiles-Atheron model 10/6/2020 6

One MKD RTB simulation The voltage time product value is around 200 u. Vs as obtained in the test For comparison with JU 3 measurement see here 10/6/2020 Document reference 7

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Output transformer impedance after 120 us Nominal flux pulse (as per high energy operation) Two-transformer configuration screen capture, two-pulses sequence: 1 st pulse – nominal flux, 2 nd pulse 100 us after. Math zoom at second pulse. C 1 – V 10(T 1)-9(T 2) ; C 2 – I(N 3 T 1&T 2) 10/6/2020 Document reference 10

Model of the MKD section of the RTL Equivalent model of one semi-saturated output transformers, 120 u. Vs after the nominal pulse 750Ω // 200Ω = 157Ω So far, line is lossless in the simulation. Simulation predicts ~13 V with one transformer at the other end of the lossless line. ~25 V with two transformers Cable datasheet gives -1 d. B/100 m 10/6/2020 Document reference 11

Conclusions • • • MKD RTB prototype integrated in JU 3, measurement link between the RTB and PTC in validation, pickups validated Simulation models of the RTL transformers are developed and validated; In order to improve the line impedance right after ‘high energy’ pulses a double-transformer output is proposed TD output has to be unidirectional (series diode to be put) TD output clamping diode has to be removed in order to deliver pulses of higher amplitude 10/6/2020 Document reference 14