Скачать презентацию Modeling a power converter using PSpice Emmanuele Ravaioli Скачать презентацию Modeling a power converter using PSpice Emmanuele Ravaioli

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Modeling a power converter using PSpice Emmanuele Ravaioli LHC-CM 16 -03 -2011 Modeling a power converter using PSpice Emmanuele Ravaioli LHC-CM 16 -03 -2011

Modeling a power converter using PSpice • Sources of information about the power converter Modeling a power converter using PSpice • Sources of information about the power converter • • Simple power converter (RPHH in RQ 4) Power converter with filter (RPTE in RB) Modular power converter (RPHE in RQD/RQF) Voltage-controlled power converter (RPLB in RCBY) • PSpice tips & tricks about power converters Emmanuele Ravaioli LHC-CM 16 -03 -2011 2

Sources of information about the power converter • General presentation about the PCs installed Sources of information about the power converter • General presentation about the PCs installed in the circuits, useful documents, simplified schematic of the circuits http: //te-epc-lpc. web. cern. ch/te-epc-lpc/general. stm • Numeric information about the PC parameters in the LHC equipment catalogue (nominal values) and in the LHC layout database (as-built values) (range of V and I, R_crowbar, modules) http: //layout. web. cern. ch/layout/ (example) https: //edms. cern. ch/nav/P: LHCPM 011: V 0/I: LHCABS 001460: V 0 (example) • Contact the persons responsible for the PC • Yves Thurel • Hugues Thiesen • Valerie Montabonnet • …etc • Electrical drawing of the PC (further details about the components, types of diodes and thyristors, paths to ground, modules, …) • Datasheets of the installed diodes, thyristors, etc Emmanuele Ravaioli LHC-CM 16 -03 -2011 3

Simple power converter (RPHH in RQ 4) -1 Power Converter 20 x free-wheel Diodes Simple power converter (RPHH in RQ 4) -1 Power Converter 20 x free-wheel Diodes Grounding point • Power converter by-passed by 20 free-wheel diodes which allow the flow of the current after the shut-down of the PC Emmanuele Ravaioli LHC-CM 16 -03 -2011 4

Simple power converter (RPHH in RQ 4) -2 • PC modeled by a current Simple power converter (RPHH in RQ 4) -2 • PC modeled by a current source • In Pspice, use an istm component: the current is ruled by an input file which can be modified using Stimulus Editor (within the Cadence suite) or manually editing the. stl (or. ctl) file with Note. Pad (preferred). • Such a file can be found in the folder of the PSpice project. Example: \cern. chdfsServicescdsuserseravaiolRB_A 12_PROJECTworklibrb_a 12_designpsp_sim_1profilestransient . STIMULUS RAMP_2 K_0 AS PWL + TIME_SCALE_FACTOR = 1 + VALUE_SCALE_FACTOR = 1 + ( 0. 000, 0) + ( 407. 71, 0) + ( 607. 71, 2000) + ( 657. 72, 0) + ( 1 K, 0) Emmanuele Ravaioli LHC-CM 16 -03 -2011 5

Simple power converter (RPHH in RQ 4) -3 • Model of the diode 245 Simple power converter (RPHH in RQ 4) -3 • Model of the diode 245 NQ 015(R) • The PSpice parameters depend on the type of diode/thyristor, on the type of junction, on the operating temperature and on the key parameters present in the datasheet. Name Min Max Default Value IS 1. 00 E-20 0. 1 1. 00 E-14 0. 000127 • Example N RS IKF XTI EG CJO M VJ FC ISR NR BV IBV TT 0. 2 1. 00 E-06 0 -100 0. 1 1. 00 E-20 0. 1 0. 3905 0. 001 1. 00 E-20 0. 5 0. 1 1. 00 E-09 1. 00 E-16 5 1000 100 5. 51 0. 001 10 10 10 0. 1 5 1000000 10 0. 001 1 0. 001 0 3 1. 11 1. 00 E-12 0. 3333 0. 75 0. 5 1. 00 E-10 2 100 0. 0001 5. 00 E-09 2 0. 001 0 2 0. 69 6. 00 E-09 0. 48 0. 6 1. 00 E-10 2 150 0. 006 5 E-09 • Note: Not all the PSpice parameters are mandatory for a good modeling. • Useful links: • http: //www. allaboutcircuits. com/vol_3/chpt_3/14. html • http: //www. ece. uci. edu/eceware/ads_docs/ccnld 019. html Emmanuele Ravaioli LHC-CM 16 -03 -2011 6

Power converter with output filter (RPTE in RB) Power Converter + 2 Thyristors Grounding Power converter with output filter (RPTE in RB) Power Converter + 2 Thyristors Grounding point Filter Inductors 6 x Crowbars with Thyristors Filter Capacitors Power Converter + 2 Thyristors Grounding point • • • PC composed of two parallel units 6 x Crowbars to allow by-pass of the PC at the shut-down (Thyristor model needed) Filter at the output of the PC PC grounded in the positive and negative branches through capacitors Resistance and inductance of PC cables taken into account (rule of thumb for L: 1 μH 1 μ ) Emmanuele Ravaioli LHC-CM 16 -03 -2011 7

Modular power converter (RPHE in RQD/RQF) -1 • 5 // 3 // 4 = Modular power converter (RPHE in RQD/RQF) -1 • 5 // 3 // 4 = 60 PC modules in parallel (see next slide) + 5 // 3 = 15 output filters • 3 paths for the current after the shut-down • 64 Schottky diodes (90% of the current) (model needed) • 120 Schottky diodes (10% of the current) (model needed) • 3 disc diodes (no current, redundant) (model needed) Emmanuele Ravaioli LHC-CM 16 -03 -2011 8

Modular power converter (RPHE in RQD/RQF) -2 • Each PC module is modeled by Modular power converter (RPHE in RQD/RQF) -2 • Each PC module is modeled by an ABM (Analog Behavior Modeling) current source • t <= t_shut-down: I_circuit = I_input • t > t_shut-down: I_circuit = V(D 1 -D 0)/10μ The PC becomes a short-circuit Emmanuele Ravaioli LHC-CM 16 -03 -2011 9

Voltage-controlled power converter (RPLB in RCBY) Fake PC Real PC Input current (continuous curve) Voltage-controlled power converter (RPLB in RCBY) Fake PC Real PC Input current (continuous curve) Imposed voltage (updated every 80 ms) Calculated reference current (updated every 80 ms) Calculated reference voltage (updated every 80 ms) • In order to simulate the discrete behavior of the electronics controlling the voltage across the PC, a new approach is followed. The PC is simulated by a voltage-controlled voltage source, whose reference value is updated discretely (in the example, every 80 ms). • The reference values of the voltage and current of the real PC are calculated by ABM components ruled by functions similar to those used by the PC electronics. every Dt: I_ref = I_input V_ref = L_circuit * ( I_ref – I_meas ) / Dt + R_circuit * I_ref ) Emmanuele Ravaioli LHC-CM 16 -03 -2011 10

PSpice tips & tricks about power converters • Pay attention: a current source is PSpice tips & tricks about power converters • Pay attention: a current source is very powerful! • If you put a current source in your model, the current in this branch WILL be the one you set. • Example: If you set a PC input current which doesn’t go to zero before the opening of an extraction resistor, you build up a huge voltage across the PC, because the current source will force the current through the resistor! • You cannot put two current source in series: PSpice would try to force two different currents in the same branch. • If you need to put them in series anyway, you can put a fake 1 GOhm resistor in parallel to one of them. This is formally allowed, and won’t change the results. • You cannot put two capacitors in series, or a capacitor in a branch which goes directly to the ground of the circuit. • Again, you’ll need to use fake 1 GOhm resistors in parallel to the capacitors. • Use your fantasy: The same PC can be modeled by means of a current source, a voltage-controlled voltage source, a current source which becomes a short-circuit, etc… With the ABM components you can model anything you need! Emmanuele Ravaioli LHC-CM 16 -03 -2011 11