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EMMA Magnet Power Supplies. December 07 EE & PS Group. DC Power Converters. Electron Ring Proposed power converter Up to 42 F magnets series connected Ex-SRS FSextB (160 kW) power converter Up to 42 D magnets series connected Ex-SRS FSextA (250 kW) power converter
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EMMAMagnet Power Supplies December 07 EE & PS Group
DC Power Converters Electron Ring Proposed power converter Up to 42 F magnets series connected Ex-SRS FSextB (160 kW) power converter Up to 42 D magnets series connected Ex-SRS FSextA (250 kW) power converter Up to 8 F & D magnets (individual) Commercial 3.0/5.0 kWpower converters ?? Correctors DL linear bipolar type (as used on ERLp) Nominal 8 A @ 12 V Transfer Line 7 Quad magnets (all individual) Commercial ?kWpower converters 1 dipole magnet Commercial ?kWpower converters Diagnostic Line 15 Quad magnets (all individual) Commercial ?kWpower converters 2 dipole magnets Commercial ?kWpower converters Notes: - Power converter quantities to be confirmed Transfer and Diagnostic line magnet ratings needed
DC Power Converters • Notes: • Voltage calculations assume 42 magnets per circuit • Voltage per magnet: FQ 4.3 V, DQ 7.5 V at nominal current • Cable run from SRS Power converters (Plant Room 2) to EMMA is approx. 225 m • Existing cable route • Typical cable volt drop at 414A is for 150 mm2 – 30 V, 400 mm2 – 11.3 V
DC Power Converters Plant Room 2 EMMA SRS FSextA Power Converter (in Plant Room 2)
DC Power Converters (ERLp) Corrector Bulk DC power converters 2 x 1500 W, 20V, 76A Supplies up to 16 channels Corrector power converter Linear, bipolar, 4 channels per 3U chassis
EMMA – Individual Power Converters Results for Genesys units: • Stability ±20ppm (8 hr period) • Resolution 15ppm (Analogue interface) • Reproducibility ±30ppm (After 24hr interruption) • Accuracy ±??ppm (To be reviewed) Genesys power ratings measured for 750W & 1.5kW ranges 3.3 kW Genesys power converter matches the F magnet rating of 4.3V (8V), 364A (400A). 3.3 kW Genesys power converter just matches the D magnet rating of 7.5V (8V), 376A (400A). However to achieve the full +10% performance will require a 5 kW unit
Pulse Power Converters Extraction Septum: Pulse width 50 μs (1/2 sinewave) Ampere-Turns 21000 Inductance 0.3 μH Requires ~21kA at 800V (1 turn magnet) or 10.5kA at 1.6kV or 5.25kA at 3.2kV SRS – Septum power converters Booster Extract & SR Injection each rated 8kA at 5kV, 25 μs pulse width (1/2 sine wave)
Pulse Power Converters Kicker: Pulse width 70 ns (1/2 sinewave) Ampere-Turns 1230 Inductance 0.41 μH Requires 1.23 kA at 22.6kV This was a challenge and considerable work has been carried out by APP to develop a practical solution.
EMMA Kicker Magnet Parameters Applied Pulse Power Collaboration Design and construction of thyristor prototype units using magnetic switching and Pulse Forming Network techniques. Kicker power converter parameters are directly affected by the compact design and require: • Fast rise / fall times • Rapid changes in current • Constraints on Pre and Post Pulses
APP Prototype Test Results – Sep 07Test Circuit C3 D2 R2 2.2R MOV 440V
Candidate design for extraction kicker APP Prototype Test Results – Sep 07 50ns Magnet Current Time
APP Prototype Test Results – Oct 07Injection Kicker • Inversion circuit
Injection specification - technically the most challenging. Control of the post pulsed energy is critical. Thyristor used as HV switch but magnetic pulse compression required. Some optimisation of the post pulse current has been attempted APP Prototype Test Results – Oct 07 Amps Magnet Current 200ns <100ns + 2% of peak - 2% of peak Time
APP Prototype Test Results –Oct 07 • Injection current pulse fall time <40ns achieved • Components ordered to increase current to 1.2 kA • Further optimisation of post current pulse required • Standard design may be possible for injection and extraction by improving rise time Magnet Current 200ns <40ns Time
APP Prototype Test Results –Dec 07 • Revised circuit using step-up transformer and PFNs • New components added to increase current to 1.2 kA
APP Prototype Test Results – Dec 07 • Injection driver test circuit at APP • Dummy magnet provided by DL • Running at full current - 1200A
APP Prototype Test Results – Dec 07 • Inversion circuit operating at 25 kV 10ns Magnet Current 40ns Time
APP Prototype Test Results – Dec 07 Oscilloscope gain increased to observe post-pulse current. Red lines are +/- 1% 100ns
Kicker Power Converters Summary of Progress - Dec 07 • Injection design established and demonstrated at full current. • Alternative extraction design demonstrated at reduced current (Sep). • Prefer same basic design for both applications. • Injection design could be used for extraction if voltage pre-pulse due to mismatch in PFN charging rates is eliminated. Work continuing to achieve this. • Jitter < 2ns. • Up to 10% change in magnet inductance can be accommodated – larger change could require major redesign.
