NSLS II Accelerator System Advisory Committee Meeting October 10 – 11 2006

1. NSLS IIAccelerator System Advisory Committee MeetingOctober 10 – 11 2006 NSLS II Storage Ring Magnet Power Supplies George Ganetis NSLS II Accelerator System Advisory Meeting SR-PS

2. NSLS II Storage Ring - Magnet Power Supplies • List of power supplies • General power supply features • Main dipole power supply • Quadrupole & sextupole power supplies • Corrector power supplies • Interlocks, safety, cabling, & racks • Summary NSLS II Accelerator System Advisory Meeting SR-PS

3. NSLS II Storage Ring - Magnet Power Supplies Power Supply List • B1-PS – a single series circuit of 60 dipole magnets. • 1251Quad.3-PS1 to 330 – 330 quadrupole magnet circuits • Quad.4-PS1 to 30 – 30 single quadrupole magnet circuits • Sext.2-PS1 to 240 – 240 single sextupole magnet circuits • Sext.25-PS1 to 120 – 120 single sextupole magnet circuits • Sext.3-PS1 to 30 – 30 single sextupole magnet circuits • B1Trim-PS1 to 60 – 60 B1 dipole trim magnet circuits (trim coils located on the B1 main dipoles) • SKQ-PS1 to 30 – 30 skew quadrupole magnets circuits • BH-PS1 to 210 – 210 intermediate speed horizontal dipole corrector magnet circuits • BV-PS1 to 180 – 180 intermediate speed vertical dipole corrector magnet circuits • FBH-PS1 to 20 – 20 fast horizontal correction dipole circuits • FBV-PS1 to 20 – 20 fast vertical correction dipole circuits • Slow power supplies – 871 • Intermediate-speed power supplies – 390 • Fast power supplies – 40 • Total number of power supplies = 1301 NSLS II Accelerator System Advisory Meeting SR-PS

4. NSLS II Storage Ring - Magnet Power Supplies General power supply features. • The main dipole, quadrupole, sextupole, trim dipole, skew quadrupole power supplies are designed to stay at a fixed current. These ps will be able to do simple software generated ramps. • Intermediate speed and fast dipole corrector power supplies will be part of beam-based feedback system. • All power supplies will designed for very high reliability. • Use of standard commercial power converters ( All ps except main dipole ) • Minimize custom designs on the power converters. • Minimize connections between ps components. • Use high performance connection between ps components. • Provide a stable and clean environment for the ps. • Design ps to allow fast and easy replacement of any failed components. • Have an R&D program on critical systems and thoroughly test prototypes. • Use instrumentation to monitor and track ps performance and the temperature of critical components in each power supply. NSLS II Accelerator System Advisory Meeting SR-PS

5. NSLS II Storage Ring - Magnet Power Supplies Main Dipole PS – General Description • Ps circuit consists of 60 dipole magnets, each 0.065 Ω and 51 mH. • Operating current is ~ 311 Amps for 3.0 GeV. • Cabling between magnets and the return bus will use 535 MCM flexible copper cable. • The power supply load is 4.044 Ω and 3.121 H. • 2-quadrant unipolar current-regulated supply. • 12-pulse SCR converters in series with the center point connected to ground. This will reduce the voltage to ground at the magnet load and reduce the voltage rating on various converter components • Each converter will have a two-stage LCRL passive filter and a series pass active filter to reduce the ripple current to low levels. • The ps will be able to run in the invert mode to ramp down the current. • Combined digital and analog control system • Precision current regulator using a DCCT (Direct Current Current Transformer) as the current feedback device. • A PLC will be used for state control (on/off commands and interlocks). NSLS II Accelerator System Advisory Meeting SR-PS

6. NSLS II Storage Ring - Magnet Power Supplies Main Dipole PS – Specifications • AC input power - 3-phase 460 VAC ~ 904 AAC ( Both power converters) • DC maximum output current – Imax - 375 ADC • DC output voltage - 1600 VDC • Operating quadrants - 2 - (V+, I+) & (V-, I+) • Small-signal -3-db bandwidth - 500 Hz • Stability – referred to Imax - 40 ppm • Absolute accuracy – referred to Imax - 100 ppm • Reproducibility long term – referred to Imax - 50 ppm • Current ripple – referred to Imax - 5 ppm 60 Hz and greater • Resolution of reference current - 18 bit + 1 LSB • Resolution of curr. measured - fast sampling - 16 bit + 1 LSB at 200 µsec • Resolution of curr. Measured - slow sampling - 22 bit + 1 LSB at 16.67 msec NSLS II Accelerator System Advisory Meeting SR-PS

7. NSLS II Storage Ring - Magnet Power Supplies Main Dipole PS Diagram NSLS II Accelerator System Advisory Meeting SR-PS

8. NSLS II Storage Ring - Magnet Power Supplies Quadrupole & Sextupole Power Supplies – General Description • These circuits will use one power supply for each magnet. • The magnet load parameters are close enough to use a single ps for the two quadrupole magnet types and single ps for all three sextupole types. • The 3.0 GeV operating current is ~ 108 Amps for the quadrupoles and ~ 182 Amps for the sextupoles. • Flexible copper cabling will connect the magnets and ps, 250 MCM for the quadrupoles and 350 MCM for the sextupoles. • The ps will be located above the magnets in the equipment area. • The ps is a unipolar, single-quadrant, current-regulated switch-mode design. • The power section is a commercial voltage-controlled switch-mode 3 kW power supply with high output bandwidth (~ 1 kHz). They fit in a standard 19-inch electronics rack and are only 3.5 inches high. These power supplies are air-cooled. • A precision analog regulator to control the current will be developed in-house. • The power supply will use a DCCT as the current feedback device. • To minimize current ripple, an additional output filter will be used. • An AC input module will turn the power supply on and off. • A microcontroller will be used for state control (on/off commands and interlocks). NSLS II Accelerator System Advisory Meeting SR-PS

9. NSLS II Storage Ring - Magnet Power Supplies Quad. & Sext. Power Supply Specifications • AC input power - 3-phase 208 VAC ~ 11 AAC • DC maximum output current – Imax - 150 ADC for Quad. & 250 ADC for Sext. • DC output voltage - 20 VDC for Quad. & 12 VDC for Sext. • Operating quadrants - 1 - (V+ , I+) • Small-signal - 3db bandwidth - 300 Hz • Stability (8 h-10 s) – referred to Imax - 200 ppm • Absolute accuracy – referred to Imax - 200 ppm • Reproducibility long term – referred to Imax - 100 ppm • Current ripple – referred to Imax - 15 ppm at 60 Hz and greater • Resolution of reference current - 16 bit + 1LSB • Resolution of current measured – fast sampling - 16 bit + 1 LSB at 200 µsec • Resolution of current measured – slow sampling - 22 bit + 1 LSB at 16.67 msec NSLS II Accelerator System Advisory Meeting SR-PS

10. NSLS II Storage Ring - Magnet Power Supplies Unipolar current regulated switch-mode ps NSLS II Accelerator System Advisory Meeting SR-PS

11. NSLS II Storage Ring - Magnet Power Supplies Corrector Power Supplies – General Description • This description applies to the dipole trim, skew quad, BH, BV, FBH & VBH power supplies • The ratings of the supplies are estimates because the magnets designs are not finished • These circuits will use one power supply for each magnet coil set. • The estimated 3.0 GeV operating current is ~ 2 Amps for the Dipole trim & skew quad, ~ 15 Amps for the BH &BV , and ~ 5 Amps for the FBH & VBH ps. • The cabling from the coil sets to the power supply will be # 14AWG copper for dipole trim, skew quad, FBH, & VBH - # 10 AWG copper for the BH & BV. • The ps will be located above the magnets in the equipment area. • The ps is a bipolar, 4-quadrant, current-regulated linear power supply design • The power section is a commercial bipolar supply with high output bandwidth (~ 10 kHz). They fit in a standard 19-inch electronics rack and are 5.25 inches high. These power supplies are air-cooled. • The power supply will have a precision current regulator using a shunt as the current feedback device. • A microcontroller or PLC will be used for state control (on/off commands and interlocks). NSLS II Accelerator System Advisory Meeting SR-PS

12. NSLS II Storage Ring - Magnet Power Supplies Power Supply Interlocks • All power supplies will have sufficient interlocks that will prevent the power supply from getting damaged due to changes in cooling conditions, ac power disturbances, and nonstandard operating conditions. • All magnet coils will have an over- temperatures interlock to prevent damage if there is a change in cooling and/or operating conditions. • All power supplies will have an electrical safety interlock that will prevent the power supply from turning on if the machine safety system requires it. Electrical Safety • All power supplies will conform to the latest BNL safety requirements, especially concerning arc flash protection. Whenever possible, NRTL-listed equipment will be used. Cable Tray & Cable Routing • Cable tray for the dipole magnet circuits will be located in the equipment area above the main tunnel. • The dipole cable will drop through the tunnel ceiling at each cell where it will connect to two dipole magnets. • There will also be a tray along the inside wall of the main tunnel only in the area of the cell. This tray will be located in a different area then the booster cable tray. NSLS II Accelerator System Advisory Meeting SR-PS

13. NSLS II Storage Ring - Magnet Power Supplies Cable Tray & Cable Routing • The dipole cables will be installed with a twist to prevent pickup for the booster circuits. All cables will be tray rated cables. • Power cables will be arranged to minimize pickup from other circuits. • All power cables will be separated from signal cables. • The quadrupole, sextupole, and corrector cables will be routed through conduit in the main tunnel ceiling. The power supply racks will be located above the conduits. The cable going through the conduit will run in the cable tray mounted on the inside wall until it is connected to the magnet. • All cables and trays will meet NEC & OSHA codes. Power Supply Racks • All storage ring power supplies except for the dipole will be mounted in sealed Nema 12 electronics racks. • These racks will have a maximum of six 3-kW power supplies installed in them. • These racks will also have power supply controls, and instrumentation installed in them. • At each cell location there are ten racks. • The racks will be located above the magnets they supply power to. • A water to air heat exchanger will cool a set of two or three racks. Cooled air will flow through the power supplies and circulate back to the heat exchanger. The heat exchanger will use chilled water and have the outlet temperature regulated. NSLS II Accelerator System Advisory Meeting SR-PS

14. NSLS II Storage Ring - Magnet Power Supplies Summary • Have identified storage ring ps requirements ( List of ps ) • Main dipole ps is well under stood. Start detail circuit modeling of ps output stage and controls. Then start prototype of ps controls for main dipole. • Quadrupole & Sextupole ps requirements are also well under stood. These should be the first prototype to be done. Important to build a three rack assembly to test thermal management of the ps in the enclosed racks. • Corrector ps needs more work to define the ratings of the ps. ( Need corrector magnet designs to mature.) • Have some concepts for ps cabling, cable tray, & rack enclosures. Need to start preliminary designs. NSLS II Accelerator System Advisory Meeting SR-PS