Synchrotron radiation facilities are flagship large-scale scientific infrastructures supporting cutting-edge research in materials science, life science, condensed matter physics, environmental science and nanotechnology. Featuring ultra-high brightness, excellent collimation, broad spectral range and high polarization, they represent the core commanding height of global scientific and technological competition. The storage ring high-voltage corrector power supply is an indispensable key component for synchrotron radiation beamlines. It delivers high-precision, ultra-stable DC output for orbit corrector magnets, focusing magnets and correction coils inside the storage ring, performing real-time beam orbit correction, maintaining closed-loop beam stability and guaranteeing photon beam quality. Its long-term voltage stability, ripple suppression, dynamic response and multi-unit synchronization directly determine beam orbit stability, photon brightness, collimation accuracy and overall experimental measurement reliability of the entire facility.
Synchrotron operation imposes extreme technical requirements far beyond conventional industrial power supplies: 1.Sub-ppm ultra-high stability: Third-generation facilities require long-term stability better than ±1 ppm/year and short-term stability ≤±0.5 ppm/8 h; fourth-generation diffraction-limited storage rings demand sub-ppm performance. Even tiny drift causes beam position jitter and degrades experimental accuracy. 2.Ultra-low ripple & noise: Output ripple directly couples into beam motion, inducing transverse oscillation and reducing coherence/brightness. Peak-to-peak ripple must be suppressed below 1 ppm with superior EMI immunity to avoid interference with beam diagnostic electronics. 3.Fast dynamic response & ultra-high linearity: Beam drift arises from charge accumulation, vacuum variation and magnet thermal drift. Corrector supplies require microsecond dynamic response and linearity better than 0.001% for real-time closed-loop orbit feedback. 4.Massive multi-device synchronization: A single storage ring integrates hundreds to thousands of corrector units, requiring nanosecond synchronous triggering to avoid global beam oscillation caused by asynchronous correction. 5.Extra-long continuous operation & high reliability: Facilities operate over 8,000 hours annually with minimal maintenance windows, demanding MTBF ≥100,000 hours and non-degrading performance throughout the full lifecycle. 6.Rugged EMC in complex field environments: Intensive magnet power converters, RF systems and beam diagnostics create severe EMI; power supplies must maintain immunity while emitting negligible interference.
This methodology establishes a full-process technical framework covering ultra-high stability topology, full-link drift optimization, ultra-low ripple suppression, multi-unit synchronization and long-lifetime reliability design. It fully satisfies corrector magnet power demands for third‑ and fourth‑generation synchrotron storage rings, providing standardized design guidelines for core-component localization of domestic large scientific facilities. To address sub-ppm stability, ultra-low ripple and fast response, the universal hybrid topology adopts pre-regulating switching stage + linear power amplification stage, combined with fully digital high-precision closed-loop control and fiber-based multi-master synchronization. It breaks traditional bottlenecks: switching power supplies cannot achieve ppm-level stability, while pure linear designs suffer from extremely low efficiency and severe heat dissipation. The hybrid scheme achieves high efficiency via front-end pre-regulation and delivers ultimate low ripple & fast response via linear post-stage, balancing energy efficiency and sub-ppm precision simultaneously. Six core design principles are defined.
1.Front-end LLC resonant pre-regulation: A full-bridge LLC converter realizes ZVS for primary switches and ZCS for rectifiers across wide input and load ranges, minimizing switching loss and EMI. Intermediate bus stability is controlled within ±0.1%, providing an ultra-stable feed for the linear stage. Multi-stage EMI filtering eliminates switching ripple propagation to the output.
2.High-power parallel linear amplification stage: Parallel linear power transistors reduce equivalent on-resistance while extending current capability. Operating within linear region, real-time voltage adjustment eliminates switching ripple entirely and achieves ultra-fast dynamic response. Key rules include: precision current sharing ≤±1% among parallel devices; adaptive differential voltage optimization to minimize power dissipation while retaining regulation margin, raising overall efficiency above 85% versus 20%–30% for traditional linear supplies; uniform thermal layout with independent cooling to eliminate local hotspots.
3.High-precision sampling & reference design: The foundation of sub-ppm stability. Redundant triple-sampling with 24-bit+ Σ-Δ ADC (≥100 kSPS) adopts 2-out-of-3 voting to avoid single-point sampling failure. Metal-foil sampling resistors feature temperature coefficient below 0.1 ppm/°C. Low-drift bandgap references achieve TC ≤0.2 ppm/°C and long-term stability ≤0.5 ppm/1000 h with independent constant-temperature shielding, keeping reference temperature fluctuation within ±0.1 °C.
4.Fully digital high-bandwidth closed-loop control: FPGA + high-resolution DAC architecture implements high-precision digital PID plus feedforward compensation for input and load transients. Settling time under step load<10 μs with voltage deviation <±1 ppm. Embedded temperature and aging compensation continuously correct output drift caused by component degradation and ambient variation.
5.Fiber-optic massive multi-unit synchronization: A central synchronous controller distributes global clock and commands via optical fiber, achieving system synchronization ≤10 ns. Each local controller supports both synchronized global operation and independent closed-loop control. Optical transmission eliminates galvanic coupling and EMI in harsh synchrotron environments.
6.Modular standardized architecture: Universal modules support flexible configuration for various magnet ratings with full interchangeability, enabling rapid replacement and minimizing downtime for large-scale deployment with thousands of units.
Ultra-high stability and ultra-low ripple optimization are implemented across electrical, thermal, mechanical and environmental dimensions: Electrically, differential sampling isolates common-mode noise; power and sensing circuits are physically separated; low-impedance power paths minimize resistive drift; multi-stage π filtering suppresses ripple below 0.5 ppm; strict single-point grounding eliminates ground-loop interference. Thermally, liquid cooling with precise temperature control (±0.2 °C) maintains core device temperature fluctuation within ±0.5 °C; references and sampling circuits adopt independent constant-temperature shielding. Mechanically, rigid monolithic aluminum housing suppresses vibration-induced contact resistance drift; double magnetic & electric shielding contains external interference and internal noise radiation. Environmentally, fully sealed enclosure prevents humidity, dust and corrosive gas degradation; internal environmental monitoring ensures long-term parameter stability.
Long-lifetime reliability and EMI robustness guarantee uninterrupted annual operation: All critical components adopt high-stability long-life grades; electrolytic capacitors are eliminated and replaced with film/ceramic types; all devices operate under heavy derating (≤50% rating). Dual redundancy is implemented for control, sampling, reference and driver circuits with seamless failover; pre-regulation modules support degraded safe operation during single-module faults. Full EMC compliance meets GB/T 17626 highest immunity levels; complete galvanic isolation and fiber driving eliminate coupled interference. Embedded health monitoring records full-lifecycle operating parameters for predictive maintenance, early degradation warning and traceable fault analysis.
Comprehensive monitoring and protection ensure storage ring safety: Full telemetry covers input/output voltage/current, device temperature, coolant status and internal ambient parameters, remotely accessible via fiber/Ethernet with up to 10-year traceable logs. Multi-layer hardware/software protection includes over/under voltage, overcurrent/short circuit, overtemperature, differential over-limit and interlock trips; hardware response<1 μs. Fast interlocking with the central storage ring protection system ensures beam safety during critical faults. Integrated self-diagnosis enables precise fault localization to shorten maintenance downtime.
In summary, this integrated methodology solves the long-standing conflict among sub-ppm stability, ultra-low ripple and high efficiency. The hybrid topology achieves sub-ppm long-term stability and output ripple below 0.5 ppm; fully digital closed-loop control delivers microsecond dynamic response; full redundancy and thermal/environmental optimization support uninterrupted long-term operation. Widely applicable to third/fourth-generation synchrotrons, diffraction-limited storage rings and free-electron laser facilities, it provides core independent technologies for domestic substitution and performance upgrading of critical power supplies for large scientific infrastructures.