Peak Power Regulation of High-Power Pulsed Power Supplies

1. Technical Challenges in Peak Power Regulation
High-power pulsed power supplies are mainly used in pulsed lasers, electromagnetic launch, and plasma processing. Their core requirement is to output pulsed energy with short duration (microsecond to millisecond level) and high peak power (megawatt to gigawatt level). During regulation, three major challenges arise: first, high peak current (up to several thousand amperes) easily causes overload damage to switching tubes; second, pulse parameters (amplitude, width, repetition frequency) require precise control, as deviations affect load performance (e.g., unstable energy of pulsed lasers reduces processing accuracy); third, dynamic load changes (e.g., plasma load impedance varies with time) require the power supply to respond quickly to maintain stable peak power.
2. Key Technologies for Peak Power Regulation
(1) Modular Topology Design
A modular Marx generator topology is adopted, with multiple high-voltage capacitors and switching tube units connected in series. By controlling the conduction sequence of each unit, peak voltage superposition and regulation are achieved. Each module is independently designed, allowing flexible adjustment of peak power by increasing or decreasing the number of modules (e.g., 10 modules in series output 100kV peak voltage, 20 modules output 200kV). Meanwhile, voltage equalization circuits between modules prevent individual modules from being damaged by excessive voltage, improving system reliability. In pulsed X-ray machine power supplies, a 16-module Marx generator outputs pulses of 150kV/50kA, with a peak power of 7.5GW and pulse width continuously adjustable between 0.5-5μs.
(2) Optimization of Energy Storage Components
Selecting energy storage components with high energy density and low loss is fundamental to peak power regulation. Supercapacitors, with high power density (up to 10kW/kg) and fast charge-discharge speed, are suitable for short-pulse (microsecond-level), high-repetition-frequency scenarios; pulsed capacitors (e.g., metallized film capacitors), with high energy density (up to 5J/cm³) and high voltage resistance (up to 100kV), are suitable for long-pulse (millisecond-level), high-peak-power scenarios. A hybrid energy storage design combining supercapacitors and pulsed capacitors balances pulse response speed and energy storage capacity. In the power supply of electromagnetic launch devices, the hybrid energy storage system releases 1MJ of energy within 10ms, with a peak power of 100MW, meeting the energy requirements of electromagnetic ejection.
(3) Fast Switching Control Technology
Fast semiconductor switches such as SiC MOSFETs and IGBTs replace traditional gas switches (e.g., spark gap switches), improving the response speed and control accuracy of switching actions. SiC MOSFETs have a switching time as short as 10ns, enabling nanosecond-level pulse width regulation; IGBTs have a current-carrying capacity of up to several thousand amperes, suitable for high-current pulse scenarios. Meanwhile, multi-switch parallel technology ensures uniform current distribution among switches through current-sharing circuits, preventing overload of individual switches. In pulsed laser power supplies, SiC MOSFET switches achieve 10ns/1kV pulse output, with peak power regulation accuracy of ±0.5%.
(4) Real-Time Feedback Control Strategy
A feedback control system of "high-speed sampling + real-time analysis + precise adjustment" is built: high-speed data acquisition cards (sampling rate ≥2GS/s) collect voltage and current waveforms of pulse output; FPGAs (Field-Programmable Gate Arrays) analyze peak power deviations in real time, generate control commands, and adjust the on-time of switching tubes and discharge speed of energy storage components. An adaptive PID control algorithm dynamically adjusts control parameters based on load impedance changes, improving the power supply's dynamic response capability. In the pulsed power supply of plasma etching equipment, the feedback control system responds to load impedance changes within 50ns, controlling peak power fluctuation within ±1%.
3. Applications and Development Directions
Peak power regulation technologies for high-power pulsed power supplies have been applied in pulsed laser processing equipment (peak power regulation accuracy ±0.3%, improving processing surface roughness to Ra0.1μm) and electromagnetic artillery test devices (peak power up to 1GW, achieving projectile initial velocity of 2km/s). In the future, with the development of wide-bandgap semiconductor devices (e.g., gallium oxide devices) and high-speed digital control technology, peak power regulation will move toward higher frequencies (gigahertz level), higher accuracy (±0.1%), and a wider adjustment range (kilowatt to gigawatt level), while achieving miniaturization and intelligence of power supplies.