Precise Injection And Stable Circulation: The Key Role Of High-voltage Doorknob Capacitors In The Pulsed Magnet Power Supply Of Synchrotron Radiation Light Sources

High-voltage doorknob capacitors in the pulsed magnet power supply of synchrotron radiation light sources
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Parameters:

Core Functions:

The leap in performance at synchrotron radiation sources is largely due to innovations in beam injection technology. In particular, innovative schemes such as on-axis displacement injection, employed by fourth-generation sources, place extremely stringent demands on pulsed magnet power supplies: they must instantly deliver massive pulsed currents to generate precisely controlled magnetic fields, effectively driving the electron beam into or out of its intended trajectory. High-voltage doorknob capacitors are the core guarantee for the high-precision and high-stability operation of these high-performance pulsed magnet power supplies.
Challenge:

Why are pulsed magnet power supply requirements so stringent?

Take the fourth-generation High Energy Synchrotron Source (HEPS) as an example. The bumper magnet used in its booster extraction system requires the pulsed power supply to output a half-sine wave with a bottom width of less than 1 millisecond, with peak current fluctuations controlled within ±0.3% and waveform consistency deviations less than 5%. Any distortion or jitter in the current waveform can lead to:

Electron beam trajectory deviation, resulting in reduced injection efficiency and impacting the stability of the storage circulation intensity.

Synchrotron radiation beam position drift, affecting the directivity and data quality of the light at downstream experimental stations.
Solution:
Perfect combination of LC resonant pulse circuit and high-performance capacitors

This type of pulse power supply often uses an LC resonant circuit topology. A high-voltage doorknob capacitor (C) and the pulse magnet inductor (L) form a resonant circuit. Switching (e.g., IGBT) control generates the required high-quality half-sine current pulses.

In this application, the performance of the doorknob capacitor directly determines the quality of the pulse waveform:

Low-inductance design ensures a sharp pulse front: The capacitor's low equivalent series inductance and the overall circuit inductance together determine the pulse rise speed. Our low-ESL doorknob capacitors effectively ensure a sharp pulse front, meeting fast response requirements.

Highly stable capacitance ensures waveform consistency: Long-term capacitance stability and low drift are key to ensuring consistent pulse waveforms from time to time. We use highly stable ceramic dielectrics to ensure minimal capacitance variation even under frequent charge and discharge cycles (e.g., 50Hz operating frequency), thereby ensuring high repeatability of the injection process.

Efficient energy recovery: To reduce energy consumption and heat load, advanced designs incorporate energy recovery circuits. The capacitor feeds back the remaining energy through the recovery circuit during the pulse interval, which not only improves the efficiency but also reduces the interference with the output pulse waveform. This also requires the capacitor to have high efficiency and fast charging and discharging capabilities.

Xian Xiwuer Electronic & Info. Co., Ltd. is a wholly state-owned company with a registered capital of 91.46 million RMB Yuan, owning a total assets of 315 million RMBYuan, under the jurisdiction of Xi'an State-owned Assets Supervision & Management Committee. There are about 400 employees, with an annual sales income of 250 million RMB Yuan.

The main products include Zinc Oxide Varistors, thermistors, H-V ceramic capacitors, SPD, and Solar Energy Surge Protective Devices. The company has advanced production equipment, including 18 large sintering furnaces, 8 automatic assembly lines, the largest energy impulse current generator and a series of special test equipment and environmental test equipment. In the same industry in China, the company has the largest production capacity and the highest degree of automation with the most complete testing methods.

Our employees are 8 with master's degrees and more than 80 engineers with senior technical titles. 12 technicians have been awarded Experts with Outstanding Contributions by the Xian municipal government, and 1 expert has been enjoying a special allowance from the State Council.

The company has five sites for business production and operation, covering an area of 50,000 square meters. Its construction area is up to more than 54,000 square meters.

· No.99, Fengqing Road, Lianhu District, Xi an(ceramic capacitor)

· No.1118, Ziqaing Road, Xincheng District, Xi' a (Headquarters, varistors, thermistors)

· No.11, Longshou South Road, Lianhu District, Xi' a (Registration, photovoltaic lightning protection box)

· Block A, No.18, Gaoxin Road, High-tech District, Xi' an

· Jinghe New Town Xi Xian New Area(the new plant)

• Xian Xiwuer Electronic and Info. Co., Ltd. is a wholly state-owned company with a registered capital of CNY 101.465 million (exchanged to USD 15.85 million), owning total assets of CNY315 million (traded to USD 49.22 million). It was established in 1976. Currently, it has about 460 employees, with an annual sales income of CN280 million (exchanged to USD43.75 million). The company has four production and business bases covering an area of 43052 square meters, and a construction area of more than 50000 square meters. The company has 8 persons with master's degrees, more than 80 engineers with senior technical titles 12 technicians who have been awarded Experts with Outstanding Contributions by the Xian municipal government, and 1 expert who has been enjoying a special allowance from the State Council.

• The main products include

            • Smart Embedded Epoxy Pole；

            • Integrated Instrument Transformer

• Capacitive Voltage Divider；

• High Voltage Capacitor Rod；

• High Voltage Film Capacitor；

• High Voltage Resistor；

• Primary and Secondary Integrated Intelligent assembly and components with the function of voltage measurement, current measurement, protection, temperature monitoring, and power supply；

• Medium-High Voltage components/parts/ assembly；

• Surge Protective Device for Power Supply System；

• Chips for lightening devices；

• Zinc Oxide Varistor；Thermistor.

Major Customers: ABB, Schneider, GE, ZTE, XD Electric, XJ Electric, PingGao Electric and etc.

• The company has the provincial Technical R&D Center. The company has developing and manufacturing experiences of the key products HV Ceramic Capacitor, SPD, Varistor, Thermistor and for nearly 20 years. There have been 32 patented technologies, 4 invention patents, and 4 national key new products. The company is in the leading position in the same industry. The company has grown very fast with a unique management system which is the fundamental guarantee to the continuous development of the enterprise under the state-owned system. In Northwest China, the company is the first to implement ISO 9001 standards and the first to promote the use of ERP management systems, having achieved ISO9001, ISO14001, and ISO45001 approval, thus standardizing and improving the management level of the company.
• Through continuous technological innovation, product R&D, and quality improvement the main technical performance and reliability of the products are at the internationally advanced level the same level as Panasonic and Siemens. The products have UL, VDE, TUV, CAS, CE, CQC, RoHS, and REACH certifications. The company has advanced production equipment among which the key production equipment and modern assembly lines are imported from Japan, the U.S.A, Germany, Korea, and Belgium including 26m large sintering tunnel furnaces8 automatic assembly lines, the largest energy impulse current generator and a series of special test equipment and environmental test equipment. In the same industry in China, the company has the largest production capacity and the highest degree of automation with the most complete testing methods. The company has two routine test laboratories with the most advanced lightning testing equipment and environmental testing equipment which comply with national standards for laboratory construction. They are the significant laboratories supported by Shaanxi Province with professional testing technicians undertaking part of the supervision and inspection of electronic products in Shaanxi Province at the same time.
• We believe we are able to supply satisfied goods and services to customers at home and abroad with the most reasonable price and the shortest delivery time. on the basis of our excellent quality assurance capacity, technical development capacity, and rich manufacturing experiences.

Through continuous technological innovation, product R&D, and quality improvement, the main technical performance and reliability of the products are at the international advanced level, at the same level as Panasonic and Siemens. The products have UL, VDE, TUV, CAS, CE, CQC, RoHS, and REACH Certification