Magnet Power Supplies, Power Converters and High Voltage Power Supplies

Customized clocked Magnet Power Supplies

Clocked magnet power supplies are used especially in beam guidance systems (particle accelerators) in nuclear research institutes and in medical technology. Particle accelerators require high-precision power supplies oft he beam guiding magnets. Decisive for the quality of the magnetic field is a very stable DC current.

The most important parameters of a magnet power supply for accelerator systems are:

  • Output DC current
  • Output DC voltage
  • Output voltage ripple
  • Stability, Accuracy and setting resolution of the output current
  • Dynamics and control quality

Since the early 80s, we have developed and manufactured different customized magnet power supplies on behalf of various nuclear research institutes and particle therapy centerns.

With years of experience, expertise and know-how, we meet all requirements and fulfill your ideas for your application. Our magnet power supplies are characterized by:

  • Extremely high reliability and durability
  • Field-proven design and technology
  • Customized solutions
  • Integrated monitoring and protection system
  • Easy maintenance and interchangeability of components

Technology in Detail

Each power supply is designed and dimensioned according to the type of magnet to be supplied, depending on the load data, the technical parameters and the application. When selecting and dimensioning the components, great importance is attached to reliability and longevity. We offer different types of power supply depending on the requirements. The power supply units are designed in such a way that a load short circuit does not damage the device even during operation.

The power supply has two seperate three-phase feed-in, one for the power section and one for the control section. The output voltage converter, which has been designed as a clock circuit, ist he controller circuit actuator. The clock circuit has a compact design so that no snubber networks are needed. The clock frequencies are in the range of kHz.  The power part is water-cooled. For digital control the principle of pulse width modulation (PWM) is used. The load current is measured by a high-precision DC current transformer (DCCT). The power supplies have appropriate suppression and filtering measures.

For the best possible system protection, the devices have a comprehensive and customer-specific expandable monitoring and protection concept. These include, for example, the following protective measures:

  • Earth fault monitoring
  • Overcurrent monitoring
  • Temperature and water flow monitoring

  • Fast turn off

  • Load short circuit detection

  • Grid monitoring

  • Overvoltage and oscillation monitoring of the output voltage

  • Monitoring of DC link voltage and overvoltage protection by thyristors

  • Monitoring of DCCT and driver card

  • Monitoring of power semiconductors

  • Monitoring against external faults e.g. water flow and temperature monitoring of the load magnet ​​​​​

Depending on the application and the customer request, the operating mode distinguishes between:

  • 1-quadrant operation: unipolar load current and unipolar load voltage
  • 2-quadrant operation: unipolar load current and bipolar load voltage with regeneration
  • 4-quadrant operation: bipolar load current and bipolar load voltage with regeneration​​​​​​

With demands for extremely steep current increases with short constant current sections for a pulse mode with an arbitrarly adjustable pulse pattern , we offer a pulsed clocked magnet power supply, which also enables 4-qaudrant operation.

On request, a magnet power supply can also be designed as a multiple unit. In this very compact design, several devices are placed in one housing.

We are specialized in offering customized solutions. For example, suitable interfaces can be developed for integration into the customer’s monitoring and control system. The monitoring system of the power supply can be extended according to customer requirements. Protection thyristors provide overvoltage protection on the load side. Quench protection systems with electronic DC circuit breaker protect a superconducting magnet in the event of a quench (loss of superconductivity). With dynamic zero-field control (degaussing), a remanent magnetic field can be reduced.

The following extensions have already been realized:

  • Protection against overvoltage on the load side by protection thyristors

  • Quench protection systems with electronic DC circuit breaker

  • Dynamic zero field control

  • Integration of a mechanical high-current switch

Pulsed high voltage power supplies for Klystrons

A Klystron is a linear-beam electron tube that generates and amplifies high-frequency signals by controlling the rate of electron current. In a Klystron, an electron current generated in vacuum and accelerated by high voltage undergoes a velocity modulation through a high-frequency alternating electric field. Klystrons are used in ultra-high frequency circuits (UHF) and microwave transmitters as well as in medical and scientific particle accelerators. Our high voltage power supplies are designed and dimensioned to customer specifications. Important parameters are:

  • Output voltage and polarity
  • Stability and ripple during pulse duration

  • Rise and fall time constant of the pulse current

  • Pulse duration and repetition frequency

With years of experience, expertise and know-how, we meet all requirements and fulfill your ideas for your application. Our high voltage power supplies are characterized by:

  • Extremely high reliability and durability

  • Field-proven design and technology

  • Customized solutions

  • Integrated monitoring and protection system

  • Easy maintenance and interchangeability of components​​​​​

References:

High Current Power Converter for feeding of superconducting dipole magnets.

  • Max. output current range: 20.000 A
  • Total deviation (∆I/I): 2,5 · 10-4
  • Max. current ramping rate (di/dt): 30 kA/s