A novel active bouncer system for klystron modulators with constant AC power consumption

Abstract

This paper presents the principles and design methodologies of a novel active bouncer system, to be implemented in a transformer-based klystron modulator, which is able to meet two different objectives: 1. Regulate the output pulse voltage flattop, and 2. Attenuate the power fluctuation withdrawn from the AC network. This solution allows the utilization of a standard constant voltage / constant current power supply as a capacitor charger. The solution consists of a 4-quadrant switching converter placed in series with the main capacitor bank (forming a unique element in parallel with the capacitor charger), controlled with specific feed-back loops to achieve the two objectives. The complete design method, including a numerical optimization, of the whole system, is presented in the paper. Analyses of the compromises between the active bouncer specifications and the other modulator sub-components design is presented as well. Abstract-This paper presents the principles and design methodologies of a novel active bouncer system, to be implemented in a transformer-based klystron modulator, which is able to meet two different objectives : 1. Regulate the output pulse voltage flattop, and 2. Attenuate the power fluctuation withdrawn from the AC network. This solution allows the utilization of a standard constant voltage / constant current power supply as a capacitor charger. The solution consists of a 4-quadrant switching converter placed in series with the main capacitor bank (forming a unique element in parallel with the capacitor charger), controlled with specific feed-back loops to achieve the two objectives. The complete design method, including a numerical optimization, of the whole system, is presented in the paper. Analyses of the compromises between the active bouncer specifications and the other modulator sub-components design is presented as well.

Proof of principle of an on-line digitizer with ±18 ppm repeatability and 1.2 μs real-time delay for power converters control loop

“…In order to reach the desired energy level, CLIC power converters [15] are required to deliver pulsed power, repeatable in the order of few tens of ppm [15]. For this purpose, a high-voltage modulator is currently under design by the laboratories for high-power electronics at ET H Zurich (CH) [17] and the LE E PCI Laval (CA) [18] (figure 7).…”

“…In fact, no significant noise components at high frequency are expected, except from switching harmonics, suitably rejected by the notches of the moving average filter. In table 1, the main requirements for the real-time digitizer for the CLIC case study [17,18] are summarized.…”

“…In order to reach the desired energy level, together with reasonable power consumption from the electrical grid [14], CLIC needs for power converters [15] with a pulsed power [16] repeatable in the order of few tens of ppm [15]. For this purpose, a high-voltage modulator is currently being designed by the laboratory for high-power electronics at ET H Zurich (CH) [17] and the LE E PCI Laval (CA) [18]. This is a typical example of new generation power converters requiring a real-time digitizer with delay in the order of few µs over a bandwidth of less than 1 MHz, with repeatability performance in the order of few ppm.…”