Development of battery powered 100kV dc power supply

Abstract

The increased interest in pulsed power field applications has generated the need for development of compact and remotely operated chargers driven by rechargeable batteries. With this objective, a compact and portable dc to dc Converter has been developed which has an output rating of 100kV, 0.4mA. The high voltage generation scheme uses a hybrid approach. The overall idea behind implementation of hybrid concept is to optimize voltage upliftment with suitable techniques for maximizing power delivered per unit volume. The proposed converter provides this feature and uses flyback converter in association with Cockcroft-Walton Multiplier [M. Jullian, Cockcroft-Walton Multiplier Optimum Design Guide V2.0, August 2005 (http//www.blazelabes.com)] for the generation of 100kV dc from 12V dc source, i.e., normal battery. In the first stage 12V dc is modulated/chopped into series of high frequency pulses by pulse width modulator and then increased in level up to 16kVpp by step up flyback transformer. Further by using n stage half wave series Cockcroft-Walton multiplier the voltage is stepped up to the level of 100kV. As switching device, state of the art metal-oxide-semiconductor field-effect transistor has been used. The obtained voltage multiplier cascade efficiency is 82.64%, whereas overall power conversion efficiency of the charging power supply is 85.47%. The control unit has been fiber optically isolated from high voltage unit due to safety consideration. The presented article explores complete design and development approach of compact and portable 100kV dc power supply which can be used for a variety of applications such as x-ray generation, ion implantation, charge particle acceleration, radio isotope production, etc.

Compact sub-kilojoule range fast miniature plasma focus as portable neutron source

“…One of the major considerations in the design was to obtain a PF device of minimum possible dimensions and mass for enhanced portability. Specifications of the capacitor bank were chosen such that for field applications FMPF-1 could be charged using battery powered high voltage supplies [23]. In order to make the system efficient, significant efforts were made to reduce the driver inductance.…”

Design and Control of a Battery Charger/Discharger Based on the Flyback Topology

“…In the literature, it is possible to find different design procedures and equations to determine the flyback magnetizing inductance (L m ), output capacitance (C dc ), and transformer's turns ratio (n) for battery charging or discharging systems. In [21,30,32], the authors introduce procedures and equations to determine L m and n, as well as other elements for the snubber circuit [21] and additional characteristics of the high-frequency transformer (HFT) [32]. An interesting aspect of the procedure presented in [21] is that it includes the calculation of three parameters required by the proposed controller (peak current mode controller with exponential compensation ramp).…”

“…An interesting aspect of the procedure presented in [21] is that it includes the calculation of three parameters required by the proposed controller (peak current mode controller with exponential compensation ramp). However, those procedures do not include the design of C dc [21,30,32] and the controllers do not regulate the DC bus voltage [21], are not clearly explained [30], or are not included [32].…”

“…Regarding the controllers proposed in the literature for battery charging systems that use flyback converters, most of the papers use linear controllers, while others use specialized controllers (like peak current control [21,34] or fuzzy controller [23]) or do not include a control structure [22,29,[31][32][33]35]. A cascade controller is used in [24][25][26], where the outer loop is a PI controller to regulate v b , and the inner loop is a PI that tracks a reference of the battery current (i b ).…”

Progress in the development of a battery-based pulsed power system

“…Chaudhari in [10] demonstrated some work with an unspecified chemistry (noted as "dry cell" in the text), to charge a 300 kV pulsed power system. The energy in this system was on a relatively small scale, 108 J. Verma in [11] used unspecified rechargeable batteries in concert with a Flyback converter to charge a 1 nF capacitor to 100 kV in 250 ms, for a total stored energy of 4 J. Allen in [12,13] was the first to demonstrate repetitive rapid capacitor charging with SLA batteries on a 30 kJ capacitor bank. Finally, Holt in [14] used lithium polymer cells to charge a 50 µF capacitor to 5 kV in 500 ms, for a total stored energy of 625 J.…”