Title :
Submicrosecond Pulsed Power Capacitors Based on Novel Ceramic Technologies
Author :
Domonkos, Matthew T. ; Heidger, Sussan ; Brown, Darwin ; Parker, Jerald V. ; Gregg, Carl W. ; Slenes, Kirk ; Hackenberger, Wes ; Kwon, Secogtae ; Loree, Ellis ; Tran, Tyrone
Author_Institution :
Air Force Res. Lab. (AFRL), Kirtland AFB, NM, USA
Abstract :
Capacitor energy density for submicrosecond discharge applications was investigated for capacitors based on the following: 1) polymer-ceramic nanocomposite (PCNC); 2) antiferroelectric (AFE); and 3) paraelectric (PE) ceramic dielectrics. The developmental PCNC dielectric enabled design, fabrication, and testing iterations to be completed relatively rapidly. The PCNC capacitors were nominally 4 nF and were tested to dc potentials of at least 75 kV. The capacitors were then charged from 20 to 48 kV with a dc high-voltage power supply and discharged into a nearly critically damped test circuit of up to 5 pulses/s (pps) repetition rate for lifetime testing. The discharge time was 65 ns. Shot life as a function of the charge voltage was compared for three design iterations. Changes in the manufacturing of the PCNC capacitors have yielded up to 100× improvements in pulse discharge life. The 1-2-kV prototype, nonlinear (antiferroelectric and paraelectric) multilayer ceramic capacitors had zero-voltage capacitance ratings of between 60 and 300 nF. They were charged to their operating voltage and discharged into a nearly critically damped load in 2-6 μs, depending on their capacitance, at repetition rates of up to 75 pps. Their operating voltage for fast, repetitive discharge was determined for lifetimes consistently over 105 shots. Discharge energy densities of 0.27-1.80 J/cc and energy losses of 7.9-36.8% were obtained for the packaged multilayer capacitors with different formulations of nonlinear dielectrics. Increased field-induced strain was correlated with increased permittivity and contributed to the limitations on the operating voltage. Multilayer ceramic capacitors fabricated from AFE and PE ceramic dielectrics have the potential to achieve high energy density owing to their high relative permittivities that vary with applied electric field, assuming they can be scaled up to sufficiently high voltages.
Keywords :
ceramic capacitors; dielectric materials; life testing; nanocomposites; polymers; power capacitors; pulsed power technology; PCNC capacitors; antiferroelectric ceramic dielectrics; capacitance 60 nF to 300 nF; capacitor energy density; discharge energy density; field-induced strain; lifetime testing; multilayer ceramic capacitors; paraelectric ceramic dielectrics; polymer-ceramic nanocomposite; pulse discharge life; pulsed power capacitors; repetitive discharge; submicrosecond discharge; voltage 20 kV to 48 kV; Capacitance; Ceramics; Circuit testing; Dielectrics; Life testing; Nonhomogeneous media; Permittivity; Power capacitors; Pulsed power supplies; Voltage; Capacitors; life estimation; pulse power systems;
Journal_Title :
Plasma Science, IEEE Transactions on
DOI :
10.1109/TPS.2010.2049124