A 432-kW peak power solid-state resonant link power modulator system

Science Applications International Corporation (SAIC) has designed, built, tested, and delivered a high power solid-state modulator system which is capable of driving multiple loads. This system consists of a number of stand-alone 432-kW peak, 108-kW average power individual modulator units based upon SAIC's Dual Resonant Link technology. Each individual modulator unit employs a specially developed control system which provides full digital control with 10-ns switch resolution, 12.5-MHz on-board sampling, and provides a 2 to 15-kHz switching frequency to the modulator circuitry. The combination of the Dual Resonant Link topology, a fully-modeled control algorithm, and the high-speed control hardware gives an individual modulator unit the capability of providing a constant, current-controlled output of up to 36-kV at 12-A (2% ripple) for a full 50-ms pulse width, while allowing for a maximum droop of 30% of the nominal 575-V input voltage. Individual control of each modulator unit is provided to accommodate varying requests of output current (3 to 13-A), pulse width (1 to 50-ms), rep rate (single shot up to 5-Hz), and current rise time (down to 200-¿s). Additionally, multiple modulator units can be operated synchronously with tight unit-to-unit jitter. The input-to-output efficiency has been measured at 89%. The volume and weight of an individual modulator unit are 8-ft
³
and 760-lbs, respectively, yielding volumetric and gravimetric peak power densities of 54-kW/ft
³
and 0.57-kW/lb, respectively. The design can accommodate 60°C ambient air and water temperatures and MIL-STD shock and vibration profiles. Finally, one of the key features of this specific design is the line replaceable unit (LRU) arrangement of the four subassemblies, each of which can be replaced in under 30-minutes.