| 摘要 |
A system and method for charging a high-voltage capacitor through the application of a current, the magnitude of which has a variable frequency, variable duty cycle waveform. Generally, energy is transferred from a power source to the high voltage capacitor via a magnetic element such as an inductor or transformer. For example, a pulsed voltage supply provides voltage pulses having a variable frequency and an adjustable duty cycle to a primary winding of a fly-back transformer. During a charging sequence in which current charge cycles are applied to the capacitor, the duty cycle of the variable frequency current waveform is controlled dynamically based on the rate at which energy can be transferred to the capacitor. Specifically, during a charge sequence, current pulses through the primary winding are controlled such that the transformer operates in a continuous mode during an initial portion of the charge sequence, and in a discontinuous mode during a subsequent portion of the charge sequence. During the continuous mode, the duration of the off or non-conduction time of the primary winding current waveform is limited to be less than or equal to a maximum time period. Within this maximum time period energy can be transferred efficiently from the transformer to the capacitor. Subsequent, inefficient conduction time is inhibited. This increases the speed at which the high voltage capacitor is charged.
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