High output power high frequency resonant load inverters
First Claim
1. High power, high frequency resonant load inverter system for providing increased output power, the system comprising:
- an inverter device which is subdivided into sections, each section comprising two sets of current switches, each set having two IGBT (Insulated Gate Bipolar Transistor) switch means connected in series, each set having an output at a midpoint between said means for feeding a respective input terminal on a power load having an LC resonant compensation, and a main driver circuit for controlling each IGBT switch means of each set, said inverter device operating with a reduced switching frequency which is lower than a LC resonant frequency by providing driver signals from said main driver unit to one section at a time, thus causing the switching frequency to become 1/n of said resonant frequency, n being the number of sections.
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Accused Products
Abstract
A new control strategy for IGBIs when used in high frequency (75 kHz-500 kHz) high power (10 kW-5 MW) inverters with series resonant load, a topology commonly used for induction heating. The strategy changes the IGBT strain elements into a total stress picture that fits the IGBT'"'"'s behaviour and internal nature better. This makes the IGBT operate much more efficient, thus increasing the maximum output power from the inverter significantly compared to a standard control scheme. This makes the IGBT based inverter a much cheaper alternative than a MOSFET inverter, which has been state of the art for this application.
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Citations
12 Claims
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1. High power, high frequency resonant load inverter system for providing increased output power, the system comprising:
an inverter device which is subdivided into sections, each section comprising two sets of current switches, each set having two IGBT (Insulated Gate Bipolar Transistor) switch means connected in series, each set having an output at a midpoint between said means for feeding a respective input terminal on a power load having an LC resonant compensation, and a main driver circuit for controlling each IGBT switch means of each set, said inverter device operating with a reduced switching frequency which is lower than a LC resonant frequency by providing driver signals from said main driver unit to one section at a time, thus causing the switching frequency to become 1/n of said resonant frequency, n being the number of sections. - View Dependent Claims (2, 3, 4, 5, 6, 7, 10, 11, 12)
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8. High power, high frequency resonant load inverter system for providing increased output power, the system comprising:
an inverter device which is subdivided into sections, each section comprising two sets of current switches, each set having two IGBT (Insulated Gate Bipolar Transistor) switch means connected in series, each set having an output at a midpoint between said means for feeding a respective input terminal on a power load having an LC resonant compensation, and a main driver circuit for controlling each IGBT switch means of each set, said inverter device operating with a reduced switching frequency which is lower than a LC resonant frequency by providing driver signals from said main driver unit to all sections simultaneously to cause all sections to deliver current output during only one cycle of the switching frequency, thus causing all sections to deliver current output at a rate 1/n of said resonant frequency, n being the number of sections. - View Dependent Claims (9)
Specification