Resonant converter control system having resonant current phase detection
First Claim
1. A resonant converter control system comprising:
- a power section including;
a main power supply having an output port for supplying a DC power signal; and
an inverter having an input port coupled to the output port of the main power supply to receive the DC power signal and a switch that turns on and off responsive to a drive signal to convert the DC power signal to a resonating AC current signal;
a drive stage coupled to the inverter, the drive stage generating the drive signal responsive to a frequency signal;
a current controller coupled to the power section to receive a first sense signal that indicates the power consumed by the power supply section, the current controller generating a first control signal responsive to the first sense signal;
a phase difference assurance circuit coupled to the inverter to receive a second sense signal that indicates the resonating AC current signal and coupled to the drive stage to receive the drive signal, the phase difference assurance circuit generating a second control signal responsive to a phase difference between the second sense signal and the drive signal; and
a frequency stage coupled to the current controller to receive the first control signal and coupled to the phase difference assurance circuit to receive the second control signal, the frequency stage generating the frequency signal responsive to the first and second control signals.
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Accused Products
Abstract
A resonant convertor control system regulates a resonant AC current based on the amount of input power consumed by the system. The switching frequency and resonant AC current are limited by a phase difference assurance circuit that compares the phase of a drive signal with the phase of the resonant AC current. By detecting the phase of the resonant current instead of the resonant voltage, it eliminates the need for the costly components required to detect the resonant voltage. The system includes a main power supply for supplying a DC power signal and an inverter that converts the DC power signal to a resonating AC current signal responsive to a drive signal from a drive stage. An input current controller receives a first sense signal that indicates the power consumed by the main power supply and generates a first control signal that regulates the power consumed by the load. A phase difference assurance circuit generates a second control signal responsive to phase difference between the resonant AC current signal and the drive signal. The second control signal adjusts the frequency signal responsive to the second control signal, thereby assuring a phase difference between the second sense signal and the drive signal and eliminating excessive current flow in the inverter.
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Citations
23 Claims
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1. A resonant converter control system comprising:
a power section including; a main power supply having an output port for supplying a DC power signal; and an inverter having an input port coupled to the output port of the main power supply to receive the DC power signal and a switch that turns on and off responsive to a drive signal to convert the DC power signal to a resonating AC current signal; a drive stage coupled to the inverter, the drive stage generating the drive signal responsive to a frequency signal; a current controller coupled to the power section to receive a first sense signal that indicates the power consumed by the power supply section, the current controller generating a first control signal responsive to the first sense signal; a phase difference assurance circuit coupled to the inverter to receive a second sense signal that indicates the resonating AC current signal and coupled to the drive stage to receive the drive signal, the phase difference assurance circuit generating a second control signal responsive to a phase difference between the second sense signal and the drive signal; and a frequency stage coupled to the current controller to receive the first control signal and coupled to the phase difference assurance circuit to receive the second control signal, the frequency stage generating the frequency signal responsive to the first and second control signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A resonant converter control system comprising:
a power section including; power input means for supplying a DC power signal; and means for converting the DC power signal to a resonating AC signal responsive to a drive signal; means for generating the drive signal responsive to a frequency signal; means for generating a first control signal to control the power consumed by the power section; means for generating a second control signal to control the phase difference between the drive signal and the resonating AC signal; and means for generating the frequency signal responsive to the first and second control signals. - View Dependent Claims (18)
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19. A method for controlling a resonant converter comprising:
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generating a drive signal responsive to a frequency signal; converting a DC power signal to a resonating AC current signal responsive to the drive signal, thereby consuming power; generating a first sense signal responsive to the power consumed; generating a first control signal responsive to the first sense signal; generating a second sense signal responsive to the resonating AC current signal; comparing the phase of the second sense signal and the phase of the drive signal, thereby generating a second control signal; adjusting the frequency signal responsive to the first control signal, thereby limiting the power consumed; and adjusting the frequency signal responsive to the second control signal, thereby assuring a phase difference between the second sense signal and the drive signal. - View Dependent Claims (20, 21, 22, 23)
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Specification