초록 ▼

An isolated DC to DC converter including zero voltage switching and a current doubler. Current sensors are located between a positive input of the DC to DC converter and a current doubler is used in an output stage of the DC to DC converter in order to enable more accurate current sensing in a main

An isolated DC to DC converter including zero voltage switching and a current doubler. Current sensors are located between a positive input of the DC to DC converter and a current doubler is used in an output stage of the DC to DC converter in order to enable more accurate current sensing in a main transformer to prevent saturation of the transformer core and provide increased efficiency and power output with lower electromagnetic noise. The input of the DC to DC converter is isolated from the output of the DC to DC converter, and the DC to DC converter may be used in a hybrid or all-electric vehicle to provide an accessory bus from a power source of the vehicle.

대표청구항 ▼

1. A DC to DC converter comprising: a full bridge inverter having a positive input, a negative input, a first output, and a second output, said full bridge inverter comprising a first high side switch, a second high side switch, a first low side switch, and a second low side switch, each of said swi

1. A DC to DC converter comprising: a full bridge inverter having a positive input, a negative input, a first output, and a second output, said full bridge inverter comprising a first high side switch, a second high side switch, a first low side switch, and a second low side switch, each of said switches having an on state and an off state wherein the switch will conduct current in the on state and will not conduct current in the off state;a current doubler connected between the first output and the second output of the full bridge inverter;a first current sensor connected between the positive input of the full bridge inverter and the first high side switch of the full bridge inverter, said first current sensor for providing a signal indicative of a current from a power source to the first high side switch; anda controller for receiving the signal indicative of the current from the power source to the first high side switch and selectively switching each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of said signal indicative of the current from the power source to the first high side switch. 2. The DC to DC converter of claim 1 further comprising a second current sensor connected between the second high side switch of the full bridge inverter and the positive input of the full bridge inverter for providing a signal indicative of a current from the power source to the second high side switch, wherein the controller is further configured to receive the signal indicative of the current from the power source to the second high side switch and selectively switch each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of said signal indicative of the current from the power source to the second high side switch. 3. The DC to DC converter of claim 1 wherein: the full bridge inverter further comprises a transformer comprising a primary and a secondary;the first output of the full bridge inverter is a first terminal of the secondary of the transformer;the second output of the full bridge inverter is a second terminal of the secondary of the transformer. 4. The DC to DC converter of claim 3 wherein the first high side switch, the second high side switch, the first low side switch, and the second low side switch are directly connected to the primary of the transformer. 5. The DC to DC converter of claim 1 wherein the current doubler comprises: a first inductor connected between the first output of the full bridge inverter and a positive output of the DC to DC converter;a second inductor connected in series with the first inductor across the output of the full bridge inverter,a first diode having an anode and a cathode, said anode connected to a negative output of the DC to DC converter and said cathode connected to a first output of the full bridge inverter; anda second diode having an anode and a cathode, said anode connected to the negative output of the DC to DC converter and said cathode connected to a second output of the full bridge inverter. 6. The DC to DC converter of claim 1 further comprising a thermal overload protection circuit for sensing a temperature of the transformer and causing the controller to disable the full bridge inverter, wherein the controller is connected to a positive output of the DC to DC converter and is configured to selectively switch each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of a voltage of the positive output of the DC to DC converter, said voltage of the positive output of the DC to DC converter being relative to a negative output of the DC to DC converter. 7. The DC to DC converter of claim 1 wherein the controller comprises a clock input for receiving a synchronization signal when the DC to DC converter is connected in parallel with a second DC to DC converter and selectively switching each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of the synchronization signal such that the switches are switched asynchronously with switches of the second DC to DC converter. 8. The DC to DC converter of claim 1 wherein: the controller selectively switches each of the first low side switch and the second low side switch between the on state and the off state at a fixed duty cycle; andthe controller adjusts a duty cycle of the first high side switch and a duty cycle of the second high side switch to control the voltage at a positive output of the DC to DC converter. 9. The DC to DC converter of claim 1 wherein the controller selectively switches each of the first high side switch, the second high side switch, the first low side switch, and the second low side switch in a soft switching scheme. 10. The DC to DC converter of claim 9 wherein the soft switching scheme is based on zero voltage switching. 11. A hybrid or all-electric vehicle comprising: a power source operating between about 250 volts and 400 volts;an electrical system configured to operate at about 12 to 14 volts or 24 to 28 volts; anda DC to DC converter connected to the power source and the electrical system, said DC to DC converter comprising:a full bridge inverter having a positive input, a negative input, a first output, and a second output, said full bridge inverter comprising a first high side switch, a second high side switch, a first low side switch, and a second low side switch, each of said switches having an on state and an off state wherein the switch will conduct current in the on state and will not conduct current in the off state;a current doubler connected between the first output and the second output of the full bridge inverter;a first current sensor connected between the positive input of the full bridge inverter and the first high side switch of the full bridge inverter, said first current sensor for providing a signal indicative of a current from a power source to the first high side switch; anda controller for receiving the signal indicative of the current from the power source to the first high side switch and selectively switching each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of said signal indicative of the current from the power source to the first high side switch. 12. The hybrid or all-electric vehicle of claim 11 further comprising a second current sensor connected between the second high side switch of the full bridge inverter and the positive input of the full bridge inverter for providing a signal indicative of a current from the power source to the second high side switch, wherein the controller is further configured to receive the signal indicative of the current from the power source to the second high side switch and selectively switch each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of said signal indicative of the current from the power source to the second high side switch. 13. The hybrid or all-electric vehicle of claim 11 wherein: the full bridge inverter further comprises a transformer comprising a primary and a secondary;the first output of the full bridge inverter is a first terminal of the secondary of the transformer;the second output of the full bridge inverter is a second terminal of the secondary of the transformer. 14. The hybrid or all-electric vehicle of claim 13 wherein the first high side switch, the second high side switch, the first low side switch, and the second low side switch are directly connected to the primary of the transformer. 15. The hybrid or all-electric vehicle of claim 11 wherein the current doubler comprises: a first inductor connected between the first output of the full bridge inverter and a positive output of the DC to DC converter;a second inductor connected in series with the first inductor across the output of the full bridge inverter,a first diode having an anode and a cathode, said anode connected to a negative output of the DC to DC converter and said cathode connected to a first output of the full bridge inverter; anda second diode having an anode and a cathode, said anode connected to the negative output of the DC to DC converter and said cathode connected to a second output of the full bridge inverter. 16. The hybrid or all-electric vehicle of claim 11 further comprising a thermal overload protection circuit for sensing a temperature of the transformer and causing the controller to disable the full bridge inverter, wherein the controller is connected to a positive output of the DC to DC converter and is configured to selectively switch each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of a voltage of the positive output of the DC to DC converter, said voltage of the positive output of the DC to DC converter being relative to a negative output of the DC to DC converter. 17. The hybrid or all-electric vehicle of claim 11 wherein the controller comprises a clock input for receiving a synchronization signal when the DC to DC converter is connected in parallel with a second DC to DC converter and selectively switching each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of the synchronization signal such that the switches are switched asynchronously with switches of the second DC to DC converter. 18. The hybrid or all-electric vehicle of claim 11 wherein: the controller selectively switches each of the first low side switch and the second low side switch between the on state and the off state at a fixed duty cycle; andthe controller adjusts a duty cycle of the first high side switch and a duty cycle of the second high side switch to control the voltage at a positive output of the DC to DC converter. 19. The hybrid or all-electric vehicle of claim 11 wherein the controller selectively switches each of the first high side switch, the second high side switch, the first low side switch, and the second low side switch in a soft switching scheme. 20. The hybrid or all-electric vehicle of claim 19 wherein the soft switching scheme is based on zero voltage switching. 21. A power system comprising: a power source operating at a first voltage;a load configured to operate at a second voltage different from the first voltage; anda DC to DC converter connected to the power source and the electrical system, said DC to DC converter comprising:a full bridge inverter having a positive input, a negative input, a first output, and a second output, said full bridge inverter comprising a first high side switch, a second high side switch, a first low side switch, and a second low side switch, each of said switches having an on state and an off state wherein the switch will conduct current in the on state and will not conduct current in the off state;a current doubler connected between the first output and the second output of the full bridge inverter;a first current sensor connected between the positive input of the full bridge inverter and the first high side switch of the full bridge inverter, said first current sensor for providing a signal indicative of a current from a power source to the first high side switch; anda controller for receiving the signal indicative of the current from the power source to the first high side switch and selectively switching each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of said signal indicative of the current from the power source to the first high side switch. 22. The power system of claim 21 further comprising a second current sensor connected between the second high side switch of the full bridge inverter and the positive input of the full bridge inverter for providing a signal indicative of a current from the power source to the second high side switch, wherein the controller is further configured to receive the signal indicative of the current from the power source to the second high side switch and selectively switch each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of said signal indicative of the current from the power source to the second high side switch. 23. The power system of claim 21 wherein: the full bridge inverter further comprises a transformer comprising a primary and a secondary;the first output of the full bridge inverter is a first terminal of the secondary of the transformer;the second output of the full bridge inverter is a second terminal of the secondary of the transformer; andthe power system is the power system of a hybrid vehicle. 24. The power system of claim 23 wherein the first high side switch, the second high side switch, the first low side switch, and the second low side switch are directly connected to the primary of the transformer. 25. The power system of claim 21 wherein the current doubler comprises: a first inductor connected between the first output of the full bridge inverter and a positive output of the DC to DC converter;a second inductor connected in series with the first inductor across the output of the full bridge inverter,a first diode having an anode and a cathode, said anode connected to a negative output of the DC to DC converter and said cathode connected to a first output of the full bridge inverter; anda second diode having an anode and a cathode, said anode connected to the negative output of the DC to DC converter and said cathode connected to a second output of the full bridge inverter. 26. The power system of claim 21 further comprising a thermal overload protection circuit for sensing a temperature of the transformer and causing the controller to disable the full bridge inverter, wherein the controller is connected to a positive output of the DC to DC converter and is configured to selectively switch each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of a voltage of the positive output of the DC to DC converter, said voltage of the positive output of the DC to DC converter being relative to a negative output of the DC to DC converter. 27. The power system of claim 21 wherein the controller comprises a clock input for receiving a synchronization signal when the DC to DC converter is connected in parallel with a second DC to DC converter and selectively switching each of the first high side switch, second high side switch, first low side switch, and second low side switch between the on state and the off state as a function of the synchronization signal such that the switches are switched asynchronously with switches of the second DC to DC converter. 28. The power system of claim 21 wherein: the controller selectively switches each of the first low side switch and the second low side switch between the on state and the off state at a fixed duty cycle; andthe controller adjusts a duty cycle of the first high side switch and a duty cycle of the second high side switch to control the voltage at a positive output of the DC to DC converter. 29. The power system of claim 21 wherein the controller selectively switches each of the first high side switch, the second high side switch, the first low side switch, and the second low side switch in a soft switching scheme. 30. The power system of claim 29 wherein the soft switching scheme is based on zero voltage switching.