Modified zero voltage transition (ZVT) full bridge converter and photovoltaic (PV) array using the same
View Patent ↗The present invention, a modified zero voltage transition (ZVT) full bridge converter, is an isolated dc/dc converter which can operate with high efficiency and high reliability in applications requiring a low input voltage and high output voltage.
1. A modified zero voltage transition (ZVT) full bridge converter comprising:
a pair of input lines;
a pair of inductorless output lines;
an input capacitor spanning the pair of input lines;
an array of switching devices, arranged in a full bridge configuration, spanning the pair of input lines after the input capacitor;
a transformer comprising a primary and a secondary, the primary of the transformer being connected to an output of the array of switching devices;
a diode rectifier connected to the secondary of the transformer, the output of the diode rectifier being connected to the pair of inductorless output lines;
and an output capacitor spanning the pair of inductorless output lines.
2. A modified ZVT full bridge converter according to claim 1 wherein the diode rectifier comprises a full bridge configuration.
3. A modified ZVT full bridge converter according to claim 1 further comprising an inductor in series with the primary of the transformer, wherein a free lead of the inductor and a free lead of the primary of the transformer are connected to the output of the array of switching devices.
4. A power system comprising:
a photovoltaic (PV) array having an output;
a zero voltage transition (ZVT) full bridge converter connected to the output of the PV array, the ZVT full bridge converter comprising a plurality of switches defining a first leg of a full bridge and a second leg of the full bridge; and
a power tracking module connected to the ZVT full bridge converter, wherein the power tracking module is configured to control a phase relationship between a first control signal and a second control signal provided to the plurality of switches based on an output power of the ZVT full bridge converter.
5. A power system according to claim 4 wherein the ZVT full bridge converter is a conventional ZVT full bridge converter.
6. A power system according to claim 4 wherein the zero voltage transition (ZVT) full bridge converter is a modified ZVT full bridge converter.
7. A power system according to claim 6 wherein the modified ZVT full bridge converter comprises:
a pair of input lines;
a pair of inductorless output lines;
an input capacitor spanning the pair of input lines;
an array of switching devices, arranged in a full bridge configuration, spanning the pair of input lines after the input capacitor;
a transformer comprising a primary and a secondary, the primary of the transformer being connected to an output of the array of switching devices;
a diode rectifier connected to the secondary of the transformer, the output of the diode rectifier being connected to the pair of inductorless output lines; and
an output capacitor spanning the pair of inductorless output lines.
8. A method for converting voltage, comprising:
providing a modified zero voltage transition (ZVT) full bridge converter, the modified ZVT full bridge converter consisting of:
a pair of input lines;
a pair of inductorless output lines;
an input capacitor spanning the pair of input lines;
an array of switching devices, arranged in a full bridge configuration, spanning the pair of input lines after the input capacitor;
a transformer comprising a primary and a secondary, the primary of the transformer being connected to an output of the array of switching devices;
a diode rectifier connected to the secondary of the transformer, an output of the diode rectifier being connected to the pair of inductorless output lines; and
an output capacitor spanning the pair of inductorless output lines;
applying a voltage to the pair of input lines; and
selectively switching the array of switching devices to control an output voltage on the pair of inductorless output lines.
9. A method according to claim 8 , wherein the modified ZVT full bridge converter further comprises an inductor in series with the primary of the transformer, and wherein a free lead of the inductor and a free lead of the primary of the transformer are connected to the output of the array of switching devices.
10. A method for generating power, comprising:
providing a power system comprising:
a photovoltaic (PV) array having an output;
a zero voltage transition (ZVT) full bridge converter connected to the output of the PV array, the ZVT full bridge converter comprising a plurality of switches defining a first leg of a full bridge and a second leg of the full bridge, and a pair of output lines; and
a power tracking module connected to the ZVT full bridge converter, wherein the power tracking module is configured to control a phase relationship between a first control signal and a second control signal provided to the plurality of switches based on an output power of the ZVT full bridge converter; and
selectively switching the array of switching devices to control an output voltage on the pair of output lines.
11. A method according to claim 10 , wherein the pair of output lines comprises a pair of inductorless output lines.