Integrated dual-output grid-to-vehicle (G2V) and vehicle-to-grid (V2G) onboard charger for plug-in electric vehicles
An integrated and isolated onboard charger for plug-in electric vehicles, includes an ac-dc converter and a dual-output dc-dc resonant converter, for both HV traction batteries and LV loads. In addition, the integrated and isolated onboard charger may be configured as unidirectional or bidirectional, and is capable of delivering power from HV traction batteries to the grid for vehicle-to-grid (V2G) applications. To increase the power density of the converter, the dual-output DC-DC resonant converter may combine magnetic components of resonant networks into a single three-winding electromagnetically integrated transformer (EMIT). The resonant converter may be configured as a half-bridge topology with split capacitors as the resonant network components to further reduce the size of converter. The integrated charger may be configured for various operating modes, including grid to vehicle (G2V), vehicle to grid (V2G) and high voltage to low voltage, HV-to-LV (H2L) charging.
1. An onboard vehicle battery charger system comprising:
an onboard charger including:
an AC-DC converter configured to be in electrical communication with a power grid; and
a DC-DC converter in electrical communication with the AC-DC converter and including:
first and second dual-active integrated bridge converters in electrical communication with a three-winding electromagnetically-integrated transformer, the three-winding electromagnetically-integrated transformer including:
a primary winding,
a first secondary winding, and
a second secondary winding,
the first and second dual-active integrated bridge converters configured to be in electrical communication with, respectively:
a high voltage power battery configured to be mounted onboard a vehicle and in electrical communication with the first secondary winding, and
a low voltage auxiliary battery configured to be mounted onboard the vehicle and in electrical communication with the second secondary winding,
wherein the onboard vehicle battery charger system enables at least one of:
charging simultaneously the high voltage power battery and the low voltage auxiliary battery from the power grid,
charging only one of the high voltage power battery or the low voltage auxiliary battery from the power grid, or
providing electrical power to the power grid from the vehicle via the high voltage power battery or the low voltage auxiliary battery, or both.
2. The system according to claim 1 ,
wherein the AC-DC converter is a first stage power factor correction AC-DC converter and
wherein the DC-DC converter in electrical communication with the AC-DC converter and including the first and second dual-active integrated bridge converters defines a second stage integrated DC-DC converter.
3. The system according to claim 2 ,
wherein an input of the first dual-active bridge converter is in electrical communication with the first stage power factor correction AC-DC converter, and an output of the first dual-active bridge converter is in electrical communication with the high voltage power battery,
wherein an output of the second dual-active bridge converter is in electrical communication with the low voltage auxiliary battery.
4. The system according to claim 3 ,
wherein the first dual-active bridge converter is intertwined with the second dual-active bridge converter through the three-winding electromagnetically-integrated transformer; and
a three bridge rectifier is in electrical communication with the three-winding electromagnetically-integrated transformer.
5. The system according to claim 4 ,
wherein the electromagnetically-integrated transformer is a transformer configured such that leakage inductances and magnetizing inductances are integrated electromagnetically within the transformer, forming thereby the electromagnetically-integrated transformer,
wherein the electromagnetically-integrated transformer includes:
a first EE core defining a base portion, a central leg and first and second peripheral legs;
a second EE core defining a base portion, a central leg and first and second peripheral legs;
a primary winding wound around the central leg of the first EE core between the first peripheral leg and the central leg and between the second peripheral leg and the central leg of the first EE core;
a secondary winding wound around the central leg of the second EE core between the first peripheral leg and the central leg and between the second peripheral leg and the central leg of the second EE core; and
a tertiary winding wound around the central leg of the second EE core between the first peripheral leg and the central leg and between the second peripheral leg and the central leg of the second EE core,
wherein edges of the legs of the first EE core align with edges of the legs of the second EE core,
wherein the tertiary winding is wound on the central leg of the second EE core below the primary winding wound on the central leg of the first EE core and above the secondary winding wound on the central leg of the second EE core,
wherein an adjustable winding gap is formed between a lower edge of the primary winding on the first EE core and an upper edge of the secondary winding on the second EE core, establishing spatial separation between the secondary winding and the primary winding, and
wherein an adjustable winding gap is formed between a lower edge of the primary winding on the first EE core and an upper edge of the tertiary winding on the second EE core, establishing spatial separation between the tertiary winding and the primary winding.
6. A three-winding electromagnetically-integrated transformer comprising:
a first EE core defining a base portion, a central leg and first and second peripheral legs;
a second EE core defining a base portion, a central leg and first and second peripheral legs;
a primary winding wound around the central leg of the first EE core between the first peripheral leg and the central leg and between the second peripheral leg and the central leg of the first EE core;
a secondary winding wound around the central leg of the second EE core between the first peripheral leg and the central leg and between the second peripheral leg and the central leg of the second EE core; and
a tertiary winding wound around the central leg of the second EE core between the first peripheral leg and the central leg and between the second peripheral leg and the central leg of the second EE core,
wherein edges of the legs of the first EE core align with edges of the legs of the second EE core
wherein the tertiary winding is wound on the central leg of the second EE core below the primary winding wound on the central leg of the first EE core and above the secondary winding wound on the central leg of the second EE core,
wherein an adjustable winding gap is formed between a lower edge of the primary winding on the first EE core and an upper edge of the secondary winding on the second EE core, establishing spatial separation between the secondary winding and the primary winding, and
wherein an adjustable winding gap is formed between a lower edge of the primary winding on the first EE core and an upper edge of the tertiary winding on the second EE core, establishing spatial separation between the tertiary winding and the primary winding.
7. The three-winding electromagnetically-integrated transformer according to claim 6 ,
wherein the edges of the legs of the first EE core that align with edges of the legs of the second EE core and the secondary winding and tertiary winding are adjacent to one another along an axis defined by the central leg of the first EE core and the central leg of the second EE core.
8. The three-winding electromagnetically-integrated transformer according to claim 7 , wherein edges of the legs of the first EE core align with edges of the legs of the second EE core and the tertiary winding is formed concentrically around the secondary winding and both the secondary winding and the tertiary winding are formed concentrically around the central leg of the second EE core, and
wherein the tertiary winding defines an adjustable concentric winding gap with respect to the secondary winding, establishing spatial separation between the tertiary winding and the secondary winding.
9. The three-winding electromagnetically-integrated transformer according to claim 6 ,
wherein the first EE core defines lower edges of the first and second peripheral legs and central leg defining the first EE core and the second EE core defines upper edges of the first and second peripheral legs and central leg defining the second EE core,
wherein a central core gap is formed by a distance between the lower edge of the central leg of the first EE core and the upper edge of the central leg of the second EE core and a first peripheral core gap is formed by a distance between the lower edge of the first peripheral leg of the first EE core and the upper edge of the first peripheral leg of the second EE core and a second peripheral core gap is formed by a distance between the lower edge of the second peripheral leg of the first EE core and the upper edge of the second peripheral leg of the second EE core, thereby causing leakage inductance yielded by the electromagnetically-integrated transformer.
10. The three-winding electromagnetically-integrated transformer according to claim 9 , wherein the distances of the first peripheral core gap, central core gap and second peripheral core gap are equal to one another.
11. The three-winding electromagnetically-integrated transformer according to claim 6 ,
wherein an adjustable winding gap is formed between the lower edge of the tertiary winding and the upper edge of the secondary winding, establishing spatial separation between the tertiary winding and the secondary winding.
12. The three-winding electromagnetically-integrated transformer according to claim 6 ,
wherein the lower edge of the first peripheral leg of the first EE core is in contact with the upper edge of the first peripheral leg of the second EE core,
wherein the lower edge of the second peripheral leg of the first EE core is in contact with the upper edge of the second peripheral leg of the second EE core, and
wherein a central gap is formed between a lower edge of the central leg of the first EE core and an upper edge of the central leg of the second EE core, thereby causing leakage inductance yielded by the electromagnetically-integrated transformer.