Core Contactless LLC Charger and Controlling Method Thereof

• US 20170077737A1
• Filed: 03/15/2016
• Published: 03/16/2017
• Est. Priority Date: 09/15/2015
• Status: Active Grant

• Current Assignee: Amicord Corp.
• Original Assignee: Amicord Corp.
• Inventors: Hsieh, Hung-I
• Granted Patent: US 10,050,464 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 2310/40 The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: H02M 3/33571 Half-bridge at primary side of an isolation transformer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The configurations of LLC charger and controlling methods thereof are provided. The proposed charger includes a transmitter-receiver (TX-RX) transformer including a TX-matrix core set (TX-MCS) and an RX-MCS, an LLC power stage electrically connected to the TX-MCS, and a rectifier electrically connected to the RX-MCS so as to charge a battery pack with a non-contact power transmission.

Claims

1. An LLC charger, comprising:

a transmitter-receiver (TX-RX) transformer including a movable matrix core set (MCS), wherein the MCS separably includes a transmitter-MCS (TX-MCS) and a receiver-MCS (RX-MCS), and charges a battery pack with a non-contact power transmission via a resonant magnetic-induction coupling (RMIC) between the TX-MCS and the RX-MCS;

a transmitter including;

an LLC power stage; and

the TX-MCS electrically connected to the LLC power stage;

a receiver including;

the RX-MCS; and

a rectifier electrically connected to the RX-MCS.

2. The LLC charger according to claim 1, further comprising a filter capacitor electrically connected to the rectifier in parallel, wherein the TX-RX transformer further includes an RMIC area and a core loss, the MCS includes plural sub-TX cores and plural sub-Rx cores, the plural sub-TX cores and the plural sub-RX cores are arranged in respective matrix forms, and the MCS is configured in the TX-RX transformer to relatively increase the RMIC area and decrease the core loss thereof.

3. The LLC charger according to claim 2, further comprising two output terminals, an input power and an output current, wherein the output current is a charging current, each the sub-TX core and each the sub-RX core are both wound with at least one winding, the rectifier includes plural rectifying devices, all windings of the sub-TX cores are connected to one another in series to distribute the input power to the sub-TX cores, each winding of each the sub-RX core is electrically connected to a corresponding rectifying device, each winding of each the sub-RX core and the corresponding rectifying device are electrically connected to the two output terminals in parallel to distribute the charging current to each the sub-RX core, and either of each the sub-TX core and each the sub-RX core is one selected from a group consisting of an EE core, an EER core and a PQ core.

4. The LLC charger according to claim 3, wherein the TX-RX transformer is suitable for vehicle-mounted charging, and further includes a primary side and a secondary side, the LLC power stage is an LLC converter, the TX-MCS is the primary side, the primary side and the LLC converter are configured in a piece of equipment, the RX-MCS is the secondary side, the secondary side is configured on a vehicle-mounted system and includes each the sub-RX core and each the rectifying device, and when the vehicle-mounted system requires charging and moves toward the equipment, the RX-MCS and the TX-MCS are aligned automatically, and engage in charging via the RMIC.

5. The LLC charger according to claim 4, wherein the LLC converter includes a power element, the equipment is configured in one of a fixed position and a non-fixed position, the vehicle-mounted system is one selected from a group consisting of a vehicle, a self-propelled robot, an emergency medical care vehicle, and a wheel chair, the TX-RX transformer further includes plural sub-TX-RX transformers, each the sub-TX-RX transformer has a specific sub-TX core and a corresponding sub-RX core, and each the sub-TX-RX transformer has a turn ratio of (n_k=N_pk/N_sk)<

1, where n_k indicates a turn ratio of the kth sub-TX-RX transformer, N_pk is a number of turns of the winding on the specific sub-TX core, N_sk is a number of turns of the winding on the specific sub-RX core, and n_k<

1 results in a relatively small exciting current on the power element to decrease the core loss.

6. The LLC charger according to claim 4, further comprising a receiving terminal, wherein the battery pack is located on the receiving terminal and has an inner resistance, the LLC converter has a resonant tank and a resonant element, the charging via RMIC only requires a primary side resonance, and is free from a secondary side resonance to engage in the non-contact power transmission and to charge the battery pack, the receiver on the vehicle-mounted system only includes the RX-MCS and the rectifier because the LLC charger can adapt the battery pack into the resonant tank, the inner resistance is reflected to the TX-MCS being the primary side of the TX-RX transformer to serve as a portion of the resonant element, a parasitic capacitance and a leakage inductance generated due to a deviation from one of a parking spot and an installation position of the vehicle-mounted system are totally absorbed into the resonant tank to enable the charging current to be free from a noise interference, even if the deviance is generated, the LLC charger can continuously transmit a power due to the LLC charger has a wide frequency response capability, and although the charging capability will be decreased, the charging will not be interrupted.

12. A controlling method for an LLC charger, wherein the LLC charger is the LLC charger as claimed in claim 1, the LLC charger further includes an output current being a charging current, and the battery pack has an inner resistance, comprising

automatically regulating the charging current according to a state of charge of the battery pack and intersections of characteristic curves under respective circuit quality factors Q_r with a constant-frequency, when the LLC charger operates at the constant-frequency and in a self-regulating control status;

and

causing the charging current to decrease so as to achieve a trickle charging mode such that the charging current can be automatically regulated to have a safe charging function, and when the battery pack gradually approaches a full capacity, the inner resistance increases, the circuit quality factor Q_r decreases, and the LLC charger has an operating point changed from a first one of the intersections to a second one of the intersections on a characteristic curve of Q_r of light-load.

13. The controlling method for the LLC charger according to claim 12, wherein the LLC charger further includes a filter capacitor electrically connected to the rectifier in parallel, the TX-RX transformer further includes an RMIC area and a core loss, the MCS includes plural sub-TX cores and plural sub-Rx cores, the plural sub-TX cores and the plural sub-RX cores are arranged in respective matrices, the MCS is configured in the TX-RX transformer to relatively increase the RMIC area and decrease the core loss.

14. The controlling method for the LLC charger according to claim 13, wherein the LLC charger further includes two output terminals and an input power, each the sub-TX core and each the sub-RX core are both wound with at least one winding, the rectifier includes plural rectifying devices, all windings of the sub-TX cores are connected to one another in series to distribute the input power to the sub-TX cores, each winding of each the sub-RX core is electrically connected to a corresponding rectifying device, each winding of each the sub-RX core and the corresponding rectifying device are electrically connected to the two output terminals in parallel to distribute the charging current to each the sub-RX core, and either of each the sub-TX core and each the sub-RX core is one selected from a group consisting of an EE core, an EER core and a PQ core.

15. The controlling method for the LLC charger according to claim 14, wherein the TX-RX transformer is suitable for vehicle-mounted charging, and further includes a primary side and a secondary side, the LLC power stage is an LLC converter, the TX-MCS is the primary side, the primary side and the LLC converter are configured in a piece of equipment, the RX-MCS is the secondary side, the secondary side is configured on a vehicle-mounted system and includes each the sub-RX core and each the rectifying device, and when the vehicle-mounted system requires charging and moves toward the equipment, the RX-MCS and the TX-MCS are aligned automatically, and engage in charging via the RMIC.

16. The controlling method for the LLC charger according to claim 15, wherein the LLC converter includes a power element, the equipment is configured in one of a fixed position and a non-fixed position, the vehicle-mounted system is one selected from a group consisting of a vehicle, a self-propelled robot, an emergency medical care vehicle, and a wheel chair, the TX-RX transformer further includes plural sub-TX-RX transformers, each the sub-TX-RX transformer has a specific sub-TX core and a corresponding sub-RX core, and each the sub-TX-RX transformer has a turn ratio of (n_k=N_pk/N_sk)<

1, where n_k indicates a turn ratio of the kth sub-TX-RX transformer, N_pk is a number of turns of the winding of the specific sub-TX core, N_sk is a number of turns of the winding of the specific sub-RX core, and n_k<

1 results in a relatively small exciting current on the power element to decrease the core loss.

17. The controlling method for the LLC charger according to claim 16, wherein the LLC charger further includes a receiving terminal, the battery pack is located on the receiving terminal, the LLC converter has a resonant tank and a resonant element, the charging via RMIC requires a primary side resonance to engage in the non-contact power transmission and to charge the battery pack, the inner resistance is reflected to the TX-MCS being the primary side of the TX-RX transformer to serve as a portion of the resonant element, a parasitic capacitance and a leakage inductance generated due to a deviation from one of a parking spot and an installation position of the vehicle-mounted system are totally absorbed into the resonant tank to enable the charging current to be free from a noise interference.

18. A controlling method for an LLC charger, wherein the LLC charger is the LLC charger as claimed in claim 1, the LLC charger further includes an output current being a charging current, and the battery pack has an inner resistance, comprising

selecting a specific operating frequency for the LLC charger corresponding to a characteristic curve of a given circuit quality factor Q_r so as to output a value of the charging current when the LLC charger operates under a variable-frequency control mode;

and

causing the LLC charger to automatically regulate the operating frequency according to a state of charge (SOC) of the battery pack on the characteristic curve of the Q_r so as to maintain the charging current as a constant current, wherein when the SOC of the battery pack increases, the inner resistance increases, the circuit quality factor Q_r decreases, and the LLC charger regulates the operating frequency so as to move an operation point of the LLC charger to a match Q_r-given characteristic curve of a relatively heavy load, and to prevent the charging current from decreasing to be maintained at the constant current to achieve a constant current charging mode.

7. A charger, comprising:

a transmitter-receiver (TX-RX) transformer including a TX-matrix core set (TX-MCS) and an RX-MCS;

an LLC power stage electrically connected to the TX-MCS; and

a rectifier electrically connected to the RX-MCS so as to charge a battery pack with a non-contact power transmission.

8. A transmitter-receiver (TX-RX) transformer comprising a matrix core set (MCS), wherein the MCS includes:

a TX-MCS; and

an RX-MCS generating a resonant magnetic-induction coupling (RMIC) with the TX-MCS so as to output a contactless power.

9. An LLC charger, comprising:

the TX-RX transformer as claimed in claim 8, wherein the MCS is movable, and charges a battery pack with a non-contact power transmission via the RMIC between the TX-MCS and the RX-MCS;

an LLC power stage electrically connected to the TX-MCS; and

a rectifier electrically connected to the RX-MCS.

10. The LLC charger according to claim 9, further comprising a transmitter and a receiver, wherein the transmitter includes the LLC power stage and the TX-MCS, and the receiver includes the RX-MCS and the rectifier.

11. A charger, comprising:

the TX-RX transformer as claimed in claim 8;

an LLC power stage electrically connected to the TX-MCS; and

a rectifier electrically connected to the RX-MCS so as to charge a battery pack with a non-contact power transmission.