Module of suppressing inrush current, method of controlling the same and on-board bidirectional charger using the same

• US 11,088,538 B2
• Filed: 05/07/2019
• Issued: 08/10/2021
• Est. Priority Date: 05/09/2018
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Sun, Hao, Chang, Lei, Zhang, Jinfa
• Primary Examiner(s): Laxton, Gary L
• Application Number:
  US16/405,018
• Publication Number:
  US 20190348833A1
• Time in Patent Office: 826 Days
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• CPC Class Codes: B60L 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: H02H 9/002 limiting inrush current on switching on of inductive loads subjected to remanence, e.g. transformers
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: H02M 1/4233 using a bridge converter comprising active switches
• CPC Class Codes: H02M 1/4258 using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage H02M1/4241 takes precedence
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 7/125 Avoiding or suppressing excessive transient voltages or currents
• CPC Class Codes: H02M 7/219 in a bridge configuration
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A module of suppressing inrush current, a method of controlling the module of suppressing inrush current and an on-board bidirectional charger using the same are provided. The on-board bidirectional charger includes a PFC-inverter module and the module of suppressing inrush current, and the module of suppressing inrush current includes a controlled switch and a suppressor of suppressing inrush current connected in parallel with the controlled switch. The charging and inverting circuits are fully multiplexed, which solves the problem that a high-power on-board charger under harsh AC power supply environment in bidirectional charging cannot provide special protection against inrush current, and can improve power density and circuit efficiency of charging and inversion, realize isolation function including reducing EMI electromagnetic interference and reducing switching interference signals, realize more convenient buck/boost functions, improve using life and performance of devices, reduce cost, and reduce the size of equipment.

Claims

1. A method of controlling a module of suppressing inrush current used in an on-board bidirectional charger, wherein:

the on-board bidirectional charger comprises a PFC-inverter module configured to convert an AC power into a DC power or convert the DC power into the AC power, the PFC-inverter module is connected to an AC input, a positive DC bus and a negative DC bus of the on-board bidirectional charger, and the PFC-inverter module comprises a bus capacitor connected between the positive DC bus and the negative DC bus; and

the module of suppressing inrush current is connected in series with the bus capacitor between the positive DC bus and the negative DC bus, and the module of suppressing inrush current comprises a controlled switch and a suppressor of suppressing inrush current connected in parallel with the controlled switch, and

the method comprises;

controlling the on-board bidirectional charger to receive an AC input power and charge the bus capacitor by a limited current through the suppressor of suppressing inrush current, wherein the controlled switch is in an off-state during the charging;

when a voltage of the bus approaches a peak value of a voltage of the AC input power, turning on the controlled switch;

controlling the PFC-inverter module to charge the bus capacitor by a constant current of a first AC current protection limit; and

when the voltage of the bus approaches a set voltage, increasing the first AC current protection limit to a normal operation limit, and charging a voltage of the bus capacitor to the set voltage.

2. The method according to claim 1, wherein the step of charging the bus capacitor by a constant current of a first AC current protection limit further comprises:

when the peak value of the voltage of the AC input power exceeds the voltage of the bus capacitor during the charging by the constant current, determining whether the current of the AC input power exceeds a second AC current protection limit;

when the current of the AC input power exceeds the second AC current protection limit, turning off the controlled switch, and charging the bus capacitor by the limited current through the suppressor of suppressing inrush current; and

when the voltage of the bus approaches or is higher than the peak value of the voltage of the AC input power again, turning on the controlled switch again, and charging the bus capacitor by the limited current of the first AC current protection limit.

3. The method according to claim 2, wherein the second AC current protection limit is higher than the first AC current protection limit.

4. The method according to claim 2, wherein a voltage generated by a current of the second AC current protection limit flowing through the module of suppressing inrush current is lower than a voltage that the DC bus can withstand.

5. The method according to claim 3, wherein, after the step of charging a voltage of the bus capacitor to the set voltage, the method further comprises:

when the voltage of the AC input power increases, keeping the controlled switch on.

6. An on-board bidirectional charger, comprising:

a PFC-inverter module, configured to convert an AC power into a DC power or convert the DC power into the AC power, the PFC-inverter module is connected to an AC input, a positive DC bus and a negative DC bus of the on-board bidirectional charger, and the PFC-inverter module comprises a bus capacitor connected between the positive DC bus and the negative DC bus;

a module of suppressing inrush current, configure to suppressing inrush current when the bus capacitor of the on-board bidirectional charger is charged, the module of suppressing inrush current is connected in series with the bus capacitor between the positive DC bus and the negative DC bus, and the module of suppressing inrush current comprises a controlled switch and a suppressor of suppressing inrush current connected in parallel with the controlled switch, wherein the suppressor of suppressing inrush current is a positive temperature coefficient resistor;

a sampling and encoding module, configured to acquire a voltage and a current of an AC input power from the PFC-inverter module, and to acquire a voltage of the bus from the module of suppressing inrush current;

an isolator, configured to isolate signals acquired from the sampling and encoding module; and

a controller, configured to control the controlled switch in the module of suppressing inrush current, based on signals acquired from the isolator.

7. The on-board bidirectional charger according to claim 6, further comprising:

a bidirectional resonant zero voltage switching DC/DC module, configured to boost or buck a voltage from the positive DC bus and the negative DC bus or a voltage from an on-board battery, wherein the bidirectional resonant zero voltage switching DC/DC module is connected to the positive DC bus, the negative DC bus and a positive terminal and a negative terminal of the on-board battery.

8. The on-board bidirectional charger according to claim 6, wherein the controlled switch is a transistor.

9. The on-board bidirectional charger according to claim 8, wherein the transistor is a MOSFET.

10. The on-board bidirectional charger according to claim 9, the MOSFET is a SiC MOSFET or GaN MOSFET.

11. The on-board bidirectional charger according to claim 7, wherein the bidirectional resonant zero voltage switching DC/DC module comprises:

a transformer comprising a primary winding and a secondary winding;

at least one primary-side bridge-arms, wherein a DC positive input terminal of each of the primary-side bridge-arms is connected to the positive DC bus, a DC negative input terminal of each of the primary-side bridge-arms is connected to the negative DC bus, and a midpoint of each of the primary-side bridge-arms is connected to a corresponding terminal of the primary winding of the transformer;

at least one secondary-side bridge-arms, wherein a DC positive output terminal of each of the secondary-side bridge-arms is connected to a positive terminal of the on-board battery, and a DC negative output terminal of each of the secondary-side bridge-arms is connected to a negative terminal of the on-board battery, and a midpoint of each of the secondary-side bridge-arms is connected to a corresponding terminal of the secondary winding of the transformer; and

at least one resonant tank, connected in series between the primary winding of the transformer and the midpoint of at least one of the primary-side bridge-arms, or between the secondary winding of the transformer and the midpoint of at least one of the secondary-side bridge-arms.

12. The on-board bidirectional charger according to claim 7, wherein the on-board bidirectional charger comprises a plurality of bidirectional resonant zero voltage switching DC/DC modules connected in parallel.

13. The on-board bidirectional charger according to claim 11, wherein a resonant capacitor is connected in series between the midpoint of one of the primary-side bridge-arms and the primary winding of the transformer, and another resonant capacitor is connected in series between the midpoint of one of the secondary-side bridge-arms and the secondary winding of the transformer.

14. The on-board bidirectional charger according to claim 6, wherein the controller communicates with a vehicle controller via an isolated CAN module.