US-20260128597-A1 - ON-BOARD CHARGER AND CONTROL METHOD THEREFOR

US20260128597A1US 20260128597 A1US20260128597 A1US 20260128597A1US-20260128597-A1

Abstract

A method for controlling an on-board charger is provided. A transformer side of an AC/AC conversion circuit is connected to an alternating current side of an AC/DC conversion circuit through a transformer. A reference peak value of a grid-side current of the on-board charger is regulated based on a deviation of a sampled value of a battery-side voltage relative to a reference value of the battery-side voltage. The reference peak value of the grid-side current is converted into an instantaneous reference value of the grid-side current based on a phase of an instantaneous sampled value of the grid-side voltage of the on-board charger. Phase-shift control is performed on the two conversion circuits based on the instantaneous reference value of the grid-side current, the instantaneous sampled value of the grid-side voltage and the sampled value of the battery-side voltage.

Inventors

Hao Wang

Assignees

SUNGROW POWER SUPPLY CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20230522
Priority Date: 20221116

Claims (14)

1 . A method for controlling an on-board charger, wherein in the on-board charger, a transformer side of a controllable bridge-type alternating-current/alternating-current conversion circuit is connected to an alternating-current side of a controllable bridge-type alternating-current/direct-current conversion circuit through a transformer, and the method for controlling the on-board charger comprises: regulating a reference peak value of a grid-side current of the on-board charger based on a deviation of a sampled value of a battery-side voltage relative to a reference value of the battery-side voltage; converting the reference peak value of the grid-side current into an instantaneous reference value of the grid-side current based on a phase of an instantaneous sampled value of the grid-side voltage of the on-board charger; performing phase-shift control on the two conversion circuits based on the instantaneous reference value of the grid-side current, the instantaneous sampled value of the grid-side voltage and the sampled value of the battery-side voltage, wherein the phase-shift control is for controlling power components in the two conversion circuits to achieve soft switching; and correcting the phase-shift control based on a deviation of the instantaneous sampled value of the grid-side current relative to the instantaneous reference value of the grid-side current.
2 . The method for controlling the on-board charger according to claim 1 , wherein the phase-shift control comprises: determining a phase-shift angle of an output voltage of the transformer side of the alternating-current/alternating-current conversion circuit and a phase-shift angle of an output voltage of the alternating-current side of the alternating-current/direct-current conversion circuit based on the instantaneous reference value of the grid-side current, the instantaneous sampled value of the grid-side voltage, the sampled value of the battery-side voltage, a switching frequency of the on-board charger and an equivalent total reactance of all passive components in the on-board charger; generating respective drive signals for the two conversion circuits based on the two phase-shift angles; and driving the two conversion circuits to perform power conversion based on the respective drive signals for the two conversion circuits.
3 . The method for controlling the on-board charger according to claim 2 , wherein the determining a phase-shift angle of an output voltage of the transformer side of the alternating-current/alternating-current conversion circuit and a phase-shift angle of an output voltage of the alternating-current side of the alternating-current/direct-current conversion circuit comprises: determining the phase-shift angle of the output voltage of the transformer side of the alternating-current/alternating-current conversion circuit and a relationship between the two phase-shift angles based on the instantaneous reference value of the grid-side current, the instantaneous sampled value of the grid-side voltage, the sampled value of the battery-side voltage, the switching frequency of the on-board charger and the equivalent total reactance of all the passive components in the on-board charger, wherein the phase-shift angle of the output voltage of the transformer side of the alternating-current/alternating-current conversion circuit is within a range for controlling the power components in the two conversion circuits to achieve the soft switching; and determining the phase-shift angle of the output voltage of the alternating-current side of the alternating-current/direct-current conversion circuit based on the phase-shift angle of the output voltage of the transformer side of the alternating-current/alternating-current conversion circuit and the relationship between the two phase-shift angles.
4 . The method for controlling the on-board charger according to claim 1 , wherein the correcting the phase-shift control based on a deviation of the instantaneous sampled value of the grid-side current relative to the instantaneous reference value of the grid-side current comprises: correcting at least one of phase-shift angles in the phase shift control.
5 . The method for controlling the on-board charger according to claim 1 , wherein the reference value of the battery-side voltage is equal to a charging voltage of a battery connected to the on-board charger under a constant voltage trickle charging condition.
6 . The method for controlling the on-board charger according to claim 1 , wherein the regulating a reference peak value of a grid-side current of the on-board charger based on a deviation of a sampled value of a battery-side voltage relative to a reference value of the battery-side voltage comprises: regulating a reference value of a battery-side current based on the deviation of the sampled value of the battery-side voltage relative to the reference value of the battery-side voltage; and regulating the reference peak value of the grid-side current based on a deviation of a sampled value of the battery-side current relative to the reference value of the battery-side current.
7 . The method for controlling the on-board charger according to claim 6 , wherein the reference value of the battery-side current is less than or equal to a charging current of a battery connected to the on-board charger under a constant current charging condition.
8 . The method for controlling the on-board charger according to claim 7 , wherein the charging current of the battery under the constant current charging condition is determined based on an operating state of the on-board charger and a user instruction.
9 . An on-board charger, comprising: a controller; a transformer; at least one passive component; a controllable bridge-type alternating-current/alternating-current conversion circuit; and a controllable bridge-type alternating-current/direct-current conversion circuit, wherein a transformer side of the alternating-current/alternating-current conversion circuit is connected to an alternating-current side of the alternating-current/direct-current conversion circuit through the transformer; a grid side of the alternating-current/alternating-current conversion circuit serves as a grid side of the on-board charger, and a direct-current side of the alternating-current/direct-current conversion circuit serves as a battery side of the on-board charger; a primary side and/or a secondary side of the transformer is provided with the at least one passive component, and each of the at least one passive component at least comprises an inductor; and both the alternating-current/alternating-current conversion circuit and the alternating-current/direct-current conversion circuit are controlled by the controller, and the controller is configured to perform the method for controlling the on-board charger according to claim 1 .
10 . The on-board charger according to claim 9 , wherein the alternating-current/alternating-current conversion circuit is implemented by a half-bridge topology or a full-bridge topology; and the alternating-current/direct-current conversion circuit is implemented by a half-bridge topology or a full-bridge topology.
11 . The on-board charger according to claim 9 , wherein the at least one passive component comprises an inductor branch, and the inductor branch comprises at least one inductor, in response to the number of the at least one inductor being greater than 1, the inductors are connected in series, connected in parallel, or connected in series and parallel.
12 . The on-board charger according to claim 11 , wherein the at least one passive component further comprises a capacitor branch, and the capacitor branch is connected in series or connected in parallel with the inductor branch, wherein, the capacitor branch comprises at least one capacitor, and in response to the number of the at least one capacitor is greater than 1, the capacitors are connected in series, connected in parallel, or connected in series and parallel.
13 . The on-board charger according to claim 9 , wherein a switching frequency of the on-board charger is greater than a resonant frequency of a resonant cavity in the on-board charger.
14 . The on-board charger according to claim 9 , further comprising two filters, wherein one of the two filters is arranged at the grid side of the alternating-current/alternating-current conversion circuit, and the other filter is arranged at the direct-current side of the alternating-current/direct-current conversion circuit.

Description

This application is a national stage filing under 35 U.S.C. § 371 of International Patent Application Serial No. PCT/CN2023/095481, filed May 22, 2023, which claims priority to Chinese Patent Application No. 202211460016.1, titled “ON-BOARD CHARGER AND CONTROL METHOD THEREFOR”, filed on Nov. 16, 2022 with the China National Intellectual Property Administration. The contents of these applications are incorporated herein by reference in their entirety. FIELD The present disclosure relates to the technical field of power electronics, and in particular to an on-board charger and a method for controlling the on-board charger. BACKGROUND At present, a two-stage isolated on-board charger is widely applied in practice and may also be referred to as a two-stage structure. A detailed structure of the two-stage isolated on-board charger may be shown in FIG. 1. The isolated two-stage structure includes a PFC (Power Factor Correction) circuit and an isolated DC/DC conversion circuit. The PFC circuit is configured to correct a power factor of a grid current and maintain stability of a voltage between two electrodes of a direct-current bus Cbus. The isolated DC/DC conversion circuit is configured to control a battery-side voltage or battery-side current of the on-board charger to implement the charging process of a battery. In general, the two-stage isolated on-board charger requires a relatively large number of power components, resulting in an increase of the overall cost of the on-board charger. In order to reduce the overall cost of the on-board charger, a single-stage isolated on-board charger may be arranged, which may also be referred to as a single-stage structure. Therefore, how to enable the single-stage isolated on-board charger to function as the two-stage isolated on-board charger to efficiently achieve the PFC function and control the battery-side voltage or battery-side current is an issue urgently addressed. SUMMARY In views of the above issue, an on-board charger and a method for controlling an on-board charger are provided according to the present disclosure, to enable the single-stage isolated on-board charger to function as the two-stage isolated on-board charger to efficiently achieve the PFC function and control the battery-side voltage or battery-side current. In order to achieve the objectives described above, the following technical solutions are provided according to embodiments of the present disclosure. In a first aspect of the present disclosure, a method for controlling an on-board charger is provided. In the on-board charger, a transformer side of a controllable bridge-type alternating-current/alternating-current (AC/AC) conversion circuit is connected to an alternating-current side of a controllable bridge-type alternating-current/direct-current (AC/DC) conversion circuit through a transformer. The method for controlling the on-board charger includes: regulating a reference peak value of a grid-side current of the on-board charger based on a deviation of a sampled value of a battery-side voltage relative to a reference value of the battery-side voltage;converting the reference peak value of the grid-side current into an instantaneous reference value of the grid-side current based on a phase of an instantaneous sampled value of the grid-side voltage of the on-board charger;performing phase-shift control on the two conversion circuits based on the instantaneous reference value of the grid-side current, the instantaneous sampled value of the grid-side voltage and the sampled value of the battery-side voltage, where the phase-shift control is for controlling power components in the two conversion circuits to achieve soft-switching; andcorrecting the phase-shift control based on a deviation of the instantaneous sampled value of the grid-side current relative to the instantaneous reference value of the grid-side current. In a second aspect of the present disclosure, an on-board charger is provided. The on-board charger includes a controller, a transformer, at least one passive component, a controllable bridge-type alternating-current/alternating-current (AC/AC) conversion circuit and a controllable bridge-type alternating-current/direct-current (AC/DC) conversion circuit. A transformer side of the AC/AC conversion circuit is connected to an alternating-current side of the AC/DC conversion circuit through the transformer; a grid side of the AC/AC conversion circuit serves as a grid side of the on-board charger, and a direct-current side of the AC/DC conversion circuit serves as a battery side of the on-board charger. A primary side and/or a secondary side of the transformer is provided with the at least one passive component, and each of the at least one passive component at least includes an inductor. Both the AC/AC conversion circuit and the AC/DC conversion circuit are controlled by the controller. The controller is configured to perform the method for controlling the on-board charger according