CN-121791692-B - Multiplexing bridge arm control method and multiplexing bridge arm system

CN121791692BCN 121791692 BCN121791692 BCN 121791692BCN-121791692-B

Abstract

The invention relates to the technical field of vehicle-mounted power supply control, in particular to a multiplexing bridge arm control method and a multiplexing bridge arm system, which are oriented to an integrated topology of multiplexing an OBC circuit and a DCDC circuit, and are used for collecting a DCDC circuit running state identifier, an OBC circuit starting signal and an alternating current input voltage sampling value by taking bridge arms H7 and H8 as fixed phase references, aligning starting time corresponding to the starting signal to the zero crossing point time of the next alternating current input voltage as the starting time of the OBC circuit under the DCDC circuit running state, switching the upper limit of output power of the DCDC circuit from a first upper limit of power to a second upper limit of power before the starting time arrives, switching the switching frequency of the DCDC circuit from the first switching frequency to the second switching frequency after the starting time arrives, and executing phase shifting control in a secondary bridge and inter-bridge phase shifting control. The method reduces the number of power devices and driving, suppresses input current impact and power factor fluctuation, and reduces electromagnetic compatibility pressure.

Inventors

FU YU
LUAN LI
HAO CHENJUN
SHAO QINGHUI

Assignees

常州是为电子有限公司

Dates

Publication Date: 20260508
Application Date: 20260305

Claims (6)

1. The multiplexing bridge arm control method is characterized by comprising the following steps of: s1, in an integrated topology of multiplexing an OBC circuit and a DCDC circuit, setting reference bridge arms H7 and H8 in the OBC circuit as fixed phase references, and acquiring a DCDC circuit running state identifier, an OBC circuit starting signal and an alternating current input voltage sampling value; S2, when the DCDC circuit running state identification indicates that the DCDC circuit is in a running state and receives the OBC circuit starting signal, detecting the zero crossing point moment of the alternating current input voltage according to the alternating current input voltage sampling value, and aligning the starting moment corresponding to the OBC circuit starting signal to the next zero crossing point moment of the alternating current input voltage to obtain the OBC circuit starting moment; S3, before the OBC circuit start-up time arrives, switching the DCDC circuit output power upper limit from a first power upper limit to a second power upper limit, and simultaneously switching the DCDC circuit switching frequency from a first switching frequency to a second switching frequency, and maintaining the second power upper limit when the OBC circuit start-up time arrives; S4, after the OBC circuit is started, respectively executing secondary side intra-bridge phase shifting control and inter-bridge phase shifting control by taking the reference bridge arms H7 and H8 as phase references; the integrated topology of the multiplexing of the OBC circuit and the DCDC circuit comprises an OBC circuit and a DCDC circuit, the OBC circuit comprises a first topology end and a second topology end, the first topology end and the second topology end are connected through a transformer T1, the DCDC circuit comprises a third topology end and a fourth topology end, the third topology end and the fourth topology end are connected through a transformer T2, the second topology end comprises switches H5, H6, H7 and H8, the switches H5 and H6 form a first bridge arm, the switches H7 and H8 form a multiplexing bridge arm, the fourth topology end comprises a second bridge arm formed by switches DC-G3 and DC-G4, the first bridge arm, the multiplexing bridge arm, the second bridge arm and a capacitor C 0 are connected in parallel, an intermediate connection point of the switches H5 and H6 and an intermediate connection point of the switches H7 and H8 are respectively connected with two secondary side ends of the transformer T1, and an intermediate connection point of the switches DC-G3 and DC-G4 and an intermediate connection point of the switches H7 and H8 are respectively connected with two primary side ends of the transformer T2; the first power upper limit is larger than the second power upper limit, and the second power upper limit is kept unchanged within a preset duration time after the OBC circuit is started; The first switching frequency corresponds to the switching frequency of the DCDC circuit in an independent working mode, the second switching frequency corresponds to the switching frequency of the OBC circuit and the DCDC circuit in a cooperative operation state, and the second switching frequency is consistent with the working frequency of the OBC circuit.
2. The method of multiplexing leg control according to claim 1 wherein the aligning the start-up time to the next ac input voltage zero-crossing time includes setting the OBC circuit start-up time to the next ac input voltage zero-crossing time immediately after the OBC circuit start-up signal arrival time when the OBC circuit start-up signal arrival time does not coincide with the ac input voltage zero-crossing time.
3. The method for controlling multiplexed bridge arms according to claim 1, wherein the secondary side intra-bridge phase shift control includes setting secondary side intra-bridge phase shift angles for secondary side bridge arms H5, H6 with respect to the reference bridge arms H7, H8, and the inter-bridge phase shift control includes setting inter-bridge phase shift angles for primary side bridge arms of an OBC circuit with respect to the reference bridge arms H7, H8.
4. The multiplexing leg control method according to claim 1 wherein the switching time of the DCDC circuit output power upper limit includes the time of arrival of the OBC circuit start-up signal and the second power upper limit is validated before the time of arrival of the OBC circuit start-up signal.
5. The multiplexing leg control method according to claim 1 wherein the OBC circuit is a unipolar matrix converter topology and the secondary intra-bridge phase shift control and the inter-bridge phase shift control are still performed in the unipolar matrix converter topology with the reference legs H7, H8 as fixed phase references.
6. The multiplexing bridge arm control method according to claim 1, wherein both ends of the multiplexing bridge arm are respectively connected to an output end of a high-voltage power supply Chi Lvbo, and an input end of the high-voltage power supply Chi Lvbo is connected to an output end of a high-voltage battery.

Description

Multiplexing bridge arm control method and multiplexing bridge arm system Technical Field The invention belongs to the technical field of vehicle-mounted power supply control, and particularly relates to a multiplexing bridge arm control method and a multiplexing bridge arm system. Background In the OBC circuit and DCDC circuit integrated architecture, the circuit form of multiplexing the OBC circuit and the DCDC circuit exists, and compared with a scheme of topological independence of a two-stage OBC circuit or an OBC circuit and a DCDC circuit, the number of power devices and the number of driving devices are reduced, and the circuit integration level is improved. Under the multiplexing architecture, if fixed frequency direct start is adopted during the operation of the DCDC circuit, the input current at the alternating side is easy to impact, the power factor and the electromagnetic compatibility index are affected, and meanwhile, in order to meet the loss constraint of the multiplexing power device, the DCDC circuit has the dynamic constraint requirement of the upper limit of the output power at the start stage of the OBC circuit. Therefore, an OBC circuit start-up control flow matched with the multiplexing bridge arm integrated topology is needed to coordinate and set the start-up time of the OBC circuit, the upper limit of the DCDC circuit power and the switching frequency of the DCDC circuit in the DCDC circuit operation state. Disclosure of Invention This section is intended to outline some aspects of embodiments of the application and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application. In order to solve the technical problems, the invention provides a multiplexing bridge arm control method, which comprises the following steps: s1, in an integrated topology of multiplexing an OBC circuit and a DCDC circuit, setting reference bridge arms H7 and H8 in the OBC circuit as fixed phase references, and acquiring a DCDC circuit running state identifier, an OBC circuit starting signal and an alternating current input voltage sampling value; S2, when the DCDC circuit running state identification indicates that the DCDC circuit is in a running state and receives the OBC circuit starting signal, detecting the zero crossing point moment of the alternating current input voltage according to the alternating current input voltage sampling value, and aligning the starting moment corresponding to the OBC circuit starting signal to the next zero crossing point moment of the alternating current input voltage to obtain the OBC circuit starting moment; s3, before the OBC circuit start-up time arrives, switching the DCDC circuit output power upper limit from a first power upper limit to a second power upper limit, and maintaining the second power upper limit when the OBC circuit start-up time arrives; And S4, after the start-up time of the OBC circuit arrives, switching the switching frequency of the DCDC circuit from the first switching frequency to the second switching frequency, and respectively executing secondary side intra-bridge phase shift control and inter-bridge phase shift control by taking the reference bridge arms H7 and H8 as phase references. As a preferable technical scheme of the multiplexing bridge arm control method, the bridge arms multiplexed in the integrated topology are an OBC circuit and a DCDC circuit, and the reference bridge arms H7 and H8 belong to the OBC circuit and keep a phase reference unchanged in the whole OBC circuit starting process. The method for controlling the multiplexing bridge arm includes setting the start time of the OBC circuit to be the zero crossing point time of the next alternating input voltage immediately after the arrival time of the start signal of the OBC circuit when the arrival time of the start signal of the OBC circuit does not coincide with the zero crossing point time of the alternating input voltage. As a preferable technical scheme of the multiplexing bridge arm control method, the first power upper limit is larger than the second power upper limit, and the second power upper limit is kept unchanged within a preset duration after the OBC circuit start-up time arrives. As a preferable technical scheme of the multiplexing bridge arm control method, the first switching frequency corresponds to the switching frequency of the DCDC circuit in an independent working mode, the second switching frequency corresponds to the switching frequency of the OBC circuit in a cooperative operation state with the DCDC circuit, and the second switching frequency is consistent with the working frequency of the OBC circuit. As a preferable technical scheme of the multiplexing bridge arm control method, the secondary side intra-bridge phase shift control comprises setting seconda