CN-121984372-A - Single-phase bidirectional AC-DC converter based on power decoupling topology and control method

CN121984372ACN 121984372 ACN121984372 ACN 121984372ACN-121984372-A

Abstract

The invention relates to the technical field of bidirectional AC-DC converters, in particular to a single-phase bidirectional AC-DC converter based on a power decoupling topology and a control method. The power supply device comprises a rectification working mode and an inversion working mode, and comprises an alternating current circuit, an alternating current filter circuit, a conversion circuit, a power decoupling circuit, a direct current circuit, a sampling circuit, a control circuit and a driving circuit, wherein the control circuit is configured with a first controller, a second controller, a third controller and a fourth controller, the first controller is used for controlling the output voltage of the direct current circuit in the rectification working mode, the second controller is used for controlling the output current of the direct current circuit in the rectification working mode, the third controller is used for controlling the output current of the power decoupling circuit in the rectification working mode, and the fourth controller is used for controlling the output current of the alternating current circuit in the inversion working mode. The invention can effectively solve the problem of inhibiting single-phase power pulsation in bidirectional power conversion.

Inventors

LING ZAIXUN
CUI YIBO
WU XIAOMIN

Assignees

湖北方源东力电力科学研究有限公司

Dates

Publication Date: 20260505
Application Date: 20251226

Claims (9)

1. The single-phase bidirectional AC-DC converter based on the power decoupling topology has a rectification working mode and an inversion working mode and comprises an alternating current circuit (1), an alternating current filter circuit (2), a conversion circuit (3), a power decoupling circuit (4), a direct current circuit (5), a sampling circuit (601), a control circuit (701) and a driving circuit (801); Wherein, the The control circuit (701) is configured with a first controller, a second controller, a third controller and a fourth controller, wherein the first controller is used for controlling the output voltage of the direct current circuit (5) in a rectification working mode, the second controller is used for controlling the output current of the direct current circuit (5) in the rectification working mode, the third controller is used for controlling the output current of the power decoupling circuit (4) in the rectification working mode, and the fourth controller is used for controlling the output current of the alternating current circuit (1) in the inversion working mode.
2. The single-phase bi-directional AC-DC converter of claim 1 wherein the AC filter circuit (2) is a C-type filter, an LC-type filter or an LCL-type filter.
3. The single-phase bidirectional AC-DC converter based on power decoupling topology of claim 2, wherein the conversion circuit (3) is a full-bridge circuit based on 4 switching tubes (Q1, Q2, Q3, Q4).
4. The single-phase bi-directional AC-DC converter of claim 3 wherein the power decoupling circuit (4) is a symmetrical half-bridge power decoupling circuit based on 2 switching tubes (Qn 1, qn 2) and 1 inductor (L).
5. The single-phase bi-directional AC-DC converter based on a power decoupling topology of claim 4, wherein the DC circuit (5) comprises 2 DC capacitors (Cdc 1, cdc 2) connected in series.
6. A control method for a single-phase bi-directional AC-DC converter based on a power decoupling topology according to any one of claims 1-5, comprising: In a rectification working mode, the output voltage and the output current of the direct current circuit (5) are collected through a sampling circuit (601), and the control of the output voltage of the direct current circuit (5), the output current of the direct current circuit (5) and the output current of the power decoupling circuit (4) is realized based on the adjustment of the control parameters of the first controller, the second controller and the third controller; In the inversion working mode, the output current of the alternating current circuit (1) is collected through the sampling circuit (601), and the control of the output current of the alternating current circuit (1) is realized based on the adjustment of the control parameters of the controller IV.
7. The control method of claim 6, wherein the first controller, the second controller and the third controller are PI controllers, the control parameters of the first controller comprise a proportional coefficient K11 and an integral coefficient K12, the control parameters of the second controller comprise a proportional coefficient K21 and an integral coefficient K22, and the control parameters of the third controller comprise a proportional coefficient K31 and an integral coefficient K32; in the rectifying working mode, the sampling circuit (601) is used for collecting the output voltage and the output current of the direct current circuit (5), and based on the adjustment of the control parameters of the first controller, the second controller and the third controller, the control of the output voltage of the direct current circuit (5), the output current of the direct current circuit (5) and the output current of the power decoupling circuit (4) is realized, comprising, Limiting the output voltage of the direct current circuit (5) to a desired voltage value; setting a proportional coefficient K11 and an integral coefficient K12 of the first controller to 0; Adjusting the proportionality coefficient K21 of the second controller until the output current of the direct current circuit (5) is no longer oscillated, and taking the proportionality coefficient K21 of the second controller as a corresponding control parameter; Maintaining the proportional coefficient K21 of the second controller unchanged, and adjusting the integral coefficient K22 of the second controller until the output current of the direct current circuit (5) is no longer oscillated, wherein the integral coefficient K22 of the second controller is used as a corresponding control parameter; releasing the limitation of the output voltage of the direct current circuit (5); Sequentially adjusting the proportionality coefficient K11 of the first controller and the proportionality coefficient K31 of the third controller until the output voltage of the direct current circuit (5) is not oscillated any more, and taking the proportionality coefficient K11 of the first controller and the proportionality coefficient K31 of the third controller at the moment as corresponding control parameters; The proportional coefficient K11 of the first controller and the proportional coefficient K31 of the third controller are maintained unchanged, the integral coefficient K12 of the first controller and the integral coefficient K32 of the third controller are sequentially adjusted until the output voltage of the direct current circuit (5) is no longer oscillated, and the integral coefficient K12 of the first controller and the integral coefficient K32 of the third controller at the moment are used as corresponding control parameters.
8. The control method according to claim 7, wherein the limiting of the output voltage of the DC circuit (5) to a desired voltage value is achieved by applying a power supply clamp circuit to an output bus of the DC circuit (5).
9. The control method of claim 6, wherein the fourth controller is a PI controller, and the control parameters of the fourth controller include a proportional coefficient K41 and an integral coefficient K42; In the inversion working mode, the sampling circuit (601) is used for collecting the output current of the alternating current circuit (1) and realizing the control of the output current of the alternating current circuit (1) based on the adjustment of the control parameter of the controller IV, Adjusting the proportionality coefficient K41 of the fourth controller until the output current of the alternating current circuit (1) is no longer oscillated, and taking the proportionality coefficient K41 of the fourth controller at the moment as a corresponding control parameter; the proportional coefficient K41 of the fourth controller is maintained unchanged, the integral coefficient K42 of the fourth controller is regulated until the output current of the alternating current circuit (1) is no longer oscillated, and the integral coefficient K42 of the fourth controller is taken as a corresponding control parameter.

Description

Single-phase bidirectional AC-DC converter based on power decoupling topology and control method Technical Field The invention relates to the technical field of bidirectional AC-DC converters, in particular to a single-phase bidirectional AC-DC converter based on a power decoupling topology and a control method. Background With the wide application of grid-connected energy storage systems, the design requirements to be met by the bidirectional AC-DC converter are more strict. In particular, in terms of the quality of the AC waveform, the bidirectional AC-DC converter needs to operate under high power factor conditions, while the AC-side current waveform must have a smaller total harmonic distortion rate to meet the requirements of grid-connected harmonic standards, and the DC-side voltage ripple needs to be smaller to meet the requirements of DC-side voltage stabilization. Currently, the prior art and methods solve the above-mentioned problems for single-phase bi-directional AC-DC converters, but all have certain limitations. For example, the traditional method for processing the DC bus voltage ripple mainly increases the bus capacitance, and absorbs the voltage ripple by using the bus capacitance, but the method greatly increases the volume of the bus capacitance and reduces the service life of the capacitance, while some topologies use a power decoupling circuit to inhibit the DC side voltage ripple, but because the structure is complex and the cost is high, the requirements of the modern power system on high-efficiency and accurate compensation are difficult to meet. Disclosure of Invention The invention provides a single-phase bidirectional AC-DC converter based on a power decoupling topology and a control method, which can overcome certain or certain defects in the prior art. The single-phase bidirectional AC-DC converter based on the power decoupling topology has a rectification working mode and an inversion working mode and comprises an alternating current circuit, an alternating current filter circuit, a conversion circuit, a power decoupling circuit, a direct current circuit, a sampling circuit, a control circuit and a driving circuit; Wherein, the The control circuit is configured with a first controller, a second controller, a third controller and a fourth controller, wherein the first controller is used for controlling the output voltage of the direct current circuit in the rectification working mode, the second controller is used for controlling the output current of the direct current circuit in the rectification working mode, the third controller is used for controlling the output current of the power decoupling circuit in the rectification working mode, and the fourth controller is used for controlling the output current of the alternating current circuit in the inversion working mode. Preferably, the ac filter circuit is a C-type filter, an LC-type filter, or an LCL-type filter. Preferably, the conversion circuit is a full-bridge circuit configured by 4 switching transistors. Preferably, the power decoupling circuit adopts a symmetrical half-bridge power decoupling circuit formed by 2 switching tubes and 1 inductor. Preferably, the dc circuit comprises 2 dc capacitors connected in series. In addition, the disclosure also provides a control method for any one of the above single-phase bidirectional AC-DC converters based on a power decoupling topology, which comprises the following steps: In a rectification working mode, the output voltage and the output current of the direct current circuit are collected through the sampling circuit, and the control of the output voltage of the direct current circuit, the output current of the direct current circuit and the output current of the power decoupling circuit is realized based on the adjustment of the control parameters of the first controller, the second controller and the third controller; In the inversion working mode, the sampling circuit is used for collecting the output current of the alternating current circuit, and the control of the output current of the alternating current circuit is realized based on the adjustment of the control parameters of the controller IV. Preferably, the first controller, the second controller and the third controller are PI controllers, wherein the control parameters of the first controller include a proportional coefficient K11 and an integral coefficient K12, the control parameters of the second controller include a proportional coefficient K21 and an integral coefficient K22, and the control parameters of the third controller include a proportional coefficient K31 and an integral coefficient K32; in the rectifying working mode, the output voltage and the output current of the direct current circuit are collected through the sampling circuit, and the control of the output voltage of the direct current circuit, the output current of the direct current circuit and the output current of the power decoupling circ