CN-122026485-A - Reverse control integrated machine circuit based on high-gain cross-linked converter

CN122026485ACN 122026485 ACN122026485 ACN 122026485ACN-122026485-A

Abstract

The application discloses a reverse control integrated machine circuit based on a high-gain cross-linked converter, and relates to the technical field of energy storage systems. The voltage boosting and reducing circuit is used for realizing power conversion and level conversion of photovoltaic input between the storage battery and the direct current bus, the inverter circuit is used for realizing power conversion and level conversion from the bus to the alternating current power grid, and a voltage reducing topological branch, a voltage boosting topological branch and a photovoltaic branch in the voltage boosting and reducing circuit form a symmetrical cross-linking structure for mode switching, so that the photovoltaic end and the storage battery end share one voltage boosting converter, the multiplexing rate, the power density and the efficiency of the circuit can be improved, the number of devices can be reduced, and the voltage withstand requirement of a switching device can be reduced.

Inventors

ZHANG JUNHONG
ZHAO LUYANG
TIAN JIAHUI
ZHANG XIAOYU
XU RONGJI
Lao Junyan

Assignees

北京建筑大学

Dates

Publication Date: 20260512
Application Date: 20260225

Claims (10)

1. The inverse control integrated machine circuit based on the high-gain cross-linked converter is characterized by comprising a step-up and step-down circuit and an inverter circuit; The buck-boost circuit is connected with the inverter circuit; the step-up and step-down circuit is used for realizing power conversion and level conversion of photovoltaic input between the storage battery and the direct current bus; the inverter circuit is used for realizing power conversion and level conversion from a bus to an alternating current power grid; the step-up/down circuit is of a symmetrical cross-linked structure; The step-up/step-down circuit specifically comprises a power supply branch, a step-down topology branch, a step-up topology branch, a photovoltaic branch and a bus capacitor circuit; The first end of the power supply branch, the first end of the buck topology branch and the second end of the boost topology branch are connected with the first end of the photovoltaic branch; The second end of the power supply branch, the first end of the boosting topology branch and the second end of the step-down topology branch are connected; The third end of the boost topology branch, the second end of the photovoltaic branch and the first end of the bus capacitor branch are connected with the first end of the inverter circuit; And the third end of the step-down topological branch, the third end of the photovoltaic branch, the second end of the bus capacitor branch and the second end of the inverter circuit are all grounded.
2. The high-gain cross-linked converter based flyback all-in-one circuit of claim 1, wherein the power supply branch comprises a power supply Vin and an input capacitor Cin connected in series; the end of the positive electrode of the power Vin in the power branch is a first end of the power branch; One end of the power supply branch where the negative electrode of the power supply Vin is located is the second end of the power supply branch.
3. The high-gain cross-linked converter based flyback all-in-one circuit of claim 1 wherein the photovoltaic branch comprises a diode D1, a photovoltaic cell PV, a first terminal P1 and a second terminal P2; The first terminal P1 is used as a first end of the photovoltaic branch; the second terminal P2 is used as a second end of the photovoltaic branch; The anode of the diode D1 is used as a third end of the photovoltaic branch; the cathode of the diode D1 is connected with the cathode of the photovoltaic cell PV; The positive electrode switch of the photovoltaic cell PV is connected to the first terminal P1 or the second terminal P2.
4. The inverse control all-in-one circuit based on the high-gain cross-linked converter of claim 3, wherein the step-down topology branch specifically comprises a switch S1, a switch S3, a capacitor C2 and an inductor L2; the first end of the inductor L2 is used as the second end of the step-down topological branch; The drain electrode of the switch S1 and the first end of the capacitor C2 are connected to serve as the first end of the step-down topological branch; the second end of the inductor L2, the source electrode of the switch S1 and the source electrode of the switch S3 are connected; the drain of the switch S3 is connected to the second terminal of the capacitor C2 as the third terminal of the buck topology.
5. The high-gain cross-linked converter based flyback all-in-one circuit of claim 4 wherein the inductor L2 is a Buck-Boost inductor.
6. The high-gain cross-linked converter-based reverse control integrated circuit of claim 4, wherein the boost topology branch specifically comprises a switch S2, a switch S4, a capacitor C1 and an inductor L1; The first end of the inductor L1 is used as the second end of the boost topology branch; The drain electrode of the switch S2 and the first end of the capacitor C1 are connected to serve as the first end of the boost topology branch; the second end of the inductor L1, the source electrode of the switch S2 and the source electrode of the switch S4 are connected; The drain of the switch S4 is connected to the second terminal of the capacitor C1 as the third terminal of the boost topology branch.
7. The high-gain cross-linked converter based flyback all-in-one circuit of claim 6, wherein the inductor L1 is a Buck-Boost inductor.
8. The high-gain cross-linked converter based reverse control all-in-one circuit of claim 1, wherein the bus capacitor branch comprises a bus capacitor Cbus; The first end of the bus capacitor Cbus is the first end of the bus capacitor branch; and the second end of the bus capacitor Cbus is the second end of the bus capacitor branch.
9. The high-gain cross-linked converter based reverse control all-in-one circuit of claim 8, wherein the inverter circuit is a two-level four-switch inverter.
10. The high-gain cross-linked converter based flyback all-in-one circuit of claim 9 wherein the inverter circuit comprises an inductor L3, a capacitor C3, a switch S5, a switch S6, a switch S7 and a switch S8; the drain of the switch S5 and the drain of the switch S7 are connected as a first end of the inverter circuit; The source of the switch S6 and the source of the switch S8 are connected as a second end of the inverter circuit; The source electrode of the switch S5 and the drain electrode of the switch S6 are connected with the first end of the inductor L3; The second end of the inductor L3 is connected with the first end of the capacitor C3; the second end of the capacitor C3 and the source of the switch S7 are connected to the drain of the switch S8.

Description

Reverse control integrated machine circuit based on high-gain cross-linked converter Technical Field The application relates to the technical field of energy storage systems, in particular to a reverse control integrated machine circuit based on a high-gain cross-linked converter. Background After the 21 st century 20 s, a photovoltaic energy storage system with a grid-connected mode gradually replaces a traditional off-grid energy storage system to become a mainstream, and the photovoltaic input of the system is of a string structure generally, so that the problems of limited load and frequent switching of the off-grid system are solved. The existing off-grid and on-grid energy storage system generally stores redundant electricity into a battery under the condition of meeting household load, the battery discharges and supplements when the generated energy cannot meet the load, and then is supplied by mains supply, and is switched to an off-grid mode when power is off, so that the system is greatly superior to a split machine system formed by combining a traditional maximum power point tracking (MaximumPowerPointTracking, MPPT) controller and an inverter. The system develops solutions such as micro-inverse balcony energy storage and integrated machine household energy storage in the market, and has a series of mature products, and has two operation modes of off-grid and grid connection. However, the existing product has the following defects that 1. The transformer has large energy storage volume/high cost/more elements, and the storage battery voltage used by the current high-power energy storage inverter is lower, so that the voltage boosting to the direct current bus is larger. The direct current side is mainly provided with a DAB bidirectional full-bridge converter or a more advanced CLLC bidirectional converter, and the direct current side is more efficient and has higher working frequency than the traditional forward/push-pull converter, but a high-frequency isolation transformer is still used for boosting, and the quantity of circuit switching elements based on the isolation transformer is generally more due to the indirect magneto-electric conversion property of the isolation transformer compared with the unavoidable increase volume of a non-isolation system, because the requirements on leakage inductance and efficiency are strict, the manufacturing cost of the whole system is improved, and the direct-alternating-direct electric energy conversion property of the isolation transformer is improved. 2. The power conversion times are more, although the output of the photovoltaic end and the storage battery after boosting is connected to the direct current bus by the existing integrated topology, the electric energy of the photovoltaic end enters the storage battery and still needs to reach the bus through the boost converter, then the electric energy is subjected to two-stage power conversion of the step-down of the isolation transformer, if the photovoltaic voltage is lower, the electric energy is boosted to the bus voltage first and then stored in the storage battery, and a large amount of energy is lost by more power conversion times. Disclosure of Invention The application aims to provide a reverse control integrated machine circuit based on a high-gain cross-linked converter, wherein a photovoltaic end and a storage battery end share one boost converter, so that the multiplexing rate, the power density and the efficiency of the circuit can be improved, and the number of devices can be reduced. In order to achieve the above object, the present application provides the following solutions: the application provides a reverse control integrated machine circuit based on a high-gain cross-linked converter, which comprises a buck-boost circuit and an inverter circuit; The buck-boost circuit is connected with the inverter circuit; the step-up and step-down circuit is used for realizing power conversion and level conversion of photovoltaic input between the storage battery and the direct current bus; the inverter circuit is used for realizing power conversion and level conversion from a bus to an alternating current power grid; the step-up/down circuit is of a symmetrical cross-linked structure; The step-up/step-down circuit specifically comprises a power supply branch, a step-down topology branch, a step-up topology branch, a photovoltaic branch and a bus capacitor circuit; The first end of the power supply branch, the first end of the buck topology branch and the second end of the boost topology branch are connected with the first end of the photovoltaic branch; The second end of the power supply branch, the first end of the boosting topology branch and the second end of the step-down topology branch are connected; The third end of the boost topology branch, the second end of the photovoltaic branch and the first end of the bus capacitor branch are connected with the first end of the inverter circuit; And