CN215378860U

CN215378860U - Photovoltaic inverter with multi-path MPPT input and photovoltaic power generation system

Info

Publication number: CN215378860U
Application number: CN202121152470.1U
Authority: CN
Inventors: 陈鹏; 王志成; 闫牧
Original assignee: Sungrow Power Supply Co Ltd
Current assignee: Sungrow Power Supply Co Ltd
Priority date: 2021-05-26
Filing date: 2021-05-26
Publication date: 2021-12-31
Anticipated expiration: 2031-05-26

Abstract

The application discloses photovoltaic inverter and photovoltaic power generation system with multichannel MPPT input to simplify the mode of connection of photovoltaic inverter input side. When the input negative electrode and the output negative electrode of the same MPPT unit in the photovoltaic inverter are the same electrical node, at least two MPPT units share a negative electrode input terminal.

Description

Photovoltaic inverter with multi-path MPPT input and photovoltaic power generation system

Technical Field

The utility model relates to the technical field of power electronics, in particular to a photovoltaic inverter with multiple MPPT inputs and a photovoltaic power generation system.

Background

Fig. 1 shows a photovoltaic inverter with multiple MPPT inputs, where the k (k is 1, 2, …, n is the total number of MPPT units) MPPT units have positive and negative input terminals (PV in fig. 1)_k+、PV_kAnd-shows) the positive and negative electrodes of the kth photovoltaic module unit are connected through two cables to form a kth MPPT outputAnd (indicated by MPPT in fig. 1), so that the photovoltaic inverter realizes independent MPPT control on each photovoltaic module unit.

However, the number of MPPT units is large, so that the number of terminals and cables used in the above connection method is large, which increases the cost and the difficulty of construction.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a photovoltaic inverter and a photovoltaic power generation system with multiple MPPT inputs to simplify the wiring manner of the input side of the photovoltaic inverter.

A photovoltaic inverter with multiple MPPT inputs is characterized in that an input negative electrode and an output negative electrode of the same MPPT unit are the same electrical node, and at least two MPPT units share a negative electrode input terminal.

Optionally, the input side of the photovoltaic inverter has one or more shared negative input terminals.

In another photovoltaic inverter with multiple MPPT inputs, the negative input electrode and the negative output electrode of the same MPPT unit are different electrical nodes, and at least two MPPT units share a positive input terminal.

Optionally, the input side of the photovoltaic inverter has one or more common positive input terminals.

In another photovoltaic inverter with multiple MPPT inputs, the input negative electrode and the output negative electrode of the same MPPT unit are different electrical nodes, and at least two MPPT units share a negative electrode input terminal.

In another photovoltaic inverter with multiple MPPT inputs, the input negative electrode and the output negative electrode of the same MPPT unit are different electrical nodes, at least two MPPT units share a positive input terminal, and at least two other MPPT units share a negative input terminal.

Optionally, the input side of the photovoltaic inverter has one or more common positive input terminals, and also has one or more common negative input terminals.

A photovoltaic power generation system, comprising: any one of the photovoltaic inverter with multiple MPPT inputs and the photovoltaic component unit arranged on the input side of the photovoltaic inverter.

Optionally, the photovoltaic module unit is a photovoltaic module, or a series combination of a plurality of photovoltaic modules, or a parallel combination of a plurality of photovoltaic modules, or a series-parallel combination of a plurality of photovoltaic modules.

According to the technical scheme, at least two MPPT units share the positive input terminal or the negative input terminal, so that the number of wiring terminals and cables used on the input side of the photovoltaic inverter is reduced, and the cost, the construction difficulty and the cable loss are reduced. In order to ensure that the original circuit function of the photovoltaic inverter is unchanged, when the wiring mode of the input side of the photovoltaic inverter is improved, whether the MPPT unit shares the positive input terminal or the negative input terminal or both can be distinguished according to whether the input negative electrode and the output negative electrode of the same MPPT unit are the same electrical node or not.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of a connection mode of an input side of a photovoltaic inverter with multiple MPPT inputs disclosed in the prior art;

fig. 2 is a schematic diagram of an MPPT unit disclosed in the prior art, in which an input cathode and an output cathode are the same electrical node;

FIG. 3 is a schematic diagram of a structure in which two MPPT units shown in FIG. 2 share a positive input terminal;

FIG. 4 is a schematic diagram of a structure in which two MPPT units of FIG. 2 share a negative input terminal;

fig. 5 is a schematic diagram illustrating an input side connection manner of a photovoltaic inverter with multiple MPPT inputs according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a connection mode of an input side of another photovoltaic inverter with multiple MPPT inputs according to an embodiment of the present invention;

fig. 7 is a schematic diagram illustrating a structure of an MPPT unit having different electrical nodes for an input cathode and an output cathode according to the prior art;

fig. 8 is a schematic diagram illustrating a structure of another MPPT unit disclosed in the prior art, in which an input cathode and an output cathode are different electrical nodes;

fig. 9 is a schematic diagram of a connection mode of an input side of another photovoltaic inverter with multiple MPPT inputs according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a connection mode of an input side of another photovoltaic inverter with multiple MPPT inputs according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

For a photovoltaic inverter with multi-path MPPT (maximum power Point Tracking) input, the utility model saves the number of wiring terminals and cables used on the input side of the photovoltaic inverter by enabling at least two paths of MPPT units to share a positive input terminal or a negative input terminal, thereby reducing the cost, the construction difficulty and the cable loss. However, in order to ensure that the original circuit function of the photovoltaic inverter is unchanged, when the connection mode of the input side of the photovoltaic inverter is improved as described above, whether the MPPT unit shares the positive input terminal or the negative input terminal or both may be distinguished according to whether the input negative electrode and the output negative electrode of the same MPPT unit are the same electrical node, and the following embodiments 1) to 2 are specifically described:

1) when the input negative electrode and the output negative electrode of the same MPPT unit are the same electrical node, at least two MPPT units share the positive input terminal, and other wiring terminals at the input end of the photovoltaic inverter maintain the original wiring mode unchanged.

Specifically, for example, a photovoltaic inverter has two MPPT inputs in common, and an MPPT unit provided therein is an MPPT unit whose input negative electrode and output positive electrode are the same electrical node as shown in fig. 2, if two such MPPT units share a positive input terminal, the two MPPT units are connected in parallel, as shown in fig. 3, and thus independent MPPT control cannot be performed on each photovoltaic module unit; if two such MPPT units share the negative input terminal, the input side voltages/currents of the two MPPT units are still independent, as shown in fig. 4, so that independent MPPT control can still be ensured for each photovoltaic module unit.

The MPPT unit having the same electrical node as the input negative electrode and the output positive electrode has many circuit topologies, and is not limited to fig. 2.

In embodiment 1), the photovoltaic inverter may have all the MPPT units share the negative input terminal, or may have only some of the MPPT units share the negative input terminal, and may autonomously set according to actual needs. In addition, the number of the shared negative connecting terminals can be optimally selected according to the total number n of the photovoltaic module units and the distance between the total number n of the photovoltaic module units, generally, when n is small and the distance is close, the number of the shared negative connecting terminals can be set to be one, and when n is large or the distance is far, the number of the shared negative connecting terminals can be set to be multiple. For example, as shown in fig. 5, when n is small and the distance is close, n MPPT units in the photovoltaic inverter share one negative input terminal PV-; as shown in fig. 6, when n is larger or the distance is longer, n MPPT units in the photovoltaic inverter are divided into two groups, and each group shares a negative input terminal PV-.

2) When the input negative electrode and the output negative electrode of the same MPPT unit are different electrical nodes (for example, the MPPT unit shown in fig. 7 or fig. 8), any one of the following three connection modes may be adopted: firstly, at least two paths of MPPT units share a positive input terminal, and other wiring terminals at the input end of the photovoltaic inverter maintain the original wiring mode; enabling at least two MPPT units to share a negative input terminal, and keeping other wiring terminals on the input side of the photovoltaic inverter unchanged in the original wiring mode; and enabling at least two MPPT units to share a positive input terminal and enabling the other at least two MPPT units to share a negative input terminal, wherein other wiring terminals on the input side of the photovoltaic inverter maintain the original wiring mode unchanged.

In embodiment 2), independent MPPT control can be performed on each photovoltaic module unit regardless of the connection mode to ensure that the voltage/current at the input side of the n MPPT units is still independent.

In addition, in the first connection mode, all MPPT units may share the positive input terminal, or only some MPPT units may share the positive input terminal, and may be autonomously provided according to actual needs. In addition, in the connection mode, the number of the shared positive connecting terminals can be optimally selected according to the total number n of the photovoltaic module units and the distance between the total number n of the photovoltaic module units, generally, when n is small and the distance is close, the number of the shared positive connecting terminals can be set to be one, and when n is large or the distance is far, the number of the shared positive connecting terminals can be set to be multiple. For example, as shown in fig. 9, when n is small and the distance is short, n MPPT units in the photovoltaic inverter share one positive input terminal PV +; as shown in fig. 10, when n is larger or the distance is longer, n MPPT units in the photovoltaic inverter are divided into two groups, and each group shares one positive input terminal PV +.

Similarly, in the second connection method, the number of MPPT units participating in the common negative input terminal may be set independently as needed. In addition, in the wiring mode II, the number of the shared negative connecting terminals can be optimized and selected according to the total number n of the photovoltaic module units and the distance between the photovoltaic module units.

Similarly, in the connection mode iii, the sum of the number of MPPT cells participating in the common positive input terminal and the number of MPPT cells participating in the common negative input terminal may be set autonomously according to actual needs. In addition, in the wiring mode III, the number of the shared negative wiring terminals and the number of the shared positive wiring terminals can be optimally selected according to the number n of the total paths of the photovoltaic module units and the distance between the photovoltaic module units.

In addition, the embodiment of the utility model also discloses a photovoltaic power generation system, which comprises: any one of the above-disclosed photovoltaic inverters having multiple MPPT inputs, and a photovoltaic module unit disposed on an input side of the photovoltaic inverter.

The photovoltaic module unit may be a photovoltaic module, or a series combination of a plurality of photovoltaic modules, or a parallel combination of a plurality of photovoltaic modules, or a series-parallel combination of a plurality of photovoltaic modules, without limitation.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A photovoltaic inverter with multi-path MPPT input is characterized in that the input negative electrode and the output negative electrode of the same MPPT unit are the same electrical node, and at least two paths of MPPT units share a negative electrode input terminal.

2. The photovoltaic inverter with multiple MPPT inputs of claim 1, wherein the photovoltaic inverter input side has one or more negative input terminals that are shared.

3. A photovoltaic inverter with multi-path MPPT input is characterized in that the input negative electrode and the output negative electrode of the same MPPT unit are different electrical nodes, and at least two paths of MPPT units share a positive input terminal.

4. The photovoltaic inverter with multiple MPPT inputs of claim 3, wherein the photovoltaic inverter input side has one or more common positive input terminals.

5. A photovoltaic inverter with multiple MPPT inputs is characterized in that the input negative electrode and the output negative electrode of the same MPPT unit are different electrical nodes, and at least two MPPT units share a negative electrode input terminal.

6. The photovoltaic inverter with multiple MPPT inputs of claim 5, wherein the photovoltaic inverter input side has one or more negative input terminals that are shared.

7. A photovoltaic inverter with multi-path MPPT input is characterized in that an input negative electrode and an output negative electrode of the same MPPT unit are different electrical nodes, at least two MPPT units share a positive input terminal, and at least two MPPT units share a negative input terminal.

8. The pv inverter with multiple MPPT inputs of claim 7, wherein the pv inverter input side has one or more common positive input terminals and one or more common negative input terminals.

9. A photovoltaic power generation system, comprising: the photovoltaic inverter with multiple MPPT inputs of any one of claims 1-8, and a photovoltaic module unit disposed on an input side of the photovoltaic inverter.

10. The photovoltaic power generation system of claim 9, wherein the photovoltaic module unit is a single photovoltaic module, or the photovoltaic module unit is a series combination of a plurality of photovoltaic modules, or the photovoltaic module unit is a parallel combination of a plurality of photovoltaic modules, or the photovoltaic module unit is a series-parallel combination of a plurality of photovoltaic modules.