CN217335068U

CN217335068U - String type photovoltaic resonance overvoltage protection and suppression system

Info

Publication number: CN217335068U
Application number: CN202221047147.2U
Authority: CN
Inventors: 何信林; 李毅; 李春丽; 张文斌; 王海强; 雷阳; 季东旭
Original assignee: Xian Thermal Power Research Institute Co Ltd
Current assignee: Xian Thermal Power Research Institute Co Ltd
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2022-08-30
Anticipated expiration: 2032-04-28

Abstract

The utility model discloses a string type photovoltaic resonance overvoltage protection and suppression system, which comprises an overvoltage discrimination module, an electronic switch trigger module, an electronic switch module, a nonlinear resistance module, a voltage current recording module and a voltage acquisition module for acquiring bus voltage; the output end of the voltage acquisition module is connected with the overvoltage judging module and the voltage and current recording module, the output end of the overvoltage judging module is connected with the control end of the electronic switch module through the electronic switch triggering module, the electronic switch module is connected with the nonlinear resistor module in series, and the system can protect and inhibit the string type photovoltaic resonance overvoltage.

Description

String type photovoltaic resonance overvoltage protection and suppression system

Technical Field

The utility model belongs to new forms of energy relay protection field relates to a string formula photovoltaic resonance overvoltage protection and suppression system.

Background

The resonance of the photovoltaic power station is caused by a plurality of reasons, namely the resonance caused by the software and hardware of a single inverter and the resonance caused by the parallel connection of the inverters. A large number of photovoltaic inverters operate simultaneously, harmonic resonance is easy to excite, and power generation continuity, economic benefits and safe operation of the photovoltaic power station are directly affected.

At present, no overvoltage protection device is arranged between a group string type photovoltaic inverter and the low-voltage side of a step-up transformer, and if resonance occurs, the resonance overvoltage is generated to endanger the insulation of the inverter, a low-voltage distribution device and the transformer, so that equipment is damaged.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome above-mentioned prior art's shortcoming, provide a string formula photovoltaic resonance overvoltage protection and suppression system, this system can protect and restrain string formula photovoltaic resonance overvoltage.

In order to achieve the above object, the string-type photovoltaic resonance overvoltage protection and suppression system of the present invention comprises an overvoltage determination module, an electronic switch trigger module, an electronic switch module, a nonlinear resistance module, a voltage-current recording module, and a voltage acquisition module for acquiring a bus voltage;

the output end of the voltage acquisition module is connected with the overvoltage judging module and the voltage and current recording module, the output end of the overvoltage judging module is connected with the control end of the electronic switch module through the electronic switch triggering module, and the electronic switch module is connected with the nonlinear resistor module in series.

The output end of the voltage acquisition module passes through the voltage processing module and the overvoltage judging module.

The device also comprises an alarm module; the overvoltage judging module is connected with the alarm module.

The current acquisition module is used for acquiring the current of the nonlinear resistance module and is connected with the voltage and current recording module.

The current acquisition module is connected with the voltage and current recording module through the current processing module.

The device also comprises an output module and an upper computer; the overvoltage judging module is connected with the upper computer through the output module.

The utility model discloses following beneficial effect has:

string formula photovoltaic resonance overvoltage protection and suppression system when concrete operation, voltage acquisition module adopts resistance partial pressure mode collection busbar voltage, handle the back through voltage processing module and send to overvoltage discrimination module, overvoltage discrimination module is according to resonance overvoltage characteristic, the amplitude is distinguished whether electric device has overvoltage between string formula photovoltaic inverter to the step up transformer low pressure side, produce when distinguishing the overvoltage, then start electronic switch trigger module, electronic switch trigger module triggers electronic switch module, the electronic switch module switches on the back, drop into nonlinear resistance module, restrain the overvoltage that produces between string formula photovoltaic inverter to the step up transformer low pressure side between the region, and delay time-sharing preface excision dc-to-ac converter, eliminate until overvoltage resonance, moreover, the steam generator is simple in structure, high durability and convenient operation.

Drawings

FIG. 1 is a schematic wiring diagram of a low voltage power distribution system;

fig. 2 is a structural diagram of the present invention.

Wherein, 1 is a voltage acquisition module, 2 is a current acquisition module, 3 is a voltage processing module, 4 is a current processing module, 5 is an overvoltage judging module, 6 is an electronic switch triggering module, 7 is an electronic switch module, 8 is a nonlinear resistor module, 9 is an output module, 10 is a voltage and current recording module, and 11 is an alarm module.

Detailed Description

In order to make the technical solution of the present invention better understood, the following figures in the embodiments of the present invention are combined to clearly and completely describe the technical solution in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments, and do not limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the protection scope of the present invention.

A schematic structural diagram according to an embodiment of the present disclosure is shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to fig. 1 and 2, the string-type photovoltaic resonance overvoltage protection and suppression system of the present invention includes a voltage acquisition module 1, a current acquisition module 2, a voltage processing module 3, a current processing module 4, an overvoltage determination module 5, an electronic switch trigger module 6, an electronic switch module 7, a nonlinear resistance module 8, an output module 9, a voltage/current recording module 9, and an alarm module 11;

the output end of the voltage acquisition module 1 is connected with an overvoltage judging module 5 and a voltage and current recording module 9 through a voltage processing module 3, the output end of the overvoltage judging module 5 is connected with the control end of an electronic switch module 7 through an electronic switch triggering module 6, the electronic switch module 7 is connected with a nonlinear resistor module 8 in series, the overvoltage judging module 5 is connected with an alarm module 11, and the overvoltage judging module 5 is connected with an upper computer through an output module 10. The current acquisition module 2 is connected with the voltage and current recording module 9 through the current processing module 4.

The voltage acquisition module 1 acquires bus voltage in a resistance voltage division mode, and then the bus voltage is rectified and filtered by the voltage processing module 3 and then is transmitted to the overvoltage judging module 5 and the voltage and current recording module 9;

the overvoltage judging module 5 judges whether an electrical device between the string photovoltaic inverter and the low-voltage side of the booster transformer has overvoltage or not according to the characteristic and the amplitude of the resonance overvoltage;

when the overvoltage is judged to be generated, the electronic switch triggering module 6 is started, the electronic switch triggering module 6 triggers the electronic switch module 7 to be conducted, so that the nonlinear resistor module 8 is put into use, and meanwhile, the judgment result is output to the upper computer through the output module 10.

The current collecting module 2 collects the current of the nonlinear resistance module 8, then the current is rectified and filtered by the current processing module 4 and then is input into the voltage and current recording module 9, and the overvoltage amplitude and the current of the nonlinear resistance module 8 are recorded by the voltage and current recording module 9.

When the overvoltage is judged to be generated, the alarm module 11 gives an alarm to remind the worker.

The utility model discloses when the resonance overvoltage takes place for electric device between group string photovoltaic inverter to the step up transformer low pressure side, drop into nonlinear resistance module 8, restrain the overvoltage that produces between group string photovoltaic inverter to the step up transformer low pressure side in the region to time delay divides the order excision dc-to-ac converter, until resonance overvoltage elimination.

Claims

1. The series photovoltaic resonance overvoltage protection and suppression system is characterized by comprising an overvoltage judgment module (5), an electronic switch triggering module (6), an electronic switch module (7), a nonlinear resistor module (8), a voltage and current recording module (9) and a voltage acquisition module (1) for acquiring bus voltage;

the output end of the voltage acquisition module (1) is connected with the overvoltage judging module (5) and the voltage and current recording module (9), the output end of the overvoltage judging module (5) is connected with the control end of the electronic switch module (7) through the electronic switch triggering module (6), and the electronic switch module (7) is connected with the nonlinear resistor module (8) in series.

2. The string-type photovoltaic resonance overvoltage protection and suppression system according to claim 1, wherein the output end of the voltage acquisition module (1) passes through the voltage processing module (3) and the overvoltage discrimination module (5).

3. The string-type photovoltaic resonant overvoltage protection and suppression system according to claim 1, further comprising an alarm module (11); the overvoltage judging module (5) is connected with the alarm module (11).

4. The string-type photovoltaic resonance overvoltage protection and suppression system according to claim 1, further comprising a current collection module (2) for collecting current of the nonlinear resistance module (8), wherein the current collection module (2) is connected with the voltage and current recording module (9).

5. The string-type photovoltaic resonance overvoltage protection and suppression system according to claim 4, wherein the current collection module (2) is connected to the voltage-current recording module (9) via the current processing module (4).

6. The string-type photovoltaic resonance overvoltage protection and suppression system according to claim 1, further comprising an output module (10) and an upper computer; the overvoltage judging module (5) is connected with an upper computer through an output module (10).