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KR-102962077-B1 - Arc Tracking Detection And Extinguishing Method For Each String Of Solar Power Generation System Applied To Combiner Box

KR102962077B1KR 102962077 B1KR102962077 B1KR 102962077B1KR-102962077-B1

Abstract

The present invention relates to a junction box to which a string-specific arc tracking detection and arc extinguishing method is applied for a photovoltaic power generation system. More specifically, the junction box to which a string-specific arc tracking detection and arc extinguishing method is applied for a photovoltaic power generation system is a junction box connected between a photovoltaic power generation array composed of a plurality of strings and a power conversion device, and comprises: a parallel reverse current prevention diode section connected in parallel in the direction of power transmission between individual strings and the power conversion device to prevent reverse current flow; a differential current sensor that senses the current and direction of all wires between individual strings from the ground terminal and all wires between individual strings and the parallel reverse current prevention diode section; an arc conduction and arc extinguishing switch that conducts in the direction of ground when a current imbalance state is detected by the differential current sensor; and a control switch installed between each connection node of an individual diode corresponding to each string and the parallel reverse current prevention diode section and the arc conduction and arc extinguishing switch; wherein the arc tracking detection and arc extinguishing method is applied, the arc tracking detection and arc extinguishing method comprises an arc detection step of detecting an arc from a current imbalance state by the differential current sensor; The present invention relates to a junction box to which a string-specific arc tracking and detection and arc extinguishing method of a photovoltaic power generation system is applied, comprising: a step of tracking and detecting an arc occurrence specific string, wherein an arc conduction and arc extinguishing switch is conducted, and a control switch connected to each string is conducted in a sequence individually set by a user to track which string the detected arc occurred in, and when the differential current sensor detects a current balance state, the string connected to the corresponding control switch is identified as having an arc; and an arc extinguishing step of conducting a control switch and an arc conduction and arc extinguishing switch corresponding to the identified arc-occurring string to extinguish the arc.

Inventors

  • 허민호
  • 박수련
  • 김규오
  • 김민성

Assignees

  • 주식회사 현대쏠라텍

Dates

Publication Date
20260507
Application Date
20250912

Claims (6)

  1. In a connection box connected between a photovoltaic power generation array composed of multiple strings and a power conversion device, The above connection box A parallel reverse current prevention diode section connected in parallel between individual strings and power converters in the direction of power transfer to prevent reverse current flow; A differential current sensor that senses the current and direction of all wires between individual strings and parallel reverse current prevention diode sections, and all wires between individual strings from the ground terminal; An arc conduction and arc extinguishing switch that conducts in the ground direction when a current imbalance state is detected by the differential current sensor; and It is configured to include a control switch installed between each string and the connection node of the corresponding individual diode of the parallel reverse current prevention diode section and the arc conduction and arc extinguishing switch. An arc detection step for detecting an arc from a current imbalance state by the differential current sensor; A step for tracking and detecting an arc occurrence specific string, wherein the arc conduction and arc extinguishing switches are conducted, and control switches connected to each string are individually conducted in a sequence set by the user to track which string the detected arc occurred in, and when the differential current sensor detects a current balance state, the string connected to the corresponding control switch is identified as having an arc; and An arc tracking detection and arc extinguishing method applied, comprising: an arc extinguishing step of extinguishing the arc by conducting a control switch corresponding to a specified arc-generated string and an arc conduction and arc extinguishing switch. A connection box to which a string-by-string arc tracking detection and arc extinguishing method for a photovoltaic power generation system is applied.
  2. In claim 1, A junction box to which a string-by-string arc tracking detection and arc extinguishing method of a photovoltaic power generation system is applied, characterized in that the above junction box can be connected and installed using a parallel reverse current prevention diode instead of a reverse current prevention diode when there is already a reverse current prevention diode installed in each string of the existing power generation facility.
  3. delete
  4. In claim 1 or 2, A connection box to which a string-by-string arc tracking detection and arc extinguishing method of a photovoltaic power generation system is applied, characterized in that the above-mentioned control switch can utilize a thyristor element.
  5. In claim 1 or 2, A junction box to which a string-by-string arc tracking detection and arc extinguishing method of a photovoltaic power generation system is applied, characterized by further including a blocking resistor that blocks an instantaneous large current generated by an arc phenomenon between the arc conduction and arc extinguishing switch and ground.
  6. In claim 1 or 2, A connection box to which a string-specific arc tracking and detection and arc extinguishing method of a photovoltaic power generation system is applied, characterized in that the arc generation specific string tracking and detection step is combined by a user, and the arc generation specific string can be tracked and detected by simultaneously turning two or more control switches on and off.

Description

Combiner Box with Arc Tracking Detection and Extinguishing Method Applied to Each String of Solar Power Generation System The present invention relates to a junction box to which a string-specific arc tracking detection and arc extinguishing method is applied for a photovoltaic power generation system. More specifically, the junction box to which a string-specific arc tracking detection and arc extinguishing method is applied for a photovoltaic power generation system is a junction box connected between a photovoltaic power generation array composed of a plurality of strings and a power conversion device, and comprises: a parallel reverse current prevention diode section connected in parallel in the direction of power transmission between individual strings and the power conversion device to prevent reverse current flow; a differential current sensor that senses the current and direction of all wires between individual strings from the ground terminal and all wires between individual strings and the parallel reverse current prevention diode section; an arc conduction and arc extinguishing switch that conducts in the direction of ground when a current imbalance state is detected by the differential current sensor; and a control switch installed between each connection node of an individual diode corresponding to each string and the parallel reverse current prevention diode section and the arc conduction and arc extinguishing switch; wherein the arc tracking detection and arc extinguishing method is applied, the arc tracking detection and arc extinguishing method comprises an arc detection step of detecting an arc from a current imbalance state by the differential current sensor; The present invention relates to a junction box to which a string-specific arc tracking and detection and arc extinguishing method of a photovoltaic power generation system is applied, comprising: a step of tracking and detecting an arc occurrence specific string, wherein an arc conduction and arc extinguishing switch is conducted, and a control switch connected to each string is conducted in a sequence individually set by a user to track which string the detected arc occurred in, and when the differential current sensor detects a current balance state, the string connected to the corresponding control switch is identified as having an arc; and an arc extinguishing step of conducting a control switch and an arc conduction and arc extinguishing switch corresponding to the identified arc-occurring string to extinguish the arc. Since the string voltage of most photovoltaic power generation systems is around 500 to 1400 V, the possibility of arc generation is greater than that of commercial AC. Furthermore, since direct current in photovoltaic power generation does not have moments where the voltage periodically drops to zero (0 V) like in AC, there is a problem in that it is very difficult to extinguish an arc once it occurs. Therefore, structurally, photovoltaic power generation systems have a greater risk of fire caused by arcs, etc., than commercial AC. In photovoltaic systems, arcs are primarily caused by poor electrical contact, insulation breakdown, damage from external impact, and long-term aging. In particular, they occur in circuits where DC current flows and appear as sparks accompanied by high heat. These arcs can instantaneously generate extremely high temperatures reaching thousands of degrees, which can ignite surrounding flammable materials and become a major cause of fire. Furthermore, since they can cause accidents such as bodily injury or death due to electric shock, arc detection and interruption technology is considered very important. Referring to Figure 1, the main causes of arc generation include: i) poor electrical contact, such as loose or unstable contact in cable connectors, switches, etc.; ii) insulation breakdown, which occurs as current passes through the insulation space as the insulation layer of a wire or cable is damaged or aged; iii) external impact and physical damage, such as the destruction of the insulation layer due to external impact on a solar panel or cable; iv) long-term aging of equipment components; and v) contaminants such as dust and dirt accumulated inside solar panels or junction boxes. With the recent increase in the installation volume of solar power facilities, the number of fires caused by arcs is also increasing every year, and research and development on arc detection and arc extinguishing are actively underway. In particular, in large-scale photovoltaic power generation systems where multiple solar strings are gathered to form an array, there are many cases where the entire power generation is halted during the process of detecting an arc. According to the prior Korean Registered Patent No. 10-2635785 (Title of Invention: String Level Safety Device for Arc Detection and Rapid Shut-off of Photovoltaic Power Generation System, Publication Date: February 13, 2024), the invention rela