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KR-102964564-B1 - Modular withdrawable VFD panel for hydrogen charging

KR102964564B1KR 102964564 B1KR102964564 B1KR 102964564B1KR-102964564-B1

Abstract

A modular pull-out VFD panel for hydrogen refueling is disclosed. The modular pull-out VFD panel for hydrogen refueling according to an embodiment of the present invention comprises: a panel assembly with an explosion-proof structure that has a Variable Frequency Drive (VFD) mounted inside, a slide in/out module mounted on the outer side of the panel assembly and mounted in a structure that is detachably slidably pulled out on a mounting rail installed at the mounting position of the panel assembly; a multi-interlock module mounted on the slide in/out module that allows for withdrawal only when the power applied to the modular pull-out VFD panel for hydrogen refueling is cut off, and restricts withdrawal so that it cannot be withdrawn without a fuzzy signal or an approval button; and an independent protection circuit module mounted inside the panel assembly that incorporates an EOCR, a fuse, and an overcurrent circuit breaker to take isolation measures in the event of an abnormality in the Variable Frequency Drive (VFD) mounted inside the panel assembly.

Inventors

  • 백민기
  • 김인수

Assignees

  • (주)동인엔시스

Dates

Publication Date
20260513
Application Date
20251201

Claims (5)

  1. As an explosion-proof panel assembly equipped with a Variable Frequency Drive (VFD) inside, A slide in/out module (110) mounted on the outer side of the panel assembly and mounted in a structure that allows for sliding and detachable mounting on a mounting rail installed at the mounting location of the panel assembly; A multi-interlock module (120) mounted on the slide in/out module (110), which allows withdrawal only when the power supplied to the modular withdrawal type VFD panel for hydrogen charging is cut off, and restricts withdrawal so that it cannot be withdrawn without a fuzzy signal (Zone 2 Ex p charging complete) or an approval button; and An independent protection circuit module (130) mounted inside the panel assembly and containing an EOCR, a fuse, and an overcurrent circuit breaker to isolate the variable frequency drive device (VFD) mounted inside the panel assembly in the event of an abnormality; Includes, A number of other modular pull-out VFD panels for hydrogen charging, power lines (101), communication lines (102) and cooling lines (103) are used in common, and When the modular pull-out VFD panel for hydrogen charging is pulled out by the above slide in/out module (110), the power line (101), communication line (102), and cooling line (103) are immediately closed, and at the same time, an insulation cover closing module (140) ensures explosion-proof safety by operating the automatic closing of the insulation cover; A modular pull-out VFD panel for hydrogen refueling characterized by including
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  3. In paragraph 1, The above cooling line (103) is, A modular pull-out VFD panel for hydrogen charging, characterized by including a common duct and a common fan that arrange an upward exhaust line and a downward intake line, reflecting the buoyancy characteristics of hydrogen.
  4. In paragraph 3, The above-mentioned modular pull-out VFD panel for hydrogen refueling is, A module-specific status display unit (150) mounted on the above slide in/out module (110), multi-interlock module (120), and independent protection circuit module (130) insulation cover closing module (140), which detects the status of each module in real time and displays module status-related information by outputting light of different colors; A modular pull-out VFD panel for hydrogen refueling characterized by including
  5. In paragraph 4, The above-mentioned modular pull-out VFD panel for hydrogen refueling is, A remote monitoring unit (160) that links with the above-mentioned module-specific status display unit (150), monitors the status of a modular pull-out VFD panel for hydrogen charging in conjunction with gas detection and ESD signals through an IoT gateway, and reports monitoring information to an operator in real time; and A predictive maintenance unit (170) that links with the above-mentioned module status display unit (150) and monitors the status of a modular pull-out VFD panel for hydrogen charging in conjunction with gas detection and ESD signals through an IoT gateway, and reports to the operator in real time whether maintenance inspection is necessary, whether an abnormality has occurred, whether a risk has occurred, and whether countermeasures are necessary based on the monitoring information; A modular pull-out VFD panel for hydrogen refueling characterized by including

Description

Modular withdrawable VFD panel for hydrogen charging The present invention relates to a modular pull-out VFD panel for hydrogen refueling, and more specifically, to a VFD panel (Variable Frequency Drive) suitable for a hydrogen refueling station environment, designed as a module-unit pull-out type so that only the faulty module can be safely replaced. Hydrogen refueling stations are environments where high-output equipment, such as high-pressure compressors, pre-coolers, and dispensers, operates continuously, and variable frequency drive (VFD) devices have been essential for driving the motors of these devices. However, conventional VFD panel structures have the problem that it is difficult to separate them into modules, and since the entire panel is often configured as a single unit, the entire equipment stops in the event of a failure. This integrated configuration is not suitable for environments requiring uninterrupted operation, such as hydrogen refueling stations, and has been pointed out as a problem due to the high operational risk that a single VFD failure leads directly to the suspension of refueling. In existing hydrogen refueling stations, VFD panels were often applied in the same form as those used in general industrial facilities. Consequently, meeting explosion-proof safety standards required attaching additional equipment or modifying the layout. However, given that hydrogen has a very high diffusion rate and a low lower explosive concentration, the open structure and cable interface methods of conventional VFD panels clearly presented safety limitations, as they could increase the potential risk of explosion. Consequently, many conventional designs lacked sufficient consideration for explosion-proofing, such as the application of Explosive Purge (Ex p) systems or the implementation of electrical and mechanical interlocks. In addition, conventional panels required specialized technicians to directly access the interior for fault diagnosis and maintenance, and in Zone 1 or Zone 2 environments within hydrogen refueling stations, such access was restricted or the procedures became very complex. Due to access restrictions, faulty modules could not be quickly isolated, and recovery was eventually performed while the entire refueling station was shut down, leading to a recurring problem of an excessively increased Mean Time to Recover (MTTR). Conventional VFD panel systems feature separate wiring for power, communication, and cooling lines, requiring cable disconnection when separating or replacing modules. This process is not only time-consuming but also poses a safety risk to workers in explosion-proof environments, as the opening of cable interfaces exposes them to potential gas leaks or ignition sources. In particular, the opening of cooling lines at hydrogen refueling stations increases the risk due to the upward tendency of hydrogen gas. In conventional technology, cases where the entire compressor system stopped due to VFD failure occurred frequently. This was because, even if a spare module was available, the panel itself did not have a modular withdrawal structure, making it impossible to selectively replace only the faulty module. Consequently, it was necessary to disconnect all connection lines and remove the entire existing equipment for replacement, which caused a charging interruption of several hours or more and significantly reduced operational efficiency. Furthermore, conventional VFD panels featured simple or absent status display functions, making it impossible to clearly distinguish the status of each component module visually. This simplistic display method made it difficult to identify the cause of a failure and created an environment where on-site operators could not respond immediately. Particularly in explosion-proof environments, where access and inspection times are limited, the inadequacy of status display resulted in a further decline in maintenance efficiency. In existing technologies, monitoring functions were also limited to a local scope, resulting in a lack of capabilities to comprehensively monitor the status of VFD panels remotely or to link with IoT gateways to coordinate with gas detection or ESD signals. Consequently, there were limitations in detecting hydrogen leaks or abnormal current conditions early and responding preemptively, and it was difficult to ensure operational stability due to the absence of predictive maintenance capabilities. Conventional VFD panels also lacked cooling structures optimized for hydrogen refueling station environments, and in many cases, duct and fan configurations designed to account for hydrogen characteristics, such as upward exhaust and downward intake structures, were not applied. As a result, thermal management efficiency was poor, and overheating occurred in some areas, causing VFD failures. This led to a more significant problem given the nature of refueling stations, where high-output equipment operates continuously. I