Ship equipment fault diagnosis device based on off-line insulation monitoring and use method

Abstract

The invention discloses a ship equipment fault diagnosis device based on off-line insulation monitoring and a use method thereof. The ship equipment fault diagnosis device comprises a microcontroller module, and a signal generation module and a signal receiving module which are connected with the microcontroller module, wherein the signal generation module can continuously inject square wave signals between a monitoring equipment line and the ground, the signal receiving module can receive signals connected with the monitoring equipment line and perform amplification filtering processing, the microcontroller module is further connected with an alarm unit, and the microcontroller module can calculate and analyze the received signal to obtain a line resistance value and send out alarm information. The ship equipment fault diagnosis device has the advantages that low-frequency square waves are injected between two phases of a device line and the ground, sampling resistance voltage of the two phases of a connecting circuit is monitored, Fourier transform is used for processing sampling data to calculate circuit insulation resistance, the line insulation state is judged, an alarm is given out when insulation faults occur in the line, the system off-line monitoring of the insulation state of a ship equipment power system is realized, and the safety is improved.

Description

technical field [0001] The invention relates to a marine equipment fault diagnosis technology, in particular to a marine equipment fault diagnosis device based on off-line insulation monitoring and its application method. Background technique [0002] Nowadays, the neutral point ungrounded (NUS) method is generally adopted in ship power grids to improve the safety of ship power supply. The characteristic of this system is that the lighting system and the power system are connected through transformers without direct connection. has less impact. When the ground capacitance of the ship power grid is not large, even if a single-phase ground short-circuit fault occurs in the ship power grid, the short-circuit current is still small, and the three-phase line voltage of the power grid can still maintain symmetry. In this way, the system does not need to trip and power off in a short period of time, thereby ensuring the continuity and reliability of the ship's power supply. Howev...

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Problems solved by technology

[0003] At the same time, with the development of modern ships in the direction of large-scale and automation, the required capacity of the power system is increasing, and the structure of the power network is becoming more and more complex and dense. In particular, the wide application of anti-radio The ground capacitance is greatly increased, resulting in an electrical connection between the phase line of the ship's power grid and the hull; and the ship's equipment, especially the ship's deck machinery, is in a harsh environment and is easily affected by factors such as salt spray, water vapor, and mold. Causes the occurrence of insulation faults in the power system; and the complex routing of the power grid system makes problems from high-impedance grounding of equipment or grid lines to direct metal grounding possible, and the amplitude of grounding current varies in a large range

[0004] If the insulation fault is not dealt with in time, it will easily lead to more serious accidents such as fire, phase-to-phase short circuit, electric shock, etc., posing a great threat to the life safety of the ship and its crew

However, the fault grounding residual current generated by the single-phase short-circuit fault of the neutral point ungrounded system is small, and the fault line selection is difficult

At present, the real-time monitoring of the insulation status of each line mostly uses manual query or the online connection device of the power grid. Hundreds of load branches are powered off one by one; although the online grid insulation monitoring device can easily detect the insulation status of the grid line in the energized state, deck machinery generally does not run for a long time, and does not send power to the system in the non-operating state. Insulation faults cannot be found through online detection. At this time, once the power is suddenly transmitted, there may be a large safety problem.

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