Fiber optic tembiricha yekuyera mudziyo we subway power system, system mugadziri, mutengesi

Fiber optic tembiricha sensor, Intelligent monitoring system, Yakaparadzirwa fiber optic mugadziri muChina

The subway power system generally consists of electrical equipment such as circuit breakers, transformers, rectifier cabinets, cables, busbars, etc. They are connected to each other by busbars, leads, cables, etc. The current flowing through the conductors and connecting parts will generate heat. Electrical equipment may have excessive local resistance due to long-term use or loose connections. When a large current passes through, it will generate high temperatures and even burn out the equipment. Naizvozvo, the quality of the conductor connection part is the key to endangering the safe operation of the power supply system, and it is also the key to the online monitoring system of power supply equipment. The main forms of faults in power supply equipment are:

1. The main forms of faults in the circuit breaker cabinet are: eccentric and loose insertion of isolation plugs on the upper and lower parts of the circuit breaker cabinet, causing overheating, poor contact between the circuit breaker and external cable joints, resulting in heating and equipment damage.

2. The main forms of faults in transformers and rectifier cabinets are: poor contact of cable joints and conductor connections leading to overheating, accelerated insulation aging leading to breakdown, resulting in phase to phase short circuits, and even equipment burning.

3. The form of cable failure in crossing tracks through pipes is: damage occurs during cable crossing due to construction or external forces, displacement and wear of the cable due to train operation vibration, and maintenance personnel cannot detect the damage to the cable inside the pipe. Under long-term current thermal effects, this damage gradually expands and deepens, leading to multiple grounding points of the cable metal sheath, resulting in circulating current in the protective layer, increasing the loss of the sheath, and in severe cases, causing the cable to overheat and burn out.

4. The form of cable failure on the upper rail is: the connection between the upper rail cable and the contact rail is not tightly pressed or gradually loosened due to harsh outdoor environments, resulting in poor contact and heating. This not only affects the quality of power supply, but can even cause equipment damage due to ignition when overheated.

5. DC grid switch cabinet: Due to design reasons, it is not possible to monitor the position status of the equipment once (in this case, the auxiliary switch contact is abnormal and cannot be switched in place, and the defect situation cannot be grasped in a timely manner). It may be due to inadequate closing, resulting in poor contact of the conductor and burning, incomplete opening, resulting in incomplete power outage, causing accidental injury or electric shock accidents.

Monitoring methods for power supply equipment

1. Online monitoring of circuit breaker cabinet

9-point method: Monitor the engagement of 6 dynamic and static contacts and 3 inlet and outlet cable joints.

2. Online monitoring of transformers and rectifier cabinets

6-point and 9-point: Monitor all incoming and outgoing cable joints.

3. Invisible monitoring of cable insulation through rails and pipes

Using distributed optical fiber to monitor the insulation condition of the cable passing through the conduit section of the track passing cable.

4. Online monitoring of cable connection quality at three rail points

Monitor the connection quality between the upper rail cable and the contact rail connection point.

5. Online monitoring of DC grid switchgear

Monitor the position of the isolation switch.

Why does the traction power supply system of rail transit need to use fluorescent fiber optic tembiricha kuyerwa

The power supply systems for traction power supply in urban rail transit in China are DC750V and DC1500V, corresponding to the current collection methods of the third rail and overhead contact network, respectively. The maximum voltage of the secondary winding of this power supply system’s transformer has exceeded 1000V, but the measurement range specified in the “Electronic Temperature Controller for Transformers” (JB/T7631-2016), which uses Pt100 as the temperature sensor, can only be limited to below 1000V. Naizvozvo, njanji yekufambisa ine yakakwira voltage kuramba zvinodiwa kune tembiricha sensor probes uye inotungamira.

The fiber optic temperature controller for rail transit uses FJINNO’s fluorescent fiber optic temperature sensor as the temperature sensing element. Iyi tembiricha inonzwa chinhu haina kudzivirirwa kune electromagnetic kukanganiswa uye inoshingirira kune yakakwira voltage (100KV/fiber kusvika pasi inotungamira kureba kwe0.4m). Fluorescent fiber optic kuyerwa kwetembiricha inocheka zvachose kukanganiswa kwezvinhu zvekuyera tembiricha zvinoendeswa kune tembiricha controller kubva kune yekuyera tembiricha sosi., kuvandudza mwero wekuchengetedza njanji.

Zvakanakira zve Fluorescent Fiber Optic Temperature Measurement System Applied in Rail Transit

Kunzvimbo yekushanda yenjanji transit transformers, kuparadzaniswa uye kudzivirira kubva kunze kwemagetsi kupindira zviratidzo zvinowanikwa kubva kune magetsi, kuguma kwekuisa chiratidzo, chiratidzo chinobuda kupera, uye tembiricha yekudzora bhokisi shell.

Iyo magetsi emagetsi sisitimu yenjanji yekufambisa traction magetsi yakavakirwa paDC750V uye DC1500V., nepo kuyerwa kwechiyero kunotsanangurwa mu “Electronic Temperature Controller for Transformers” (JB/T7631-2005), which uses Pt100 as the temperature sensor, can only be limited to below 1000V. Naizvozvo, iyo fiber optic tembiricha controller ine yakanyanya kusimba voltage kuramba uye inogona kumira 100KV.

Mukupindura kuvibration, huruva, mwando, kusvibiswa kwemafuta uye dzimwe nzvimbo dzekushanda panzvimbo, multi-layer protective measures are taken to ensure that the optical fiber temperature controller for rail transit has good electromagnetic compatibility, kuve nechokwadi chekushanda kwakagadzikana uye kwakavimbika kwemutongi wekushisa.