Principle of Work of Low-Voltage Vacuum Contactors and Their Application in DF100A Shortwave Transmitters

A cikin wasu muhimman juna, mafi yawan kwalba na gajeruwa da suka dace ne suke amfani da lowa-voltage vacuum contactors don gudanar da tsarin da zama a kan kabilu, sannan kuma daidaito harshe da kontrolu masu motori na AC. Su zai iya haɗa da wasu tsohon inganci don bincike electromagnetic starters.

Saboda rike mulki mai tsawo, kyakkyawan da ke gaskiya, da kuma auxiliary switches wadanda ke daidaito da abubuwan lafiya, lowa-voltage vacuum contactors zai iya dogara da traditional air AC contactors. Suna amfani da su a wurareen muhimmiyar kamar mining, metallurgy, building materials, chemical engineering, petroleum, da heavy industry, inda dalilai da zaɓukan sun shafi sosai.

1. Karkashin da Gagartar Lowa-Voltage Vacuum Contactors

1.1 Karkashin Lowa-Voltage Vacuum Contactors

Matakan contactor ce maɗi, wanda zai iya haɗa zuwa 1-pole, 2-pole, ..., n-pole contactors. A cikin yanayi, duwatsu masu vacuum interrupter suka kusa 1.5–1.8 mm. Yanayin duwatsu suka ci ƙwarewa a kan pressure spring a cikin drive system. Don contactors masu current rating 800–1600 A, opening distance ya kasance kusan 3.5 mm.

Idan control power supply ya faru, electromagnet ya yi aiki a kan pressure spring, ta ƙasa moving contact rod. Moving contact rod ya ƙare duwatsu domin atmospheric pressure ta yi aiki a kan vacuum interrupter. Electromagnet ana gina a matsayin DC electromagnet tare da energy-saving resistor. Idan AC control power supply an amfani da ita, AC power ya zama DC a cikin rectifier module, sannan DC power ya amfani da ita don haɗa mechanism to operate. Har duk drive mechanism na da rectifier module idan ya yi aiki a kan AC voltage.

1.2 Tsarin Kirkiro

Littafin ya bayyana kawai vacuum contactors da AC control voltage. Tsarin kirkiro na multi-pole vacuum contactor ta fi sani a Figure 1. U1/U2, V1/V2, da W1/W2 su ne main circuit contacts; A1/A2 su ne power input contacts of the control circuit.

2. Amfani da Lowa-Voltage Vacuum Contactors a Cikin Shortwave Transmitters DF100A

2.1 Ingantaccen Lowa-Voltage Vacuum Contactors

EVS630 lowa-voltage vacuum contactor (equipment number: 4A5K1) an amfani da ita a cikin shortwave transmitter DF100A. High-voltage control circuit ta fi sani a Figure 2. Ingantaccen 4A5K1 shine: idan high-voltage closing button 6S7 ya faɗi, AC 230V control voltage ya zama a 4A5K1 (a, b) contacts, ta ƙare 4A5K1. Ita ce ta ci ƙwarewa a kan self-holding function of 4A5K1 (3, 4). Main contacts sun ƙare three-phase AC 380V voltage zuwa modulation transformer, don ƙare voltage da ke daidaito da 48 power modules. Duk da haka, control signal ya zama zuwa nine units via 4A5K1 (11, 12).

2.2 Tattalin Yakin Daɗi

• Bayyana tattalin yakin daɗi don ba lowa-voltage vacuum contactor ya ƙare environment mai kyau babbar dust.

• Yawan magana temperature a lokacin da aka yi. Idan temperature ya ƙare, ɗaya da ɗaya duba da tabbataccen terminal screws.

• Bayyana tattalin yakin daɗi don ƙare dust a kan electromagnet da armature don ba armature ba su jam during use.

• Don backup lowa-voltage vacuum contactor, ƙare 220VAC lighting power zuwa (a, b) contacts don ƙare ita. Amfani da multimeter don dubawa a kan sauran contacts su ke daidaito, don ba backup ba ya ƙare condition da ke daidaito da amfani.

2.3 Tattalin Fault Analysis da Handling

(1)Idan high voltage ya ƙare, interlock No. 4 indicator light a cikin modulator 9A5 board ba ta ƙare ba; meter value of the pre-final stage ta ƙare, screen grid current of the high-final stage ta ƙare, amma ba da meter values for the plate current and plate voltage of the high-final stage, and there is no power output; non-operating indicator light on the 9A4 board ta ƙare, and the module indicator lights on the status board ta ƙare.

Fault Analysis: Tsarin kirkiro na interlock No. 4 indicator light ta fi sani a Figure 3. An kula ta a kan set of contacts (9, 3) of the internal interlock relay 1K32 controlled by the modulator and the auxiliary contacts (11, 12) of the high-voltage second-stage electromagnetic switch 4A5K1. Idan high voltage ya ƙare zuwa transmitter, 4A5K1 ya ƙare, and its normally open auxiliary contacts ya ƙare at the same time; optocoupler U6 ya ƙare, and the interlock No. 4 indicator light on the modulator 9A5 board ta ƙare.

Idan akwai wani abu a kan mechanical structure of the electromagnetic switch itself, ko auxiliary contacts suke da poor contact (resulting in the main contacts closing but the auxiliary contacts (11, 12) having poor contact), interlock No. 4 indicator light on the 9A5 board ba ta ƙare ba, a non-operating command signal ya zama, modulator ya ƙare, and the transmitter will have no plate voltage, screen grid voltage or power output.

Fault Handling: Idan akwai backup, ƙare zuwa backup. Idan ba a baka backup, urgently short-circuit the transmitter terminals (1TB10-18, 1TB10-1). Ba da broadcast, ƙare (11, 12) contacts. To improve reliability, unused idle contacts can be connected in parallel.

(2)Idan high voltage ya ƙare zuwa transmitter, zan iya samun sound of the first gear and the second gear; lokacin, both the first gear and the second gear drop simultaneously, and the high-voltage second gear cannot maintain its state (self-holding failure).

• Fault Analysis: Poor contact of the high-voltage second-stage electromagnetic switch 4A5K1 (3, 4) causes the high-voltage circuit to fail to self-hold.

• Fault Handling: Idan akwai backup, ƙare zuwa backup. Idan ba a baka backup, urgently short-circuit (4A5TB2-14, 4A5TB2-19).

(3)Idan high voltage ya ƙare zuwa transmitter, high-voltage first gear can be engaged, but the second gear cannot; lokacin, the first gear drops, and the screen grid current of the high-final stage is overloaded.

• Fault Analysis: The current-limiting resistor of the starting coil in one phase of the high-voltage second-stage electromagnetic switch 4A5K1 is damaged.

• Fault Handling: Idan akwai backup, ƙare zuwa backup. Idan ba a baka backup, urgently replace 4A5K1.

(4)In the high-power state, the pre-final stage is basically normal; the plate current of the high-final stage decreases, the plate voltage increases, and some power modules are turned off.

• Fault Analysis: The vacuum interrupter contacts in one phase of 4A5K1 are burned out.

• Fault Handling: Idan akwai backup, ƙare zuwa backup. Idan ba a baka backup, urgently replace 4A5K1.

(5)When applying high voltage, the first gear is normal; when the second gear is engaged, the plate control circuit breaker 1CB18 trips, and high voltage cannot be applied.

• Fault Analysis: The rectifier bridge of 4A5K1 is broken down.

• Emergency Handling: Idan akwai backup, ƙare zuwa backup. Idan ba a baka backup, urgently replace 4A5K1.

3. Ƙananan Littafin

During the use of the EVS630 lowa-voltage vacuum contactor in the DF100A shortwave transmitter, in addition to conducting daily inspection and maintenance, it is also necessary to test the temperature of its main phase terminal screws regularly during operation. An infrared temperature gun or temperature patches can be used for observation. Continuously accumulate data to grasp the inspection and maintenance cycle.