CN201515229U

CN201515229U - Special contactor for switching capacitors

Info

Publication number: CN201515229U
Application number: CN2009201740883U
Authority: CN
Inventors: 杨建华
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-08-24
Filing date: 2009-08-24
Publication date: 2010-06-23
Anticipated expiration: 2019-08-24

Abstract

The utility model relates to a special contactor for switching capacitors, which is provided with a contactor control device consisting of a power supply phase detection circuit, a charging circuit for charging the capacitors in advance, a real-time and on-line detection device of action time of the contactor, a coil driving circuit and a central processing unit (CPU) controller. The charging circuit can provide voltage which is consistent with a certain-moment phase of a three-phase power supply. The CPU controller sends out a switching-on drive signal in advance according to a switching-on time to enable the main contact of the contactor to be switched on at the phase, thereby the capacitors can be switched without inrush current.

Description

The special-purpose contactor of capacitor switching

Affiliated technical field

The utility model relates to a kind of contactor, in particular for the special-purpose contactor of capacitor switching.

Background technology

At present, the capacitor switching device mainly contains three kinds in the reactive power compensator: contactor, noncontacting switch, combination switch, in the reactive power compensator opening-closing capacitor bank process, the initial voltage of capacitor group is zero, and is closing a floodgate moment, and line voltage is often non-vanishing again, the voltage that is added in capacitor group two ends is raise suddenly, and produce a very big inrush phenomenon, not only electrical network is impacted, and influence the useful life of capacitor; The special-purpose contactor of conventional electric capacity suppresses to shove by the auxiliary contact that adds the band current-limiting resistance, shoves in 20 times that generally can be controlled at rated current the inhibition poor effect of shoving; Noncontacting switch adopts the power electronic device controllable silicon as switching device, drop into capacitor when realizing the line voltage zero passage, effectively avoided the generation of shoving, and silicon controlled self work energy consumption is big, need the forced heat radiation measure, run counter to the energy-conservation aim of reactive power compensation; Combination switch is that noncontacting switch and contactor are united two into one, noncontacting switch work during switching, the generation of avoiding shoving, normal work stage is taken on by contactor, reduce energy consumption, but combination switch the failure rate and the cost of switching device have also been improved when increasing the complexity of switching device.

Summary of the invention

In order to overcome the effectively deficiency of suppression capacitor inrush phenomenon of existing contactor, the utility model provides a kind of special-purpose contactor of capacitor switching, based on existing contactor, realize operating passing zero, be lowly shove, capacitor switching switch cheaply.

The technical scheme that its technical problem that solves the utility model adopts is: the special-purpose contactor of capacitor switching that comprises the contactor body also has a contactor control device, this device is by the power phase testing circuit, can carry out the charging circuit of pre-charge to capacitor, contactor real time on-line detection device operate time, coil driver and cpu controller are formed, contactor checkout gear operate time is by the feed motion time of a contactor main contacts open and-shut mode transducer real-time online measuring contactor, main contacts open and-shut mode transducer is the auxiliary contact that are positioned on the contactor body, and these auxiliary contact and main contacts action are synchronously; Charging circuit is connected with contactor main circuit leading-out terminal by disconnecting relay, can provide and a certain corresponding to voltage of the phase place moment of three phase mains to capacitor, this phase place can be chosen in a certain phase voltage zero passage of three phase mains constantly, and the power phase testing circuit is the zero-crossing pulse circuit of this phase voltage; By the monitoring of power phase testing circuit, in the moment of leading this feed motion time of phase place of following one-period, cpu controller sends the combined floodgate drive signal, realizes that the contactor main contacts is in this phase close; Cpu controller is used to calculate drive signal and sends the weighted average that contactor feed motion time value constantly is this contactor history feed motion time, has reduced the random error of contactor operate time greatly, has improved the accuracy of closing moment; Owing to filled with and the corresponding to voltage of this combined floodgate phase place to capacitor in advance, when contactor was closed, capacitor inserted power circuit with equipotential, has realized the no-flashy-flow switching.

The beneficial effects of the utility model are, adopt existing contactor technology, have realized the operating passing zero of capacitor cheaply by electron controls technology, have avoided inrush phenomenon, reduce the impact to electrical network, prolong the useful life of contactor and capacitor; With respect to existing no-flashy-flow switching technology, reliability is higher, and energy consumption is littler.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is a schematic block circuit diagram of the present utility model.

Fig. 2 is the circuit theory diagrams of embodiment.

1. power phase testing circuits among the figure, 2. charging circuit, 3. contactor checkout gear operate time, 4. coil driver, 5CPU controller, 6. main contacts open and-shut mode transducer, 7. contactor body, 8. disconnecting relay, 9. auxiliary contact.

Embodiment

In Fig. 1, the control device of the special-purpose contactor of capacitor switching is by power phase testing circuit (1), can carry out the charging circuit (2) of pre-charge to capacitor, contactor real time on-line detection device operate time (3), coil driver (4) and cpu controller (5) are formed, contactor checkout gear operate time (3) is by the feed motion time of a contactor main contacts open and-shut mode transducer (6) real-time online measuring contactor, charging circuit (2) can provide and a certain corresponding to voltage of the phase place moment of three phase mains to capacitor, monitoring by power phase testing circuit (1), in the moment of leading this feed motion time of phase place of following one-period, cpu controller (5) sends the combined floodgate drive signal and gives coil driver (4), realizes that the contactor main contacts is in this phase close; Cpu controller (5) is used to calculate drive signal and sends the weighted average that contactor feed motion time value constantly is this contactor history feed motion time, reduced the random error of contactor operate time greatly, improved the accuracy of closing moment, owing to filled with and the corresponding to voltage of this combined floodgate phase place to capacitor in advance, when contactor is closed, capacitor inserts power circuit with equipotential, has realized the no-flashy-flow switching.

In embodiment illustrated in fig. 2, when the closing moment of contactor is selected in A phase power source voltage and is zero, Dui Ying BC phase voltage value is respectively ± 270V therewith, charging circuit as shown in Figure 2, the A phase power supply of 220VAC passes through the transformer pressure regulation to 191VAC, its crest voltage is 270V, by current-limiting resistance R respectively through 2 anti-phase diode D1, after the filtering of D2 half-wave, be connected to the leading-out terminal of contactor B C phase via disconnecting relay (8), N also is connected to the leading-out terminal of contactor A phase mutually by disconnecting relay (8), filled with and the corresponding to voltage of this combined floodgate phase place to capacitor; Power phase testing circuit (1) is the voltage zero-cross circuit of power supply A phase, when A phase supply voltage zero passage, provide triggering signal to cpu controller (5), it's feed motion time of zero phase is past the leading next one of cpu controller (5), send coil drive signal and give coil driver (4), make contactor closure when A phase voltage zero passage, this moment, the phase voltage of three phase mains was identical with the current potential that electric capacity has charged, had realized the no-flashy-flow switching.The main contacts open and-shut mode transducer (6) that the measurement contactor feed motion time is used has adopted the built-in auxiliary contact (9) of contactor body (7) in the present embodiment, these auxiliary contact and contactor main contacts are installed on the same motion, realize synchronous deciliter, accurate with what guarantee to measure.

Claims

1. special-purpose contactor of the capacitor switching that comprises the contactor body, it is characterized in that: it also has a contactor control device, this device by the power phase testing circuit, can form charging circuit, contactor real time on-line detection device operate time, coil driver and cpu controller that capacitor carries out pre-charge, contactor checkout gear operate time is by the feed motion time of a contactor main contacts open and-shut mode transducer real-time online measuring contactor, and charging circuit can provide and a certain corresponding to voltage of the phase place moment of three phase mains to capacitor; By the monitoring of power phase testing circuit, in the moment of leading this feed motion time of phase place, cpu controller sends the combined floodgate drive signal, realizes that the contactor main contacts is in this phase close.

2. the special-purpose contactor of capacitor switching according to claim 1, it is characterized in that: main contacts open and-shut mode transducer is the auxiliary contact that are positioned on the contactor body, these auxiliary contact and main contacts action are synchronously.

3. the special-purpose contactor of capacitor switching according to claim 1 is characterized in that: the electric capacity charging voltage is chosen in a certain phase voltage zero passage of three phase mains constantly, and the power phase testing circuit is the zero-crossing pulse circuit of this phase voltage.

4. the special-purpose contactor of capacitor switching according to claim 1, it is characterized in that: charging circuit is connected with contactor main circuit leading-out terminal by disconnecting relay, realizes capacitor is charged.

5. the special-purpose contactor of capacitor switching according to claim 1 is characterized in that: cpu controller is used to calculate drive signal and sends the weighted average that contactor feed motion time value constantly is this contactor history feed motion time.