CN201146370Y

CN201146370Y - Apparatus for reducing excitation inrush current of rectifier transformer

Info

Publication number: CN201146370Y
Application number: CNU2007200611918U
Authority: CN
Inventors: 梁永万; 柏云杉; 高小清; 汪浩龙
Original assignee: GUANGZHOU ELECTRICAL EQUIPMENT SCIENTIFIC RESEARCH INST
Current assignee: GUANGZHOU ELECTRICAL EQUIPMENT SCIENTIFIC RESEARCH INST
Priority date: 2007-12-10
Filing date: 2007-12-10
Publication date: 2008-11-05
Anticipated expiration: 2017-12-10

Abstract

The utility model discloses a device used for reducing the inrush of a rectifier transformer, which comprises a main circuit breaker QF, a main circuit-break operating mechanism QF-P, a switch on button SB1, a switch off button SB2, a relay K, a contact-typed relay KM, a time-delay relay KT and a power resistor R. The three main contacts of the contact-typed relay KM are respectively connected with one power resistor R in series and are connected with the switch of the main circuit breaker QF in the input of every phase in a parallel way; the voltage input terminal of the main circuit-break operating mechanism QF-P is connected with a phase voltage Ua and a null line N. The input terminal of the phase voltage Ua and the null line N are connected in a parallel way, which is used in a switch on control circuit for controlling the closing of the main circuit breaker QF and time-delay contact-typed relay KM and used in a switch off control circuit for controlling the opening of the main circuit breaker QF. The device used for reducing the inrush of the rectifier transformer can greatly reduce the inrush of a three phase rectifier transformer and ensure that the circuit breaker is prevented from tripping caused by excessive inrush in the rectifier transformer during every switch on operation.

Description

Reduce the device of rectifier transformer magnetizing inrush current

Technical field

The utility model relates to a kind of device of magnetizing inrush current, particularly relates to a kind of device that is used to reduce the rectifier transformer magnetizing inrush current.

Background technology

Traditional rectification circuit is that rectifier transformer directly connects the three-phase voltage input by threephase switch QF, directly outputs to rectifying part V after the transformation.When closing unloaded three-phase rectifier transformer; because the core sataration of transformer can produce the sizable magnetizing inrush current of numerical value, its peak value can reach 10 to 20 times of rated current under the serious situation; thereby cause circuit breaker fast tripping protection action, even the upper level circuit breaker protection action of bypassing the immediate leadership.Phase angle when magnetizing inrush current and combined floodgate has much relations.The peak value of electric current appears at behind the combined floodgate moment through about half cycle.Because the elementary winding of rectifier transformer has resistance, this electric current is decayed in time and is reached the steady-state value of no-load current at last.The size of remanent magnetism all has relation in the phase place of the impedance in the time of its decay and the capacity of rectifier transformer, loop, iron core character, applied voltage and the iron core.The magnetizing inrush current of rectifier transformer idle-loaded switching-on is shorter owing to its duration, transformer itself be there is no much harm, but frequent divide-shut brake, can shorten the life-span of circuit breaker greatly, bring inconvenience also for the operation of device operator, the repeatedly impact of big electric current in addition can cause the mechanical stress effect between the rectifier transformer winding, make fixture loosening, influence the useful life of rectifier transformer.Therefore manage to reduce the magnetizing inrush current of rectifier transformer, circuit breaker is unlikely because magnetizing inrush current is excessive trips, have positive meaning.

The utility model content

The purpose of this utility model is for a kind of device that is used to reduce rectifier transformer device magnetizing inrush current is provided, and makes when rectifier transformer starts Current Control in proper range, avoids magnetizing inrush current excessive and trip.

The technical solution adopted in the utility model is: a kind of device that reduces the rectifier transformer magnetizing inrush current, comprise: main circuit breaker QF, the main open-circuit operation QF-P of mechanism, switch knob SB1, opening button SB2, relay K, contact relay K M, time-delay relay KT and power resistor R, three main contacts of contact relay K M connect separately and are connected in parallel on behind the power resistor R on the switch of main circuit breaker QF in every input mutually; The voltage input end of the main open-circuit operation QF-P of mechanism meets phase voltage Ua and zero line N, and wherein the time-delay contact KT2 of time-delay relay KT is connected in the switching signal control port of the main open-circuit operation QF-P of mechanism; The contact K3 of relay K is connected in the sub-gate signal control port of the main open-circuit operation QF-P of mechanism; In parallel being used to controlled the combined floodgate control loop of main circuit breaker QF time-delay contact relay K M closure and is used to control the separating brake control loop that main circuit breaker QF disconnects between phase voltage Ua input and the zero line.

Three main contacts of described contact relay K M are connected in parallel on the switch of main circuit breaker QF in every input mutually after connecting separately and connecting power supply triple-pole switch KF on three branch roads of a power resistor R.

Described combined floodgate control loop is formed by being connected in parallel between phase voltage Ua input and the zero line three loops, is respectively: 1, the coil → phase voltage input of zero line N → relay K contact K1 → opening button SB2 → relay K; 2, coil → phase voltage input of the contact K2 → time-delay relay KT of zero line N → main circuit breaker switch normally-closed contact QF4 → relay K; 3, coil → phase voltage input of zero line N → time-delay relay KT snap action contact KT1 → contact relay K M.

Described separating brake control loop is formed the coil → phase voltage input of zero line N → switch knob SB1 → opening button SB2 → relay K by being connected in parallel between phase voltage Ua input and the zero line loop.

Described phase voltage input is connected with the fuse protection silk.

The utility model compared with prior art, it is series connection power resistor reduced-voltage starting in closing circuit, treat that the rectifier transformer charging finishes, after the equilibrium establishment magnetic field, again rectifier transformer is dropped into fully, thereby reach the magnetizing inrush current when reducing three-phase rectifier transformer greatly, circuit breaker can not trip because the magnetizing inrush current of rectifier transformer is excessive when guaranteeing each the combined floodgate.

Description of drawings

Fig. 1 is the utility model circuit theory winding diagram;

Embodiment

A kind of device that reduces the rectifier transformer magnetizing inrush current, comprise main circuit breaker QF, the main open-circuit operation QF-P of mechanism, power supply triple-pole switch KF, switch knob SB1, opening button SB2, relay K, contact relay K M, time-delay relay KT and power resistor R1, R2, R3, after on three main contacts of contact relay K M are connected three branch roads of power resistor R1, a R2, R3 separately, connecting power supply triple-pole switch KF, be connected in parallel on the switch of main circuit breaker QF in every input mutually.

The voltage input end of the main open-circuit operation QF-P of mechanism meets phase voltage Ua and zero line N, and wherein the time-delay contact KT2 of time-delay relay KT is connected in the closing coil control port of the main open-circuit operation QF-P of mechanism; The contact K3 of relay K is connected in the switching winding control port of the main open-circuit operation QF-P of mechanism; The combined floodgate control loop that is used to control main circuit breaker QF time-delay contact relay K M closure in parallel between phase voltage Ua input and the zero line, the combined floodgate control loop is formed by being connected in parallel between phase voltage Ua input and the zero line three loops, is respectively: 1, the coil → phase voltage input of zero line N → relay K contact K1 → opening button SB2 → relay K; 2, coil → phase voltage input of the contact K2 → time-delay relay KT of zero line N → main circuit breaker switch normally-closed contact QF4 → relay K; 3, coil → phase voltage input of zero line N → time-delay relay KT snap action contact KT1 → contact relay K M.

Also in parallelly between phase voltage Ua input and zero line be used to control the separating brake control loop that main circuit breaker QF disconnects; Coil → phase voltage the input of zero line N → switch knob SB1 → opening button SB2 → relay K.Be connected with the fuse protection silk at above-mentioned phase voltage input.

Carry out control operation by following order:

Behind the power turn-on triple-pole switch KF, press switch knob SB1, make the coil of relay K get electronic work, and keep normally opened contact K2 closure by the contact K1 of relay K.Make K1 maintenance operating state and make time-delay relay KT coil get electronic picking up counting, closed snap action contact KT1.While contact relay K M gets electric, makes three main contact closures.Power resistor R1, R2 and R3 on the triple line devote oneself to work, the rectifier transformer reduced-voltage starting.Time-delay relay KT picks up counting, and 1-3 is relay delayed contact KT2 action after second, and main circuit breaker QF-P operating mechanism closing coil is charged, and main circuit breaker QF is closed a floodgate.Normally-closed contact QF4 opens after the main circuit breaker QF closure, time-delay relay KT coil losing electricity, snap action contact KT1 opens, contact relay K M coil losing electricity, three main contacts of relay K M are opened, power resistor R1, R2 and R3 withdraw from from major loop, and power supply is powered to rectifier transformer through main circuit breaker QF.

Sub-switching operation directly gets final product by opening button SB2.By opening button SB2, relay K 1 coil losing electricity, relay normally-closed contact K3 closure, main circuit breaker QF-P operating mechanism switching winding is charged, makes the action of main circuit breaker QF separating brake.

By such method, can reduce the magnetizing inrush current when closing three-phase rectifier transformer greatly, circuit breaker can not trip because the magnetizing inrush current of rectifier transformer is excessive when guaranteeing each the combined floodgate.

The utility model adopts unenclosed construction, all devices all to be fixed on the thick steel plate of 3mm, only needs during application be fixed on the installation site of main circuit breaker both sides and get final product base plate is installed.The external wiring part of device is all guided on the terminal board, only need add the device of a little, and just can carry out circuit easily and connect, thus the repertoire of implement device.

In the foregoing description, relay K adopts Omron MK3P2AC220V relay; Time-delay relay KT adopts DHC2-H-1 (1 second-10 seconds) AC220V type; Contact relay K M adopts the 3TH82-62E-0XM0AC220V type; Triple-pole switch KF adopts C65N/3P 10A type; Power resistor R1～R3 adopts the DQR-750W-50RHG type.

Claims

1, a kind of device that reduces the rectifier transformer magnetizing inrush current, it is characterized in that: comprise main circuit breaker QF, the main open-circuit operation QF-P of mechanism, switch knob SB1, opening button SB2, relay K, contact relay K M, time-delay relay KT and power resistor R, three main contacts of contact relay K M are connected separately and are connected in parallel on behind the power resistor R on the switch of main circuit breaker QF in every input mutually; The voltage input end of the main open-circuit operation QF-P of mechanism meets phase voltage Ua and zero line N, and wherein the time-delay contact KT2 of time-delay relay KT is connected in the switching signal control port of the main open-circuit operation QF-P of mechanism; The contact K3 of relay K is connected in the sub-gate signal control port of the main open-circuit operation QF-P of mechanism; In parallel being used to controlled the combined floodgate control loop of main circuit breaker QF time-delay contact relay K M closure and is used to control the separating brake control loop that main circuit breaker QF disconnects between phase voltage Ua input and the zero line.

2, the device of reduction rectifier transformer magnetizing inrush current according to claim 1, it is characterized in that: three main contacts of described contact relay K M are connected in parallel on the switch of main circuit breaker QF in every input mutually after connecting separately and connecting power supply triple-pole switch KF on three branch roads of a power resistor R.

3, the device of reduction rectifier transformer magnetizing inrush current according to claim 1, it is characterized in that: described combined floodgate control loop is formed by being connected in parallel between phase voltage Ua input and the zero line three loops, is respectively: (1) successively through the coil of zero line N, relay K contact K1, opening button SB2, relay K to the phase voltage input; (2) successively through the coil of contact K2, the time-delay relay KT of zero line N, main circuit breaker switch normally-closed contact QF4, relay K to the phase voltage input; (3) successively through the coil of zero line N, time-delay relay KT snap action contact KT1, contact relay K M to the phase voltage input.

4, the device of reduction rectifier transformer magnetizing inrush current according to claim 1 is characterized in that: described separating brake control loop for successively through the coil of zero line N, switch knob SB1, opening button SB2, relay K to the phase voltage input.

5, according to the device of claim 1,3 or 4 described reduction rectifier transformer magnetizing inrush currents, it is characterized in that: described phase voltage input is connected with the fuse protection silk.