A fast demagnetization circuit for free-oscillation power transformer

Abstract

The present invention relates to a free oscillation type power transformer rapid demagnetization circuit. The free oscillation type power transformer rapid demagnetization circuit comprises a status indication module, a switching power supply module, a capacitor bank module, a control module, and a working indication circuit; the status indication module, the switching power supply module, the capacitor bank module, the control module, and the working indication circuit are connected in sequence. The free oscillation type power transformer rapid demagnetization circuit is a high-efficiency demagnetization circuit for power transformers, which is designed to efficiently and quickly complete the demagnetization of power transformers to prevent equipment failures caused by the misoperation of transformer protection caused by the huge excitation surge current when the transformer is transmitting power, delaying power transmission, thereby causing power system accidents, which have a great impact on people's lives and property, traffic safety, production and life.

Description

Technical Field

[0001] The invention provides a free oscillation type power transformer rapid demagnetization circuit, and relates to the technical field of transformers. Background Art

[0002] Large power transformers are designed with a large magnetic flux density that is easily close to the saturation value. As long as there is a small amount of residual magnetism in the iron core, the transformer will trip the protection action of the transformer due to the saturation of the iron core when transmitting power, resulting in power transmission failure and delay. Especially for high-power DC projects, it will cause the power plant to be unable to transmit a large amount of electricity, and at the same time the power grid is insufficient, affecting the safe operation of the power grid and causing immeasurable losses to people's lives and property. In order to prevent such accidents from happening, it is necessary to demagnetize the transformer. The power demagnetization device invented in this article can quickly demagnetize the transformer, thereby preventing the occurrence of accidents in the power system, and at the same time can eliminate the residual magnetism of the transformer to prevent the power from being transmitted, endangering the safety of the country and people's lives and property. Summary of the invention

[0003] In view of the above problems, the present invention aims to solve the above problems. One object of the present invention is to provide a free oscillation power transformer rapid demagnetization circuit that solves the above problems. Specifically, the present invention is a power rapid demagnetization circuit with high demagnetization efficiency, simple structure and high reliability.

[0004] The technical solution of the present invention is: a free oscillation power transformer rapid demagnetization circuit, comprising a status indication module 1, a switching power supply module 2, a capacitor bank module 3, a control module 4, and a work indication circuit 5; the status indication module 1, the switching power supply module 2, the capacitor bank module 3, the control module 4, and the work indication circuit 5 are connected in sequence, and the work indication circuit 5 is then connected to a transformer coil 6.

[0005] Furthermore, the state indicating module 1 comprises sockets J01, J02, diodes D1, D2, DW31, resistors R1, R2, R31, triode T2, LED lamp, and AC switch K1; the socket J01 is respectively connected to the anode of the diode D1 and the contact 1 of the AC switch K1, the cathode of D1 is connected to the first end of the resistor R1, the second end of R1 is respectively connected to the collector of the triode T2 and the anode of the green light emitting diode G in the LED lamp, the contact 2 of the AC switch K1 is respectively connected to the anode of the diode D2 and the input end L of the switching power supply module 2, the cathode of D2 is connected to the first end of R2, and the cathode of R2 is connected to the collector of the triode T2 and the anode of the green light emitting diode G in the LED lamp. The second terminal is connected to the anode of the red light-emitting diode R in the LED lamp, the cathode of the red light-emitting diode R is connected to the base of T2, the anode of the blue light-emitting diode B in the LED lamp is connected to the first end of R31, the second terminal of R31 is connected to the interface P1+, the cathode of the blue light-emitting diode B is connected to the cathode of DW31, the anode of DW31 is connected to the interface P1-, the emitter of T2, the cathode of the green light-emitting diode G, and the contact 3 of the AC switch K1 are all connected to the socket J01, the contact 4 of the AC switch K1 is connected to the input terminal N of the switching power supply module 2, and the interfaces P1+ and P1- serve as the two output terminals of the switching power supply module 2.

[0006] Furthermore, the switching power supply module 2 adopts a 250V 10A constant current and voltage limiting charging module.

[0007] Furthermore, the capacitor bank module 3 includes a DC switch K2, interfaces P+, P-, diodes D41, D42, capacitors C51, C52; the output end of the switching power supply module 2 is connected to the DC switch K2, and the DC switch K2 is connected to the interfaces P+, P-, the interface P+ is respectively connected to the cathode of the diode D41, the first end of the capacitor C51, and the first input end of the control module 4, the anode of the diode D41 and the second end of the capacitor C51 are connected together and are connected to the anode of D42 and the first end of C52, and the cathode of D42 and the second end of C52 are connected to the interface P- and the second input end of the control module 4.

[0008] Furthermore, the control module 4 includes a shunt FL, an electronic oscilloscope SW, a time relay SJ, and an operational amplifier OP1; the shunt FL is respectively connected to the capacitor group module 3 and the working indication circuit 5, the two ends of the shunt FL are also connected to the two input ends of the operational amplifier OP1, the output end of the operational amplifier OP1 is respectively connected to the electronic oscilloscope SW and the linear rectifier circuit XZ, the linear rectifier circuit XZ is also connected to the base of the triode T31, the collector of T31 is connected to the base of the triode T32, the emitter of T32 is connected to 24V+, the collector of T32 is respectively connected to the cathode of the diode DF30 and one end of the time relay SJ, the emitter of T31 is connected to the first end of the resistor RF30, the second end of RF30, the anode of DF30, and the other end of the time relay SJ are all grounded.

[0009] Furthermore, the work indication circuit 5 includes a relay J3, a start button QA, a stop button TK, resistors R61, R62, a two-color integrated light-emitting diode D60, sockets J71, J72, diodes TVS61, TVS62, D61, D62, and triodes T61, T62; the contact 3 of the relay J3 and the first end of the start button QA are both connected to the first output terminal interface P1+ of the switch power module 2, the contact 4 of the relay J3 is connected to the second end of the start button QA after being connected to its contact 2, the contact 2 of the relay J3 is respectively connected to the first end of the stop button TK and the first end of the time relay SJ of the control module 4, the second end of the stop button TK and the second end of the time relay SJ are both connected to the second output terminal interface P1- of the switch power module 2, and the contacts 5 and 7 of the relay J3 are respectively connected to the control module 4. The first output end and the second output end of the module 4 are connected, the contact 6 of the relay J3 is respectively connected to the socket J71 and the first end of the resistor R61, the second end of R61 is connected to the first end of D60, the second end of D60 is connected to the first end of the resistor R62, the second end of R62 is connected to the contact 8 of the relay J3 and the socket J72, the sockets J71 and J72 are also respectively connected to the two ends of the transformer coil 6, the contact 6 of the relay J3 is also respectively connected to the cathode of the diode TVS61, the cathode of D62, and the collector of the triode T61, the anode of TVS61 is connected to the base of T61, the emitter of T61 is connected to the anode of D61, the contact 8 of the relay J3 is also respectively connected to the cathode of D61, the collector of T62, and the cathode of the diode TVS62, the anode of D62 is connected to the emitter of T62, and the base of T62 is connected to the anode of the diode TVS62.

[0010] The beneficial effects of the present invention are as follows: the present invention provides an electric rapid demagnetization circuit with high demagnetization efficiency, simple structure and high reliability, which is a high-efficiency demagnetization circuit for power transformers, and is intended to efficiently and quickly complete the demagnetization of power transformers to prevent equipment failures caused by malfunction of transformer protection due to the huge excitation surge current when the transformer is transmitting power, delaying power transmission and thus causing power system accidents, which have a great impact on people's lives and property, traffic safety, and production and life.

[0011] Other characteristic features and advantages of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated into the specification and constitute a part of the specification, illustrate embodiments of the present invention and are used together with the description to explain the principles of the present invention. In these drawings, similar reference numerals are used to represent similar elements. The drawings described below are some embodiments of the present invention, but not all embodiments. For those of ordinary skill in the art, other drawings can be obtained from these drawings without paying creative work.

[0013] Figure 1 The schematic diagram of the structure of the fast demagnetization circuit of the free oscillation power transformer of the present invention is exemplarily shown;

[0014] Figure 2 The schematic diagram of the local control circuit structure of the free oscillation power transformer rapid demagnetization circuit of the present invention is shown as an example Figure 1 ;

[0015] Figure 3 The schematic diagram of the local circuit detail structure of the free oscillation power transformer rapid demagnetization circuit of the present invention is exemplarily shown.

[0016] Figure 1 The numbers in the figure are: 1-status indication module, 2-switching power supply module, 3-capacitor bank module, 4-control module, 5-working indication circuit, 6-transformer coil. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0018] The free oscillation type power transformer rapid demagnetization circuit provided according to the present invention is described in detail below in conjunction with the accompanying drawings.

[0019] Example 1: Figure 1-2 As shown, a free-oscillation power transformer rapid demagnetization circuit includes a status indication module 1, a switching power supply module 2, a capacitor bank module 3, a control module 4, and a work indication circuit 5; the status indication module 1, the switching power supply module 2, the capacitor bank module 3, the control module 4, and the work indication circuit 5 are connected in sequence, and the work indication circuit 5 is then connected to the transformer coil 6.

[0020] Furthermore, the state indicating module 1 comprises sockets J01, J02, diodes D1, D2, DW31, resistors R1, R2, R31, triode T2, LED lamp, and AC switch K1; the socket J01 is respectively connected to the anode of the diode D1 and the contact 1 of the AC switch K1, the cathode of D1 is connected to the first end of the resistor R1, the second end of R1 is respectively connected to the collector of the triode T2 and the anode of the green light emitting diode G in the LED lamp, the contact 2 of the AC switch K1 is respectively connected to the anode of the diode D2 and the input end L of the switching power supply module 2, the cathode of D2 is connected to the first end of R2, and the cathode of R2 is connected to the collector of the triode T2 and the anode of the green light emitting diode G in the LED lamp. The second terminal is connected to the anode of the red light-emitting diode R in the LED lamp, the cathode of the red light-emitting diode R is connected to the base of T2, the anode of the blue light-emitting diode B in the LED lamp is connected to the first end of R31, the second terminal of R31 is connected to the interface P1+, the cathode of the blue light-emitting diode B is connected to the cathode of DW31, the anode of DW31 is connected to the interface P1-, the emitter of T2, the cathode of the green light-emitting diode G, and the contact 3 of the AC switch K1 are all connected to the socket J01, the contact 4 of the AC switch K1 is connected to the input terminal N of the switching power supply module 2, and the interfaces P1+ and P1- serve as the two output terminals of the switching power supply module 2.

[0021] Furthermore, the switching power supply module 2 adopts a 250V 10A constant current and voltage limiting charging module.

[0022] Furthermore, the capacitor bank module 3 includes a DC switch K2, interfaces P+, P-, diodes D41, D42, capacitors C51, C52; the output end of the switching power supply module 2 is connected to the DC switch K2, and the DC switch K2 is connected to the interfaces P+, P-, the interface P+ is respectively connected to the cathode of the diode D41, the first end of the capacitor C51, and the first input end of the control module 4, the anode of the diode D41 and the second end of the capacitor C51 are connected together and are connected to the anode of D42 and the first end of C52, and the cathode of D42 and the second end of C52 are connected to the interface P- and the second input end of the control module 4.

[0023] Furthermore, the control module 4 includes a shunt FL, an electronic oscilloscope SW, a time relay SJ, and an operational amplifier OP1; the shunt FL is respectively connected to the capacitor group module 3 and the working indication circuit 5, the two ends of the shunt FL are also connected to the two input ends of the operational amplifier OP1, the output end of the operational amplifier OP1 is respectively connected to the electronic oscilloscope SW and the linear rectifier circuit XZ, the linear rectifier circuit XZ is also connected to the base of the triode T31, the collector of T31 is connected to the base of the triode T32, the emitter of T32 is connected to 24V+, the collector of T32 is respectively connected to the cathode of the diode DF30 and one end of the time relay SJ, the emitter of T31 is connected to the first end of the resistor RF30, the second end of RF30, the anode of DF30, and the other end of the time relay SJ are all grounded.

[0024] Furthermore, the work indication circuit 5 includes a relay J3, a start button QA, a stop button TK, resistors R61, R62, a two-color integrated light-emitting diode D60, sockets J71, J72, diodes TVS61, TVS62, D61, D62, and triodes T61, T62; the contact 3 of the relay J3 and the first end of the start button QA are both connected to the first output terminal interface P1+ of the switch power module 2, the contact 4 of the relay J3 is connected to the second end of the start button QA after being connected to its contact 2, the contact 2 of the relay J3 is respectively connected to the first end of the stop button TK and the first end of the time relay SJ of the control module 4, the second end of the stop button TK and the second end of the time relay SJ are both connected to the second output terminal interface P1- of the switch power module 2, and the contacts 5 and 7 of the relay J3 are respectively connected to the control module 4. The first output end and the second output end of the module 4 are connected, the contact 6 of the relay J3 is respectively connected to the socket J71 and the first end of the resistor R61, the second end of R61 is connected to the first end of D60, the second end of D60 is connected to the first end of the resistor R62, the second end of R62 is connected to the contact 8 of the relay J3 and the socket J72, the sockets J71 and J72 are also respectively connected to the two ends of the transformer coil 6, the contact 6 of the relay J3 is also respectively connected to the cathode of the diode TVS61, the cathode of D62, and the collector of the triode T61, the anode of TVS61 is connected to the base of T61, the emitter of T61 is connected to the anode of D61, the contact 8 of the relay J3 is also respectively connected to the cathode of D61, the collector of T62, and the cathode of the diode TVS62, the anode of D62 is connected to the emitter of T62, and the base of T62 is connected to the anode of the diode TVS62.

[0025] The working principle of the present invention is as follows: the first part of the 220V industrial frequency AC power supply is connected to the device through the sockets J01 and J02, J01 is connected to the live wire L, and J02 is connected to the neutral wire N. When J01 and J02 have AC input voltage, the power passes through D1→R1→LED (G) (the green light-emitting diode G in the LED lamp) in sequence, and at this time, the LED emits green light. When the K1 switch is turned on and the switching power supply module M (switching power supply module 2) has input voltage, the current passes through D2→R2→LED (R) (the red light-emitting diode R in the LED lamp)→the c pole of the transistor T2→the e pole of the transistor T2, and at this time, the LED (R) emits red light. Since the LED (G) is connected between the c pole of the transistor T2→the e pole of the transistor T2, the transistor T2 is turned on, and the voltage between the c and e poles is only about 0.3V, so the LED (G) will not emit light. When the K2 switch is turned on and the M switch power supply charges the capacitor, the indicator light circuit power supply flows from the positive electrode P+ → resistor R31 → LED (B) (the blue light-emitting diode B in the LED lamp) → DW31 → P-. At this time, LED (B) lights up. Since the LED is a package of three LEDs R, G, and B, when LED (R) and LED (B) light up at the same time, the LED turns purple. Of course, for the LED to turn purple, the voltage on the capacitor needs to be charged to 220V or above.

[0026] The functions of the control module 4 are: (1) converting the 10A current into a 100mV DC for use by the electronic oscilloscope SW to observe the change of the current in the circuit. (2) supplying the SJ time relay. If the device is to stop working, the current in the circuit needs to be close to 0A, the SJ time relay is disconnected, the J3 relay is demagnetized and restored, and the demagnetization current loop is disconnected. The SW in the control module 4 can be a DSO138 oscilloscope, Figure 3 In the figure, OP1 is an operational amplifier, and the input mode is differential amplification factor of 500. SW can be a DSO138 oscilloscope module. XZ can be a full-wave linear rectifier circuit module composed of dual operational amplifiers. SJ is a time relay, which is closed instantly when powered on and disconnected after 300S when powered off, that is, the demagnetization current decays to less than 100mA. When the duration exceeds 300S, the contact is disconnected and the demagnetization stops. Figure 2 In the figure, TK is the stop button TK. When TK is turned on, the circuit is automatically disconnected after demagnetization is completed and the device stops working.

[0027] Figure 1 In the circuit, TVS61, D61, T61, TVS62, D62 and T62 form a high-power bidirectional overvoltage limiting circuit. When the demagnetization device stops running (J3 is disconnected), the freewheeling current in the transformer coil will cause the voltage across J71 and J72 to exceed 250V. The high-power high-voltage transistor T1 (or T2) will be turned on to prevent the freewheeling current from producing a very high voltage to damage the insulation of the transformer.

[0028] When removing the connecting wires on the device, you should first short-circuit the transformer coil with a short-circuit wire before removing it to prevent the overvoltage produced by the follow-up current from endangering the safety of the testers.

[0029] Start the device. (1) Connect the power supply from J01 and J02, and the LED lights up green. (2) Open the K1 switch. When the switching power supply module M has input voltage, the LED turns red. The K2 switch is turned on, and the switching power supply module M charges the capacitor C51. When the voltage reaches 220V, the LED changes from red to purple. (3) Turn TK to the start position. (4) Connect QA, the coil between the 1st and 2nd pins of J3 is energized, the 3rd and 4th normally open contacts of J3 are closed, the 5th and 6th contacts of the J3 relay, and the 7th and 8th contacts are connected. C51, C52 and the inductance of the transformer coil oscillate freely, and the current changes according to the sine wave. Due to the resistance in the circuit, the energy of the oscillation will be slowly consumed by the resistance, and the power amplitude will become smaller and smaller, and finally close to zero, achieving the purpose of demagnetization.

[0030] Figure 1 , Figure 2 In the calculation, all P+ are connected to the same point, and similarly, all P- are also connected to the same point.

[0031] When you see that the current waveform amplitude in the electronic oscilloscope is as small as 0.1A, you can open the TK switch to the disconnect position. At this time, when the current passes through zero, the J3 self-holding circuit is disconnected and the demagnetization is completed.

[0032] D60 is a two-color integrated light-emitting diode. When the J71 terminal is at a positive potential, the left light-emitting diode emits red light. If the J71 terminal is at a negative potential, the right light-emitting diode in D60 emits green light. The higher the voltage, the brighter the indicator light.

[0033] This device is small in size, light in weight, and cheap in price. You can buy several of them at the same time. The demagnetization speed can increase the work efficiency by 90% compared with the traditional demagnetization method.

[0034] The contents described above may be implemented individually or in combination in various ways, and these variations are all within the protection scope of the present invention.

[0035] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the article or device including the elements.

[0036] The above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the present invention. The present invention is described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A free-oscillation power transformer rapid demagnetization circuit, characterized in that: It comprises a status indication module (1), a switching power supply module (2), a capacitor bank module (3), a control module (4), and a working indication circuit (5); the status indication module (1), the switching power supply module (2), the capacitor bank module (3), the control module (4), and the working indication circuit (5) are connected in sequence, and the working indication circuit (5) is further connected to a transformer coil (6); The state indicating module (1) comprises sockets J01, J02, diodes D1, D2, DW31, resistors R1, R2, R31, transistor T2, LED lamp, and AC switch K1; the socket J01 is respectively connected to the anode of the diode D1 and the contact 1 of the AC switch K1, the cathode of D1 is connected to the first end of the resistor R1, the second end of R1 is respectively connected to the collector of the transistor T2 and the anode of the green light emitting diode G in the LED lamp, the contact 2 of the AC switch K1 is respectively connected to the anode of the diode D2 and the input end L of the switching power supply module (2), the cathode of D2 is connected to the first end of R2, and the second end of R2 is connected to the collector of the transistor T2 and the anode of the green light emitting diode G in the LED lamp, The anode of the red light emitting diode R in the LED lamp is terminated, the cathode of the red light emitting diode R is connected to the base of T2, the anode of the blue light emitting diode B in the LED lamp is connected to the first end of R31, the second terminal of R31 is connected to the interface P1+, the cathode of the blue light emitting diode B is connected to the cathode of DW31, the anode of DW31 is connected to the interface P1-, the emitter of T2, the cathode of the green light emitting diode G, and the contact 3 of the AC switch K1 are all connected to the socket J01, the contact 4 of the AC switch K1 is connected to the input terminal N of the switching power module (2), and the interfaces P1+ and P1- serve as two output terminals of the switching power module (2); The capacitor bank module (3) comprises a DC switch K2, interfaces P+, P-, diodes D41, D42, capacitors C51, C52; the output end of the switch power supply module (2) is connected to the DC switch K2, which is in turn connected to the interfaces P+, P-; the interface P+ is respectively connected to the cathode of the diode D41, the first end of the capacitor C51, and the first input end of the control module (4); the anode of the diode D41 and the second end of the capacitor C51 are connected together and then connected to the anode of D42 and the first end of C52; the cathode of D42 and the second end of C52 are both connected to the interface P- and the second input end of the control module (4); The control module (4) comprises a shunt FL, an electronic oscilloscope SW, a time relay SJ, and an operational amplifier OP1; the shunt FL is respectively connected to the capacitor bank module (3) and the working indication circuit (5); the two ends of the shunt FL are also connected to the two input ends of the operational amplifier OP1; the output end of the operational amplifier OP1 is respectively connected to the electronic oscilloscope SW and the linear rectifier circuit XZ; the linear rectifier circuit XZ is also connected to the base of the triode T31; the collector of T31 is connected to the base of the triode T32; the emitter of T32 is connected to 24V+; the collector of T32 is respectively connected to the cathode of the diode DF30 and one end of the time relay SJ; the emitter of T31 is connected to the first end of the resistor RF30; the second end of RF30, the anode of DF30, and the other end of the time relay SJ are all grounded; The work indication circuit (5) comprises a relay J3, a start button QA, a stop button TK, resistors R61, R62, a two-color integrated light-emitting diode D60, sockets J71, J72, diodes TVS61, TVS62, D61, D62, and transistors T61, T62; the contact 3 of the relay J3 and the first end of the start button QA are both connected to the first output terminal interface P1+ of the switch power module (2); the contact 4 of the relay J3 is connected to the second end of the start button QA after being connected to its contact 2; the contact 2 of the relay J3 is respectively connected to the first end of the stop button TK and the first end of the time relay SJ of the control module (4); the second end of the stop button TK and the second end of the time relay SJ are both connected to the second output terminal interface P1- of the switch power module (2); the contact 5 and the contact 7 of the relay J3 are respectively connected to the control module (4). The first output terminal and the second output terminal of the module (4) are connected, the contact 6 of the relay J3 is respectively connected to the socket J71 and the first end of the resistor R61, the second end of R61 is connected to the first end of D60, the second end of D60 is connected to the first end of the resistor R62, the second end of R62 is connected to the contact 8 of the relay J3 and the socket J72, the sockets J71 and J72 are also respectively connected to the two ends of the transformer coil (6), the contact 6 of the relay J3 is also respectively connected to the cathode of the diode TVS61, the cathode of D62, and the collector of the triode T61, the anode of TVS61 is connected to the base of T61, the emitter of T61 is connected to the anode of D61, the contact 8 of the relay J3 is also respectively connected to the cathode of D61, the collector of T62, and the cathode of the diode TVS62, the anode of D62 is connected to the emitter of T62, and the base of T62 is connected to the anode of the diode TVS62.

2. The free oscillation power transformer rapid degaussing circuit according to claim 1 is characterized in that: The switching power supply module (2) adopts a 250V 10A constant current and voltage limiting charging module.

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