CN207801779U - A Pulse Current Generator Based on LC Resonant Circuit - Google Patents

Abstract

the generator comprises a transformer, a rectifier bridge, a current limiting resistor, a direct current supporting branch, a controllable rectifier branch and a L C resonant branch, wherein one end of the primary side of the transformer is connected with a power grid, the other end of the primary side of the transformer is grounded, one end of the secondary side of the transformer is connected with an alternating current side branch of the rectifier bridge, the other end of the secondary side of the transformer is connected with a direct current side branch of the rectifier bridge, the direct current supporting branch and the controllable rectifier branch are connected in parallel, the current limiting resistor R is connected between the direct current side branch and the direct current supporting branch of the rectifier bridge in series, one end of an inductor L is connected with the controllable rectifier branch, and the other end of the capacitor C is connected with the direct current supporting branch.

Description

A Pulse Current Generator Based on LC Resonant Circuit

technical field

The present application relates to the technical field of power equipment, in particular to a pulse current generator based on an LC resonant circuit.

Background technique

The pulse current generator is an electrical test signal instrument used to send out current signals and generate required parameters. It has the characteristics of high voltage, high current, and strong pulse. In recent years, with the continuous development of the power system, pulse current generators have also been used to identify and judge the station area ownership of the sub-subscriber ammeters.

At present, a common pulse current generator includes a charging branch, a charging cable, and a peaking circuit. The peaking circuit includes a peaking switch and a peaking capacitor. One end of the peaking capacitor is a ground electrode plate, and the other end of the peaking capacitor is a high-voltage electrode. The high-voltage electrode plate is connected to one end of the high-voltage electrode of the peaking switch as an integrated structure. The other end of the peaking switch is the output electrode of the pulse source. The high-voltage electrode plate of the peaking capacitor is connected to the charging branch through a charging cable. An insulating shell is provided, and the insulating shell, the ground electrode plate of the peaking capacitor, and the high-voltage electrode plate together form a closed cavity filled with a gas medium.

However, the above-mentioned pulse current generator is not isolated from the power grid, which is likely to cause safety problems, and the characteristics of the pulse current emitted are not obvious, resulting in the pulse current signal being easily confused with the interference signal on the power grid, and it is impossible to accurately identify and judge the station area. The station area of the user's electric meter.

Utility model content

The present application provides a pulse current generator based on an LC resonant circuit to solve the safety problem in the actual use process and the problem of not being able to accurately identify and judge the station ownership of the sub-subscriber electric meter of the station station.

A pulse current generator based on an LC resonance circuit, comprising: a transformer, a rectifier bridge, a current limiting resistor, a DC support branch, a controllable rectification branch and an LC resonance branch;

The transformer includes a primary side and a secondary side, one end of the primary side is connected to the power grid, and the other end is grounded; the rectifier bridge includes a DC side branch and an AC side branch, and one end of the secondary side is connected to the AC side branch connected, and the other end is connected to the DC side branch;

The DC side branch of the rectifier bridge, the DC support branch and the controllable rectification branch are connected in parallel with each other;

The current limiting resistor is connected in series between the DC side branch and the DC support branch;

The LC resonance branch includes an inductor L and a capacitor C, one end of the inductor L is connected to the controllable rectification branch, the other end is connected to one end of the capacitor C, and the other end of the capacitor C is connected to the DC Support branch connections.

Optionally, the transformer is a single-phase step-up transformer with a step-up factor of 1:2.

Optionally, the rectifier bridge is a single-phase rectifier bridge.

Optionally, the DC support branch includes capacitors C1 and C2, and the capacitor C1 is connected in series with the capacitor C2.

Optionally, the controllable rectification branch includes thyristors SCR1 and SCR2, and the thyristor SCR1 and the thyristor SCR2 are connected in series in the same direction.

Optionally, a common end of the inductor L and the capacitor C in the LC resonant branch is connected to a power grid.

The technical solution provided by the application includes the following beneficial technical effects:

Compared with the prior art, this application provides a pulse current generator based on an LC resonant circuit. By setting a transformer, the pulse current generating circuit is isolated from the grid potential, and through the fast conduction characteristics of the thyristor in the controllable rectification branch , so that the pulse current signal has a square wave characteristic and contains rich spectrum components, and can also make positive and negative pulse current rounds occur. The rectifier bridge can convert AC power into pulsating DC power through the unidirectional conduction characteristics of diodes. LC resonant circuit The frequency amplitude conversion and frequency phase conversion of the signal are carried out, which enriches the signal characteristics of the pulse current. The pulse current generator of the present application is safe and reliable, and can accurately identify and judge the station area ownership of the electric meter of the subordinate user of the station area substation.

Description of drawings

In order to illustrate the technical solution of the present application more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, on the premise of not paying creative labor, Additional drawings can also be derived from these drawings.

FIG. 1 is a circuit diagram of a pulse current generator based on an LC resonant circuit provided in an embodiment of the present application.

Explanation of reference signs: 1. Transformer; 2. Rectifier bridge; 3. Current limiting resistor; 4. DC support branch; 5. Controllable rectification branch; 6. LC resonance branch.

Detailed ways

Referring to FIG. 1 , it is a circuit diagram of a pulse current generator based on an LC resonant circuit provided in this embodiment. The present application provides a pulse current generator based on an LC resonance circuit, including: a transformer 1 , a rectifier bridge 2 , a current limiting resistor 3 , a DC support branch 4 , a controllable rectification branch 5 and an LC resonance branch 6 .

The transformer 1 includes a primary side and a secondary side, one end of the primary side of the transformer 1 is connected to the power grid, and the other end is grounded; the rectifier bridge 2 includes a DC side branch and an AC side branch, and the secondary side of the transformer 1 One end is connected to the AC side branch of the rectifier bridge 2 , and the other end is connected to the DC side branch of the rectifier bridge 2 .

The DC side branch of the rectifier bridge 2 , the DC support branch 4 and the controllable rectification branch 5 are connected in parallel with each other.

The current limiting resistor 3 is connected in series between the DC side branch of the rectifier bridge 2 and the DC support branch 4 .

The LC resonance branch 6 includes an inductance L and a capacitor C, one end of the inductance L is connected to the controllable rectification branch 5, the other end is connected to one end of the capacitor C, and the other end of the capacitor C is connected to the The DC support branch 4 is connected.

It should be noted that the other end of the capacitor C is connected between the negative output end of the capacitor C1 and the positive input end of the capacitor C2 in the DC support branch 4 , and the distance from the connection point to the capacitors C1 and C2 is equal.

Optionally, the transformer 1 is a single-phase step-up transformer with a step-up coefficient of 1:2. A transformer is a device that uses the principle of electromagnetic induction to change the current and voltage. It consists of a primary coil, a secondary coil, and an iron core. The main functions of the transformer are voltage transformation, current transformation, impedance transformation, isolation, and voltage stabilization. Transformers are divided into single-phase transformers and three-phase transformers according to the number of phases. There is only one winding on the iron core of the single-phase transformer, which transforms the one-phase power supply to the secondary side output, which is used for single-phase load and transformer group. There are three windings on the iron core of the three-phase transformer, which can transform the three-phase power supply to the secondary side winding at the same time, and its output is also a three-phase power supply, which is used for raising and lowering the voltage of the three-phase system. In this embodiment, a single-phase transformer is selected. The single-phase transformer has a simple structure, small size, and low loss, mainly due to small iron loss. The single-phase transformer belongs to the isolation transformer, and the isolation transformer can realize the potential isolation between the pulse current generating circuit and the power grid, thereby increasing the safety of the device. The primary and secondary windings of the transformer are made of good insulating material to achieve the desired isolation voltage. The isolation transformer adopts a special structure, so that the equipment on both sides of the transformer changes from an electrical connection to a magnetic transfer, which isolates dangerous voltages and prevents communication and remote equipment from being damaged by lightning strikes and potential backlash.

Optionally, the rectifier bridge 2 is a single-phase rectifier bridge. The single-phase rectifier bridge is composed of four diodes, the AC side branch of the rectifier bridge 2 is composed of two diodes connected in series in the same direction, the DC side branch of the rectifier bridge 2 is also composed of two diodes connected in series in the same direction, and the AC side of the rectifier bridge 2 The side branch is connected in parallel with the DC side branch of the rectifier bridge 2 to jointly form a rectifier bridge circuit. The function of the single-phase rectifier bridge is to convert the alternating current with a level floating around zero into a pulsating direct current through the one-way conduction characteristic of the diode. It has the advantages of simple structure, small size, convenient use and simple assembly.

It should be noted that one end of the secondary side of the transformer 1 is connected between the two diodes of the AC side branch of the rectifier bridge 2, and the other end of the secondary side of the transformer 1 is connected between the two diodes of the DC side branch of the rectifier bridge 2 between.

Optionally, the DC support branch 4 includes capacitors C1 and C2, and the capacitor C1 is connected in series with the capacitor C2.

Capacitor C1 and capacitor C2 have the characteristics of charging and discharging and the ability to prevent the passage of DC current and allow the passage of AC current. During the process of charging and discharging the capacitor, the charge on the two plates has a process of accumulation, that is, the voltage has a process of building up. The voltage on the capacitor Cannot be mutated. In a DC circuit, a capacitor is equivalent to an open circuit. After electrification, the plates of the capacitor are charged to form a voltage, but because of the insulating material in the middle, the entire capacitor is non-conductive. In an AC circuit, the direction of the current changes as a function of time, and the process of charging and discharging a capacitor has time. During this period, a changing electric field is formed between the plates, and this electric field also changes with time. The function. In fact, the current is passed between the capacitors in the form of an electric field.

It should be noted that the current limiting resistor 3 is connected in series between the outlet terminal of the DC side branch of the rectifier bridge 2 and the negative output terminal of the capacitor C2 in the DC support branch 4 .

Optionally, the controllable rectification branch 5 includes thyristors SCR1 and SCR2, and the thyristor SCR1 and the thyristor SCR2 are connected in series in the same direction.

It should be noted that one end of the inductor L in the LC resonant branch 6 is connected between the thyristors SCR1 and SCR2, and the distance from the connection point to the thyristors SCR1 and the thyristors SCR2 is equal.

The thyristor has a square chip support plate, the module voltage drop is small, the power consumption is low, the efficiency is high, and the power saving effect is good. Excellent thermal conductivity, heat-conducting insulating packaging material, good insulation and moisture-proof performance, the main circuit of the thyristor is isolated from the trigger control circuit, and the heat-conducting bottom plate, the heat-conducting bottom plate is not charged, the insulation strength is high, and it is safe to use. The thyristor has fast closing speed, small on-resistance, and can work normally under high current and high voltage. It has a long life, simple driving, easy control, and simple structure, which effectively saves product cost, easy maintenance, easy operation, and high cost performance. , so the thyristor is chosen as the switch. In this embodiment, two thyristors are connected in series in the same direction, and the fast turn-on characteristics of the thyristor components can not only realize the square wave characteristics of the pulse current, so that it contains rich spectrum components, but also realize the positive and negative pulse current rounds Occurs, the pulse current detection method can be diversified.

Optionally, the common end of the inductor L and the capacitor C in the LC resonant branch 6 is connected to the power grid.

Utilizing the amplitude-frequency characteristics and phase-frequency characteristics of the LC resonant circuit, not only frequency selection can be performed, that is, useful frequency components can be selected from the input signal to suppress useless frequency components or noise, but also the frequency amplitude conversion and frequency phase of the signal can be performed. Conversion, the signal characteristics of the pulse current are enriched by LC resonance technology.

Optionally, the wires connecting the transformer 1, the rectifier bridge 2, the current limiting resistor 3, the DC support branch 4, the controllable rectification branch 5 and the LC resonant branch 6 are any one of copper and aluminum. The copper wire has high conductivity and low loss. The mechanical properties of copper are better than aluminum. It has good ductility, is easy to process and install, and has high fatigue resistance. The wire with copper core is used in various pulse current generator circuits. The connection of components improves the service life of the pulse current generator.

The working process of the pulse current generator based on the LC resonant circuit provided in this embodiment is as follows:

When pulse current is not needed, the thyristors SCR1 and SCR2 in the controllable rectification branch 5 are not triggered, and the capacitors C1 and C2 in the DC support branch 4 are charged through the transformer 1 and the rectifier bridge 2 . If it is necessary to send a forward pulse current, trigger and turn on the SCR1 of the series thyristor in the controllable rectification branch 5, at this time, the voltage of the capacitor C1 is applied to the LC resonant branch 6 through the SCR1 to output a positive pulse current oscillation signal, if Negative pulse current needs to be sent, triggering and turning on the SCR2 of the series thyristor in the controllable rectification branch 5, at this time, the voltage of the capacitor C2 is applied to the LC resonant branch 6 through the SCR2 to output a positive pulse current oscillation signal.

To sum up, the pulse current generator based on the LC resonant circuit provided by this application, through the transformer 1, the rectifier bridge 2, the current limiting resistor 3, the DC support branch 4, the controllable rectification branch 5 and the LC resonant branch 6 for combined connection, can be isolated from the grid, and send out pulse current signals with obvious characteristics. Therefore, the pulse current generator is safe and reliable, and can accurately identify and judge the ownership of the sub-subscriber electric meter of the station substation.

It should be noted that the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that an article or device comprising a set of elements includes not only those elements but also items not expressly listed. other elements, or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above descriptions are only specific implementation manners of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

It should be understood that the present application is not limited to what has been described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (6)

1. a kind of impulse current generator based on LC resonance circuit, which is characterized in that including：Transformer (1), rectifier bridge (2), Current-limiting resistance (3), DC support branch (4), controlled rectification branch (5) and LC resonance branch (6)；

The transformer (1) includes primary and secondary side, and described primary side one end is connect with power grid, other end ground connection；The rectifier bridge (2) include DC side branch and exchange side branch, described pair side one end connect with the exchange side branch, the other end and it is described directly Flow collateral road connection；

Rectifier bridge (2) the DC side branch, the DC support branch (4) and the controlled rectification branch (5) are parallel with one another；

The current-limiting resistance (3) is series between the rectifier bridge (2) DC side branch and the DC support branch (4)；

The LC resonance branch (6) includes inductance L and capacitance C, and the one end the inductance L is connect with the controlled rectification branch (5), The other end is connect with one end of the capacitance C, and the other end of the capacitance C is connect with the DC support branch (4).

2. the impulse current generator according to claim 1 based on LC resonance circuit, which is characterized in that the transformer (1) it is single-phase step-up transformer, boosting coefficient is 1:2.

3. the impulse current generator according to claim 1 based on LC resonance circuit, which is characterized in that the rectifier bridge (2) it is single-phase rectification bridge.

4. the impulse current generator according to claim 1 based on LC resonance circuit, which is characterized in that the direct current branch It includes capacitance C1 and C2 to support branch (4), and the capacitance C1 connects with the capacitance C2.

5. the impulse current generator according to claim 1 based on LC resonance circuit, which is characterized in that described controllable whole Stream branch (5) includes thyristor SCR1 and SCR2, the thyristor SCR1 and the thyristor SCR2 series aiding connections.

6. the impulse current generator according to claim 1 based on LC resonance circuit, which is characterized in that the LC resonance The inductance L in branch (6) is connect with the common end of the capacitance C with power grid.