CN218767187U

CN218767187U - Interface circuit for insulation detection of excitation winding

Info

Publication number: CN218767187U
Application number: CN202223000559.3U
Authority: CN
Inventors: 郝家骥; 毛建伟; 吴永俭; 张楠
Original assignee: Tianjin Ruixinchuanghe Electrical Co ltd
Current assignee: Tianjin Ruixinchuanghe Electrical Co ltd
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-03-28
Anticipated expiration: 2032-11-03

Abstract

The utility model provides an excitation winding is interface circuit for insulation detection, including the detection circuitry who concatenates with excitation coil, detection circuitry is including two J1 double-gate switches, two excitation coil and R5 analog resistance have concatenated respectively between two inputs of J1 double-gate switch, R5 analog resistance is 510K ohmic resistance. The utility model discloses can realize that power detects, ground connection simulation detects, normally detects and polarity exchange detects the transform between the different detection function of power supply.

Description

Interface circuit for insulation detection of excitation winding

Technical Field

The utility model relates to a motor excitation winding detects technical field to ground insulation damage, concretely relates to excitation winding is interface circuit for insulation detection.

Background

The field insulation resistance detection device of the generator or the exciter is used for the automatic detection device of the generator field grounding of the brushless excitation system. The excitation system failure caused by the damage of the generator field winding to the ground insulation is easy to cause the risk of magnetic loss, so the insulation detection of the generator field winding is very necessary.

Because the exciting voltage of the exciting winding of the generator is added with an inductive voltage in the insulation test loop, when the exciting voltage value accounts for a certain proportion of the direct current test voltage value, the test sensitivity is reduced, and in order to improve the detection precision, the positive and negative polarities of the external direct current test power supply are automatically exchanged and then tested again. When the insulation of the excitation winding is detected, the interface unit connected with the generator is included, the function of the interface unit is to measure the ground current of the magnetic field, but the conventional interface unit is only used for detecting and transmitting data with a single function.

SUMMERY OF THE UTILITY MODEL

In view of this, the to-be-solved problem of the present invention is to provide an interface circuit for insulation detection of excitation winding, which can realize the conversion between different detection functions of power detection, ground simulation detection, normal detection and polarity exchange detection power supply.

In order to solve the technical problem, the utility model discloses a technical scheme is:

the utility model provides an excitation winding is interface circuit for insulation detection, including the detection circuitry who concatenates with excitation coil, detection circuitry is including two J1 double-gate switches, two it has excitation coil and the R5 analog resistance that is used for simulating ground fault and detects to concatenate respectively between two input of J1 double-gate switch.

Furthermore, the output ends of the two J1 double-gate switches are communicated, the R1 resistor, the R2 resistor and the two J2 double-gate switches, the input ends of which are communicated, are serially connected to the detection circuit, and the input end of one J2 double-gate switch is correspondingly connected to the output end of one J1 double-gate switch;

and two output ends of the two J2 double-gate switches are respectively communicated with the R1 resistor and the R2 resistor.

Further, an R6 resistor used for sampling is connected between the R1 resistor and the R2 resistor in series, and two ends of the R6 resistor are connected with a sampling circuit in parallel;

the sampling circuit comprises a 19 port and a 18 port which are respectively and electrically connected with a U1 isolation amplification chip at two ends of the R6 resistor, wherein a 1 port of the U1 isolation amplification chip is connected with a 3 port of the U2 amplifier, and a 6 port of the U2 amplifier is in data intercommunication with the controller.

Furthermore, a power supply circuit is arranged on the detection circuit, the power supply circuit comprises a detection power supply for providing alternating current, the output end of the detection power supply is connected with an H bridge rectifier circuit, the output end of the H bridge rectifier circuit is connected with an R11 resistor and an R12 resistor in series, and the R12 resistor is connected with a C1 capacitor for stabilizing voltage in parallel.

Furthermore, the R12 resistor is connected in parallel with a plurality of serially connected RD resistors, and two ends of one RD resistor are respectively connected with the 19 port and the 18 port of the U1 isolation amplification chip.

Furthermore, a 19 port of the U1 isolation amplification chip is electrically connected with one end of an RD-5 resistor and one end of an R6 resistor, respectively, the 19 port of the U1 isolation amplification chip is connected with an output end of a J3 double-gate switch, and two input ends of the J3 double-gate switch are electrically connected with the other end of the RD-5 resistor and the other end of the R6 resistor, respectively.

Further, the model of the U1 isolation amplification chip is AD210, and the model of the U2 amplifier is LM201.

Further, the J1 double-gate switch, the J2 double-gate switch and the J3 double-gate switch are respectively controlled by a J1 relay, a J2 relay and a J3 relay, and the connection modes of the J1 relay, the J2 relay and the J3 relay are the same;

one end of the J3 relay is grounded, the other end of the J3 relay is communicated with a control switch in the controller to electrify the J3 relay, and the J3 relay is connected with a D7 diode in parallel.

The utility model has the advantages and positive effects that:

two J1 double-gate switches and two J2 double-gate switches are arranged on the detection circuit in series, and the two J1 double-gate switches and the two J2 double-gate switches are controlled by corresponding J1 relays and J2 relays so as to realize the conversion of functions among grounding simulation detection, normal detection and polarity exchange detection. Meanwhile, a J3 double-gate switch is arranged between the sampling circuit and the detection circuit, and the control interface unit realizes power supply detection or conversion of other functional time.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a circuit diagram of a detection circuit in an interface circuit for insulation detection of an excitation winding according to the present invention;

fig. 2 is a circuit diagram of sampling and amplifying in an interface circuit for insulation detection of an excitation winding according to the present invention;

fig. 3 is a connection circuit diagram of a J1 relay, a J2 relay and a J3 relay in an interface circuit for detecting insulation of an excitation winding of the utility model.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1 to fig. 2, the utility model provides an excitation winding is interface circuit for insulation detection, including detection circuitry, detection circuitry is used for concatenating with the excitation coil of motor (corresponding the insulation measurement input signal in fig. 1), and detection circuitry has concatenated power supply circuit for provide stable dc power supply. The detection circuit is provided with a sampling resistor in series, the two ends of the sampling resistor are connected with a sampling amplifying circuit in parallel, the sampling amplifying circuit obtains the voltage at the two ends of the sampling resistor, the voltage is input into a controller (corresponding to the insulation measurement signal in fig. 2) after amplification processing, and the controller judges whether a ground fault exists according to the received data. The controller only needs to use a programmable logic controller, and no special model requirement exists.

In order to ensure the accuracy of detection, the detection process comprises power supply detection, grounding simulation detection, normal detection and polarity exchange detection. The power supply detection is used for judging and detecting actual voltage provided by the power supply, and the grounding simulation detection is used for judging results given by the controller when the detection circuit is directly grounded so as to determine whether the detection circuit can normally work. Normally detect and accomplish once and detect, polarity exchange detects and exchanges the positive negative pole that detects the power, and when carrying out once and detecting, two sets of detection data judge whether earth fault appears jointly, guarantee the accuracy that detects.

Two J1 double-gate switches are connected to the detection circuit in series, and two input ends of the J1 double-gate switches are connected with an excitation coil and an R5 analog resistor in series respectively. When analog grounding detection is carried out, the R5 analog resistor is connected into the detection circuit by simultaneously controlling the two J1 double-gate switches, preferably, the resistance value of the R5 analog resistor is 510K ohms; when the detection is normal, the two J1 double-gate switches are controlled to act simultaneously so as to connect the excitation coil into the detection circuit.

The output end of two J1 double-gate switches is connected and set up, still is equipped with two J2 double-gate switches on the detection circuit in cluster, and the input intercommunication setting of two J2 double-gate switches, and the input of a J2 double-gate switch corresponds the output of connecting a J1 double-gate switch. The detection circuit comprises an R1 resistor and an R2 resistor which are connected in series, and the resistors and the R2 resistor are both used for limiting the current communicated with the detection circuit. Two output ends of the two J2 double-gate switches are respectively communicated with the R1 resistor and the R2 resistor, and the R1 resistor and the R2 resistor are divider resistors. And the polarity exchange detection is carried out by controlling the two J2 double-brake switches to act and changing the current flowing direction on the exciting coil.

And an R6 resistor is connected between the R1 resistor and the R2 resistor in series, the R6 resistor is a sampling resistor, and two ends of the R6 resistor are connected with a sampling circuit in parallel. The sampling circuit comprises a U1 isolation amplification chip, the output end of the U1 isolation amplification chip is connected with a U2 amplifier, a port 19 and a port 18 of the U1 isolation amplification chip are respectively and electrically connected with the two ends of a resistor R6 to obtain the loading voltage on the resistor R6, a port 1 of the U1 isolation amplification chip is connected with a port 3 of the U2 amplifier, and a port 6 of the U2 amplifier is in data intercommunication with a controller. And the voltage loaded on the R6 resistor is sequentially amplified by the U1 isolation amplification chip and the U2 amplifier and then input into the controller. Preferably, the model of the U1 isolation amplification chip is AD210, and the signal of the U2 amplifier is LM201.

The power supply circuit comprises a detection power supply, the detection power supply is used for providing alternating current with fixed pressure intensity, and the pressure intensity can be controlled by the controller so as to detect motors with different models. The output end of the detection power supply is connected with an H bridge type rectifying circuit to convert alternating current into direct current. The output end of the H bridge rectifier circuit is connected with an R11 resistor and an R12 resistor in series, and the R11 resistor and the R12 resistor divide voltage.

The detection circuit is connected with the R12 resistor in parallel, so that the voltage applied to the detection circuit is the same as the voltage at two ends of the R12 resistor, and the R12 resistor is connected with the C1 capacitor for stabilizing voltage in parallel, so that the stability of the voltage at two ends of the R12 resistor is ensured.

In order to ensure the accuracy of the detection result, the power supply detection (the detection of the magnitude of the voltage supplied by the detection power supply) is carried out before the insulation detection. In order to detect the detection power supply, the R12 resistors are connected with a plurality of RD resistors in parallel, for example, the RD resistors can be set to be five, and are respectively an RD-1 resistor, an RD-2 resistor, an RD-3 resistor, an RD-4 resistor and an RD-5 resistor which are arranged in series, two ends of the RD-5 resistor are respectively and electrically connected with a port 19 and a port 18 of the U1 isolation amplification chip to obtain voltages applied to two ends of the RD-5 resistor, and the voltages are amplified by the sampling amplification circuit and then input into the controller to obtain actual voltages of the detection power supply.

And the 18 port of the U1 isolation amplification chip is respectively and electrically connected with one end of the RD-5 resistor and one end of the R6 resistor, the 19 port of the U1 isolation amplification chip is connected with the output end of the J3 double-gate switch, and the two input ends of the J3 double-gate switch are respectively and electrically connected with the other ends of the RD-5 resistor and the R6 resistor. The internal switches of the J3 double-gate switch are opposite in form and are controlled by a J3 relay. The U1 isolation amplification chip can respectively acquire the voltage at two ends of the RD-5 resistor or the R6 resistor.

As shown in fig. 3, one end of the J3 relay is grounded, the other end is connected to a power detection switch in the controller to supply power to the J3 relay, and the J3 relay is connected in parallel with a D7 diode. The J1 double-gate switch is corresponding to a J1 relay to control the action of the J1 double-gate switch, the J2 double-gate switch is corresponding to a J2 relay to control the action of the J2 double-gate switch, and the connection mode of the J1 relay and the J2 relay is the same as that of the J3 relay.

The utility model discloses a theory of operation and working process as follows:

when current is detected: the J3 relay is electrified to enable the J3 double-gate switch to act, the RD-5 resistor is connected between the 18 port and the 19 port of the U1 isolation amplification chip in series, the detection power supply is started, the RD resistors are electrified, the sampling amplification circuit obtains voltages at two ends of the RD-5 resistor and inputs the voltages into the controller after amplification, the controller provides whether the voltage of the detection power supply is normal or not, the J3 relay is powered off after detection is completed, and the R6 resistor is communicated with the 18 port and the 19 port of the U1 isolation amplification chip.

When the grounding simulation is detected: the J1 relay is electrified to enable the J1 double-gate switch to act, the R5 analog resistor is connected between the two J1 double-gate switches, the sampling amplification circuit obtains voltages at two ends of the R6 resistor and inputs the voltages into the controller after amplification, and the controller judges whether a ground fault exists or not so as to determine whether the circuit can normally operate or not. And then after the completion, the J1 relay is powered off, and the excitation coil is connected between the two J1 double-gate switches in series.

During normal actual detection, the R1 resistor is connected with one end of the excitation coil, the R2 resistor is connected with the other end of the excitation coil, and the sampling amplification circuit directly collects voltages at two ends of the R6 resistor and inputs the voltages into the controller after amplification treatment. When polarity exchange detection is needed, the J2 relay is electrified, and the two J1 double-brake switches act to enable the two ends of the excitation coil to be reversely communicated with the R1 resistor and the R2 resistor. When the current direction in the magnet exciting coil is backward, the sampling amplifying circuit acquires the voltage at two ends of the R6 resistor for the second time, and inputs the voltage into the controller after amplification, and the controller gives feedback whether generating the ground fault according to the data acquired twice.

The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should be covered by the present patent.

Claims

1. The interface circuit for detecting the insulation of the excitation winding is characterized by comprising a detection circuit connected with an excitation coil in series, wherein the detection circuit comprises two J1 double-gate switches, and the excitation coil and an R5 analog resistor for simulating the detection of the ground fault are respectively connected between two input ends of the J1 double-gate switches in series.

2. The interface circuit for detecting insulation of an excitation winding according to claim 1, wherein output ends of two J1 double-gate switches are connected, an R1 resistor, an R2 resistor and two J2 double-gate switches with input ends connected are connected in series on the detection circuit, and an input end of one J2 double-gate switch is correspondingly connected with an output end of one J1 double-gate switch;

3. The interface circuit for detecting insulation of the excitation winding according to claim 2, wherein an R6 resistor for sampling is connected in series between the R1 resistor and the R2 resistor, and a sampling circuit is connected in parallel to two ends of the R6 resistor;

the sampling circuit comprises a U1 isolation amplification chip with a 19 port and a 18 port which are respectively and electrically connected with two ends of the R6 resistor, wherein a 1 port of the U1 isolation amplification chip is connected with a 3 port of the U2 amplifier, and a 6 port of the U2 amplifier is in data intercommunication with the controller.

4. An interface circuit for detecting insulation of an excitation winding according to claim 1, wherein a power supply circuit is provided on the detection circuit, the power supply circuit includes a detection power supply for supplying alternating current, an output terminal of the detection power supply is connected with an H-bridge rectifier circuit, output terminals of the H-bridge rectifier circuit are connected in series with an R11 resistor and an R12 resistor, and the R12 resistor is connected in parallel with a C1 capacitor for stabilizing voltage.

5. The interface circuit for detecting insulation of the excitation winding according to claim 4, wherein the R12 resistor is connected in parallel with a plurality of serially connected RD resistors, and two ends of one RD resistor are respectively connected with the 19 port and the 18 port of the U1 isolation amplification chip.

6. The interface circuit for detecting insulation of an excitation winding according to claim 3, wherein the 19 ports of the U1 isolation amplification chip are electrically connected with one end of an RD-5 resistor and one end of an R6 resistor, respectively, the 19 ports of the U1 isolation amplification chip are connected with the output end of a J3 double-gate switch, and two input ends of the J3 double-gate switch are electrically connected with the other end of the RD-5 resistor and the other end of the R6 resistor, respectively.

7. The interface circuit for detecting insulation of an excitation winding according to claim 6, wherein the U1 isolation amplification chip is AD210, and the U2 amplifier is LM201.

8. The interface circuit for detecting insulation of an excitation winding according to claim 1, wherein the J1 double-gate switch, the J2 double-gate switch and the J3 double-gate switch are respectively controlled by a J1 relay, a J2 relay and a J3 relay, and the connection modes of the J1 relay, the J2 relay and the J3 relay are the same;