Electronic coil state monitoring device

Abstract

The invention relates to an electronic coil state monitoring device with a high-resistance characteristic and low-current starting. The electronic coil state monitoring device comprises a low-current forming and photoelectric conversion isolation unit, a comparison and judgment unit, an outlet contact driving unit and a power supply circuit unit, the low-current forming and photoelectric conversion isolation unit is used for detecting a low-current signal of an electronic coil loop of the high / low-voltage switch circuit breaker, amplifying the low-current signal and transmitting the low-current signal to the comparison and judgment unit through photoelectric isolation; the comparison and judgment unit is used for comparing the low-current signal isolated and amplified by the low-current formation and photoelectric conversion isolation unit with a preset limit value, and judging the state of the electronic coil according to a comparison result; the outlet contact driving unit is used for controlling closing or opening of an outlet relay according to the judged state of the electronic coil; and the power supply circuit unit is used for supplying power to the units. According to the invention, integrity monitoring of a nonlinear novel electronic coil loop can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of electronic coil status monitoring, and in particular to an electronic coil status monitoring device with high resistance characteristics and low current startup. Background Art

[0002] High / low voltage switch circuit breakers of power systems are widely used in the field of power systems. At present, the operating coils of high / low voltage switch circuit breakers of power systems on the market are divided into electromagnetic coils and electronic coils. With the rapid development of power systems, due to the characteristics of large operating current of electromagnetic coils and small operating current of electronic coils, the operating coils of high / low voltage switch circuit breakers of power systems are continuously transformed from traditional large current inductive coils to low current electronic coils. Low current electronic coils have been widely used in high / low voltage switch circuit breakers due to their small operating current, sensitivity and fast characteristics. This causes the traditional intermediate relays used in the traditional switch position monitoring and operation loop monitoring circuit design to fail to respond correctly, and the low internal resistance of the traditional intermediate relay will cause the low current electronic coil to lock the circuit breaker, resulting in the switch with electronic coil being unable to perform a second automatic operation after being operated once. Summary of the invention

[0003] The purpose of the present application is to provide an electronic coil state monitoring device with high resistance characteristics and low current startup, so as to realize the integrity monitoring of a nonlinear new type of electronic coil loop.

[0004] To achieve the above-mentioned purpose, the present application provides an electronic coil state monitoring device, comprising a low current forming and photoelectric conversion isolation unit (1), a comparison judgment unit (2), an output contact driving unit (3) and a power supply circuit unit (4);

[0005] The low current forming and photoelectric conversion isolation unit (1) is used to detect the low current signal of the electronic coil loop of the high / low voltage switch circuit breaker, amplify the low current signal and transmit it to the comparison and judgment unit (2) through photoelectric isolation;

[0006] The comparison and judgment unit (2) is used to compare the low current signal isolated and amplified by the low current forming and photoelectric conversion isolation unit (1) with a preset limit value, and determine the state of the electronic coil according to the comparison result;

[0007] The output contact driving unit (3) is used to control the closing or opening of the output relay according to the determined state of the electronic coil;

[0008] The power supply circuit unit (4) is used to provide power for the low current forming and photoelectric conversion isolation unit (1), the comparison judgment unit (2), and the output contact driving unit (3).

[0009] Preferably, the low current forming and photoelectric conversion isolation unit (1) comprises a rectifier circuit (10), a limiting resistor (11), a coupling capacitor (12), a low current amplifying circuit (13) and a photoelectric isolation circuit (14);

[0010] The rectifier circuit (10) is used to convert alternating current into direct current;

[0011] The first end of the limiting resistor (11) is connected to the ground capacitor (12), and the second end of the limiting resistor (11) is connected to the input end of the low current amplifier circuit (13), so as to form a current of no more than 1 mA in the DC circuit;

[0012] The ground capacitor (12) is connected in parallel with the output of the rectifier circuit (10) to eliminate the filtering of the induced weak AC signal of the line;

[0013] The output end of the low current amplifying circuit (13) is connected to the input end of the photoelectric isolation circuit (14) for amplifying the low current signal;

[0014] The photoelectric isolation circuit (14) is used to convert the current signal input by the low current amplifier circuit (13) into a light response signal and transmit the light response signal to the comparison and judgment unit (2).

[0015] Preferably, the comparison and judgment unit (2) comprises an operational amplifier circuit (21) and a reference voltage forming unit (22), wherein the operational amplifier circuit (21) compares the low current forming unit with the light response signal output by the photoelectric conversion isolation unit (1).

[0016] The reference voltage forming unit (22) is used to form a voltage limit signal of a minimum starting current. When the light response signal input by the low current forming and photoelectric conversion isolation unit (1) is greater than or equal to the voltage limit signal, the operational amplifier circuit (21) outputs a high level signal to the output contact driving unit (3). When the light response signal input by the low current forming and photoelectric conversion isolation unit (1) is less than the voltage limit signal, the operational amplifier circuit (21) outputs a low level signal to the output contact driving unit (3).

[0017] Preferably, the output contact driving unit (3) comprises a pull-down clamping resistor (31), a base current limiting pull-down driving voltage regulator (32), a triode (33), a relay coil (34), an output contact (35)

[0018] and an indicator light (36);

[0019] The pull-down clamping resistor (31) is connected to the output end of the operational amplifier circuit (21); the output signal of the operational amplifier circuit (21) is connected to the base of the transistor (33) after passing through the base current limiting pull driving voltage regulator tube (32); the emitter of the transistor (33) is connected to 0V through the indicator light (36); and the collector of the transistor (33) is connected to the relay coil (34);

[0020] When the operational amplifier circuit (21) outputs a high level, the transistor (33) is in saturation conduction, the relay coil (34) is energized and actuated, and the normally open contact of the output contact (35) is closed and the normally closed contact is opened; when the operational amplifier circuit (21) outputs a low level, the transistor (33) is in a cut-off state, the relay coil (34) loses power and resets, and the normally open contact of the output contact (35) is disconnected and the normally closed contact is closed; the indicator light (36) is used to indicate the state of the transistor (33); when the transistor (33) is turned on, the indicator light (36) lights up, indicating that the relay coil (34) is energized.

[0021] Preferably, the power supply circuit unit (4) comprises a rectifier circuit (41), a power circuit (42), a voltage divider circuit (43), a voltage stabilizing circuit (44), a power protection unit and a feedback unit (45); the input power is converted into direct current through the rectifier circuit (41); the direct current is output to the power protection unit and the feedback unit (45) for real-time monitoring and protection; the direct current is divided through the voltage divider circuit (43); the divided voltage is provided to the power circuit (42) and the voltage stabilizing circuit (44); the power circuit (42) provides sufficient power, and the voltage stabilizing circuit (44) further adjusts the voltage to ensure the stability of the output voltage; finally, the stable voltage output by the voltage stabilizing circuit (44) is supplied to the subsequent functional circuit unit for use.

[0022] This application has the following beneficial effects:

[0023] The present application forms a low current and photoelectric conversion isolation unit. The present invention can accurately detect the low current signal of the electronic coil circuit of the high / low voltage switch circuit breaker, improve the sensitivity and reliability of monitoring, and adopt photoelectric isolation technology. The present invention realizes the isolation and amplification of the low current signal, effectively reduces the interference in the signal transmission process, and ensures the accuracy of monitoring. The comparison and judgment unit can judge the low current signal according to the preset limit value, accurately reflect the state of the electronic coil, and provide protection for the safe operation of the power system. The output contact drive unit can control the closing or disconnection of the output relay according to the state of the electronic coil, realize the real-time monitoring of the switch position and the operation circuit, prevent the misoperation caused by the low current electronic coil, and improve the safety and stability of the power system. In summary, the present invention provides a high-resistance characteristic low-current start-up electronic coil state monitoring device for the high / low voltage switch circuit breaker of the power system, which effectively solves the shortcomings of the traditional monitoring device in the application of low current electronic coils and improves the operation efficiency and safety of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a structural diagram of an electronic coil state monitoring device with high resistance characteristics and low current startup in one embodiment of the present application.

[0026] Figure 2 A circuit diagram of a low current forming and photoelectric conversion isolation unit and a comparison and judgment unit in one embodiment of the present application.

[0027] Figure 3 This is a circuit diagram of an outlet contact driving unit and a power supply circuit unit in one embodiment of the present application. DETAILED DESCRIPTION

[0028] The detailed description of the drawings is intended as an illustration of the current embodiment of the present application, and is not intended to represent the only form in which the present application can be implemented. It should be understood that the same or equivalent functions can be accomplished by different embodiments intended to be included in the spirit and scope of the present application.

[0029] See also Figure 1 , one embodiment of the present application provides an electronic coil state monitoring device with high resistance characteristics and low current startup, comprising a low current forming and photoelectric conversion isolation unit 1, a comparison judgment unit 2, an output contact driving unit 3 and a power supply circuit unit 4;

[0030] The low current forming and photoelectric conversion isolation unit 1 is used to detect the low current signal of the high / low voltage switch circuit breaker electronic coil loop, amplify the low current signal and transmit it to the comparison and judgment unit 2 through photoelectric isolation; specifically, since the low current signal may be very weak and needs to be amplified by a signal conditioning circuit, photoelectric isolation not only improves the reliability of signal transmission, but also increases the safety of the system because it can prevent electrical faults caused by ground potential differences and the like.

[0031] The comparison and judgment unit 2 is used to compare the low current signal after the low current formation and photoelectric conversion isolation unit 1 is isolated and amplified with a preset limit value, and determine the state of the electronic coil according to the comparison result. The electronic coil state includes open circuit, closed state, etc.

[0032] The outlet contact driving unit 3 is used to control the closing or opening of the outlet relay (i.e., the traditional intermediate relay used in the design of the traditional switch position monitoring and operation loop monitoring circuit) according to the determined electronic coil state;

[0033] The outlet contact driving unit 3 controls the closing or opening of the outlet relay according to the state of the electronic coil. The outlet relay is used to control high voltage or high current switches in the power system, such as circuit breakers, disconnectors, etc. In a complex control loop, the outlet relay is used as an intermediate link for signal transmission, amplifying the control signal to a level sufficient to drive a larger load. The relay provides an electrical isolation means to protect the control circuit from the influence of the high voltage and high current of the main circuit. The outlet contact driving unit 3 receives a signal from the comparison and judgment unit 2, which represents the state of the electronic coil (for example, open circuit, closed circuit). If the comparison and judgment unit 2 determines that the state of the electronic coil is closed, the outlet contact driving unit 3 will close the contact of the outlet relay, allowing current to flow through the relay, thereby driving the subsequent switch action or signal transmission. If the comparison and judgment unit 2 determines that the state of the electronic coil is disconnected, the outlet contact driving unit 3 will disconnect the contact of the outlet relay, cut off the current, prevent erroneous switch action or signal transmission, and protect the system from damage.

[0034] The power supply circuit unit 4 is used to provide power for the low current forming and photoelectric conversion isolation unit 1 , the comparison and judgment unit 2 , and the output contact driving unit 3 .

[0035] Furthermore, if Figure 2 As shown, the low current forming and photoelectric conversion isolation unit 1 includes a rectifier circuit 10, a limiting resistor 11, a coupling capacitor 12, a low current amplifying circuit 13 and a photoelectric isolation circuit 14.

[0036] The rectifier circuit 10 is used to convert AC power into DC power;

[0037] The first end of the limiting resistor 11 is connected to the ground capacitor 12, and the second end of the limiting resistor 11 is connected to the input end of the low current amplifier circuit 13, so as to form a current not greater than 1 mA in the DC circuit; specifically, the limiting resistor 11 adopts a resistance value not less than 500K Ω High-precision linear resistor and linear sliding resistor, the total resistance is not less than 100K Ω resistance loop to form a current not greater than 1 mA in the 110V and 220V DC loops;

[0038] The ground capacitor 12 is connected in parallel with the output of the rectifier circuit 10 to eliminate the filtering of the induced weak AC signals of the line, which may be caused by external electromagnetic interference (EMI) or the characteristics of the line itself. By connecting the ground capacitor 12 to the circuit, these high-frequency noises can be effectively bypassed to the ground, thereby providing a cleaner DC signal;

[0039] The output end of the low current amplifier circuit 13 is connected to the input end of the photoelectric isolation circuit 14, and is used to amplify the low current signal; specifically, the low current amplifier circuit 13 is sent to the differential amplifier through a current amplifier IC with the characteristics of high amplification factor, low power consumption, low noise, and wide bandwidth, and then output to the subsequent circuit by the operational amplifier;

[0040] The photoelectric isolation circuit 14 is used to convert the current signal input by the low current amplifier circuit 13 into a light response signal and transmit it to the comparison and judgment unit 2; specifically, the photoelectric isolation 14 uses a low current to amplify the emitter follower current and then connects it to the primary side of the photoelectric coupler, accurately responding to the strength of the low current signal; finally, the current signal of 0.5mA~2mA is transmitted to the next subsequent circuit through the light response signal, realizing state signal collection, isolation and transmission, and has a wide range of applications.

[0041] Furthermore, if Figure 2 As shown, the comparison and judgment unit 2 includes an operational amplifier circuit 21 and a reference voltage forming unit 22. The operational amplifier circuit 21 compares the low current formation with the light response signal output by the photoelectric conversion isolation unit 1.

[0042] The reference voltage forming unit 22 is used to form a voltage limit signal of the minimum starting current. When the light response signal formed by the low current and the input of the photoelectric conversion isolation unit 1 is greater than or equal to the voltage limit signal, the operational amplifier circuit 21 outputs a high level signal to the output contact driving unit 3. When the light response signal formed by the low current and the input of the photoelectric conversion isolation unit 1 is less than the voltage limit signal, the operational amplifier circuit 21 outputs a low level signal to the output contact driving unit 3.

[0043] Specifically, the comparison and judgment unit 2 is the core processing part in the electronic coil state monitoring device, which is responsible for evaluating and judging the light response signal output by the low current forming and photoelectric conversion isolation unit 1. The main function of the operational amplifier circuit 21 is to compare the light response signal from the photoelectric isolation circuit 14 with the voltage limit signal provided by the reference voltage forming unit 22. The operational amplifier is a high-gain voltage amplifier with a differential input. When the voltage at the positive input terminal (non-inverting input terminal) of the operational amplifier is higher than the voltage at the negative input terminal (inverting input terminal), the output of the operational amplifier will tend to the positive power supply voltage; otherwise, it will tend to the negative power supply voltage or the ground level. The operational amplifier circuit 21 compares the light response signal (converted into a voltage signal) output by the photoelectric isolation circuit 14 with the voltage limit provided by the reference voltage forming unit 22. If the voltage represented by the light response signal is greater than or equal to the reference voltage, the operational amplifier circuit 21 will output a high-level signal; if it is less than the reference voltage, a low-level signal will be output.

[0044] The reference voltage forming unit 22 is used to generate a stable voltage signal, which represents the voltage limit of the minimum starting current. This limit is a key parameter for determining whether the electronic coil works normally.

[0045] Through this comparison and judgment mechanism, the comparison and judgment unit 2 can accurately monitor the state of the electronic coil and control the action of the relay through the output contact driving unit 3, thereby realizing effective monitoring and control of the high / low voltage switch circuit breaker of the power system.

[0046] Furthermore, if Figure 3 As shown, the output contact driving unit 3 includes a pull-down clamping resistor 31, a base current limiting pull-down driving voltage regulator 32, a transistor 33, a relay coil 34, an output contact 35 and an indicator light 36, forming a driving circuit with wide adaptability, reducing the output driving current of the upper chip and avoiding malfunction due to interference in static state.

[0047] The pull-down clamping resistor 31 is connected to the output end of the operational amplifier circuit 21. The output signal of the operational amplifier circuit 21 is connected to the base of the transistor 33 after passing through the base current limiting pull-driving voltage regulator tube 32. The emitter of the transistor 33 is connected to 0V through the indicator light 36, and the collector of the transistor 33 is connected to the relay coil 34. Specifically, the pull-down clamping resistor 31 is used to ensure that when the operational amplifier circuit 21 outputs a low level, the base of the transistor 33 can be pulled to a low level to prevent malfunction due to input suspension or interference. The base current limiting pull-driving voltage regulator tube 32 is used to stabilize the voltage of the base of the transistor 33 and limit the base current flowing through the transistor to protect the transistor from being damaged by overcurrent. The relay coil 34 will generate a magnetic field when energized to attract the contacts of the relay to operate. When the operational amplifier circuit 21 outputs a high level, the transistor 33 is in saturation conduction, the relay coil 34 is energized and activated, the normally open contact of the output contact 35 is closed, and the normally closed contact is opened; when the operational amplifier circuit 21 outputs a low level, the transistor 33 is in a cut-off state, the relay coil 34 loses power and resets, the normally open contact of the output contact 35 is disconnected, and the normally closed contact is closed, and the indicator light 36 is used to indicate the state of the transistor 33. When the transistor 33 is turned on, the indicator light 36 lights up, indicating that the relay coil 34 is energized.

[0048] Through this design, the output contact driving unit 3 can effectively convert the digital signal of the comparison and judgment unit 2 into the physical action of controlling the relay coil, and provide intuitive visual feedback through the indicator light 36. Such a driving circuit has a wide range of adaptability, can reduce the output driving current of the upper chip, and improve the stability and anti-interference ability of the system.

[0049] Furthermore, if Figure 3 As shown, the power supply circuit unit 4 includes a rectifier circuit 41, a power circuit 42, a voltage divider circuit 43, a voltage stabilizing circuit 44, a power protection unit and a feedback unit 45. The input power is converted into direct current through the rectifier circuit 41, and the direct current is output to the power protection unit and the feedback unit 45 for real-time monitoring and protection. The direct current is divided by the voltage divider circuit 43, and the divided voltage is provided to the power circuit 42 and the voltage stabilizing circuit 44. The power circuit 42 provides sufficient power, and the voltage stabilizing circuit 44 further adjusts the voltage to ensure the stability of the output voltage. Finally, the stable voltage output by the voltage stabilizing circuit 44 is supplied to the subsequent functional circuit unit for use.

[0050] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An electronic coil state monitoring device, characterized in that: It comprises a low current forming and photoelectric conversion isolation unit (1), a comparison and judgment unit (2), an output contact driving unit (3) and a power supply circuit unit (4); The low current forming and photoelectric conversion isolation unit (1) is used to detect the low current signal of the electronic coil loop of the high / low voltage switch circuit breaker, amplify the low current signal and transmit it to the comparison and judgment unit (2) through photoelectric isolation; The comparison and judgment unit (2) is used to compare the low current signal isolated and amplified by the low current forming and photoelectric conversion isolation unit (1) with a preset limit value, and determine the state of the electronic coil according to the comparison result; The output contact driving unit (3) is used to control the closing or opening of the output relay according to the determined state of the electronic coil; The power supply circuit unit (4) is used to provide power for the low current forming and photoelectric conversion isolation unit (1), the comparison judgment unit (2), and the output contact driving unit (3).

2. The electronic coil state monitoring device according to claim 1, characterized in that: The low current forming and photoelectric conversion isolation unit (1) comprises a rectifier circuit (10), a limiting resistor (11), a coupling capacitor (12), a low current amplifying circuit (13) and a photoelectric isolation circuit (14); The rectifier circuit (10) is used to convert alternating current into direct current; The first end of the limiting resistor (11) is connected to the ground capacitor (12), and the second end of the limiting resistor (11) is connected to the input end of the low current amplifier circuit (13), so as to form a current of no more than 1 mA in the DC circuit; The ground capacitor (12) is connected in parallel with the output of the rectifier circuit (10) to eliminate the filtering of the induced weak AC signal of the line; The output end of the low current amplifier circuit (13) is connected to the input end of the photoelectric isolation circuit (14) for amplifying the low current signal; The photoelectric isolation circuit (14) is used to convert the current signal input by the low current amplifier circuit (13) into a light response signal and transmit the light response signal to the comparison and judgment unit (2).

3. The electronic coil state monitoring device according to claim 2, characterized in that: The comparison and judgment unit (2) comprises an operational amplifier circuit (21) and a reference voltage forming unit (22), wherein the operational amplifier circuit (21) compares the low current forming unit with the light response signal output by the photoelectric conversion isolation unit (1). The reference voltage forming unit (22) is used to form a voltage limit signal of a minimum starting current. When the light response signal input by the low current forming and photoelectric conversion isolation unit (1) is greater than or equal to the voltage limit signal, the operational amplifier circuit (21) outputs a high level signal to the output contact driving unit (3). When the light response signal input by the low current forming and photoelectric conversion isolation unit (1) is less than the voltage limit signal, the operational amplifier circuit (21) outputs a low level signal to the output contact driving unit (3).

4. The electronic coil state monitoring device according to claim 3, characterized in that: The output contact driving unit (3) comprises a pull-down clamping resistor (31), a base current limiting pull-down driving voltage regulator (32), a triode (33), a relay coil (34), an output contact (35) and an indication signal lamp (36); The pull-down clamping resistor (31) is connected to the output end of the operational amplifier circuit (21); the output signal of the operational amplifier circuit (21) is connected to the base of the transistor (33) after passing through the base current limiting pull driving voltage regulator tube (32); the emitter of the transistor (33) is connected to 0V through the indicator light (36); and the collector of the transistor (33) is connected to the relay coil (34); When the operational amplifier circuit (21) outputs a high level, the transistor (33) is in saturation conduction, the relay coil (34) is energized and actuated, and the normally open contact of the output contact (35) is closed and the normally closed contact is opened; when the operational amplifier circuit (21) outputs a low level, the transistor (33) is in a cut-off state, the relay coil (34) loses power and resets, and the normally open contact of the output contact (35) is disconnected and the normally closed contact is closed; the indicator light (36) is used to indicate the state of the transistor (33); when the transistor (33) is turned on, the indicator light (36) lights up, indicating that the relay coil (34) is energized.

5. The electronic coil state monitoring device according to claim 4, characterized in that: The power supply circuit unit (4) comprises a rectifier circuit (41), a power circuit (42), a voltage divider circuit (43), a voltage stabilizing circuit (44), a power protection unit and a feedback unit (45). The input power is converted into direct current through the rectifier circuit (41), and the direct current is output to the power protection unit and the feedback unit (45) for real-time monitoring and protection. The direct current is divided by the voltage divider circuit (43), and the divided voltage is provided to the power circuit (42) and the voltage stabilizing circuit (44). The power circuit (42) provides sufficient power, and the voltage stabilizing circuit (44) further adjusts the voltage to ensure the stability of the output voltage. Finally, the stable voltage output by the voltage stabilizing circuit (44) is supplied to the subsequent functional circuit unit for use.

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