Multistage serial voltage-stabilizing input circuit

Abstract

The utility model relates to a multi-stage serial voltage-stabilizing input circuit, which effectively solves the problems that the existing input acquisition circuit cannot thoroughly process transient high voltage, and an optocoupler can be burnt out if an ultrahigh-voltage and high-frequency interference signal is encountered, and the like. Comprising a CPU control circuit, and the CPU control circuit comprises a CPU controller. The input circuit comprises two input ports, and the two input ports are respectively a positive pole input port and a negative pole input port; the over-voltage protection circuit is convenient to use, and through the arrangement of the first voltage-regulator tube, the second voltage-regulator tube and the resistance voltage division circuit, when peak pulse signals connected in series into a loop impact a component, the first voltage-regulator tube is conducted, primary over-voltage protection is carried out on the optocoupler, and over-voltage protection is carried out on the optocoupler. When the first voltage-regulator tube is not enough to achieve the purpose of voltage stabilization due to ultrahigh voltage caused by a certain reason in a loop, the second voltage-regulator tube is conducted, and strong current is shunted through a resistor R64 connected in parallel with the second voltage-regulator tube, so that components at the rear end are protected, and the purpose of secondary voltage stabilization is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric power systems, in particular to a multi-stage serial voltage-stabilizing open-in circuit. Background Art

[0002] The acquisition of input electrical signals is a function that secondary protection devices in the field of power distribution must have. The input circuit not only collects digital signals such as the on / off position of the circuit breaker, the energy storage status, and the non-electrical signal of the transformer, but also has to have certain high reliability, high speed and anti-interference functions.

[0003] At present, the input circuits of secondary devices in the field of power distribution mostly use active input and passive input functions. The passive input method requires a stable input power supply signal to be provided externally. The correct collection of the input signal is related to the safe operation of the entire power grid.

[0004] In the Chinese patent application No. 202211568309.1, there is disclosed a DC wide voltage input open-in acquisition circuit, including a voltage stabilizing and current limiting module, a photoelectric isolation module, an output signal amplifying module, and a signal acquisition module; the external end of the voltage stabilizing and current limiting module is connected to the positive and negative ends of the input DC voltage, and its internal end is connected to one end of the photoelectric isolation module; the other end of the photoelectric isolation module is connected to one end of the output signal amplifying module; the other end of the output signal amplifying module is connected to the signal acquisition module; the voltage stabilizing and current limiting module is used to suppress the input current and filter the interference voltage, the photoelectric isolation module insulates the output and the input, performs electrical isolation of the input and output, amplifies the low acquisition signal through the output signal amplifying module, and the signal acquisition module acquires the amplified signal. It can meet the requirements of different DC voltage level input, has strong anti-interference ability, and is suitable for the scene of different DC voltage level open-in acquisition. However, this DC wide voltage input open-in acquisition circuit is not thorough enough in processing transient high voltage. When collecting the open-in signal, if it encounters ultra-high voltage and high frequency interference signals, it will also burn out the rear-end optical coupler. Utility Model Content

[0005] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the utility model is to provide a multi-stage serial voltage-stabilized open-in circuit, which effectively solves the problems mentioned in the background technology.

[0006] The technical solution is as follows: the utility model comprises:

[0007] A CPU control circuit, wherein the CPU control circuit includes a CPU controller;

[0008] An input circuit, wherein the input circuit comprises two input ports, wherein the two input ports are respectively a positive input port and a negative input port;

[0009] The open-in acquisition circuit comprises an optical coupler, the input end of the optical coupler is respectively connected in series with the two input ports, the output end of the optical coupler is connected to the CPU controller, and the output end of the optical coupler is connected to a power supply;

[0010] A resistor voltage divider circuit, the resistor voltage divider circuit comprising a plurality of resistors connected in series, the resistor voltage divider circuit being respectively connected to the two input ports and the input end of the optical coupler;

[0011] A primary surge protection circuit, the primary surge protection circuit comprising a surge protector, the surge protector being connected in parallel with the two input ports;

[0012] A secondary protection circuit, the secondary protection circuit comprising a first voltage regulator tube, the first voltage regulator tube is connected in parallel with a resistor voltage divider circuit;

[0013] A three-level protection circuit, wherein the three-level protection circuit comprises a second voltage regulator tube, and the second voltage regulator tube is connected in parallel with the first voltage regulator tube.

[0014] Preferably, a transient voltage suppressor diode is connected in parallel to the input end of the optical coupler.

[0015] Preferably, an inductor is connected in series between the open-input acquisition circuit and the input circuit.

[0016] Preferably, an adjustment resistor is connected in parallel between the open-input acquisition circuit and the input circuit.

[0017] Preferably, a capacitor is connected in parallel between the input end of the optical coupler and the two input ports.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. By setting the first voltage regulator, when the voltage at the node is higher than the voltage regulation value of the voltage regulator, the voltage regulator starts to work and "absorbs" the excess voltage through its own reverse breakdown characteristics, thereby ensuring the stability of the voltage at the node.

[0020] 2. Through the setting of the first voltage-stabilizing tube, the second voltage-stabilizing tube and the resistor voltage-divider circuit, when the peak pulse signal in series with the loop impacts the components, the first voltage-stabilizing tube is turned on first to perform preliminary overvoltage protection on the optocoupler. When the ultra-high voltage caused by some reason in the loop makes the first voltage-stabilizing tube insufficient to achieve the voltage stabilization purpose, the second voltage-stabilizing tube is turned on, and the strong current is shunted through the parallel resistor R64 to protect the components at the back end, thereby achieving the purpose of secondary voltage stabilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a circuit diagram of the utility model.

[0022] Figure 2It is a schematic diagram of the process of the utility model.

[0023] Explanation of the symbols in the schematic diagram:

[0024] 10. CPU controller; 11. Positive input port; 12. Negative input port; 13. Power supply; 20. Optocoupler; 30. Surge protector; 40. First voltage regulator; 41. Second voltage regulator; 50. Transient voltage suppressor diode; 60. Inductor; 70. Adjustment resistor; 80. Capacitor. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] Depend on Figure 1 to Figure 2 Given, including:

[0027] CPU control circuit, the CPU control circuit includes a CPU controller 10;

[0028] An input circuit, the input circuit comprising two input ports, the two input ports being a positive input port 11 and a negative input port 12;

[0029] The open-in acquisition circuit includes an optical coupler 20, the input end of the optical coupler 20 is connected in series with the two input ports respectively, the output end of the optical coupler 20 is connected to the CPU controller 10, and the output end of the optical coupler 20 is connected to the power supply 13;

[0030] A resistor voltage divider circuit, wherein the resistor voltage divider circuit includes a plurality of resistors connected in series with each other, and the resistor voltage divider circuit is respectively connected to two input ports and the input end of the optocoupler 20, wherein the resistors connected in series between the positive input port 11 and the input end of the optocoupler 20 are respectively resistors R60, resistor R62 and resistor R64, and the above three resistors form a forward voltage divider resistor, and the resistors connected in series between the negative input port 12 and the input end of the optocoupler 20 are respectively resistors R61 and resistor R63, and the above two resistors form a negative voltage divider resistor, and after the two input ports are connected to the voltage signal, the voltage signal is connected to the optocoupler 20 after passing through the forward voltage divider resistor and the negative voltage divider resistor, and the optocoupler 20 collects the signal and transmits it to the CPU controller 10, thereby completing a whole open-in sampling loop;

[0031] A primary surge protection circuit, the primary surge protection circuit includes a surge protector 30, the surge protector 30 is connected in parallel with the two input ports, and by setting the surge protector 30, a large energy interference source is discharged in time to protect the internal resistance and other components of the subsequent stage;

[0032] A secondary protection circuit includes a first voltage regulator 40, which is connected in parallel with a resistor voltage divider circuit. In order to keep the voltage at the node of the optocoupler 20 always stable, the first voltage regulator 40 is provided. When the voltage at the node is higher than the voltage regulation value of the voltage regulator, the voltage regulator starts to work and "absorbs" the excess voltage through its own reverse breakdown characteristics, thereby ensuring the stability of the voltage at the node.

[0033] The three-level protection circuit includes a second voltage-stabilizer tube 41, which is connected in parallel with the first voltage-stabilizer tube 40, and the second voltage-stabilizer tube 41 is connected in parallel with the resistor R64. When the open-in circuit works normally, the first voltage-stabilizer tube 40 and the second voltage-stabilizer tube 41 are in a short-circuit state, and the optocoupler 20 loop can normally collect the open-in circuit. When the peak pulse signal in series with the loop impacts the components, the first voltage-stabilizer tube 40 is turned on first to perform preliminary overvoltage protection on the optocoupler 20. When the high voltage in the loop caused by some reason makes the first voltage-stabilizer tube 40 insufficient to achieve the voltage regulation purpose, the second voltage-stabilizer tube 41 is turned on, and the strong current is shunted through the parallel resistor R64 to protect the back-end components. It should be noted that after the second voltage-stabilizer tube 41 is turned on, the resistor R64 is basically in a short-circuit state, thereby achieving the purpose of secondary voltage regulation.

[0034] refer to Figure 1 As shown, a transient suppression diode 50 is connected in parallel to the input end of the optocoupler 20. If there is a reverse electromotive force at the input end of the optocoupler 20 (for example, a reverse spike voltage generated when the inductive load is disconnected), the transient suppression diode 50 can provide reverse protection to prevent the reverse voltage from being too high and damaging the optocoupler 20. At the same time, the transient suppression diode 50 can be used as a simple clamping circuit. When the input end of the optocoupler 20 is subjected to a reverse voltage shock, the diode is immediately turned on to limit the reverse voltage to below its reverse breakdown voltage, thereby protecting the optocoupler 20 from failure due to an excessively high reverse voltage.

[0035] refer to Figure 1 As shown, an inductor 60 is connected in series between the open-in acquisition circuit and the input circuit. When the circuit is working normally, when an interference signal is connected to the negative input terminal, it is filtered by the inductor 60 to eliminate the phenomenon that the open-in signal malfunctions due to the unstable level of the negative input terminal.

[0036] refer to Figure 1 As shown, in order to better control the driving current of the optocoupler 20 and protect the optocoupler 20 , an adjustment resistor 70 is connected in parallel between the open-input acquisition circuit and the input circuit.

[0037] refer to Figure 1 As shown, a capacitor 80 is connected in parallel between the input end of the optocoupler 20 and the two input ports. As a filter element, it can effectively absorb high-frequency noise and interference pulses in the circuit and reduce their influence on the input end of the optocoupler 20. At the same time, the optocoupler 20 itself has parasitic capacitance 80. Especially in high-speed switching applications, the parasitic capacitance 80 will affect the rising and falling edge speeds of the signal. A capacitor 80 of appropriate size connected in parallel can compensate for the effect of the parasitic capacitance 80, speed up the switching speed of the optocoupler 20, and improve the response performance of the circuit.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage serial voltage-stabilized open-in circuit, comprising: A CPU control circuit, the CPU control circuit comprising a CPU controller (10); An input circuit, the input circuit comprising two input ports, the two input ports being a positive input port (11) and a negative input port (12); An open-in acquisition circuit, the open-in acquisition circuit comprising an optical coupler (20), the input end of the optical coupler (20) being respectively connected in series with two input ports, the output end of the optical coupler (20) being connected with a CPU controller (10), and the output end of the optical coupler (20) being connected with a power supply (13); A resistor voltage divider circuit, the resistor voltage divider circuit comprising a plurality of resistors connected in series, the resistor voltage divider circuit being respectively connected to the two input ports and the input end of the optical coupler (20); A primary surge protection circuit, the primary surge protection circuit comprising a surge protector (30), the surge protector (30) being connected in parallel to two input ports; A secondary protection circuit, the secondary protection circuit comprising a first voltage regulator tube (40), the first voltage regulator tube (40) being connected in parallel with a resistor voltage divider circuit; A three-level protection circuit, the three-level protection circuit comprising a second voltage regulator tube (41), the second voltage regulator tube (41) being connected in parallel with the first voltage regulator tube (40).

2. A multi-stage serial voltage-stabilized open-in circuit according to claim 1, characterized in that: A transient voltage suppression diode (50) is connected in parallel to the input end of the optical coupler (20).

3. A multi-stage serial voltage-stabilized open-in circuit according to claim 1, characterized in that: An inductor (60) is connected in series between the open-in acquisition circuit and the input circuit.

4. The multi-stage serial voltage-stabilized open-in circuit according to claim 1, characterized in that: An adjusting resistor (70) is connected in parallel between the open-in acquisition circuit and the input circuit.

5. The multi-stage serial voltage-stabilized open-in circuit according to claim 1, characterized in that: A capacitor (80) is connected in parallel between the input end of the optical coupler (20) and the two input ports.

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