A power supply circuit and a substation patrol system

Abstract

The utility model discloses a rectifier circuit in the power supply circuit in prior art exists the problem that the conduction voltage drop is big, provides a kind of power supply circuit and transformer substation inspection system.Power supply circuit includes: operational amplifier AMP1, and there is resistance R1 in series between the opposite input end of operational amplifier AMP1 and voltage reducing circuit;The same phase input end of operational amplifier AMP1 is connected to ground through resistance R2;The output of operational amplifier AMP1 is connected to the opposite input end of operational amplifier AMP1 through diode D1;Operational amplifier AMP2, the output of operational amplifier AMP1 is connected to operational amplifier AMP2 in series diode D2, resistance R3 in proper order;The junction of diode D2 and resistance R3 is connected to the opposite input end of operational amplifier AMP1 through feedback resistance Rf1;The output of operational amplifier AMP2 is connected to the opposite input end of operational amplifier AMP2 through feedback resistance Rf2.

Description

Technical Field

[0001] This utility model relates to the field of power supply technology, and in particular to a power supply circuit and a substation inspection system. Background Technology

[0002] In MES (Manufacturing Execution System), the power supply circuit, as a key component of its underlying hardware support, ensures the system's accurate acquisition and continuous control of real-time data from the production site.

[0003] Most existing power supply circuits use bridge rectifier circuits as the rectifier circuit. Bridge rectifier circuits have drawbacks such as large on-state voltage drop, small signal distortion, and insufficient harmonic suppression. Utility Model Content

[0004] This invention addresses the problems of large on-state voltage drop, small signal distortion, and insufficient harmonic suppression in existing power supply circuits, and provides a power supply circuit and substation inspection system.

[0005] The technical solution adopted in this utility model is:

[0006] A power supply circuit includes a rectifier circuit, a PFC circuit, and a point-of-load (POL) circuit. The rectifier circuit is connected to an external power supply, the POL circuit is connected to a load, and a step-down circuit is provided between the rectifier circuit and the external power supply circuit to output the voltage for normal operation of the rectifier circuit. The rectifier circuit includes:

[0007] Operational amplifier AMP1 has a resistor R1 connected in series between its inverting input and the buck converter; its non-inverting input is grounded through a resistor R2; and its output is connected to its inverting input through a diode D1.

[0008] Operational amplifier AMP2 is connected in series with diode D2 and resistor R3 to the inverting input of operational amplifier AMP2.

[0009] The connection between diode D2 and resistor R3 is connected to the inverting input of operational amplifier AMP1 through feedback resistor Rf1; the output of operational amplifier AMP2 is connected to the inverting input of operational amplifier AMP2 through feedback resistor Rf2; the output of operational amplifier AMP2 is grounded through capacitor C1 to filter out high-frequency noise; the non-inverting input of operational amplifier AMP2 is grounded through resistor R4.

[0010] The resistance of feedback resistor Rf2 is equal to that of resistor R3; the resistance of feedback resistor Rf1 is twice that of resistor R1.

[0011] Furthermore, the PFC circuit includes:

[0012] Inductor L1, the first end of which is connected to the output of operational amplifier AMP2;

[0013] The drain of the MOSFET is connected to the second terminal of inductor L1.

[0014] The controller is connected to the gate of the MOSFET and is used to control the switching on and off of the MOSFET.

[0015] Diode D3, the anode of diode D3 is connected to the drain of MOSFET;

[0016] Capacitor C2 has its first terminal connected to the cathode of diode D3, and its second terminal grounded. The voltage across capacitor C2 is the output voltage of the PFC circuit.

[0017] Furthermore, the MOSFET is an NMOS transistor.

[0018] Furthermore, the controller is an STM32 microcontroller.

[0019] The point-of-load (POL) circuit is connected to the controller, and the POL circuit outputs multiple signals with different voltage values ​​to the load.

[0020] The point-of-load (POL) circuit has multiple PWM signal filtering modules, each of which outputs a smooth DC voltage.

[0021] Furthermore, each PWM signal filtering module is connected to an STM32 microcontroller. The input of the PWM signal filtering module is connected to the STM32 microcontroller. The PWM signal filtering module has an internal filtering circuit. The output of the PWM signal filtering module is connected to the load.

[0022] Furthermore, the filtering circuit inside the PWM signal filtering module includes an inductor L2 and a capacitor C3 connected in series. One end of the capacitor C3 connected to the inductor L2 is the output terminal of the PWM signal filtering module, and the other end of the capacitor C3 is grounded.

[0023] Based on the same inventive concept, this utility model also provides a substation inspection system, which includes the aforementioned power supply circuit and multiple cameras;

[0024] All of the cameras are deployed inside the substation to collect images of the power equipment and video data on the position and status of switches and circuit breakers.

[0025] The power supply circuit is connected to the substation AC bus and all cameras, converting the electrical energy from the substation AC bus (such as AC220V / 380V) into the DC voltage (such as DC 12V / 24V) required by all cameras, ensuring continuous operation of the cameras (the smooth DC voltage output by the PWM signal filtering module in each power supply circuit enters the camera).

[0026] Furthermore, the substation inspection system also includes a wheeled robot, which is equipped with a visible light camera, an infrared thermal imager, and acoustic sensors to collect multimodal sensing data from power equipment.

[0027] The beneficial effects of this utility model are:

[0028] The power supply circuit and rectifier circuit in the substation inspection system disclosed in this utility model, through the open-loop differential mode amplification factor of the operational amplifier of hundreds of thousands of times, can turn on the operational amplifier even if the amplification voltage is only a few microvolts, thereby changing the working state of diodes D1 and D2, thus making the rectification of the rectifier circuit more precise. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is the circuit diagram for the power supply circuit;

[0031] Figure 2 This is a circuit diagram of an STM32 microcontroller and a PWM signal filtering module. Detailed Implementation

[0032] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0033] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this invention.

[0034] The embodiments of the utility model will now be described in detail with reference to the accompanying drawings.

[0035] As attached Figure 1 As shown, the power supply circuit disclosed in this embodiment includes a rectifier circuit, a PFC circuit, and a point-of-load (POL) circuit. The rectifier circuit is connected to an external power supply, and the POL circuit is connected to the load.

[0036] A step-down circuit is provided between the rectifier circuit and the external power supply circuit to output the voltage for normal operation of the rectifier circuit.

[0037] The rectifier circuit includes: operational amplifier AMP1, operational amplifier AMP2, resistor R1, resistor R2, diode D1, diode D2, resistor R3, feedback resistor Rf1, feedback resistor Rf2, resistor R4, and capacitor C1.

[0038] A resistor R1 is connected in series between the inverting input terminal of operational amplifier AMP1 and the buck circuit; the non-inverting input terminal of operational amplifier AMP1 is grounded through a resistor R2; the output terminal of operational amplifier AMP1 is connected to the inverting input terminal of operational amplifier AMP1 through a diode D1.

[0039] The output of operational amplifier AMP1 is connected in series with diode D2 and resistor R3 to the inverting input of operational amplifier AMP2.

[0040] The connection between diode D2 and resistor R3 is connected to the inverting input of operational amplifier AMP1 through feedback resistor Rf1; the output of operational amplifier AMP2 is connected to the inverting input of operational amplifier AMP2 through feedback resistor Rf2; the output of operational amplifier AMP2 is grounded through capacitor C1 to filter out high-frequency noise; the non-inverting input of operational amplifier AMP2 is grounded through resistor R4.

[0041] Among them, the resistance of feedback resistor Rf2 is equal to that of resistor R3; the resistance of feedback resistor Rf1 is twice that of resistor R1.

[0042] The working principle of this rectifier circuit is as follows: The AC voltage ui output by the step-down circuit (such as a step-down transformer) is input to the inverting input terminal of the operational amplifier AMP1 through resistor R1, and the non-inverting input terminal of the operational amplifier AMP1 is grounded through resistor R2. When the input is in the positive half-cycle, the operational amplifier AMP1 outputs a negative voltage, diode D1 is reverse-biased and cut off, diode D2 is turned on, and the circuit realizes the inverse proportional operation. The voltage uo1 at the anode of diode D2 is -2 times ui.

[0043] When the input of the step-down circuit (such as a step-down transformer) is in the negative half-cycle, the operational amplifier AMP1 outputs a positive voltage, diode D1 is forward-biased and diode D2 is reverse-biased and cut off, the current in the feedback resistor Rf1 is zero, the voltage at the anode of diode D2 is 0V, and the voltage at the inverting input of operational amplifier AMP2 is ui.

[0044] Analysis of the inverting summation circuit composed of operational amplifier AMP2 shows that the output voltage of operational amplifier AMP2 is uo = -uo1 - ui. When ui > 0, uo1 = -2ui, uo = 2ui - ui = ui; when ui < 0, uo1 = 0, uo = -ui, so uo = |ui|.

[0045] The output of operational amplifier AMP2 is filtered by capacitor C1 to remove high-frequency noise, and finally achieves rectification and amplification, outputting a smooth DC voltage to complete the rectification function.

[0046] The beneficial effects of the above technical solution are as follows: the rectifier circuit, through the open-loop differential amplification factor of the operational amplifier of hundreds of thousands of times, can turn on the operational amplifier even if the amplification voltage is only a few microvolts, thereby changing the working state of diodes D1 and D2, thus making the rectification of the rectifier circuit more precise.

[0047] Furthermore, the PFC circuit includes: inductor L1, controller, diode D3, and capacitor C2.

[0048] The first terminal of inductor L1 is connected to the output terminal of operational amplifier AMP2;

[0049] The drain of the MOSFET is connected to the second terminal of inductor L1.

[0050] The controller is connected to the gate of the MOSFET and is used to control the switching on and off of the MOSFET.

[0051] The anode of diode D3 is connected to the drain of the MOSFET;

[0052] The first terminal of capacitor C2 is connected to the cathode of diode D3, the second terminal of capacitor C2 is grounded, and the voltage across capacitor C2 is the output voltage of the PFC circuit.

[0053] Furthermore, the MOSFET is an NMOS transistor.

[0054] Furthermore, the controller is an STM32 microcontroller because STM32 microcontrollers have many library functions and are technically mature and easy to develop.

[0055] Furthermore, the point-of-load (POL) circuit is connected to the controller, and the POL circuit outputs multiple signals with different voltage values ​​to the load.

[0056] Furthermore, the point-of-load (POL) circuit has multiple PWM signal filtering modules, each of which outputs a smooth DC voltage.

[0057] Furthermore, as shown in the appendix Figure 2 As shown, each PWM signal filtering module is connected to an STM32 microcontroller. The input of the PWM signal filtering module is connected to the STM32 microcontroller. The PWM signal filtering module has an internal filtering circuit. The output of the PWM signal filtering module is connected to the load LOAD.

[0058] The working principle of the PWM signal filtering module is as follows: the microcontroller outputs PWM signals of different waveforms into the corresponding PWM signal filtering module, and the PWM signal filtering module outputs a smooth voltage through its internal filtering circuit to the load.

[0059] Furthermore, as shown in the appendix Figure 2 As shown, the filtering circuit inside the PWM signal filtering module includes an inductor L2 and a capacitor C3 connected in series. One end of the capacitor C3 connected to the inductor L2 is the output terminal of the PWM signal filtering module, and the other end of the capacitor C3 is grounded.

[0060] Inductor L2 and capacitor C3 form an LC filter circuit. Since inductors and capacitors have almost no energy loss, the LC filter circuit has better energy utilization than the RC filter circuit and the RL filter circuit.

[0061] Based on the same inventive concept, this embodiment also provides a substation inspection system, which includes the aforementioned power supply circuit and multiple cameras;

[0062] All of the cameras are deployed inside the substation to collect images of the power equipment and video data on the position and status of switches and circuit breakers.

[0063] The power supply circuit is connected to the substation AC bus and all cameras, converting the electrical energy from the substation AC bus (such as AC220V / 380V) into the DC voltage (such as DC 12V / 24V) required by all cameras, ensuring continuous operation of the cameras (the smooth DC voltage output by the PWM signal filtering module in each power supply circuit enters the camera).

[0064] Furthermore, the substation inspection system also includes a wheeled robot, which is equipped with a visible light camera, an infrared thermal imager, and acoustic sensors to collect multimodal sensing data from power equipment.

Claims

1. A power supply circuit, comprising a rectifier circuit, a PFC circuit, and a point-of-load (POL) circuit, wherein the rectifier circuit is connected to an external power supply, and the POL circuit is connected to a load, characterized in that, A step-down circuit is provided between the rectifier circuit and the external power supply circuit to output the voltage for normal operation of the rectifier circuit; the rectifier circuit includes: Operational amplifier AMP1 has a resistor R1 connected in series between its inverting input and the buck converter; its non-inverting input is grounded through a resistor R2; and its output is connected to its inverting input through a diode D1. Operational amplifier AMP2 is connected in series with diode D2 and resistor R3 to the inverting input of operational amplifier AMP2. The connection between diode D2 and resistor R3 is connected to the inverting input of operational amplifier AMP1 through feedback resistor Rf1; the output of operational amplifier AMP2 is connected to the inverting input of operational amplifier AMP2 through feedback resistor Rf2; the output of operational amplifier AMP2 is grounded through capacitor C1 to filter out high-frequency noise; the non-inverting input of operational amplifier AMP2 is grounded through resistor R4. The resistance value of the feedback resistor Rf2 is equal to the resistance value of the resistor R3; The resistance of the feedback resistor Rf1 is twice the resistance of the resistor R1.

2. The power supply circuit according to claim 1, characterized in that, The PFC circuit includes: Inductor L1, the first end of which is connected to the output of operational amplifier AMP2; The drain of the MOSFET is connected to the second terminal of inductor L1. The controller is connected to the gate of the MOSFET and is used to control the switching on and off of the MOSFET. Diode D3, the anode of diode D3 is connected to the drain of MOSFET; Capacitor C2 has its first terminal connected to the cathode of diode D3, and its second terminal grounded. The voltage across capacitor C2 is the output voltage of the PFC circuit.

3. The power supply circuit according to claim 2, characterized in that, The MOSFET is an NMOS transistor.

4. The power supply circuit according to claim 2, characterized in that, The controller is an STM32 microcontroller.

5. The power supply circuit according to any one of claims 2-4, characterized in that, The point-of-load (POL) circuit is connected to the controller, and the POL circuit outputs multiple signals with different voltage values ​​to the load.

6. The power supply circuit according to claim 5, characterized in that, The point-of-load (POL) circuit has multiple PWM signal filtering modules, each of which outputs a smooth DC voltage.

7. The power supply circuit according to claim 6, characterized in that, Each PWM signal filtering module is connected to an STM32 microcontroller. The input of the PWM signal filtering module is connected to the STM32 microcontroller. The PWM signal filtering module has an internal filtering circuit. The output of the PWM signal filtering module is connected to the load.

8. The power supply circuit according to claim 7, characterized in that, The filtering circuit inside the PWM signal filtering module includes an inductor L2 and a capacitor C3 connected in series. One end of the capacitor C3 connected to the inductor L2 is the output terminal of the PWM signal filtering module, and the other end of the capacitor C3 is grounded.

9. A substation inspection system, characterized in that, Includes a power supply circuit as described in any one of claims 1-8, and multiple cameras; All of the cameras are deployed inside the substation to collect images of the power equipment and video data on the position and status of switches and circuit breakers. The power supply circuit is connected to the substation's AC bus and all cameras, converting the electrical energy from the substation's AC bus into the DC voltage required by all cameras to ensure continuous operation of the cameras.

10. The substation inspection system according to claim 9, characterized in that, The substation inspection system also includes wheeled robots, which are equipped with visible light cameras, infrared thermal imagers, and acoustic sensors to collect multimodal sensing data from power equipment.

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