Novel precise induction current voltage stabilizing circuit for reclosing

Abstract

The utility model relates to a novel precise induction current voltage stabilizing circuit for reclosing, which comprises a sampling circuit, a voltage stabilizing circuit and a control circuit, a sampling resistor in the sampling circuit is connected with an output end UI of the voltage stabilizing circuit, the control circuit and the sampling circuit are connected with a single chip microcomputer, the control circuit comprises a chip U6, and the chip U6 is connected with the single chip microcomputer. An SW pin of the chip U6 is connected with a moss tube Q4 in the voltage stabilizing circuit, the U6 monitors bus voltage of reclosing and controls the moss tube Q4 to switch on and off the sampling circuit to charge the C1, when the bus voltage is higher than DC12V, the moss tube Q4 is switched on, and when the bus voltage is lower than DC12V, the moss tube Q4 is switched off. The utility model is suitable for a low-voltage AC 220V three-phase power distribution system, induced current is obtained from the three-phase current transformer, and after the induced current passes through the three rectifier bridges, a voltage-stabilized DC 12V is output for the system to work through the control of the U6MT3608 to the Q4MOS tube.

Description

Technical Field

[0001] The utility model relates to the technical field of reclosing control circuits, in particular to a novel precise induction current voltage stabilizing circuit for reclosing. Background Art

[0002] In the existing low-voltage AC220V three-phase power distribution system, it is necessary to collect the induced current through the mutual inductor to obtain the specific value of the three-phase current, and at the same time, it is necessary to meet the requirement of outputting a stable voltage. However, the existing circuit structure is complex and the sampling accuracy is insufficient. Summary of the invention

[0003] The utility model aims to provide a novel accurate induction current voltage stabilizing circuit for reclosing switch to solve the above technical problems.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A novel precise inductive current voltage stabilizing circuit for a reclosing switch, characterized in that it comprises a sampling circuit, a voltage stabilizing circuit and a control circuit, wherein the sampling resistor in the sampling circuit is connected to the output terminal UI of the voltage stabilizing circuit, the control circuit and the sampling circuit are connected to a single-chip microcomputer, the control circuit comprises a chip U6, the SW pin of the chip U6 is connected to a Morse tube Q4 in the voltage stabilizing circuit, wherein U6 monitors the bus voltage of the reclosing switch and controls the Morse tube Q4 to disconnect the sampling circuit to charge C1, when the bus voltage is higher than DC12V, the Morse tube Q4 is turned on, and when it is lower than DC12V, Q4 is disconnected.

[0006] The utility model is further configured that a diode D31 and a resistor R52 are connected between the FB pin of the chip U6 and the single-chip computer, resistors R50 and R51 are arranged between the resistor R52 and the FB pin of the chip U6, the resistor R51 is grounded, the IN pin and the EN pin of the chip U6 are connected to R53, and the R53 is connected to the capacitor C26.

[0007] The utility model is further configured that the gate of the MOS tube Q4 is connected to the SW pin of the chip U6, the resistor R26 and the resistor R48, the resistor R26 and the resistor R48 are connected to the capacitor C1, a diode D6 is connected between the drain and the source of the MOS tube Q4, and the drain of the MOS tube Q4 is connected to the sampling resistors R20, R27, and R32.

[0008] The utility model is further arranged that one end of the sampling resistors R20, R27, R32 is connected to rectifier bridges D1, D2 and D3, the rectifier bridges D1, D2, D3 are connected to the three-phase current transformer CN2, the rectifier bridges D1, D2, D3 are respectively connected to resistors R25, R38 and R24, and the resistors R25, R38, R24 are connected to the operational amplifier circuit.

[0009] Beneficial effects of the utility model: The utility model is suitable for low-voltage AC220V three-phase power distribution system. By obtaining the induced current on the three-phase current transformer, after passing through three rectifier bridges, through the control of U6MT3608 on Q4 MOS tube, a stable DC12V is output for system operation. At the same time, the three-phase induced current is sampled through three sampling resistors R20, R27, and R32, and connected to the single-chip microcomputer to calculate the three-phase current through the operational amplifier circuit. The specific principle is as follows: U6 MT3608 controls Q4 to disconnect the induced current loop to charge C1 by monitoring the bus voltage. When it is higher than DC12V, Q4 is turned on, and when it is lower than DC12V, Q4 is disconnected; U6 MT3608 has a switching frequency of up to 1.2MHz to ensure the stability of the power supply voltage. At the same time, this circuit will cause distortion of the three-phase induced current waveform when the power of the current transformer is insufficient. Therefore, the single chip microcomputer in the utility model generates a 2KHZ PWM wave with a duty cycle of 50%, which is connected to MCU_C, so that when the PWM wave is at a high level, U6 can unconditionally control Q4 to pull in, so that the current is no longer charged, the sampling waveform returns to normal, and charging control is performed when the PWM wave is at a low level. This solution can maintain sampling accuracy when a stable power supply is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0011] Figure 1 The electrical schematic diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0012] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0013] like Figure 1As shown, the utility model is a novel accurate induction current voltage stabilizing circuit for reclosing, comprising a sampling circuit, a voltage stabilizing circuit and a control circuit, wherein the sampling resistor in the sampling circuit is connected to the output terminal UI of the voltage stabilizing circuit, the control circuit and the sampling circuit are connected to a single-chip microcomputer, the control circuit comprises a chip U6, the SW pin of the chip U6 is connected to a Morse tube Q4 in the voltage stabilizing circuit, wherein U6 monitors the bus voltage of the reclosing and controls the Morse tube Q4 to disconnect the sampling circuit to charge C1, when the bus voltage is higher than DC12V, the Morse tube Q4 is turned on, and when it is lower than DC12V, Q4 is disconnected.

[0014] A diode D31 and a resistor R52 are connected between the FB pin of the chip U6 and the single-chip microcomputer, a resistor R50 and a resistor R51 are arranged between the resistor R52 and the FB pin of the chip U6, the resistor R51 is grounded, the IN pin and the EN pin of the chip U6 are connected to R53, and the R53 is connected to a capacitor C26. The gate of the MOS tube Q4 is connected to the SW pin of the chip U6, the resistor R26 and the resistor R48, and the resistor R26 and the resistor R48 are connected to a capacitor C1, a diode D6 is connected between the drain and the source of the MOS tube Q4, and the drain of the MOS tube Q4 is connected to sampling resistors R20, R27, and R32. One end of the sampling resistors R20, R27, and R32 is connected to rectifier bridges D1, D2, and D3, and the rectifier bridges D1, D2, and D3 are connected to a three-phase current transformer CN2. The rectifier bridges D1, D2, and D3 are respectively connected to resistors R25, R38, and R24, and the resistors R25, R38, and R24 are connected to an operational amplifier circuit.

[0015] The utility model is suitable for low-voltage AC220V three-phase power distribution system. By obtaining the induced current on the three-phase current transformer, after passing through three rectifier bridges, through the control of U6 MT3608 on Q4 MOS tube, a stable DC12V is output for system operation. At the same time, the three-phase induced current is sampled through three sampling resistors R20, R27, and R32, and connected to the single-chip microcomputer to calculate the three-phase current through the operational amplifier circuit. The specific principle is as follows: U6 MT3608 controls Q4 to disconnect the induced current loop to charge C1 by monitoring the bus voltage. When it is higher than DC12V, Q4 is turned on, and when it is lower than DC12V, Q4 is disconnected; U6 MT3608 has a switching frequency of up to 1.2MHz to ensure the stability of the power supply voltage. At the same time, this circuit will cause the distortion of the three-phase induced current waveform when the power of the current transformer is insufficient. Therefore, the single chip microcomputer in the utility model generates a 2KHZ PWM wave with a duty cycle of 50%, which is connected to MCU_C, so that when the PWM wave is at a high level, U6 can unconditionally control Q4 to pull in, so that the current is no longer charged, the sampling waveform returns to normal, and charging control is performed when the PWM wave is at a low level. This solution can maintain sampling accuracy when a stable power supply is obtained.

[0016] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0017] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0018] The above description shows and describes several preferred embodiments of the utility model, but as before, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention and creation of this article through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A new accurate induction current voltage stabilizing circuit for reclosing, characterized in that: It includes a sampling circuit, a voltage stabilizing circuit and a control circuit. The sampling resistor in the sampling circuit is connected to the output end UI of the voltage stabilizing circuit. The control circuit and the sampling circuit are connected to a single-chip microcomputer. The control circuit includes a chip U6. The SW pin of the chip U6 is connected to a MOS tube Q4 in the voltage stabilizing circuit. U6 monitors the bus voltage of the reclosing switch and controls the MOS tube Q4 to disconnect the sampling circuit to charge C1. When the bus voltage is higher than DC12V, the MOS tube Q4 is turned on, and when it is lower than DC12V, Q4 is disconnected.

2. A novel accurate induction current voltage stabilizing circuit for reclosing as claimed in claim 1, characterized in that: A diode D31 and a resistor R52 are connected between the FB pin of the chip U6 and the microcontroller, resistors R50 and R51 are arranged between the resistor R52 and the FB pin of the chip U6, the resistor R51 is grounded, the IN pin and the EN pin of the chip U6 are connected to R53, and the capacitor C26 is connected to R53.

3. A novel accurate induction current voltage stabilizing circuit for reclosing as claimed in claim 1, characterized in that: The gate of the MOS tube Q4 is connected to the SW pin of the chip U6, the resistor R26 and the resistor R48, the resistor R26 and the resistor R48 are connected to the capacitor C1, the diode D6 is connected between the drain and the source of the MOS tube Q4, and the drain of the MOS tube Q4 is connected to the sampling resistors R20, R27, and R32.

4. A novel accurate induction current voltage stabilizing circuit for reclosing as claimed in claim 3, characterized in that: One end of the sampling resistors R20, R27, and R32 is connected to rectifier bridges D1, D2, and D3, and the rectifier bridges D1, D2, and D3 are connected to a three-phase current transformer CN2. The rectifier bridges D1, D2, and D3 are respectively connected to resistors R25, R38, and R24, and the resistors R25, R38, and R24 are connected to an operational amplifier circuit.

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