Intelligent circuit protection device

Abstract

The utility model discloses an intelligent circuit protection device. The device comprises a microcontroller, a fault indication circuit, a main power supply circuit and an auxiliary power supply circuit, the auxiliary power supply circuit comprises a rechargeable battery, a battery charging circuit, a battery discharging circuit and a battery voltage sampling circuit; the input end of the battery voltage sampling circuit is connected with the rechargeable battery, and the output end of the battery voltage sampling circuit is connected with an AD port of the microcontroller; the input end of the battery charging circuit is connected with a system power supply VDD, the output end of the battery charging circuit is simultaneously connected with the input end of the battery discharging circuit and the rechargeable battery, and the control end of the battery charging circuit is connected with one I / O port of the microcontroller; the battery discharging circuit comprises a charge pump, a diode, a manual control switch and a voltage division circuit. According to the utility model, the fault information can be inquired under the condition that the main power supply is interrupted, and the working time and the service life of the rechargeable battery serving as the auxiliary power supply can be prolonged to the maximum extent.

Description

Technical Field

[0001] The utility model belongs to the technical field of power transmission and distribution safety protection, and specifically relates to an intelligent circuit protection device. Background Art

[0002] Intelligent circuit protection devices represented by intelligent circuit breakers are mainly used in power distribution networks to distribute electrical energy and protect lines and power equipment from overload, short circuit, ground fault, undervoltage, etc. Intelligent circuit protection devices usually use electronic trip devices with precise selection protection and multi-functions, which are particularly suitable for distribution networks that need to improve power supply reliability and avoid unnecessary power outages. Intelligent circuit protection devices usually use current transformers to sample current signals. The sampled current signals are sent to the A / D port of the microprocessor through the signal conditioning circuit to calculate the current value. When the current exceeds the predetermined value, the electronic trip device issues an alarm or sends a trip signal to the execution circuit after a delay, and the circuit breaker is opened through the actuator to protect the line and load equipment from damage. Intelligent circuit protection devices can be powered by the energy coil of the current transformer and the auxiliary power supply together, but in some special cases, the main power supply is interrupted due to a fault, and the user cannot query the trip fault information through the electronic trip device. Therefore, intelligent circuit protection devices often need to use batteries as auxiliary power supplies to query the trip fault information when the main power supply is interrupted. Batteries used as auxiliary backup power sources are generally divided into two categories: non-rechargeable and rechargeable. Non-rechargeable batteries have a very limited service life and require frequent replacement by the user, so they are generally not recommended. Rechargeable batteries, although they have a longer service life, are difficult to manage the charge and discharge of the batteries, extend the battery life, and use as backup power sources for intelligent circuit protection devices for a longer period of time. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an intelligent circuit protection device which can query fault information according to user needs when the main power supply is interrupted and can maximize the working time and service life of a rechargeable battery used as an auxiliary power supply.

[0004] The utility model specifically adopts the following technical solutions to solve the above technical problems:

[0005] An intelligent circuit protection device comprises a microcontroller, a fault indication circuit connected to the microcontroller for indicating fault information, a main power supply circuit and an auxiliary power supply circuit; the auxiliary power supply circuit comprises a rechargeable battery, a battery charging circuit, a battery discharging circuit and a battery voltage sampling circuit; the input end of the battery voltage sampling circuit is connected to the rechargeable battery, and the output end of the battery voltage sampling circuit is connected to an AD port of the microcontroller; the input end of the battery charging circuit is connected to a system power supply VDD, and the output end of the battery charging circuit is simultaneously connected to the input end of the battery discharging circuit and the rechargeable battery, and the control end of the battery charging circuit is connected to an I / O port of the microcontroller; the battery discharging circuit is connected to the input end of the battery discharging circuit and the rechargeable battery, and the control end of the battery charging circuit is connected to an I / O port of the microcontroller; The circuit comprises: a charge pump, a diode, a manual control switch, and a voltage divider circuit, wherein the positive electrode of the diode serves as the input end of the battery discharge circuit, the negative electrode of the diode is simultaneously connected to the input end of the charge pump and one end of the manual control switch, the other end of the manual control switch is simultaneously connected to the enable end of the charge pump and the input end of the voltage divider circuit, the output end of the voltage divider circuit is connected to another I / O port of the microcontroller, the output end of the charge pump is simultaneously connected to the output end of the main power supply circuit, the microcontroller and the power supply input end of the fault indication circuit; the microcontroller is configured to drive the fault indication circuit to display the fault information stored in the microcontroller when a voltage output is detected at the output end of the voltage divider circuit.

[0006] Preferably, the manual control switch is a push button switch.

[0007] Preferably, the fault indication circuit comprises a group of indicator lights corresponding to different types of faults.

[0008] Further preferably, the different types of faults include charging faults of rechargeable batteries.

[0009] Compared with the prior art, the utility model has the following beneficial effects:

[0010] The utility model adopts a rechargeable battery as an auxiliary power source, improves the battery discharge circuit, utilizes a charge pump to output a stable working power source, and in view of the situation that the main power supply is interrupted and fault information needs to be queried, the circuit is designed to activate the battery discharge circuit by manual control, which is beneficial to the saving of battery power and the improvement of battery service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A circuit diagram of a specific implementation of the intelligent circuit protection device of the utility model;

[0012] Figure 2 This is a circuit diagram of another specific implementation of the intelligent circuit protection device of the utility model. DETAILED DESCRIPTION

[0013] In view of the shortcomings of the existing technology, the solution of the utility model is to use a rechargeable battery as an auxiliary power supply, improve the battery discharge circuit, use a charge pump to output a stable working power supply, and in case the main power supply is interrupted and fault information needs to be queried, the circuit is designed to activate the battery discharge circuit through manual control, which is beneficial to saving battery power and increasing the battery life.

[0014] The technical solution of this utility model is as follows:

[0015] An intelligent circuit protection device comprises a microcontroller, a fault indication circuit connected to the microcontroller for indicating fault information, a main power supply circuit and an auxiliary power supply circuit; the auxiliary power supply circuit comprises a rechargeable battery, a battery charging circuit, a battery discharging circuit and a battery voltage sampling circuit; the input end of the battery voltage sampling circuit is connected to the rechargeable battery, and the output end of the battery voltage sampling circuit is connected to an AD port of the microcontroller; the input end of the battery charging circuit is connected to a system power supply VDD, and the output end of the battery charging circuit is simultaneously connected to the input end of the battery discharging circuit and the rechargeable battery, and the control end of the battery charging circuit is connected to an I / O port of the microcontroller; the battery discharging circuit is connected to the input end of the battery discharging circuit and the rechargeable battery, and the control end of the battery charging circuit is connected to an I / O port of the microcontroller; The circuit comprises: a charge pump, a diode, a manual control switch, and a voltage divider circuit, wherein the positive electrode of the diode serves as the input end of the battery discharge circuit, the negative electrode of the diode is simultaneously connected to the input end of the charge pump and one end of the manual control switch, the other end of the manual control switch is simultaneously connected to the enable end of the charge pump and the input end of the voltage divider circuit, the output end of the voltage divider circuit is connected to another I / O port of the microcontroller, the output end of the charge pump is simultaneously connected to the output end of the main power supply circuit, the microcontroller and the power supply input end of the fault indication circuit; the microcontroller is configured to drive the fault indication circuit to display the fault information stored in the microcontroller when a voltage output is detected at the output end of the voltage divider circuit.

[0016] In order to facilitate public understanding, the technical solution of the utility model is described in detail below through two specific embodiments and in conjunction with the accompanying drawings:

[0017] The first specific embodiment is an intelligent circuit breaker, and its circuit structure is as follows Figure 1As shown, it includes: a microcontroller N2, a fault indication circuit connected to the microcontroller for indicating fault information, and a main power supply circuit and an auxiliary power supply circuit; the auxiliary power supply circuit includes a rechargeable battery, a battery charging circuit, and a battery voltage sampling circuit; the microcontroller controls the battery charging circuit to charge the rechargeable battery through the I / O port, and monitors the battery voltage in real time through the battery voltage sampling circuit; the battery discharge circuit adopts a charge pump to output a stable working power supply VCC to the microcontroller and the fault indication circuit when the main power supply is disconnected, and adopts a button switch to manually control the output power supply of the battery discharge circuit.

[0018] The battery charging circuit of this embodiment includes: a capacitor C1, a diode D1, resistors R1-R5, a transistor V1, and a transistor V2, and the connection method thereof is as follows: Figure 1 When charging the battery BT1, the microcontroller N2 outputs a high level through I / O0 to turn on the transistor V2, and the C pole of the transistor V2 is pulled down to obtain a low level, so that the BE pole of the transistor V1 obtains a bias voltage to turn on the transistor V1. The resistor R1 is used as a bias resistor and is connected between the BE poles of the transistor V1. The resistor R2 is connected in series between the B pole of the transistor V1 and the C pole of the transistor V2 to adjust the base current I of the transistor V1. B ; The system power supply VDD charges the battery BT1 through the transistor V1, the diode D1 and the resistor R5.

[0019] The battery voltage VBAT is divided by a battery voltage sampling circuit composed of a diode D3 and resistors R6 and R7 and input to the AD port AN0 of the microcontroller N2 for monitoring the battery voltage.

[0020] like Figure 1As shown, the battery discharge circuit includes: a diode D2, a button switch S1, resistors R8 and R9, a charge pump N1, capacitors C2 and C3; when discharging the battery BT1, the battery voltage VBAT is input to the battery discharge circuit through the diode D2, and only when the button S1 is pressed, the voltage output by the diode D2 is input to the enable terminal EN of the charge pump N1 through the button S1, so that the output terminal OUT of the charge pump N1 outputs the working voltage VCC, and after being divided by the voltage divider circuit composed of resistors R8 and R9, it is input to the I / O1 port of the microcontroller N2, which is used for the microcontroller N2 to confirm whether the button S1 is pressed, and the other voltage output by the diode D2 is directly input to the input terminal IN of the charge pump N1. The input voltage range of the charge pump N1 in this embodiment is 1.8V~3.6V. When the voltage of the battery input to the charge pump N1 meets this range, the charge pump N1 outputs the working voltage VCC of 3.3V. When the microcontroller N2 obtains the working voltage VCC and works normally, and after judging that the confirmation button S1 is pressed, the fault indication circuit is controlled through the I / O port to display the circuit breaker trip fault information. The fault information is stored in the non-volatile data memory after the microcontroller detects the main circuit overload or short circuit and issues a trip command to interrupt the main circuit.

[0021] The fault indication circuit in this embodiment includes a group of LED indicators corresponding to different types of faults, and indicates the corresponding fault information by lighting different LED lights. The LED lights used for trip fault indication are divided into L, S, I, and G, corresponding to long delay fault trip, short circuit short delay fault trip, short circuit instantaneous trip fault, and ground fault trip, respectively. The four trip fault indicators are connected to I / O2~I / O5 of the microcontroller through current limiting resistors R10~R13. Figure 1 As shown, the fault indication circuit in this embodiment also includes an LED lamp VBAT-L for indicating a charging fault of the battery BT1. When the microcontroller N2 detects that the battery voltage VBAT still does not reach the minimum input voltage threshold of the charge pump within a preset time (for example, 1 minute) after the transistor V1 is turned on for charging, the LED lamp VBAT-L flashes to indicate that the battery voltage is low, reminding the user that the battery needs to be maintained or replaced. The LED lamp VBAT-L is connected to the microcontroller I / O6 through the resistor R14.

[0022] like Figure 1As shown, the main power circuit in this embodiment includes two diodes D4 and D5 connected in series and a grounding capacitor C4. The system power VDD is stepped down by the diodes D4 and D5 connected in series to generate an operating voltage VCC, which is provided to the microcontroller and the fault indication circuit as an operating power supply. When the operating voltage VCC is continuously generated by the system power VDD, the microcontroller N2 monitors the battery voltage VBAT in real time through the AD port AN0. When VBAT is lower than a first preset voltage (for example, the median of the input voltage range of the charge pump, such as 2.7V), the I / O0 port is controlled to turn on the transistor V1 to charge the battery. When the VBAT voltage reaches a second preset voltage (for example, the upper limit of the input voltage range of the charge pump, 3.6V), the transistor V1 is turned off and the battery is no longer charged.

[0023] The circuit structure of the second specific embodiment is as follows Figure 2 As shown, the overall Figure 1 The circuits are the same, the difference is that the fault indication circuit uses LCD, that is, the fault information is displayed through the LCD, and the microcontroller and LCD are connected through data / control lines. In order to save battery power, when powered by batteries, LCD generally does not need backlight display.

Claims

1. An intelligent circuit protection device, comprising a microcontroller, a fault indication circuit connected to the microcontroller for indicating fault information, a main power supply circuit and an auxiliary power supply circuit; characterized in that: The auxiliary power supply circuit includes a rechargeable battery, a battery charging circuit, a battery discharging circuit, and a battery voltage sampling circuit; the input end of the battery voltage sampling circuit is connected to the rechargeable battery, and the output end of the battery voltage sampling circuit is connected to an AD port of a microcontroller; the input end of the battery charging circuit is connected to the system power supply VDD, the output end of the battery charging circuit is simultaneously connected to the input end of the battery discharging circuit and the rechargeable battery, and the control end of the battery charging circuit is connected to an I / O port of the microcontroller; the battery discharging circuit includes: a charge pump, a diode, a manual control switch, and a voltage divider circuit, the positive electrode of the diode is used as the input end of the battery discharging circuit, the negative electrode of the diode is simultaneously connected to the input end of the charge pump and one end of the manual control switch, the other end of the manual control switch is simultaneously connected to the enable end of the charge pump and the input end of the voltage divider circuit, the output end of the voltage divider circuit is connected to another I / O port of the microcontroller, and the output end of the charge pump is simultaneously connected to the output end of the main power supply circuit, the microcontroller and the power input end of the fault indication circuit; the microcontroller is configured to drive the fault indication circuit to display the fault information stored in the microcontroller when a voltage output is detected at the output end of the voltage divider circuit.

2. The intelligent circuit protection device according to claim 1, characterized in that: The manual control switch is a push button switch.

3. The intelligent circuit protection device according to claim 1, characterized in that: The fault indication circuit includes a group of indicator lights corresponding to different types of faults.

4. The intelligent circuit protection device as claimed in claim 3, characterized in that: The different types of failures include a charging failure of a rechargeable battery.

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