Circuit structure of motor protector

Abstract

The utility model discloses a circuit structure of a motor protector, which comprises a current and voltage acquisition part connected with an external motor and used for acquiring current and voltage when the external motor operates; the single-chip microcomputer part comprises a 32-bit single-chip microcomputer chip and a peripheral circuit, an electric energy metering program is arranged in the 32-bit single-chip microcomputer chip, and the 32-bit single-chip microcomputer chip is connected with the current and voltage acquisition part; the man-machine interaction part is connected with the single-chip microcomputer part and is used for receiving and displaying the electric energy data output by the single-chip microcomputer part; the communication part is connected with the single chip microcomputer part; the transmitting output part is connected between the single chip microcomputer part and the man-machine interaction part; and the relay output part is connected between the singlechip part and an external motor. Compared with the prior art, the circuit structure of the motor protector can simply and effectively realize electric energy metering by arranging a relatively strong single chip microcomputer chip built-in electric energy metering program, so that an extra metering chip does not need to be arranged.

Description

Technical Field

[0001] The utility model relates to a motor protector, more specifically to a circuit structure of a motor protector. Background Art

[0002] Motors are commonly used in low-voltage power supply and distribution systems. During use, the motors need to be packaged to ensure safe and stable operation to prevent the motors from burning out or causing major safety accidents. Most motor distribution circuits in low-voltage power supply and distribution systems are equipped with intelligent low-voltage motor protectors. The single-chip microcomputer in the motor protector is used as a controller to achieve intelligent and comprehensive protection of the motor. In the current use of motor protectors, most of them will add an energy metering chip, and the energy metering chip is used to achieve energy metering during motor operation. For example, the invention patent with patent number 200810011577.7, entitled "Intelligent Low-Voltage Motor Protector with Energy Metering Function", discloses a method of connecting an ADE7758 metering chip to a host module to achieve energy metering. However, the metering chip must be set to achieve the metering function of the above protector, which will undoubtedly increase the cost of the product. Utility Model Content

[0003] In view of the shortcomings of the prior art, the purpose of the utility model is to provide a circuit structure of a motor protector with lower cost.

[0004] To achieve the above object, the utility model provides the following technical solution: a circuit structure of a motor protector, characterized in that it includes:

[0005] The current and voltage acquisition part is connected to the external motor and is used to acquire the current and voltage when the external motor is running;

[0006] The single-chip microcomputer part is a 32-bit single-chip microcomputer chip and peripheral circuits. The 32-bit single-chip microcomputer chip has a built-in electric energy metering program and is connected to the current and voltage acquisition part to receive the current and voltage collected when the external motor is running, calculate the electric energy data and output it;

[0007] The human-computer interaction part is connected with the single-chip microcomputer part to receive the electric energy data output by the single-chip microcomputer part and then display it;

[0008] The communication part is connected with the single-chip microcomputer part to establish communication between the single-chip microcomputer part and the host computer;

[0009] The transmission output part is connected to the single-chip microcomputer part to convert the PWM signal output by the single-chip microcomputer part into an industrial standard current signal for output;

[0010] The relay output part is connected between the single-chip microcomputer part and the external motor to receive the control quantity output by the single-chip microcomputer part and transmit it to the external motor to control the operation of the external motor.

[0011] As a further improvement of the present invention, the current and voltage acquisition part includes:

[0012] A voltage collection circuit is connected to the external motor and the single-chip microcomputer part to collect voltage data of the external motor when it is running and to the single-chip microcomputer part;

[0013] A current collection circuit is connected to the external motor and the single-chip microcomputer part to collect current data of the external motor when it is running and to the single-chip microcomputer part;

[0014] The leakage current collection circuit is connected to the external motor and the single-chip microcomputer part to collect the leakage current data of the external motor when it is running and transmit it to the single-chip microcomputer part.

[0015] As a further improvement of the present invention, the leakage current collection circuit comprises:

[0016] The leakage current transformer CT4 is arranged at the position of the external motor and is used to sense the leakage current of the external motor;

[0017] The operational amplifier U1B has a common-phase input terminal, a reverse input terminal and an output terminal. The common-phase input terminal is connected to a resistor R1 and then connected to a leakage transformer CT4. The reverse input terminal is connected to a resistor R2 and then connected to the leakage transformer CT4. Resistors R3 and R4 connected in parallel are also connected between the resistors R1 and R2. The common-phase input terminal is connected to a capacitor C1 and then connected to the reverse input terminal. The output terminal is also connected to a resistor R5 and then connected to the output terminal. The output terminal is connected to the single-chip computer part. The output terminal is also connected to a capacitor C2 and then grounded.

[0018] As a further improvement of the present utility model, the current acquisition circuit includes:

[0019] A current transformer CT1 has an input end and an output end, the input end is connected to an external motor, the output end is connected to a resistor R66 and then to a single-chip microcomputer part, and resistors R62 and R63 are connected in parallel between the resistor R66 and the output end, one end of the resistor R66 relative to the current transformer CT1 is also connected to a resistor R64 and then to a resistor R65 and then to relative ground, a node between the resistor R64 and the resistor R65 is connected to a capacitor C43 and then to relative ground, and is also connected to the single-chip microcomputer part, and one end of the resistor R66 relative to the output end of the current transformer CT1 is connected to a capacitor C42 and then to relative ground.

[0020] As a further improvement of the present utility model, the communication part includes:

[0021] The communication chip U has a power supply terminal, a data input terminal and a data output terminal. The data input terminal is connected to the single-chip computer part, and the data output terminal is connected to the host computer through a bus. The power supply terminal is connected to an inductor L and then connected to a power supply. Both ends of the inductor L are connected to capacitors and then grounded.

[0022] The beneficial effect of the utility model is that by setting the current and voltage acquisition part, the current and voltage when the motor is running can be effectively acquired, and by setting the single-chip computer part, the acquired current and voltage can be effectively received, so as to realize the use of the relay output part to control the motor, and then realize the motor protection, and by setting the single-chip computer part to the STM32F103ZET6 chip and peripheral circuit, the chip built-in electric energy metering program can be realized, so as to realize electric energy metering without the need to set up an additional metering chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a module block diagram of the circuit structure of the motor protector of the utility model;

[0024] Figure 2 for Figure 1 Circuit diagram of the microcontroller part;

[0025] Figure 3 for Figure 1 Circuit diagram of the current and voltage acquisition part;

[0026] Figure 4 for Figure 1 Circuit diagram of the human-computer interaction part;

[0027] Figure 5 for Figure 1 Circuit diagram of the transmitter output part;

[0028] Figure 6 for Figure 1 Circuit diagram of the relay output part;

[0029] Figure 7 for Figure 1 Circuit diagram of the communication part;

[0030] Figure 8 for Figure 3 Circuit diagram of leakage current collection circuit;

[0031] Fig. 9 for Figure 3 Circuit diagram of the current acquisition circuit. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0033] Reference Figures 1 to 9 As shown, a circuit structure of a motor protector of this embodiment is characterized by comprising:

[0034] The current and voltage acquisition part 1 is connected to the external motor and is used to acquire the current and voltage when the external motor is running;

[0035] The single-chip microcomputer part 2 is an STM32F103ZET6 chip and peripheral circuits. The STM32F103ZET6 chip has a built-in electric energy metering program and is connected to the current and voltage acquisition part 1 to receive the collected current and voltage of the external motor when it is running, calculate the electric energy data and output it;

[0036] The human-computer interaction part 3 is connected to the single-chip computer part 2 to receive the electric energy data output by the single-chip computer part 2 and then display it;

[0037] The communication part 4 is connected to the single chip computer part 2 to establish communication between the single chip computer part 2 and the host computer;

[0038] The transmission output part 5 is connected to the single chip computer part 2 to convert the PWM signal output by the single chip computer part 2 into an industrial standard current signal and then output it;

[0039] The relay output part 6 is connected between the single-chip computer part 2 and the external motor to receive the control quantity output by the single-chip computer part 2 and transmit it to the external motor to control the operation of the external motor. In the process of using the protector of this embodiment, it is only necessary to connect the current and voltage acquisition part 1 and the relay output part 6 to the running motor. In this way, the protection of the motor and the electric energy metering can be realized through the single-chip computer part 2. In this embodiment, the STM32F103ZET6 chip and the peripheral circuit are used as the single-chip computer part 2. The strong computing power of the STM32F103ZET6 chip can be used to realize the built-in electric energy metering program, thereby achieving the effect of electric energy metering without setting a metering chip, thereby realizing a lower-cost motor protector.

[0040] As an improved specific implementation, the current and voltage acquisition part 1 includes:

[0041] A voltage collection circuit 11 is connected to the external motor and the single-chip microcomputer part 2 to collect voltage data of the external motor when it is running and to the single-chip microcomputer part 2;

[0042] A current collection circuit 12 is connected to the external motor and the single chip computer part 2 to collect current data of the external motor when it is running and to the single chip computer part 2;

[0043] The leakage current collection circuit 13 is connected to the external motor and the single-chip microcomputer part 2 to collect the leakage current data of the external motor when it is running to the single-chip microcomputer part 2. Through the setting of the above structure, the voltage, current and leakage current collection can be effectively realized. Therefore, through the setting of the single-chip microcomputer part 2 and the relay output part 6, the operation of the motor can be effectively protected and the measurement of electric energy can be realized at the same time.

[0044] As an improved specific implementation, the leakage current collection circuit 13 includes:

[0045] The leakage current transformer CT4 is arranged at the position of the external motor and is used to sense the leakage current of the external motor;

[0046] The operational amplifier U1B has a common-phase input terminal, a reverse input terminal and an output terminal. The common-phase input terminal is connected to a resistor R1 and then connected to a leakage transformer CT4. The reverse input terminal is connected to a resistor R2 and then connected to a leakage transformer CT4. Resistors R3 and R4 connected in parallel are also connected between the resistors R1 and R2. The common-phase input terminal is connected to a capacitor C1 and then connected to the reverse input terminal. The output terminal is also connected to a resistor R5 and then connected to the output terminal. The output terminal is connected to the single-chip computer part 2. The output terminal is also connected to a capacitor C2 and then grounded. Through the setting of the above structure, the leakage current of the motor can be simply and effectively detected. At the same time, through the setting of the operational amplifier U1B, the leakage current can be amplified simply and effectively, so that the leakage current of the motor can be well detected.

[0047] As an improved specific implementation, the current acquisition circuit 12 includes:

[0048] A current transformer CT1, wherein the current transformer CT1 has an input end and an output end, wherein the input end is connected to an external motor, and the output end is connected to a resistor R66 and then to the single-chip computer part 2, and resistors R62 and R63 connected in parallel are connected between the resistor R66 and the output end, wherein the resistor R66 is connected to a resistor R64 at one end relative to the current transformer CT1 and then to a resistor R65 and then to relative ground, wherein a node between the resistor R64 and the resistor R65 is connected to a capacitor C43 and then to relative ground, and is also connected to the single-chip computer part 2, wherein the resistor R66 is connected to a capacitor C42 at one end relative to the output end of the current transformer CT1 and then to relative ground, and through the arrangement of the above structure, the running current of the motor can be detected simply and effectively, and through the combination of multiple resistors, the running current of the motor can be filtered and adjusted, so that it can be better input into the single-chip computer part 2, and the running current of the motor can be detected.

[0049] As an improved specific implementation, the communication part 4 includes:

[0050] The communication chip U has a power supply terminal, a data input terminal and a data output terminal. The data input terminal is connected to the single-chip computer part 2, and the data output terminal is connected to the host computer through a bus. The power supply terminal is connected to the inductor L and then connected to the power supply. Both ends of the inductor L are connected to the ground after being connected to capacitors. Through the setting of the inductor L and the capacitor, the power supply of the communication chip U can be effectively filtered to ensure that the communication chip U can work normally.

[0051] In summary, by setting the current and voltage acquisition part 1, the single-chip computer part 2, the human-computer interaction part 3, the communication part 4 and the transmission output part 5, the protection of the motor operation can be simply and effectively realized, and by setting the single-chip computer part 2 to the STM32F103ZET6 chip and the peripheral circuit, the strong computing power of the STM32F103ZET6 chip can be used to realize the built-in electric energy metering program, thereby effectively reducing the production cost of the protector.

[0052] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A circuit structure of a motor protector, characterized in that: include: The current and voltage acquisition part (1) is connected to the external motor and is used to acquire the current and voltage when the external motor is running; The single-chip microcomputer part (2) is a 32-bit single-chip microcomputer chip and peripheral circuits. The 32-bit single-chip microcomputer chip has a built-in electric energy metering program and is connected to the current and voltage acquisition part (1) to receive the current and voltage collected when the external motor is running, calculate the electric energy data, and then output it; The human-computer interaction part (3) is connected to the single-chip computer part (2) to receive the electric energy data output by the single-chip computer part (2) and then display it; The communication part (4) is connected to the single chip computer part (2) to establish communication between the single chip computer part (2) and the host computer; The transmission output part (5) is connected to the single chip computer part (2) to convert the PWM signal output by the single chip computer part (2) into an industrial standard current signal and then output it; The relay output part (6) is connected between the single chip computer part (2) and the external motor to receive the control quantity output by the single chip computer part (2) and transmit it to the external motor to control the operation of the external motor.

2. The circuit structure of the motor protector according to claim 1 is characterized in that: The current and voltage acquisition part (1) comprises: A voltage collection circuit (11) is connected to the external motor and the single-chip microcomputer part (2) to collect voltage data of the external motor when it is running and to the single-chip microcomputer part (2); A current collection circuit (12) is connected to the external motor and the single chip microcomputer part (2) to collect current data of the external motor when it is running and transmit it to the single chip microcomputer part (2); The leakage current collection circuit (13) is connected to the external motor and the single chip computer part (2) to collect leakage current data when the external motor is running and transmit it to the single chip computer part (2).

3. The circuit structure of the motor protector according to claim 2 is characterized in that: The leakage current collection circuit (13) comprises: The leakage current transformer CT4 is arranged at the position of the external motor and is used to sense the leakage current of the external motor; An operational amplifier U1B, the operational amplifier U1B having a non-inverting input terminal, a reverse input terminal and an output terminal, the non-inverting input terminal being connected to a resistor R1 and then connected to a leakage transformer CT4, the reverse input terminal being connected to a resistor R2 and then connected to the leakage transformer CT4, a resistor R3 and a resistor R4 being connected in parallel between the resistor R1 and the resistor R2, the non-inverting input terminal being connected to a capacitor C1 and then connected to the reverse input terminal, the non-inverting input terminal being connected to a resistor R5 and then connected to the output terminal, the output terminal being connected to a single chip computer part (2), the output terminal being further connected to a capacitor C2 and then grounded.

4. The circuit structure of the motor protector according to claim 3 is characterized in that: The current collection circuit (12) comprises: A current transformer CT1, the current transformer CT1 having an input end and an output end, the input end being connected to an external motor, the output end being connected to a resistor R66 and then connected to a single chip computer part (2), and resistors R62 and R63 being connected in parallel to each other are connected between the resistor R66 and the output end, the resistor R66 being connected to a resistor R64 and then to a resistor R65 at one end relative to the current transformer CT1 and then to a relative ground, the node between the resistor R64 and the resistor R65 being connected to a capacitor C43 and then to a relative ground, and also being connected to the single chip computer part (2), the resistor R66 being connected to a capacitor C42 at one end relative to the output end of the current transformer CT1 and then to a relative ground.

5. The circuit structure of the motor protector according to any one of claims 1 to 4, characterized in that: The communication part (4) comprises: The communication chip U comprises a power supply terminal, a data input terminal and a data output terminal, wherein the data input terminal is connected to the single chip computer part (2), the data output terminal is connected to the host computer via a bus, the power supply terminal is connected to an inductor L and then connected to a power supply, and both ends of the inductor L are connected to capacitors and then grounded.

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