CN215728464U - Three-phase current detection circuit of motor comprehensive protector - Google Patents
Three-phase current detection circuit of motor comprehensive protector Download PDFInfo
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- CN215728464U CN215728464U CN202121589003.5U CN202121589003U CN215728464U CN 215728464 U CN215728464 U CN 215728464U CN 202121589003 U CN202121589003 U CN 202121589003U CN 215728464 U CN215728464 U CN 215728464U
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Abstract
The utility model relates to a three-phase current detection circuit of a motor comprehensive protector, which is characterized by comprising the following components: the phase-failure signal sampling circuit, the phase-failure signal negative voltage sampling circuit, the phase-failure negative voltage and overload signal voltage division circuit and the phase-failure signal gate circuit are electrically connected in sequence. The utility model relates to a three-phase current detection circuit of a motor comprehensive protector, which is characterized in that three single-winding current sensors are designed, and can complete the signal output of open-phase and overload protection; and the overload signal is the simultaneous detection of three-phase current, thus improving the function and the protection reliability of the protector and reducing the manufacturing cost of the protector.
Description
Technical Field
The utility model relates to the technical field of current detection, in particular to a three-phase current detection circuit of a comprehensive protector of a motor.
Background
At present, the same type of motor protector has the following characteristics: four current sensors are adopted, three of the four current sensors are responsible for phase loss detection, and one current sensor is responsible for overload detection, so that the cost is high. The overload current can only detect one of the three phases, and cannot be detected if the overload occurs in the other two phases. When the motor is not connected, the control circuit of the motor cannot be electrified and debugged, because the protector judges that the phase-lack fault exists when the three-phase current is 0. Some motor protectors use three current sensors, but each sensor has two sets of coil windings, adding complexity to the manufacturing process of the sensor and complexity to the assembly process of the protector.
Thus, significant advances in the art are needed.
SUMMERY OF THE UTILITY MODEL
The present invention provides a three-phase current detection circuit of a motor integrated protector, which includes:
the device comprises an overload signal sampling circuit, a phase-failure signal negative voltage sampling circuit, a phase-failure negative voltage and overload signal voltage division circuit which are electrically connected in sequence.
Preferably, the overload signal sampling circuit includes: current sensors LA, LB, LC, diodes D1, D2, D3, capacitor C1; one end of the current sensor LA is connected with one end of the current sensor LB and one end of the current sensor LC and both are grounded; the other end of the current sensor LA is connected with the anode of a diode D1, the other end of the current sensor LB is connected with the anode of a diode D2, and the other end of the current sensor LC is connected with the anode of a diode D3; the cathode of the diode D1 is connected to the cathodes of the diode D2 and the diode D3, and to one end of the capacitor C1.
Preferably, the phase-missing signal negative voltage sampling circuit includes: diodes D4, D5, and D6, and capacitors C2, C3, and C4, wherein the anode of diode D4 is connected to one end of capacitor C2, the anode of diode D5 is connected to one end of capacitor C3, the anode of diode D6 is connected to one end of capacitor C4, and the other end of capacitor C2 is connected to the other end of capacitor C3 and the other end of capacitor C4, respectively.
Preferably, the open-phase negative voltage and overload signal voltage division circuit includes: the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5 and the resistor R6 are connected, one end of the resistor R4 is connected with one end of the resistor R1, one end of the resistor R5 is connected with one end of the resistor R2, one end of the resistor R6 is connected with one end of the resistor R3, and the other end of the resistor R1 is connected with the other end of the resistor R2 and the other end of the resistor R3 respectively.
Preferably, the three-phase current detection circuit of the motor comprehensive protector further comprises a phase-lack signal gate circuit.
Preferably, the phase-missing signal gate circuit includes: diodes D7, D8, D9: the cathode of the diode D7 is connected to the cathode of the diode D8 and the cathode of the diode D9, respectively.
Preferably, the open-phase signal gate circuit further includes a resistor R7, one end of the resistor R7 is connected to the negative electrode of the diode D9, and the other end of the resistor R7 is grounded.
The three-phase current detection circuit of the motor comprehensive protector has the following beneficial effects: three single-winding current sensors are designed, and signal output of open-phase and overload protection can be completed; the overload signal is detected by three-phase current simultaneously, and can be effectively detected as long as one phase is overloaded, so that the function and the protection reliability of the protector are improved, and the manufacturing cost of the protector is reduced; the motor control circuit can also be debugged under the condition that the motor is not connected.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts. The utility model will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a circuit diagram of a three-phase current detection circuit of a motor integrated protector according to the present invention;
FIG. 2 is another circuit diagram of a three-phase current detection circuit of the motor integrated protector according to the present invention;
fig. 3 is another circuit diagram of the three-phase current detection circuit of the motor integrated protector.
Fig. 4 is a schematic diagram of the negative signal output of the three-phase current detection circuit of the motor comprehensive protector.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.
In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
Example one
Fig. 1 is a circuit diagram of a three-phase current detection circuit of a motor integrated protector according to the present invention. As shown in fig. 1, the three-phase current detection circuit of the integrated motor protector according to the first embodiment of the present invention at least includes an overload signal sampling circuit, a phase-defect signal negative voltage sampling circuit, a phase-defect negative voltage and overload signal voltage dividing circuit, which are electrically connected in sequence.
The overload signal sampling circuit includes: current sensors LA, LB, LC, diodes D1, D2, D3, capacitor C1; one end of the current sensor LA is connected with one end of the current sensor LA and one end of the current sensor LC and both are grounded; the other end of the current sensor LA is connected with the anode of a diode D1, the other end of the current sensor LB is connected with the anode of a diode D2, and the other end of the current sensor LC is connected with the anode of a diode D3; the cathode of the diode D1 is connected to the cathodes of the diode D2 and the diode D3, and to one end of the capacitor C1.
The phase-lacking signal negative voltage sampling circuit includes: diodes D4, D5, and D6, and capacitors C2, C3, and C4, wherein the anode of diode D4 is connected to one end of capacitor C2, the anode of diode D5 is connected to one end of capacitor C3, the anode of diode D6 is connected to one end of capacitor C4, and the other end of capacitor C2 is connected to the other end of capacitor C3 and the other end of capacitor C4, respectively. The open-phase negative voltage and overload signal voltage division circuit comprises: the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5 and the resistor R6 are connected, one end of the resistor R4 is connected with one end of the resistor R1, one end of the resistor R5 is connected with one end of the resistor R2, one end of the resistor R6 is connected with one end of the resistor R3, and the other end of the resistor R1 is connected with the other end of the resistor R2 and the other end of the resistor R3 respectively.
The other end of the capacitor C1 is connected to the other end of the capacitor C2, the other end of the capacitor C3, and the other end of the capacitor C4, respectively. The anode of the diode D4 is also connected to the other end of the resistor R4, the anode of the diode D5 is also connected to the other end of the resistor R5, and the anode of the diode D6 is also connected to the other end of the resistor R6. The cathode of the diode D1, the cathode of the diode D2 and the cathode of the diode D3 are connected with the other end of the resistor R1, the other end of the resistor R2 and the other end of the resistor R3. One end of the resistor R1 is also connected to the a-phase signal output, which is the a-phase signal. One end of the resistor R2 is also connected to the B-phase signal output, which is the B-phase signal. One end of the resistor R3 is also connected to the phase C signal, which is a phase C signal.
The working principle of the circuit is as follows: when the motor normally operates, three-phase currents respectively obtain alternating current voltage signals through LA, LB and LC current sensors, the voltage signals are not divided into phases, one path of the voltage signals is rectified by diodes D1, D2 and D3, and is filtered by a capacitor C1 to obtain direct current positive voltage, when the current of the motor is increased, the voltage is increased, and an output overload signal is strengthened. The other group is rectified by diodes D4, D5 and D6, and after being filtered by capacitors C2, C3 and C4, the other group respectively outputs three normal operation voltage signals with negative polarity relative to A, B, C phases, the three voltages are respectively connected in series by a resistor R1, resistors R4 and R2, resistors R5, R3 and R6 and then are connected to the positive voltage of an overload signal, after voltage division, A, B, C three-phase signals are respectively obtained, and when the motor works normally, the output voltage is lower or negative. When any phase is out of phase, the negative voltage disappears or weakens, and the divided signal voltage becomes high, thereby obtaining an out-of-phase signal. Thus, complete overload and three-way open-phase signals can be obtained. Because the output overload signal and the phase-lack signal are analog quantities, when the current of the motor is seriously unbalanced, the circuit also has the function of protecting the motor. When the motor is not connected, the overload and phase-lack signals are not output. The circuit can also be used for the open-phase protection of other three-phase electrical appliances.
Example two
Fig. 2 is a circuit diagram of a three-phase current detection circuit of a motor integrated protector according to the present invention. As shown in fig. 2, the phase-loss circuit at least comprises an overload signal sampling circuit, a phase-loss signal negative voltage sampling circuit, a phase-loss negative voltage and overload signal voltage division circuit and a phase-loss signal gate circuit which are electrically connected in sequence.
The overload signal sampling circuit includes: current sensors LA, LB, LC, diodes D1, D2, D3, capacitor C1; one end of the current sensor LA is connected with one end of the current sensor LB and one end of the current sensor LC and both are grounded; the other end of the current sensor LA is connected with the anode of a diode D1, the other end of the current sensor LB is connected with the anode of a diode D2, and the other end of the current sensor LC is connected with the anode of a diode D3; the cathode of the diode D1 is connected to the cathodes of the diode D2 and the diode D3, and to one end of the capacitor C1.
The phase-lacking signal negative voltage sampling circuit includes: diodes D4, D5, and D6, and capacitors C2, C3, and C4, wherein the anode of diode D4 is connected to one end of capacitor C2, the anode of diode D5 is connected to one end of capacitor C3, the anode of diode D6 is connected to one end of capacitor C4, and the other end of capacitor C2 is connected to the other end of capacitor C3 and the other end of capacitor C4, respectively. The open-phase negative voltage and overload signal voltage division circuit comprises: the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5 and the resistor R6 are connected, one end of the resistor R4 is connected with one end of the resistor R1, one end of the resistor R5 is connected with one end of the resistor R2, one end of the resistor R6 is connected with one end of the resistor R3, and the other end of the resistor R1 is connected with the other end of the resistor R2 and the other end of the resistor R3 respectively.
The phase-missing signal gate circuit includes: diodes D7, D8, D9: the cathode of the diode D7 is connected to the cathode of the diode D8 and the cathode of the diode D9, respectively.
The other end of the capacitor C1 is connected to the other end of the capacitor C2, the other end of the capacitor C3, and the other end of the capacitor C4, respectively. The anode of the diode D4 is also connected to the other end of the resistor R4, the anode of the diode D5 is also connected to the other end of the resistor R5, and the anode of the diode D6 is also connected to the other end of the resistor R6. The cathode of the diode D1, the cathode of the diode D2 and the cathode of the diode D3 are connected with the other end of the resistor R1, the other end of the resistor R2 and the other end of the resistor R3. One end of the resistor R1 is also connected to the anode of the diode D7, which is the a-phase signal. One end of the resistor R2 is also connected to the anode of the diode D8, which is a B-phase signal. One end of the resistor R3 is also connected to the anode of the diode D9, which is a C-phase signal. The negative electrodes of the diode D7, the diode D8 and the diode D9 are output as phase-loss signals. Resistor R7 is the open-phase signal load resistance (optional). The other end of the resistor R1, the other end of the resistor R2, and the other end of the resistor R3 are all overload signal outputs.
The working principle of the circuit is as follows: when the motor normally operates, three-phase currents respectively obtain alternating current voltage signals through LA, LB and LC current sensors, the voltage signals are not divided into phases, one path of the voltage signals is rectified by diodes D1, D2 and D3, and is filtered by a capacitor C1 to obtain direct current positive voltage, when the current of the motor is increased, the voltage is increased, and an output overload signal is strengthened. The other group is rectified by diodes D4, D5 and D6, and after being filtered by capacitors C2, C3 and C4, the other group respectively outputs three normal operation voltage signals with negative polarity relative to A, B, C phases, the three voltages are respectively connected in series by a resistor R1, resistors R4 and R2, resistors R5, R3 and R6 and then are connected to the positive voltage of an overload signal, after voltage division, A, B, C three-phase signals are respectively obtained, and when the motor works normally, the output voltage is lower or negative. When any phase is out of phase, the negative voltage disappears or weakens, and the divided signal voltage becomes high, thereby obtaining an out-of-phase signal. Thus, complete overload and three-way open-phase signals can be obtained. The or gate circuit composed of diodes D7, D8 and D9 is used to output the phase-lacking signal after the three signals are collected together. Because the output overload signal and the phase-lack signal are analog quantities, when the current of the motor is seriously unbalanced, the circuit also has the function of protecting the motor. When the motor is not connected, the overload and phase-lack signals are not output. The circuit can also be used for the open-phase protection of other three-phase electrical appliances.
EXAMPLE III
Fig. 3 is a circuit diagram of a three-phase current detection circuit of a motor integrated protector according to the present invention. As shown in fig. 3, the phase-loss circuit at least comprises an overload signal sampling circuit, a phase-loss signal negative voltage sampling circuit, a phase-loss negative voltage and overload signal voltage dividing circuit and a phase-loss signal gate circuit which are electrically connected in sequence.
The overload signal sampling circuit includes: current sensors LA, LB, LC, diodes D1, D2, D3, capacitor C1; one end of the current sensor LA is connected with one end of the current sensor LB and one end of the current sensor LC and both are grounded; the other end of the current sensor LA is connected with the anode of a diode D1, the other end of the current sensor LB is connected with the anode of a diode D2, and the other end of the current sensor LC is connected with the anode of a diode D3; the cathode of the diode D1 is connected to the cathodes of the diode D2 and the diode D3, and to one end of the capacitor C1.
The phase-lacking signal negative voltage sampling circuit includes: diodes D4, D5, and D6, and capacitors C2, C3, and C4, wherein the anode of diode D4 is connected to one end of capacitor C2, the anode of diode D5 is connected to one end of capacitor C3, the anode of diode D6 is connected to one end of capacitor C4, and the other end of capacitor C2 is connected to the other end of capacitor C3 and the other end of capacitor C4, respectively. The open-phase negative voltage and overload signal voltage division circuit comprises: the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5 and the resistor R6 are connected, one end of the resistor R4 is connected with one end of the resistor R1, one end of the resistor R5 is connected with one end of the resistor R2, one end of the resistor R6 is connected with one end of the resistor R3, and the other end of the resistor R1 is connected with the other end of the resistor R2 and the other end of the resistor R3 respectively.
The phase-missing signal gate circuit includes: diodes D7, D8, D9: the cathode of the diode D7 is connected to the cathode of the diode D8 and the cathode of the diode D9, respectively.
The difference from the first embodiment is that the open-phase signal gate circuit further includes a resistor R7, one end of the resistor R7 is connected to the negative electrode of the diode D9, and the other end of the resistor R7 is grounded.
The other end of the capacitor C1 is connected to the other end of the capacitor C2, the other end of the capacitor C3, and the other end of the capacitor C4, respectively. The anode of the diode D4 is also connected to the other end of the resistor R4, the anode of the diode D5 is also connected to the other end of the resistor R5, and the anode of the diode D6 is also connected to the other end of the resistor R6. The cathode of the diode D1, the cathode of the diode D2 and the cathode of the diode D3 are connected with the other end of the resistor R1, the other end of the resistor R2 and the other end of the resistor R3. One end of the resistor R1 is also connected to the anode of the diode D7, and this signal is an a-phase open-phase signal. One end of the resistor R2 is also connected to the anode of the diode D8, and this signal is a phase-B open-phase signal. One end of the resistor R3 is also connected to the anode of the diode D9, and this signal is a C-phase open-phase signal. The cathode of the diode D7, the cathode of the diode D8 and the cathode of the diode D9 are all open-phase signal outputs. The other end of the resistor R1, the other end of the resistor R2, and the other end of the resistor R3 are all overload signal outputs.
The working principle of the circuit is as follows: when the motor normally operates, three-phase current respectively obtains voltage signals through LA, LB and LC current sensors, the voltage of the signals is not divided into phases, one path of the signals is rectified by diodes D1, D2 and D3, and the signals are filtered by a capacitor C1 to obtain direct-current positive voltage, when the current of the motor is increased, the voltage is increased along with the current, and the output overload signal is strengthened. The other group is rectified by diodes D4, D5 and D6, voltage signals with negative polarity of three paths relative to A, B, C phases are respectively output after being filtered by capacitors C2, C3 and C4, the voltage signals are respectively connected in series with resistors R1, R4 and R2 and resistors R5, R3 and R6 and then connected to the positive voltage of an overload signal, A, B, C three-phase signals are respectively obtained after voltage division, and when the motor normally works, the output voltage is lower or negative. When any phase is in phase loss, the negative voltage or the low voltage of the phase disappears, the voltage of the voltage signal after voltage division becomes high, three-way phase loss signals are obtained, and complete overload and three-way phase loss signals can be obtained. The or gate circuit composed of diodes D7, D8 and D9 is used to output the phase-lacking signal after the three signals are collected together. Because the output overload signal and the phase-lack signal are analog quantities, when the current of the motor is seriously unbalanced, the circuit also has the function of protecting the motor. When the motor is not connected, the overload and phase-lack signals are not output, so that the motor control circuit can be debugged under the condition of not connecting the motor. The circuit can also be used for the open-phase protection of other three-phase electrical appliances.
Fig. 4 is a schematic diagram of the negative signal output of the three-phase current detection circuit of the motor comprehensive protector. As shown in fig. 4, the difference from fig. 3 is that the negative signal is output, i.e., reversed polarity schematic diagram, and the polarity of the output signal is changed because the diode is reversed, but the protection function is the same.
Through the design of the above embodiment, the utility model has the beneficial effects that: three single-winding current sensors are designed, and signal output of open-phase and overload protection can be completed; and the overload signal is detected by three-phase current simultaneously, so that the overload signal can be effectively detected as long as one phase is overloaded, the function and the protection reliability of the protector are improved, and the manufacturing cost of the protector is reduced. The motor control circuit can also be debugged under the condition that the motor is not connected.
While the utility model has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the utility model. In addition, many modifications may be made to adapt a particular situation to the teachings of the utility model without departing from its scope. Therefore, it is intended that the utility model not be limited to the particular embodiments disclosed, but that the utility model will include all embodiments falling within the scope of the appended claims.
Claims (7)
1. A three-phase current detection circuit of a motor comprehensive protector is characterized by comprising: the device comprises an overload signal sampling circuit, a phase-failure signal negative voltage sampling circuit, a phase-failure negative voltage and overload signal voltage division circuit which are electrically connected in sequence.
2. The motor protector three-phase current detection circuit as claimed in claim 1, wherein the overload signal sampling circuit comprises: current sensors LA, LB, LC, diodes D1, D2, D3, capacitor C1; one end of the current sensor LA is connected with the LB end of the current sensor and one end of the current sensor LC and both are grounded; the other end of the current sensor LA is connected with the anode of a diode D1, the other end of the current sensor LB is connected with the anode of a diode D2, and the other end of the current sensor LC is connected with the anode of a diode D3; the cathode of the diode D1 is connected to the cathodes of the diode D2 and the diode D3, and to one end of the capacitor C1.
3. The three-phase current detection circuit of the motor comprehensive protector as claimed in claim 1, wherein the open-phase signal negative voltage sampling circuit comprises: diodes D4, D5, and D6, and capacitors C2, C3, and C4, wherein the anode of diode D4 is connected to one end of capacitor C2, the anode of diode D5 is connected to one end of capacitor C3, the anode of diode D6 is connected to one end of capacitor C4, and the other end of capacitor C2 is connected to the other end of capacitor C3 and the other end of capacitor C4, respectively.
4. The motor protector three-phase current detection circuit as claimed in claim 1, wherein the open-phase negative voltage and overload signal voltage division circuit comprises: the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5 and the resistor R6 are connected, one end of the resistor R4 is connected with one end of the resistor R1, one end of the resistor R5 is connected with one end of the resistor R2, one end of the resistor R6 is connected with one end of the resistor R3, and the other end of the resistor R1 is connected with the other end of the resistor R2 and the other end of the resistor R3 respectively.
5. The motor protector three-phase current detection circuit of claim 1 further comprising a phase-loss signal gate circuit.
6. The motor protector three-phase current detection circuit as claimed in claim 5, wherein the open-phase signal gate circuit comprises: diodes D7, D8, and D9, and the cathode of diode D7 is connected to the cathode of diode D8 and the cathode of diode D9, respectively.
7. The three-phase current detection circuit of the motor comprehensive protector as claimed in claim 5, wherein the open-phase signal gate circuit further comprises a resistor R7, one end of the resistor R7 is connected with the cathode of the diode D9, and the other end of the resistor R7 is grounded.
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| CN202121589003.5U CN215728464U (en) | 2021-07-13 | 2021-07-13 | Three-phase current detection circuit of motor comprehensive protector |
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| CN202121589003.5U CN215728464U (en) | 2021-07-13 | 2021-07-13 | Three-phase current detection circuit of motor comprehensive protector |
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