CN112993941B - Motor overload protection circuit - Google Patents
Motor overload protection circuit Download PDFInfo
- Publication number
- CN112993941B CN112993941B CN202110459804.8A CN202110459804A CN112993941B CN 112993941 B CN112993941 B CN 112993941B CN 202110459804 A CN202110459804 A CN 202110459804A CN 112993941 B CN112993941 B CN 112993941B
- Authority
- CN
- China
- Prior art keywords
- resistor
- triode
- operational amplifier
- power supply
- power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
- H02H7/085—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against excessive load
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K13/00—Thermometers specially adapted for specific purposes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/30—Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/34—Testing dynamo-electric machines
- G01R31/343—Testing dynamo-electric machines in operation
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
- H02P29/02—Providing protection against overload without automatic interruption of supply
- H02P29/024—Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
- Protection Of Generators And Motors (AREA)
Abstract
The overload protection circuit of the motor of the invention, the overload detection circuit enters the current signal/temperature signal detected when the motor runs into the comparator and compares with the current/temperature setting value during overload, the current signal/temperature signal is output after time accumulation enters the integrator, and the average value of the current signal and the temperature signal after comparison is calculated by the averager, the overload detection circuit respectively calculates the difference value of the rated power of the motor, the power supply power and the load power through two comparators, whether the motor is abnormal is judged through the output voltage of the complementary symmetrical circuit, the overload protection trigger circuit judges whether the integrator signal is abnormal through an OR gate circuit, the overload and change rate signal is high, when the power supply power and the load power are normal, the overload protection is triggered, wherein the average value signal output by the averager is taken as the power supply of the trigger circuit, the signal after time accumulation of the first integrator, and the power supply power abnormal signal are fed back to the trigger circuit, the conduction speed of the trigger circuit is changed, and the unnecessary overload protection is avoided.
Description
Technical Field
The invention relates to the technical field of motor protection, in particular to a motor overload protection circuit.
Background
The motor overload means that the general motor has a fixed running power, called rated power, and the unit is watt (W), and if the actual using power of the motor exceeds the rated power of the motor under certain conditions (mechanical jamming, bearing abrasion, low power supply voltage, high loaded power and the like), the phenomenon is called motor overload.
The motor can cause the body to generate heat seriously when overloading, the current exceeds the rated current, abnormal vibration and sound are produced, the rotating speed is reduced, the phenomenon of locked rotor appears when the motor is serious, the insulation damage can be caused, the service life is influenced, and even the motor is burnt out.
Disclosure of Invention
In view of the above situation, an object of the present invention is to provide an overload protection circuit for a motor, which can analyze the cause of overload and adjust the cause in time to avoid unnecessary overload protection.
The technical scheme includes that the overload protection circuit comprises an overload detection circuit, an overload detection circuit and an overload protection trigger circuit, wherein the overload detection circuit enables a detected current signal when a motor runs to enter a first comparator to be compared with a current setting value when the motor runs, one path of the detected current signal enters a mean value device, the other path of the detected current signal enters a first integrator to carry out time accumulation on the compared signal and then outputs the compared signal, a detected temperature signal when the motor runs enters a second comparator to be compared with the temperature setting value when the motor runs, the other path of the detected temperature signal enters the mean value device to calculate the average value output of the compared current signal and temperature signal, the other path of the detected temperature signal enters a second integrator to carry out time accumulation on the compared signal and then outputs the compared signal, the overload detection circuit respectively calculates the difference values of the rated power of the motor, the power supply power and the load power through a comparator taking an operational amplifier AR5 as a core and a comparator taking an operational amplifier AR6 as a core, the difference signal triggers a complementary symmetrical circuit composed of triodes Q5 and Q6 and a complementary symmetrical circuit output voltage composed of triodes Q7 and Q8 respectively to judge whether the power supply power and the load power are abnormal, the overload protection triggering circuit judges whether the signal is abnormal after the time accumulation of a first integrator and a second integrator through the on-off voltage of an OR gate circuit composed of a triode Q1 and a triode Q2, when the signal is abnormal, a +5V trigger thyristor VS1 is conducted, a photoelectric coupler U2 is conducted, the triggering circuit composed of a unijunction transistor T2 as a core is conducted, a triode Q3 is conducted, the +5V is added to a pin 1 of the photoelectric coupler U1, a pin 2 of the photoelectric coupler U1 is connected with a low level through a NAND gate-gate U3 logic operation when the power supply power and the load power are normal, the photoelectric coupler U1 is conducted, and overload protection is triggered, the power supply power and the load power are normal, when the load power is abnormal, the power supply power compensation and the load control are respectively driven, wherein an average value signal output by the averager supplies power to the trigger circuit, and a signal obtained after the time of the first integrator is accumulated, the power supply power and the load power abnormal signal change the conduction speed of the trigger circuit, so that the conduction in an inverse time limit mode according to the overload degree is realized.
The invention has the beneficial effects that: the method comprises the steps that 1, a detected current signal/temperature signal during the operation of a motor enters a first/second comparator to be compared with a current/temperature setting value during overload, a difference signal is positive, a first/second integrator outputs the compared signal after time accumulation, and the average value of the compared current signal and the compared temperature signal is calculated through a mean value device to be output, so that the overload detection precision is improved; the difference values of the rated power of the motor, the power supply power and the load power are respectively calculated through a comparator taking the operational amplifier AR5 as a core and a comparator taking the operational amplifier AR6 as a core, and the difference value signals trigger a complementary symmetrical circuit consisting of the triodes Q5 and Q6 and a complementary symmetrical circuit consisting of the triodes Q7 and Q8 to output voltages so as to judge whether the power supply power and the load power are abnormal or not.
2, judging whether the signals are abnormal after the time accumulation of the first integrator and the second integrator by the conducting and stopping voltage of an OR gate circuit consisting of a triode Q1 and a triode Q2, when the overload is generated and the change rate signal is high, turning on a trigger thyristor VS1 at +5V, turning on a photoelectric coupler U2, immediately turning on a trigger circuit, turning on a triode Q3, adding +5V to a pin 1 of the photoelectric coupler U1, when the power supply and the load power are normal by the pin 2 of the photoelectric coupler U1, namely when the two input ends of the NAND gate U3 are both high, performing logic operation of the NAND gate U3 to access a low level, turning on the photoelectric coupler U1 to trigger overload protection, and respectively driving to perform power supply power compensation and load control when the power supply and the load power are abnormal, wherein the average value signal output by the mean value device supplies power to the trigger circuit, the higher the value is, the faster the trigger circuit is conducted, the signal is added to the negative electrode of the variable capacitance diode VD1 after the time of the first integrator is accumulated, a reverse bias voltage is provided, the size of the junction capacitance of the variable capacitance diode VD1 is changed, the charging time of the resistor R17, the variable capacitance diode VD1 and the capacitance C6 is changed, namely the conduction speed of the trigger circuit is changed, a power supply power and/or load power abnormal signal is fed back to the grid electrode of the field effect tube T1, the conduction speed of the trigger circuit is changed, when the power supply power and/or the load power are abnormal, power supply power compensation and load control are preferentially carried out, the effect of delaying the conduction or non-conduction of the trigger circuit is achieved, the overload reason caused by the analysis can be analyzed and the adjustment is carried out in time, the unnecessary overload protection is avoided, and the working quality and the working efficiency are improved.
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 embodiments or the description of 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 drawings without creative efforts.
Fig. 1 is a schematic circuit diagram of the present invention.
Detailed Description
The foregoing and other technical and other features and advantages of the invention will be apparent from the following more particular description of the embodiments of the invention, as illustrated in the accompanying drawings in which reference is made to FIG. 1. The structural contents mentioned in the following embodiments are all referred to the attached drawings of the specification.
Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.
In the first embodiment, the overload protection circuit of the motor comprises an overload detection circuit, an overload detection circuit and an overload protection trigger circuit, wherein the overload detection circuit enables a detected current signal when the motor runs to enter a first comparator after resistance-capacitance filtering and bidirectional amplitude limiting, the current signal is compared with a current setting value when the motor runs, when a difference signal is positive, the current signal passes through a unidirectional conductive diode D9, one path of the current signal enters an averaging device, the other path of the current signal enters a first integrator to perform time accumulation on the compared signal and then output, the detected temperature signal when the motor runs enters a second comparator after the resistance-capacitance filtering and the bidirectional amplitude limiting, the temperature signal is compared with the temperature setting value when the motor runs, a feedback resistor R12A is arranged for amplitude modulation, the amplitude modulation is started until the same current signal and temperature signal amplitude reflect the overload degree of the motor, when the difference signal is positive, the current signal passes through a unidirectional conductive diode D10, and then one path of the current signal enters the averaging device, calculating the average value output of the compared current signal and temperature signal, improving the overload detection precision, and outputting the compared signal after the other path enters a second integrator to accumulate the time, wherein the overload detection circuit calculates the difference value between the rated power of the motor and the power of the power supply through a comparator consisting of an operational amplifier AR5 and a resistor R24-a resistor R26, the difference value signal triggers the output voltage of a complementary symmetrical circuit consisting of triodes Q5 and Q6 to judge whether the power of the power supply is abnormal, namely when the power of the power supply is higher than the lowest allowance of the rated power of the motor, the triode Q6 is conducted, 5V is added to a pin A of a NAND gate U3, when the power of the power supply is lower than the lowest allowance of the rated power of the motor, the triode Q5 is conducted, 3V is fed back to an overload protection trigger circuit, and the difference value between the rated power of the motor and the load power is calculated through the comparator consisting of the operational amplifier AR6 and the resistor R30-a resistor R31, the difference signal triggers the output voltage of a complementary symmetrical circuit consisting of a triode Q7 and a triode Q8 respectively to judge whether the load power is abnormal, namely when the rated power of a motor is higher than the lowest allowance of the load power, the triode Q8 is conducted, +5V is added to a pin B of a NAND gate U3, when the rated power of the motor is lower than the lowest allowance of the load power, the triode Q7 is conducted, -3V is fed back to an overload protection trigger circuit for judging whether the motor is overloaded caused by a power supply and a load, the overload protection trigger circuit judges whether signals are abnormal after time accumulation of a first integrator and a second integrator through the conducting and stopping voltage of an OR gate circuit consisting of the triode Q1 and the triode Q2, and when the overload protection trigger circuit is abnormal, namely when the overload and the change rate signal is high, the +5V trigger thyristor VS1 is conducted, a photoelectric coupler U2 is conducted, and a trigger circuit consisting of the unijunction transistor T2, a resistor R17-a resistor R19, a varactor VD1, a capacitor C6 and a field effect tube T1 which are connected in series is immediately conducted, the triode Q3 is conducted, 5V is added to a pin 1 of a photoelectric coupler U1, when a pin 2 of the photoelectric coupler U1 is normal in power supply power and load power, namely when two input ends of a NAND gate U3 are both high level, the NAND gate U3 is logically operated to be connected with low level, the photoelectric coupler U1 is conducted, namely power supply power and load power are eliminated, overload protection is triggered when faults such as mechanical jamming and the like can not be eliminated by adjusting the power supply power and the load power and motor overload can not be eliminated, when the power supply power and the load power are abnormal, power supply power compensation and load control are respectively driven to be carried out, wherein an average value signal output by a mean value device is used for supplying power to a trigger circuit, the higher the value of the average value is, the conduction of the trigger circuit is faster, a signal after the time of a first integrator is accumulated is added to the negative pole of a variable capacitance diode VD1, the method comprises the steps of providing reverse bias voltage, changing the size of a junction capacitor of a variable capacitance diode VD1, changing the charging time of a resistor R17, the variable capacitance diode VD1 and a capacitor C6, namely changing the conduction speed of a trigger circuit, feeding a power supply power and/or load power abnormal signal back to a grid electrode of a field effect transistor T1, changing the resistance value between a drain and a source of the field effect transistor T1, changing the charging time of the resistor R17, the variable capacitance diode VD1 and the capacitor C6, further changing the conduction speed of the trigger circuit, preferentially compensating the power supply power and controlling the load when the power supply power and/or the load power are abnormal, playing a role in delaying the conduction or non-conduction of the trigger circuit, analyzing the overload reason caused by the overload and adjusting the overload reason in time, avoiding unnecessary overload protection, and improving the working quality and the working efficiency.
In the second embodiment, on the basis of the first embodiment, the overload detection circuit detects a current signal (current detected by a current transformer, and the current is converted into voltage through a resistor and a reactance converter) when the motor operates, the detected current signal enters a first comparator consisting of an operational amplifier AR1, a resistor R2 and a voltage regulator tube SZ1 after being subjected to resistance-capacitance filtering by a resistor R1 and a capacitor C1, and a diode D1 and a diode D2 after being subjected to bidirectional amplitude limiting, the detected current signal is compared with a current setting value (provided by a resistor R2 and a voltage regulator tube SZ1 voltage division circuit) when the motor operates, if a difference signal is positive, the difference signal passes through a diode D9 conducting in a unidirectional manner, then one path of the difference signal enters an averaging device consisting of the operational amplifier AR7, the resistor R7-resistor R10, the capacitor C3 and a capacitor C4, and the other path of the difference signal enters a first integrator consisting of the operational amplifier AR2, the resistor R3-resistor R5 and the capacitor C2 to accumulate the time of the compared signal and output the compared signal, the temperature signal (which can be a temperature sensor such as a PTC thermistor) detected when the motor runs is subjected to resistance-capacitance filtering by a resistor R11 and a capacitor C7, and a diode D3 and a diode D4 are subjected to bidirectional amplitude limiting and then enter a second comparator consisting of an operational amplifier AR3, a resistor R12, a voltage regulator tube SZ2 and a resistor R12A to be compared with a temperature setting value (provided by a voltage divider circuit of the resistor R12 and the voltage regulator tube SZ 2) during overload, wherein a feedback resistor R12A is arranged for amplitude modulation, the same current signal and temperature signal amplitude reflect the overload degree of the motor, a difference signal is positive and then enters an averaging device consisting of the operational amplifier AR7, a resistor R7-a resistor R10 and the capacitors C3 and C4 through a diode D10 conducting in a unidirectional mode, one path of the current signal and temperature signal after comparison is calculated, the average value of the current signal and the temperature signal after comparison is output, and the other path of the current signal and temperature signal after comparison enters the operational amplifier AR4, the resistor R13, the resistor R14, the second integrator consisting of a resistor R16 and a capacitor C2 is used for accumulating time and outputting a compared signal, and comprises a resistor R1 and a resistor R11, wherein the left end of the resistor R1 is connected with a current signal, the other end of the resistor R1 is respectively connected with one end of a grounded capacitor C1, the anode of a diode D1, the cathode of a diode D2 and the non-inverting input end of an operational amplifier AR1, the cathode of the diode D1 is connected with a power supply +12V, the anode of the diode D2 is connected with the ground, the inverting input end of the operational amplifier AR1 is respectively connected with one end of a resistor R2 and the cathode of a voltage regulator tube SZ1, the other end of the resistor R2 is connected with a power supply +5V, the anode of the voltage regulator tube SZ1 is connected with the ground, the output end of the operational amplifier AR1 is connected with the anode of a diode D9, the cathode of the diode D9 is respectively connected with one end of a resistor R4, one end of a grounded capacitor C3 and one end of a resistor R7, the other end of the resistor R4 is respectively connected with the inverting input end of the operational amplifier AR2, the non-inverting input end of the operational amplifier AR2 is connected with one end of a grounding resistor R5, the output end of the operational amplifier AR2 is connected with the other end of a resistor R3 and the other end of a capacitor C2, the left end of a resistor R11 is connected with a temperature signal, the other end of the resistor R11 is respectively connected with one end of a grounding capacitor C7, the anode of a diode D3, the cathode of a diode D4 and the non-inverting input end of the operational amplifier AR3, the cathode of the diode D3 is connected with a power supply +12V, the anode of the diode D4 is connected with the ground, the inverting input end of the operational amplifier AR3 is respectively connected with one end of a resistor R12, the cathode of a voltage regulator tube SZ2 and one end of a resistor R12A, the other end of a resistor R12V is connected with the cathode of the resistor R12V, the anode of the voltage regulator tube SZ2 is connected with the ground, the output end of the operational amplifier AR3 is respectively connected with the other end of a resistor R12A and the anode of a diode D10, the cathode of a diode D10 is respectively connected with one end of a resistor R9, the cathode of the voltage regulator, one end of a grounded capacitor C4 and one end of a resistor R13, the other end of the resistor R13 is respectively connected with the inverting input end of an operational amplifier AR4, one end of a resistor R16 and one end of a capacitor C8, the non-inverting input end of the operational amplifier AR4 is connected with one end of a grounded resistor R14, the output end of the operational amplifier AR4 is connected with the other end of the resistor R16 and the other end of the capacitor C8, the non-inverting input end of the operational amplifier AR7 is connected with one end of a grounded resistor R10, the other end of the resistor R7 is respectively connected with one end of the resistor R8, the other end of the resistor R9 and the inverting input end of the operational amplifier AR7, and the other end of the resistor R8 is connected with the output end of the operational amplifier AR 7.
In a third embodiment, based on the first embodiment, the overload detection circuit calculates the difference between the rated power of the motor and the power supply power (which can be measured by a power measuring instrument, or the power supply voltage is measured by a voltmeter, and the power supply current is measured by an ammeter, and the product is calculated, which is the prior art, and is not described in detail herein), the difference signal triggers the output voltage of the complementary symmetric circuit composed of the transistors Q5 and Q6 to determine whether the power supply power is abnormal, that is, when the power supply power is higher than the lowest margin of the rated power of the motor, the transistor Q6 is turned on, and +5V is added to the pin a of the nand gate U3, and when the power supply power is lower than the lowest margin of the rated power of the motor (usually, the lowest margin value can be determined according to the type of the power supply, the motor, and the loss of the motor), the transistor Q5 is turned on, -3V is fed back to the overload protection trigger circuit, a comparator composed of an operational amplifier AR6 and a resistor R30-a resistor R31 is used to calculate a difference between a rated power of the motor and a load power (an actual power of a load device dragged by the motor can be measured by a power measuring instrument), the difference signal triggers an output voltage of a complementary symmetrical circuit composed of transistors Q7 and Q8 respectively to judge whether the load power is abnormal, that is, when the rated power of the motor is higher than a lowest margin of the load power, the transistor Q8 is conducted, +5V is added to a pin B of the nand gate U3, when the rated power of the motor is lower than the lowest margin of the load power, the transistor Q7 is conducted, -3V is fed back to the overload protection trigger circuit to judge whether the motor is overloaded by the power supply and the load, the overload protection trigger circuit comprises an operational amplifier AR5 and an operational amplifier AR6, an inverting input terminal of the operational amplifier AR5 is connected with one end of a resistor R24 respectively, one end of a resistor R25, the other end of a resistor R24 and the other end of a resistor R30 are connected with the rated power of the motor, the non-inverting input end of an operational amplifier AR5 and one end of a grounding resistor R26 are connected with the power supply power, the output end of the operational amplifier AR5 is respectively connected with the other end of the resistor R25 and one end of a resistor R27, the other end of the resistor R27 is respectively connected with the base electrode of a triode Q6 and the base electrode of the triode Q5, the collector electrode of the triode Q6 is connected with +5V, the emitter electrode of the triode Q6 is connected with the emitter electrode of the triode Q5, the collector electrode of the triode Q5 is connected with-3V, one end of the resistor R30 is respectively connected with one end of a resistor R31 and the inverting input end of the operational amplifier AR6, the non-inverting input end of the operational amplifier AR6 and one end of a grounding resistor R33 are connected with the load power, the output end of the operational amplifier AR6 is respectively connected with the other end of the resistor R31 and one end of the resistor R32, the other end of the resistor R32 is respectively connected with the base electrode of the triode Q8 and the base electrode of the triode Q7, the collector electrode of the triode Q8 is connected with the collector electrode of the triode Q7.
In the fourth embodiment, on the basis of the first embodiment, the overload protection trigger circuit judges whether the signal is abnormal after the time accumulation of the first integrator and the second integrator through the conducting and stopping voltage of the or gate circuit formed by the triode Q1 and the triode Q2, when the signal is abnormal, the +5V triggers the thyristor VS1 to conduct, the +5V is added to the pin 1 of the photoelectric coupler U2, the photoelectric coupler U2 conducts, the unijunction transistor T2, the resistor R17-the resistor R19, the serially connected varactor VD1, the capacitor C6 and the field effect transistor T1 conduct immediately, the triode Q3 conducts, the +5V is added to the pin 1 of the photoelectric coupler U1, when the pin 2 of the photoelectric coupler U1 is in normal power and load power, that is, when both input ends of the nand gate U3 are in high power, the logical operation of the nand gate U3 is switched into low level, the photoelectric coupler U1 conducts, namely, when the power supply power and the load power are abnormal, the faults such as motor overload and mechanical jamming can not be eliminated by adjusting the power supply power and the load power, the overload protection is triggered, when the power supply power and the load power are abnormal, the power supply power compensation (for example, the power supply power factor compensation is carried out, which is the prior art, and is not detailed herein), and the load control (for example, the feeding equipment dragged by a load can adjust the feeding amount) are respectively driven to be carried out, wherein an average value signal output by an averager supplies power to a trigger circuit, the higher the value is, the faster the trigger circuit is conducted, a signal is added to the cathode of a variable capacitance diode VD1 after the time accumulation of a first integrator, the reverse bias voltage is provided, the size of the junction capacitance of the variable capacitance diode VD1 is changed, the charging time of a resistor R17, the variable capacitance diode VD1 and a capacitor C6 is changed, and the conduction speed of the trigger circuit is also changed, the power supply power and/or load power abnormal signal is fed back to the grid of the field effect transistor T1, the resistance value between the drain and the source of the field effect transistor T1 is changed, the charging time of the resistor R17, the variable capacitance diode VD1 and the capacitor C6 is changed, further, the conduction speed of the trigger circuit is changed, when the power supply power and/or the load power is abnormal, the power supply power compensation and the load control are preferentially carried out, the effect of delaying the conduction or non-conduction of the trigger circuit is achieved, the overload reason caused by the overload can be analyzed and timely adjusted, the unnecessary overload protection is avoided, the device comprises a triode Q1, a triode Q2 and a NOR gate U2, the base electrode of the triode Q1 is connected with the output end of an operational amplifier AR2 through the resistor R6, the base electrode of the triode Q2 is connected with the output end of the operational amplifier AR4 through a resistor R15, the collector electrode of the triode Q1 and the collector electrode of the triode Q2 are connected with +5V of a power supply, the emitter electrode of the triode Q1 is respectively connected with the emitter electrode of the triode Q2, one end of a ground resistor R16, one end of a ground capacitor C5 and the control electrode of a thyristor VS1, the anode of the thyristor VS1 is connected with +5V of the power supply, the cathode of the thyristor VS1 is connected with a pin 1 of a photoelectric coupler U2, the pin 2 of the photoelectric coupler U2 is connected with the ground, a pin 3 of the photoelectric coupler U2 is respectively connected with one end of a resistor R17, the anode of a variable capacitance diode VD1, the emitter electrode of a unijunction transistor T2 and the source electrode of a field effect tube T1, and the pin 4 is connected with +5V of the power supply through a resistor R17A; the negative electrode of the variable capacitance diode VD1 is respectively connected with one end of a grounding capacitor C6 and the base electrode of a triode Q1, the second base electrode of a unijunction transistor T2 is connected with one end of a resistor R18, the other end of the resistor R18, the other end of a resistor R17 and the drain electrode of a field effect tube T1 are connected with the output end of an operational amplifier AR7, the first base electrode of the unijunction transistor T2 is respectively connected with one end of a grounding resistor R19, the negative electrode of a voltage regulator SZ3 and the base electrode of the triode Q3, the positive electrode of the voltage regulator SZ3 is connected with the ground, the collector electrode of the triode Q3 is connected with a power supply +5V, the emitter electrode of the triode Q3 is respectively connected with one end of a grounding resistor R20 and the pin 1 of a photoelectric coupler U1, the pin 2 of the pin U1 is connected with the pin Y of a NAND gate U3, the pin A of the U3 is respectively connected with one end of a grounding resistor R28 and the negative electrode of a diode D6, the anode of the diode D6 is connected to the emitter of the transistor Q6 and one end of the resistor R29A, the other end of the resistor R29A is connected to the cathode of the diode D5, the anode of the diode D5 is connected to one end of the ground resistor R29, one end of the resistor R21, the anode of the diode D8, and one end of the ground resistor R35, the other end of the resistor R21 is connected to the anode of the electrolytic capacitor E1, the gate of the fet T1, one end of the ground resistor R21A, and one end of the resistor R21B, the other end of the resistor R21B is connected to the power supply +2V, the cathode of the electrolytic capacitor E1 is connected to ground, the pin B of the nand gate U3 is connected to one end of the ground resistor R34 and the cathode of the diode D7, the anode of the diode D7 is connected to the emitter of the transistor Q8 and one end of the resistor R35A, and the other end of the resistor R35A is connected to the cathode of the diode D8.
When the overload detection circuit is used, a detected current signal when the motor runs enters a first comparator after resistance-capacitance filtering and bidirectional amplitude limiting, the current signal is compared with a current setting value when the motor runs, if the difference signal is positive, the current signal passes through a diode D9 conducting in a unidirectional mode, one path of the current signal enters a mean device, the other path of the current signal enters a first integrator, the compared signal is subjected to time accumulation and then output, a detected temperature signal when the motor runs enters a second comparator after the resistance-capacitance filtering and bidirectional amplitude limiting, the temperature signal is compared with the temperature setting value when the motor runs, a feedback resistor R12A is arranged for amplitude modulation, the amplitude of the current signal and the temperature signal which are the same reflects the overload degree of the motor, if the difference signal is positive, the current signal passes through a diode D10 conducting in a unidirectional mode, one path of the current signal and the temperature signal enters the mean device, and the mean value of the current signal and the temperature signal after comparison is calculated and output, the overload detection circuit calculates the difference between the rated power of the motor and the power of the power supply through the comparator, the difference signal triggers the output voltage of a complementary symmetrical circuit consisting of triodes Q5 and Q6 to judge whether the power of the power supply is abnormal, namely when the power of the power supply is higher than the lowest allowance of the rated power of the motor, the triode Q6 is conducted, +5V is added to a pin A of a NAND gate U3, when the power of the power supply is lower than the lowest allowance of the rated power of the motor, the triode Q5 is conducted, -3V is fed back to the overload protection trigger circuit, the difference between the rated power of the motor and the load power is calculated through the comparator, the difference signal respectively triggers the output voltage of the complementary symmetrical circuit consisting of the triodes Q7 and Q8 to judge whether the load power is abnormal, namely when the rated power of the motor is higher than the lowest allowance of the load power, the triode Q8 is conducted, +5V is added to a pin B of a NAND gate U3, when the rated power of the motor is lower than the lowest allowance of the load power, the triode Q7 is conducted, -3V is fed back to an overload protection trigger circuit for judging whether the motor is overloaded due to power supply and load, the overload protection trigger circuit judges whether signals are abnormal after the time accumulation of a first integrator and a second integrator is carried out through the voltage after the conduction and the cut-off of an OR gate circuit, when the time accumulation of the first integrator and the second integrator is abnormal, the +5V triggers the conduction of a thyristor VS1 and the conduction of a photoelectric coupler U2, the trigger circuit is immediately conducted, the triode Q3 is conducted, +5V is added to a pin 1 of the photoelectric coupler U1, when the power supply and the load power are normal, namely when the two input ends of the NAND gate U3 are both high, the logical operation of the U3 is connected to low level, namely, the photoelectric coupler U1 is conducted, and the power supply power and the load power are abnormal, when the faults such as overload of a motor and mechanical jamming cannot be eliminated by adjusting power supply and load power, overload protection is triggered, and when the power supply and load power are abnormal, power supply power compensation and load control are respectively driven to be performed, wherein an average value signal output by an averager supplies power to a trigger circuit, the higher the value of the average value signal is, the faster the trigger circuit is conducted, a signal is added to the negative electrode of a variable capacitance diode VD1 after time accumulation of a first integrator to provide reverse bias voltage, the size of a junction capacitor of the variable capacitance diode VD1 is changed, the charging time of a resistor R17, the variable capacitance diode VD1 and a capacitor C6 is changed, namely the conduction speed of the trigger circuit is changed, a power supply power and/or load power abnormal signal is fed back to the grid electrode of a field effect tube T1, the resistance between the drain and the source of the field effect tube T1 is changed, and the resistance between the drain and the source of the resistor R17, the variable capacitance diode VD1, the drain and the source, the capacitor C6 is charged for a long time, so that the conduction speed of the trigger circuit is changed, when the power supply power and/or the load power are abnormal, the power supply power compensation and the load control are preferentially carried out, the effect of delaying the conduction or non-conduction of the trigger circuit is achieved, the overload reason caused by the overload can be analyzed and timely adjusted, and unnecessary overload protection is avoided.
Claims (1)
1. The overload protection circuit of the motor comprises an overload detection circuit, an overload detection circuit and an overload protection trigger circuit, and is characterized in that the overload detection circuit enables a detected current signal when the motor runs to enter a first comparator to be compared with an overload current setting value, one path of the detected current signal enters an averaging device, the other path of the detected current signal enters a first integrator to carry out time accumulation on the compared signal and then outputs the compared signal, a detected temperature signal when the motor runs enters a second comparator to be compared with the overload temperature setting value, the other path of the detected current signal enters the averaging device to calculate the average value output of the compared current signal and temperature signal, the other path of the detected current signal enters a second integrator to carry out time accumulation on the compared signal and then outputs the compared signal, the overload detection circuit respectively calculates the difference values of the rated power of the motor, the power supply power and the load power through a comparator taking an operational amplifier AR5 as a core and a comparator taking an operational amplifier AR6 as a core, the difference signal triggers a complementary symmetrical circuit composed of triodes Q5 and Q6 and a complementary symmetrical circuit output voltage composed of triodes Q7 and Q8 respectively to judge whether the power supply power and the load power are abnormal, the overload protection triggering circuit judges whether the signal is abnormal after the time accumulation of a first integrator and a second integrator through the on-off voltage of an OR gate circuit composed of a triode Q1 and a triode Q2, when the signal is abnormal, a +5V trigger thyristor VS1 is conducted, a photoelectric coupler U2 is conducted, so that a triggering circuit composed of a unijunction transistor T2 as a core is conducted, a triode Q3 is conducted, the +5V is added to a pin 1 of the photoelectric coupler U1, a pin 2 of the photoelectric coupler U1 is connected with a low level through a NAND gate U3 logic operation when the power supply power and the load power are normal, the photoelectric coupler U1 is conducted to trigger overload protection, when the power supply power and the load power are abnormal, the power supply power compensation and the load control are respectively driven, wherein an average value signal output by the averager supplies power to the trigger circuit, and a signal obtained after the time of the first integrator is accumulated, the power supply power and the load power abnormal signal change the conduction speed of the trigger circuit, so that the reverse time limit conduction according to the overload degree is realized;
wherein, the overload detection circuit comprises a resistor R1 and a resistor R11, the left end of the resistor R1 is connected with a current signal, the other end of the resistor R1 is respectively connected with one end of a grounding capacitor C1, the anode of a diode D1, the cathode of a diode D2 and the non-inverting input end of an operational amplifier AR1, the cathode of the diode D1 is connected with a power supply +12V, the anode of the diode D2 is connected with the ground, the inverting input end of the operational amplifier AR1 is respectively connected with one end of the resistor R2 and the cathode of a voltage-stabilizing tube SZ1, the other end of the resistor R2 is connected with the power supply +5V, the anode of the voltage-stabilizing tube SZ1 is connected with the ground, the output end of the operational amplifier AR1 is connected with the anode of a diode D9, the cathode of the diode D9 is respectively connected with one end of a resistor R4, one end of the grounding capacitor C3 and one end of a resistor R7, the other end of the resistor R4 is respectively connected with the inverting input end of the operational amplifier AR2, one end of the resistor R3 and one end of a capacitor C2, the non-inverting input end of the operational amplifier AR2 is connected with one end of a grounding resistor R5, the output end of the operational amplifier AR2 is connected with the other end of a resistor R3 and the other end of a capacitor C2, the left end of the resistor R11 is connected with a temperature signal, the other end of the resistor R11 is respectively connected with one end of a grounding capacitor C7, the anode of a diode D3, the cathode of a diode D4 and the non-inverting input end of the operational amplifier AR3, the cathode of the diode D3 is connected with a power supply +12V, the anode of the diode D4 is connected with the ground, the inverting input end of the operational amplifier AR3 is respectively connected with one end of a resistor R12, the cathode of a voltage regulator tube SZ2 and one end of a resistor R12A, the other end of a resistor R12V, the anode of a voltage regulator tube SZ2 is connected with the ground, the output end of the operational amplifier AR3 is respectively connected with the other end of a resistor R12A and the anode of a diode D10, the cathode of a diode D10 is respectively connected with one end of a resistor R9, one end of a grounding capacitor C4, the other end of a capacitor C4, one end of a resistor R13, the other end of the resistor R13 is connected with the inverting input end of the operational amplifier AR4, one end of a resistor R16 and one end of a capacitor C8 respectively, the non-inverting input end of the operational amplifier AR4 is connected with one end of a grounding resistor R14, the output end of the operational amplifier AR4 is connected with the other end of the resistor R16 and the other end of the capacitor C8, the non-inverting input end of the operational amplifier AR7 is connected with one end of a grounding resistor R10, the other end of the resistor R7 is connected with one end of the resistor R8, the other end of the resistor R9 and the inverting input end of the operational amplifier AR7 respectively, and the other end of the resistor R8 is connected with the output end of the operational amplifier AR 7;
the overload detection circuit comprises an operational amplifier AR5 and an operational amplifier AR6, wherein the inverting input end of the operational amplifier AR5 is respectively connected with one end of a resistor R24 and one end of a resistor R25, the other end of the resistor R24 and the other end of a resistor R30 are connected with the rated power of a motor, the non-inverting input end of the operational amplifier AR5 and one end of a grounding resistor R26 are connected with the power supply, the output end of the operational amplifier AR5 is respectively connected with the other end of the resistor R25 and one end of a resistor R27, the other end of the resistor R27 is respectively connected with the base electrode of a triode Q6 and the base electrode of the triode Q5, the collector electrode of the triode Q6 is connected with +5V, the emitter of the triode Q6 is connected with the emitter of the triode Q5, the collector of the triode Q5 is connected with a power supply of-3V, one end of a resistor R30 is respectively connected with one end of a resistor R31 and the reverse-phase input end of an operational amplifier AR6, the in-phase input end of the operational amplifier AR6 and one end of a grounding resistor R33 are connected with load power, the output end of the operational amplifier AR6 is respectively connected with the other end of the resistor R31 and one end of a resistor R32, the other end of the resistor R32 is respectively connected with the base of the triode Q8 and the base of the triode Q7, the collector of the triode Q8 is connected with the power supply of +5V, the emitter of the triode Q8 is connected with the emitter of the triode Q7, and the collector of the triode Q7 is connected with the power supply of-3V;
the overload protection trigger circuit comprises a triode Q1, a triode Q2 and a photoelectric coupler U2; the base electrode of the triode Q1 is connected with the output end of the operational amplifier AR2 through a resistor R6, the base electrode of the triode Q2 is connected with the output end of the operational amplifier AR4 through a resistor R15, the collector electrode of the triode Q1 and the collector electrode of the triode Q2 are connected with a power supply +5V, the emitter electrode of the triode Q1 is respectively connected with the emitter electrode of the triode Q2, one end of a grounding resistor R16, one end of a grounding capacitor C5 and the control electrode of a thyristor VS1, the anode of the thyristor VS1 is connected with the power supply +5V, the cathode of the thyristor VS1 is connected with a pin 1 of a photoelectric coupler U2, the pin 2 of the photoelectric coupler U2 is connected with the ground, a pin 3 of the photoelectric coupler U2 is respectively connected with one end of a resistor R17, the anode of a varactor VD1, the emitter electrode of a unijunction transistor T2 and the source electrode of a field effect transistor T1, and the pin 4 is connected with the power supply +5V through a resistor R17A; the negative electrode of the varactor VD1 is respectively connected with one end of a grounding capacitor C6 and the base electrode of a triode Q1, the second base electrode of a unijunction transistor T2 is connected with one end of a resistor R18, the other end of the resistor R18, the other end of a resistor R17 and the drain electrode of a field effect transistor T1 are connected with the output end of an operational amplifier AR7, the first base electrode of the unijunction transistor T2 is respectively connected with one end of a grounding resistor R19, the negative electrode of a voltage regulator SZ3 and the base electrode of a triode Q3, the positive electrode of the voltage regulator SZ3 is connected with the ground, the collector electrode of the triode Q3 is connected with a power supply +5V, the emitter electrode of the triode Q3 is respectively connected with one end of a grounding resistor R20 and the pin 1 of a photoelectric coupler U1, the pin 2 of the NAND gate U1 is connected with the pin Y of the NAND gate U3, the pin A of the U3 is respectively connected with one end of a grounding resistor R28 and the negative electrode of a diode D6, the positive electrode of the diode D6 is connected with the emitting electrode of the triode Q6 and one end of the resistor R29A, the other end of the resistor R29A is connected with the negative electrode of the diode D5, the positive electrode of the diode D5 is respectively connected with one end of the grounding resistor R29, one end of the resistor R21, the positive electrode of the diode D8 and one end of the grounding resistor R35, the other end of the resistor R21 is respectively connected with the positive electrode of the electrolytic capacitor E1, the grid electrode of the field effect tube T1, one end of the grounding resistor R21A and one end of the resistor R21B, the other end of the resistor R21B is connected with the power supply +2V, the negative electrode of the electrolytic capacitor E1 is connected with the ground, the pin B of the NAND gate U3 is respectively connected with one end of the grounding resistor R34 and the negative electrode of the diode D7, the positive electrode of the diode D7 is connected with the emitting electrode of the triode Q8 and one end of the resistor R35A, and the other end of the resistor R35A is connected with the negative electrode of the diode D8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110459804.8A CN112993941B (en) | 2021-04-27 | 2021-04-27 | Motor overload protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110459804.8A CN112993941B (en) | 2021-04-27 | 2021-04-27 | Motor overload protection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112993941A CN112993941A (en) | 2021-06-18 |
| CN112993941B true CN112993941B (en) | 2022-10-18 |
Family
ID=76340340
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110459804.8A Active CN112993941B (en) | 2021-04-27 | 2021-04-27 | Motor overload protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112993941B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113612427A (en) * | 2021-07-30 | 2021-11-05 | 北京曙光航空电气有限责任公司 | Linear actuator control circuit |
| CN114019373B (en) * | 2021-11-01 | 2022-06-07 | 常州机电职业技术学院 | Efficient servo motor automatic test system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1812217A (en) * | 2005-01-27 | 2006-08-02 | 滨州职业学院 | Motor controlling protector |
| CN110098592A (en) * | 2019-06-19 | 2019-08-06 | 河南工业职业技术学院 | Electrical system overload protection arrangement |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1033776C (en) * | 1985-07-12 | 1997-01-08 | 路易斯·W·帕克 | Energy economizer controlled-current start and protection for induction motors |
| KR101500854B1 (en) * | 2013-08-23 | 2015-03-10 | 계양전기 주식회사 | Motor control apparatus having protection function and method using the same |
| CN108832600B (en) * | 2018-06-11 | 2024-03-19 | 贵州航天林泉电机有限公司 | Motor overcurrent protection circuit capable of resisting locked rotor and protecting current from linearly increasing along with output power |
| CN110829355B (en) * | 2019-11-29 | 2021-06-22 | 郑州工程技术学院 | Mechanical equipment overload protection device |
| CN111463874A (en) * | 2020-04-10 | 2020-07-28 | 南京沃瑞新能源科技有限公司 | Overload protection circuit and overload control method for AC/DC conversion charger of new energy automobile |
| CN111431183B (en) * | 2020-05-14 | 2022-10-04 | 河南工业职业技术学院 | Power control device |
-
2021
- 2021-04-27 CN CN202110459804.8A patent/CN112993941B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1812217A (en) * | 2005-01-27 | 2006-08-02 | 滨州职业学院 | Motor controlling protector |
| CN110098592A (en) * | 2019-06-19 | 2019-08-06 | 河南工业职业技术学院 | Electrical system overload protection arrangement |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112993941A (en) | 2021-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112993941B (en) | Motor overload protection circuit | |
| RU2457596C2 (en) | Overvoltage protection device | |
| CN104849565B (en) | A kind of lead accumulator internal resistance detection circuit | |
| CN104092260B (en) | High-power linear regulated power supply suitable for storage battery | |
| CN103185866B (en) | Battery detection circuit, detection method and detection system | |
| WO2020177639A1 (en) | Insulation detection circuit and detection method, and battery management system | |
| CN111490519A (en) | Overvoltage and overcurrent protection chip | |
| CN106505513B (en) | A kind of LED drive power and its output end short-circuit protection circuit | |
| CN114362487B (en) | Active current-sharing driving control circuit of parallel power device | |
| CN110557058B (en) | Starting protection circuit of direct-current brushless motor | |
| CN111431183B (en) | Power control device | |
| CN208723823U (en) | The protection circuit of driving circuit | |
| CN210123455U (en) | Battery voltage sampling circuit and battery management system | |
| CN107888063B (en) | A kind of output current peak coefficient method and device improving inverter | |
| CN114019373B (en) | Efficient servo motor automatic test system | |
| CN216437055U (en) | Overcurrent protection circuit and air conditioner | |
| CN115693790A (en) | Phase prejudgment-based uninterrupted power supply operation system and method | |
| CN208508504U (en) | Load short-circuit protection circuit, circuit system and outdoor machine of air-conditioner | |
| CN210894548U (en) | Discharge overcurrent protection test circuit | |
| CN217085211U (en) | Current detection device for storage battery | |
| CN113162190B (en) | Lithium battery pack control circuit and method based on 0Z8952 chip | |
| CN219420346U (en) | Weak current on-off circuit of battery and lithium battery | |
| CN218298859U (en) | Electronic box temperature control circuit | |
| CN218848215U (en) | VGA-based constant power load device | |
| CN117639166A (en) | Nickel-hydrogen power supply charge-discharge control management system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: Motor overload protection circuit Effective date of registration: 20230509 Granted publication date: 20221018 Pledgee: Industrial and Commercial Bank of China Limited Rongcheng sub branch Pledgor: Shandong Fuzhi Daxing Motor Co.,Ltd. Registration number: Y2023980040114 |