Integrated single-phase motor control system

Abstract

The invention provides an integrated single-phase motor control system which comprises a starting signal input end, a steering signal input end, a voltage comparison circuit, a charging and discharging adjusting circuit, a charging capacitor, a starting capacitor control circuit and a motor steering control circuit. The charging and discharging adjusting circuit is used for charging the charging capacitor and inputting the charging voltage of the charging capacitor into the voltage comparison circuit in real time, and the resistance value of the charging and discharging adjusting circuit is set according to the power of the motor and the weight of the load; and the voltage comparison circuit is used for generating a stabilized voltage after receiving the starting signal, comparing the stabilized voltage with the voltage of the charging capacitor, and turning off the starting capacitor control circuit when the voltage of the charging capacitor is greater than the stabilized voltage so as to keep the normal operation of the motor. According to the invention, the charging and discharging time of the starting capacitor can be flexibly adjusted and accurately controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of single-phase motors, and in particular to an integrated single-phase motor control system. Background Art

[0002] The single-phase motor uses a centrifugal switch to cut off the starting capacitor. When the motor is started without load, the motor can quickly reach the rated centrifugal switch cut-off speed. When the motor is started with load, the motor start-up time is extended. If the load is too heavy, the motor may not reach the centrifugal switch cut-off speed for a long time. At this time, the starting capacitor is always connected, which will increase the motor current, make abnormal noises, and cause serious heat generation. In severe cases, the motor will burn out. Summary of the invention

[0003] The present invention provides an integrated single-phase motor control system, which is used to solve the defects of slow motor starting and easy damage caused by improper selection of starting capacitor when starting a single-phase motor in the prior art, and realizes flexible adjustment and precise control of the charging and discharging time of the starting capacitor.

[0004] The present invention provides an integrated single-phase motor control system, comprising a start signal input end, a steering signal input end, a voltage comparison circuit, a charge and discharge regulation circuit, a charging capacitor, a start capacitor control circuit and a motor steering control circuit, wherein the start signal input end is respectively connected to the input end of the voltage comparison circuit and the motor steering control circuit, the output end of the motor steering control circuit is connected to the input end of the charge and discharge regulation circuit, the output end of the charge and discharge regulation circuit is respectively connected to one end of the charging capacitor and the input end of the voltage comparison circuit, the other end of the charging capacitor is grounded, the output end of the voltage comparison circuit is connected to the start capacitor control circuit, and the start capacitor control circuit is connected to the single-phase motor; The charge-discharge regulating circuit is used to charge the charging capacitor according to the motor steering signal output by the motor steering control circuit, and input the voltage used to charge the charging capacitor into the voltage comparison circuit in real time, wherein the resistance value of the charge-discharge regulating circuit is set according to the power of the motor and the weight of the load; The voltage comparison circuit is used to generate a regulated voltage after receiving a start signal, and compare the regulated voltage with the voltage of the charging capacitor. When the voltage of the charging capacitor is greater than the regulated voltage, the start capacitor control circuit is turned off to keep the motor running normally.

[0005] According to the integrated single-phase motor control system provided by the present invention, the voltage comparison circuit comprises: a first voltage stabilizing unit, a second voltage stabilizing unit, a voltage comparison unit, and a capacitor switching unit; The input end of the first voltage stabilizing unit is connected to the start signal input end, the output end of the first voltage stabilizing unit is connected to the input end of the voltage comparison unit, and the first voltage stabilizing unit is used to generate a regulated voltage according to the received external voltage, and input the regulated voltage to the voltage comparison unit; The input end of the second voltage stabilizing unit is connected to the voltage input end; the output end of the second voltage stabilizing unit is connected to the input end of the voltage comparison unit, and the second voltage stabilizing unit is used to receive the power supply voltage input from the voltage input end, and provide a constant working voltage and working current for the voltage comparison unit to ensure that the voltage comparison unit works in a stable state; The two input ends of the voltage comparison unit are respectively connected to the output ends of the first voltage stabilizing unit and the charge and discharge regulating circuit, and the output end of the voltage comparison unit is connected to the input end of the capacitor switching unit, for comparing the received voltage of the charging capacitor with the stabilizing voltage, and outputting voltage control signals of different directions to the capacitor switching unit, so that the capacitor switching unit controls the shutdown and connection of the startup capacitor control circuit according to the received voltage control signal.

[0006] According to the integrated single-phase motor control system provided by the present invention, The received voltage of the charging capacitor is compared with the regulated voltage. When the voltage of the charging capacitor is less than the regulated voltage, a positive voltage control signal is output to the capacitor switching unit so that the capacitor switching unit controls the starting capacitor control circuit to remain on and keep charging the charging capacitor; when the voltage of the charging capacitor is greater than the regulated voltage, a negative voltage control signal is output to the capacitor switching unit so that the capacitor switching unit controls the starting capacitor control circuit to be turned off.

[0007] According to the integrated single-phase motor control system provided by the present invention, the first voltage stabilizing unit includes: a first resistor, a first voltage stabilizing tube; One end of the first resistor is connected to the start signal input end, and the connection point between the other end of the first resistor and the first voltage regulator is the output end of the first voltage regulator unit, the output end is connected to the input end of the voltage comparison unit, and the other end of the first voltage regulator is grounded; when the start signal input end inputs the start voltage, the first resistor and the first voltage regulator are used as a reference voltage for comparing the charging voltage of the charging capacitor; wherein the voltage value of the voltage regulator can be adjusted according to actual needs by adjusting the first voltage regulator.

[0008] According to the integrated single-phase motor control system provided by the present invention, the voltage comparison unit includes: a first PNP type transistor, a second PNP type transistor, a third PNP type transistor, a fourth PNP type transistor, a first NPN type transistor, and a second NPN type transistor; The base of the first PNP transistor is connected to the output end of the first voltage stabilizing unit as the positive input end of the voltage comparison unit, and the emitter of the first PNP transistor is connected to the first voltage stabilizing branch and the base of the second PNP transistor respectively; The emitter of the second PNP transistor is connected to the emitter of the second voltage stabilizing branch and the third PNP transistor respectively, and the collector of the second PNP transistor is connected to the collector of the first NPN transistor; The base of the third PNP transistor is connected to the emitter of the fourth PNP transistor, and the base of the fourth PNP transistor serves as a negative input terminal of the voltage comparison unit, and is used to be connected to one end of the charging capacitor; the collector of the third PNP transistor and the collector of the second NPN transistor are connected together as an output terminal of the voltage comparison unit, and are used to be connected to the input terminal of the capacitor switching unit; The base of the first NPN transistor is connected to the base of the second NPN transistor, and the emitters of the first PNP transistor, the fourth PNP transistor, the first NPN transistor and the second NPN transistor are grounded respectively.

[0009] According to the integrated single-phase motor control system provided by the present invention, the capacitor switching unit includes: a third NPN transistor, a fourth NPN transistor; The base of the third NPN transistor is used as the input end of the capacitor switching unit and is connected to the output end of the voltage comparison unit. The emitter of the third NPN transistor and the emitter of the fourth NPN transistor are grounded respectively; the collector of the third NPN transistor is connected to the base of the fourth NPN transistor; The collector of the fourth NPN transistor serves as the output end of the capacitor switching unit and is used to be connected to the startup capacitor control circuit.

[0010] According to the integrated single-phase motor control system provided by the present invention, the charging and discharging regulation circuit includes: a charging unit, the charging unit is connected to the charging capacitor and is used to charge the charging capacitor, the charging unit includes: a jumper terminal and a plurality of resistance branches; the jumper terminal includes a plurality of output pins, each of the output pins is connected to a resistance branch; Each of the resistance branches is formed by a resistor and a voltage stabilizing diode connected in series; By adjusting the output pin of the jumper terminal to select a suitable resistance branch to form a charging circuit with the charging capacitor, the charging time of the charging capacitor is adjusted; wherein, the charging time of the charging capacitor needs to be greater than the charging time of the starting capacitor.

[0011] According to the integrated single-phase motor control system provided by the present invention, the charging time of the charging capacitor is adjusted according to the following formula: ; Wherein, t is the charging time of the charging capacitor, R is the resistance of the selected charging resistor, C01 is the capacitance of the charging capacitor, V1 is the regulated voltage input to the voltage comparison unit, V0 is the initial voltage value on the charging capacitor, and Vt is the voltage value on the charging capacitor at time t.

[0012] According to the integrated single-phase motor control system provided by the present invention, the charge and discharge regulation circuit also includes a discharge unit, which is connected to the starting capacitor control circuit and is used to form a discharge loop with the starting capacitor in the starting capacitor control circuit when the starting capacitor control circuit is in an off state, so as to quickly discharge the starting capacitor to prevent the starting capacitor from overcurrent, overvoltage and overheating shock.

[0013] According to the integrated single-phase motor control system provided by the present invention, the starting capacitor control circuit comprises: a two-way normally open relay, a starting capacitor and a running capacitor; The dual-circuit normally open relay is connected between the wiring terminals of the motor, the starting capacitor is connected between the wiring terminals of the motor, and the running capacitor is connected between the wiring terminals of the motor.

[0014] According to the integrated single-phase motor control system provided by the present invention, the dual-circuit normally open relay comprises: a first normally open contact and a second normally open contact; The first normally open contact corresponds to the forward start-up process of the motor, and the second normally open contact corresponds to the reverse start-up process of the motor; When the motor steering control circuit needs to control the motor to run forward, when the charging voltage is less than the regulated voltage, the dual-circuit normally open relay is energized, the normally open contact of the first normally open contact is closed, the starting capacitor control circuit is connected, and the starting capacitor and the running capacitor are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the first normally open contact is disconnected, the starting capacitor control circuit is disconnected, and the motor is operated by the running capacitor to ensure the forward operation of the motor; When the motor steering control circuit needs to control the motor to reverse operation, when the charging voltage is less than the regulated voltage, the dual-circuit normally open relay is energized, the normally open contact of the second normally open contact is closed, the starting capacitor control circuit is turned on, and the starting capacitor and the running capacitor are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the second normally open contact is disconnected, the starting capacitor control circuit is disconnected, and the motor is operated by the running capacitor to ensure the reverse operation of the motor.

[0015] The integrated single-phase motor control system provided by the present invention charges the charging capacitor according to the motor steering signal output by the motor steering control circuit through the charge and discharge regulating circuit, and inputs the voltage used to charge the charging capacitor into the voltage comparison circuit in real time, wherein the resistance value of the charge and discharge regulating circuit is set according to the power of the motor and the weight of the load; after receiving the start signal, the voltage comparison circuit generates a regulated voltage, and compares the regulated voltage with the voltage of the charging capacitor, and when the voltage of the charging capacitor is greater than the regulated voltage, the start capacitor control circuit is turned off to keep the motor running normally. The present invention does not rely on traditional mechanical methods, but adopts electronic control methods to achieve precise control of the charge and discharge time of the start capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is one of the structural schematic diagrams of the integrated single-phase motor control system provided by the present invention.

[0018] Figure 2 It is a structural schematic diagram of a voltage comparison circuit provided by the present invention.

[0019] Figure 3 It is a structural schematic diagram of the first voltage stabilizing unit in the voltage comparison circuit provided by the present invention.

[0020] Figure 4 It is a structural schematic diagram of the second voltage stabilizing unit in the voltage comparison circuit provided by the present invention.

[0021] Figure 5 This is the second structural schematic diagram of the integrated single-phase motor control system provided by the present invention.

[0022] Figure 6 The invention provides a principle block diagram of the motor steering control circuit. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The features of the terms "first" and "second" in the present invention may include one or more of the features explicitly or implicitly. In the description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" means at least one of the connected objects, and the character " / " generally indicates that the related objects are in an "or" relationship.

[0025] In a single-phase motor, the function of the starting capacitor is to help generate a rotating magnetic field by changing the phase of the current, so that the motor can start. When the motor's rotor speed reaches 70% to 80% of the rated value, the centrifugal switch will automatically trip, thereby disconnecting the starting capacitor. After that, the motor continues to operate with the running winding coil. If reversal is required, the output end of any winding can be swapped to achieve this. This connection method is usually used in applications with large and unstable loads, such as air compressors, cutting machines, woodworking machine tools, etc.

[0026] For four-quadrant working conditions, which involve the forward and reverse movement of the equipment as well as the generation and consumption of energy, the motor may not start normally if a centrifugal switch is used. Specifically, the size of the starting capacitor of a single-phase motor affects the motor mainly in terms of the starting current and the torque during motor operation. When the starting capacitor of a single-phase motor is too large, the starting current of the motor is too large, which will cause the grid voltage to drop, causing tripping or burning of the fuse. When the capacitance of a single-phase motor is too small, it will cause difficulty in starting the motor, prolong the starting time, or even fail to start. At the same time, too small a capacitance will also increase the torque of the motor during operation, but the current will also increase accordingly, causing the motor to overheat or even burn out. Therefore, choosing a suitable starting capacitor is crucial for the normal operation of a single-phase motor.

[0027] In view of this, the present invention provides an integrated single-phase motor control system, which determines the selection of capacitors according to the specific parameters and operating requirements of the motor to ensure that the motor can be started smoothly and run stably without being damaged.

[0028] In some specific embodiments of the present invention, Figure 1As shown, the present solution provides an integrated single-phase motor control system, including: a start signal input terminal START, a steering signal input terminal IN3, a voltage comparison circuit 110, a charge and discharge regulation circuit 120, a charging capacitor 130, a start capacitor control circuit 140 and a motor steering control circuit 150, the start signal input terminal START is respectively connected to the input terminals of the voltage comparison circuit 110 and the motor steering control circuit 150, the output terminal of the motor steering control circuit 150 is connected to the input terminal of the charge and discharge regulation circuit 120, the output terminal of the charge and discharge regulation circuit 120 is respectively connected to one terminal of the charging capacitor 130 and the input terminal of the voltage comparison circuit 110, the other terminal of the charging capacitor 130 is grounded, the output terminal of the voltage comparison circuit 110 is connected to the start capacitor control circuit 140, and the start capacitor control circuit 140 is connected to the single-phase motor; The charge-discharge regulating circuit 120 is used to charge the charging capacitor according to the motor steering signal output by the motor steering control circuit 150, and input the voltage used to charge the charging capacitor 130 to the voltage comparison circuit 110 in real time. The resistance value of the charge-discharge regulating circuit 120 is set according to the power of the motor and the weight of the load; The voltage comparison circuit 110 is used to generate a regulated voltage after receiving a start signal, and compare the regulated voltage with the voltage of the charging capacitor 130. When the voltage of the charging capacitor 130 is greater than the regulated voltage, the start capacitor control circuit 140 is turned off to keep the motor running normally.

[0029] In one embodiment of the present invention, the motor steering control circuit 150 is used to control the steering of the motor when receiving a steering signal input from the steering signal input terminal IN3, so that the motor is in a forward rotation state or a reverse rotation state.

[0030] In another embodiment of the present invention, the output end of the charge and discharge regulation circuit 120 is also connected to the starting capacitor control circuit 140, and is used to form a discharge loop with the starting capacitor of the starting capacitor control circuit 140 when the starting capacitor control circuit 140 is in the off state, so as to quickly discharge the starting capacitor, so as to effectively prevent the risk of overcurrent, overvoltage and overheating shock of the starting capacitor when the motor is frequently started.

[0031] It should be noted that the existing motor starting scheme cannot reasonably select the starting capacitor according to the specific parameters and operating requirements of the motor, and the starting capacitor can only be disconnected through a centrifugal switch, which is more troublesome to operate. In addition, the starting capacitor disconnection relies on traditional mechanical methods, and the efficiency and accuracy are difficult to guarantee.

[0032] Therefore, the present invention flexibly adjusts and accurately controls the charging time of the charging capacitor and the on-off of the starting capacitor in the starting capacitor control circuit 140 by setting a voltage comparison circuit and a charge and discharge adjustment circuit, and controls the steering of the motor by electronic control by setting a motor steering control circuit.

[0033] In some possible embodiments of the present invention, Figure 2 As shown, the voltage comparison circuit 110 includes: a first voltage stabilizing unit, a second voltage stabilizing unit, a voltage comparison unit, and a capacitor switching unit; The input end of the first voltage stabilizing unit is connected to the start signal input end START, and the output end of the first voltage stabilizing unit is connected to the input end of the voltage comparison unit, for generating a regulated voltage according to the received external voltage (generally 24V voltage), and inputting the regulated voltage to the voltage comparison unit; The input end of the second voltage stabilizing unit is connected to the voltage input end VIN, the output end of the second voltage stabilizing unit is connected to the input end of the voltage comparison unit, and the second voltage stabilizing unit is used to receive the power supply voltage output by the voltage input end VIN, and provide a constant working voltage and working current for the voltage comparison unit to ensure that the voltage comparison unit works in a stable state; The two input ends of the voltage comparison unit are respectively connected to the output ends of the first voltage stabilizing unit and the charge and discharge regulating circuit, and the output end of the voltage comparison unit is connected to the input end of the capacitor switching unit, for comparing the received voltage of the charging capacitor 130 with the regulated voltage, and outputting voltage control signals of different directions to the capacitor switching unit, so that the capacitor switching unit controls the shutdown and connection of the startup capacitor control circuit 140 according to the received voltage control signal.

[0034] Specifically, this embodiment provides an implementation method of a voltage comparison circuit, which receives the regulated voltage generated by the first voltage stabilizing unit and the voltage used by the charge and discharge regulating circuit 120 to charge the charging capacitor 130 respectively through the voltage comparison unit, and after comparing the two voltages, outputs voltage control signals of different directions to the capacitor switching unit. The capacitor switching unit controls the connection and disconnection of the start-up capacitor control circuit 140 according to the received voltage control signal.

[0035] In a possible embodiment, the received voltage of the charging capacitor is compared with the regulated voltage. When the voltage of the charging capacitor is less than the regulated voltage, a positive voltage control signal is output to the capacitor switching unit; when the voltage of the charging capacitor is greater than the regulated voltage, a negative voltage control signal is output to the capacitor switching unit so that the capacitor switching unit controls the startup capacitor control circuit to shut down.

[0036] Further, determining whether to turn on and off the startup capacitor control circuit 140 according to the received voltage control signal specifically includes: When the capacitor switching unit receives the forward voltage control signal, it controls the startup capacitor control circuit 140 to remain in the on state, so as to keep charging the charging capacitor continuously; When the capacitor switching unit receives a negative voltage control signal, it controls the startup capacitor control circuit 140 to turn off.

[0037] In a possible embodiment, if Figure 3 As shown, the first voltage stabilizing unit includes: a first resistor R08 and a first voltage stabilizing tube DW02; Specifically, one end of the first resistor R08 is connected to the start signal input terminal START, and the connection point between the other end of the first resistor R08 and the first voltage regulator DW02 is the output end of the first voltage regulator unit, and the output end is connected to the input end of the voltage comparison unit, and the other end of the first voltage regulator DW02 is grounded; when the start signal input terminal START inputs the start voltage, the first resistor R08 and the first voltage regulator DW02 generate a regulated voltage as a reference voltage, which is used as a reference voltage for comparing the charging voltage of the charging capacitor. The voltage value of the regulated voltage can be adjusted by adjusting the first voltage regulator DW02 according to actual needs.

[0038] In a possible embodiment, if Figure 4 As shown, the second voltage stabilizing unit includes: a second resistor R04, a first constant-voltage constant-current source D20, a first diode D2, a second constant-voltage constant-current source D18, a second diode D3, a third constant-voltage constant-current source D17, a fourth constant-voltage constant-current source D19, and a second voltage stabilizing tube DW01; the second voltage stabilizing unit provides a stable operating voltage and operating current for the transistor of the voltage comparison unit to ensure that the voltage comparison unit operates in a stable state.

[0039] Among them, the first constant voltage and constant current source D20 and the first diode D2 form a first voltage stabilizing branch; the second constant voltage and constant current source D18 forms a second voltage stabilizing branch, the second diode D3 and the third constant voltage and constant current source D17 form a third voltage stabilizing branch, and the fourth constant voltage and constant current source D19 and the second voltage stabilizing tube DW01 form a fourth voltage stabilizing branch; A parallel node of the first voltage stabilizing branch, the second voltage stabilizing branch, the third voltage stabilizing branch and the fourth voltage stabilizing branch connected in parallel is connected to one end of the second resistor, and the other end of the second resistor is connected to the voltage input terminal VIN.

[0040] In a possible embodiment, see Figure 5The voltage comparison unit in the voltage comparison circuit includes: a first PNP transistor Q600, a second PNP transistor Q3, a third PNP transistor Q4, a fourth PNP transistor Q5, a first NPN transistor Q6, and a second NPN transistor Q7; Specifically, the base of the first PNP transistor Q600 is connected to the output end of the first voltage stabilizing unit as the positive input end of the voltage comparison unit, and the emitter of the first PNP transistor Q600 is connected to the first voltage stabilizing branch and the base of the second PNP transistor Q3 respectively; The emitter of the second PNP transistor Q3 is connected to the second voltage stabilizing branch and the emitter of the third PNP transistor Q4 respectively, and the collector of the second PNP transistor Q3 is connected to the collector of the first NPN transistor Q6; The base of the third PNP transistor Q4 is connected to the third voltage stabilizing branch and the emitter of the fourth PNP transistor Q5 respectively; the base of the fourth PNP transistor Q5 serves as a negative input terminal of the voltage comparison unit, and is used to be connected to one end of the charging capacitor 130; the collector of the third PNP transistor Q4 and the collector of the second NPN transistor Q7 are connected together as an output terminal of the voltage comparison unit, and are used to be connected to the input terminal of the capacitor switching unit; The base of the first NPN transistor Q6 is connected to the base of the second NPN transistor Q7, and the emitters of the first PNP transistor Q600, the fourth PNP transistor Q5, the first NPN transistor Q6 and the second NPN transistor Q7 are grounded respectively.

[0041] Possibly, the capacitor switching unit includes: a third NPN transistor Q9, a fourth NPN transistor Q10; Among them, the base of the third NPN transistor Q9 serves as the input end of the capacitor switching unit, and is used to be connected to the output end of the voltage comparison unit, and the emitter of the third NPN transistor Q9 and the emitter of the fourth NPN transistor Q10 are grounded respectively; the collector of the third NPN transistor Q9 is connected to the fourth voltage stabilizing branch and the base of the fourth NPN transistor Q10 respectively; The collector of the fourth NPN transistor Q10 serves as the output end of the capacitor switching unit and is used to be connected to the startup capacitor control circuit 140 .

[0042] In a possible embodiment, the starting capacitor control circuit includes: a dual-circuit normally open relay, a starting capacitor and a running capacitor; The dual-circuit normally open relay is connected between the wiring terminals of the motor, the starting capacitor is connected between the wiring terminals of the motor, and the running capacitor is connected between the wiring terminals of the motor.

[0043] In a possible embodiment, the dual-circuit normally-open relay includes: a first normally-open contact and a second normally-open contact; The first normally open contact corresponds to the forward start-up process of the motor, and the second normally open contact corresponds to the reverse start-up process of the motor; When the motor steering control circuit needs to control the motor to run forward, when the charging voltage is less than the regulated voltage, the two-way normally open relay is energized, the normally open contact of the first normally open contact is closed, the starting capacitor control circuit is connected, and the starting capacitor and the running capacitor are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the first normally open contact is disconnected, the starting capacitor control circuit is disconnected, and the motor is operated by the running capacitor to ensure the forward operation of the motor; When the motor steering control circuit needs to control the motor to reverse operation, when the charging voltage is less than the regulated voltage, the dual-circuit normally open relay is energized, the normally open contact of the second normally open contact is closed, the starting capacitor control circuit is turned on, and the starting capacitor and the running capacitor are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the second normally open contact is disconnected, the starting capacitor control circuit is disconnected, and the motor is operated by the running capacitor to ensure the reverse operation of the motor.

[0044] Specifically, Figure 5 and Figure 6 As shown, the starting capacitor control circuit 140 includes: a dual-circuit normally open relay K, a starting capacitor CDJ and a running capacitor CBB; The dual-circuit normally open relay K is connected between the terminal V1 and the terminal V2 of the motor, the starting capacitor CDJ is connected between the terminal V2 and the terminal Z1 of the motor, and the running capacitor CBB is connected between the terminal V1 and the terminal Z1 of the motor.

[0045] In some possible implementations of the present invention, the dual-circuit normally open relay K includes: a first normally open contact QDC1 and a second normally open contact QDC11; The first normally open contact QDC1 corresponds to the motor forward start process, and the second normally open contact QDC11 corresponds to the motor reverse start process; When the motor steering control circuit needs to control the motor to run forward, when the charging voltage is less than the regulated voltage, the dual-circuit normally open relay K is energized, the normally open contact of the first normally open contact QDC1 is closed, the starting capacitor control circuit 140 is turned on, and the starting capacitor CDJ and the running capacitor CBB are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the first normally open contact QDC1 is disconnected, the starting capacitor control circuit 140 is disconnected, and the motor is operated by the running capacitor to ensure the forward operation of the motor.

[0046] When the motor steering control circuit needs to control the motor to reverse operation, when the charging voltage is less than the regulated voltage, the dual-circuit normally open relay K is energized, the normally open contact of the second normally open contact QDC11 is closed, the starting capacitor control circuit 140 is turned on, and the starting capacitor CDJ and the running capacitor CBB are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the second normally open contact QDC11 is disconnected, the starting capacitor control circuit 140 is disconnected, and the motor is operated by the running capacitor to ensure the reverse operation of the motor.

[0047] Through the arrangement of the above-mentioned embodiments, the present invention can compare the voltages at both ends of the voltage comparison unit. If the charging voltage of the charging capacitor 130 is greater than the regulated voltage, the starting capacitor control circuit 140 where the starting capacitor is located is disconnected, and the charging capacitor stops charging, thereby preventing the starting capacitor from being always connected, the motor current from increasing, the motor from heating up severely, and the risk of the motor being burned out.

[0048] The charge and discharge regulation circuit 120 provided in the embodiment of the present invention includes: a charging unit, which is connected to the charging capacitor 130 and is used to charge the charging capacitor 130; wherein, according to different motor parameters such as motor power and demand, the resistance value of the charging unit is adjusted to achieve precise control of the charging time of the charging capacitor.

[0049] Specifically, Figure 5 As shown, the charging unit includes: a jumper terminal CN2 and a plurality of resistance branches; The jumper terminal CN2 includes a plurality of output pins, each of which is connected to a resistor branch; Each of the resistance branches is formed by a resistor and a voltage stabilizing diode connected in series; The charge and discharge regulation circuit is used to adjust the output pin of the jumper terminal according to the load weight at the load end, so as to select a suitable resistance branch and the charging capacitor to form a charging circuit, and adjust the charging time of the charging capacitor; wherein the charging time of the charging capacitor must be greater than the charging time of the starting capacitor. In a possible embodiment, when the weight of the load at the motor load end changes, the motor starting time will also be different. At this time, the starting time can be adjusted by Figure 5 The jumper terminal CN2 in the circuit is set with different resistance values ​​to adjust the charging and discharging time of the charging capacitor 130 to adapt to the motor starting time point under different load conditions.

[0050] In a possible embodiment, the charging time of the charging capacitor is adjusted according to the following formula: ; Wherein, t is the charging time of the charging capacitor, R is the resistance of the selected charging resistor, C01 is the capacitance of the charging capacitor, V1 is the regulated voltage input to the voltage comparison unit, V0 is the initial voltage value on the charging capacitor, and Vt is the voltage value on the charging capacitor at time t.

[0051] In a possible embodiment, the charge and discharge regulation circuit also includes a discharge unit, which is connected to the starting capacitor control circuit and is used to form a discharge loop with the starting capacitor in the starting capacitor control circuit when the starting capacitor control circuit is in an off state, so as to quickly discharge the starting capacitor to prevent the starting capacitor from overcurrent, overvoltage and overheating shock.

[0052] In the existing single-phase motor control scheme, after the starting capacitor is disconnected from the motor auxiliary winding, when the motor is started frequently, the starting capacitor will experience overcurrent, overvoltage and overheating shock, which greatly reduces the service life of the starting capacitor.

[0053] In view of the above problems, the embodiment of the present invention adds a rapid discharge function for the starting capacitor through a discharge unit. When the starting capacitor control circuit 140 is turned off, the starting capacitor is discharged quickly, reducing the risk of the motor being impacted when it is restarted.

[0054] The above-mentioned design of the embodiment of the present invention can accurately control the shutdown time point of the starting capacitor control circuit according to different power motors and different load conditions. In a possible embodiment, the integrated single-phase motor control system is also provided with a temperature signal input terminal and an emergency stop signal input terminal; the temperature signal input terminal is used to detect the temperature of the motor, and when the motor is detected to be overheated, the motor is quickly shut down to avoid damage to the motor.

[0055] The emergency stop signal input terminal is used to detect the emergency stop signal during the operation of the motor, so as to quickly shut down the motor in case of an emergency to avoid accidents.

[0056] Specifically, the motor steering control circuit is connected to the temperature signal input terminal and the emergency stop signal input terminal respectively; When the motor temperature inputted at the temperature signal input terminal exceeds a preset temperature threshold, the motor steering control circuit is disconnected and the motor stops working; When the emergency stop signal inputted from the emergency stop signal input terminal is received, the motor steering control circuit is disconnected and the motor stops working.

[0057] Based on the above embodiments, the working process and working principle of the integrated single-phase motor control system are described in detail from the overall architecture.

[0058] by Figure 5Taking the circuit as an example, the specific working process of the integrated single-phase motor control system includes: Step 1: Power on: In this step, the voltage input terminal inputs 220V voltage, that is, the power supply is powered on, and the integrated single-phase motor control system enters the standby state. At this time, the motor brake is in a mechanical locking state, and the motor speed is 0.

[0059] Step 2: Power the relay input of the motor control circuit: In this step, firstly, it is detected whether the emergency stop signal is turned on. When the emergency stop button is turned on, the main contactor in the motor control circuit is energized, the motor control circuit is connected, and the relay input terminal that controls the forward and reverse rotation of the motor is powered.

[0060] Step 3: Start the motor: Before the motor starts, it is necessary to select appropriate running capacitor CBB and starting capacitor CDJ. The capacitance values ​​of the running capacitor CBB and the starting capacitor CDJ can be calculated by the following formula.

[0061] Specifically, the running capacitor CBB has a capacity of C1: (1); Where: I is the motor phase current; f is the motor power frequency; U is the motor phase voltage; cosφ is the motor power factor, which is 0.5 to 0.7. The operating voltage of the running capacitor CBB is greater than or equal to (2 to 2.3)U.

[0062] On this basis, the capacitance value C2 of the starting capacitor CDJ can be obtained: (2).

[0063] The charging time of the starting capacitor can be calculated based on the capacitance value of the starting capacitor CDJ and the charging voltage to be reached for charging the starting capacitor (generally 220V voltage).

[0064] In order to improve the motor starting efficiency, it is necessary to accurately control the disconnection time point of the starting capacitor. Specifically, the capacitance value of the charging capacitor is selected based on the condition that the charging time of the charging capacitor 130 is greater than the charging time of the starting capacitor.

[0065] The charging time t of the charging capacitor 130, i.e., the time for the starting capacitor to provide the starting torque for the motor, can be calculated according to the following formula: (3) Wherein, R is the resistance of the selected charging resistor, C01 is the capacitance of the charging capacitor, V1 is the regulated voltage input to the voltage comparison unit, V0 is the initial voltage value on the charging capacitor, and Vt is the voltage value on the charging capacitor at time t.

[0066] Depending on the load size, the motor start time point is different, and the capacitance value of the selected charging capacitor, the charging time of the charging capacitor can be adjusted by setting different resistance values ​​through the jumper terminal CN2 to adapt to the motor start time point under different load conditions.

[0067] Detect whether the forward and reverse buttons are pressed. When it is detected that the forward button is pressed, the starting capacitor of the single-phase motor is turned on, the running capacitor is turned on, and the starting capacitor and the running capacitor are connected in parallel to provide starting torque for the motor, so as to increase the starting torque of the motor so that the motor can be started at the required starting time point, that is, the motor can run forward; when it is detected that the reverse button is pressed, the starting capacitor of the single-phase motor is turned on, the running capacitor is turned on, and the starting capacitor and the running capacitor are connected in parallel to provide starting torque for the motor to increase the starting torque of the motor so that the motor can be started at the required starting time point, that is, the motor can run in the reverse direction.

[0068] In this step, if Figure 6 As shown, in forward rotation, U2Z2 is connected to the neutral line, and U1V1 is connected to the live line. U2Z2 is connected, that is, the tail ends of the two running windings are connected, and U1V1 is connected, that is, the head end of the running winding is connected to one end of the running capacitor. In reverse rotation, Z2U1 is connected, and U2V1 is connected. Z2U1 is connected, that is, one end of the two windings is connected together, and U2V1 is connected, that is, the tail end of the running winding is connected to one end of the running capacitor. Compared with forward rotation, the head and tail ends of the running winding are changed to achieve the change of direction.

[0069] After determining the direction of the motor, the disconnection time of the starting capacitor is precisely controlled according to different power motors and different load conditions. Figure 5 , the transistor Q10 controls the relay K to be closed and disconnected to control the start capacitor on and off; after the series resistor R08 of the first voltage stabilizing unit receives the START start signal, the regulated voltage generated by the series resistor R08 and the voltage regulator DW02 is input to the voltage comparison unit. When the START start signal and the motor steering button are pressed, the CW or CCW end of the charge and discharge regulation circuit 120 corresponding to the motor steering is set high by the START signal. At this time, a suitable resistor (R14~R19) is selected from the charge and discharge regulation circuit 120 and the corresponding voltage regulator (DW04~DW09) and the charging capacitor 130 to form an RC charging circuit to charge the charging capacitor 130. At this time, the relay K is in the energized state, the start capacitor is connected, and the running capacitor CBB and the start capacitor CDJ are connected in parallel to provide the motor with starting torque. When the charging voltage of the charging capacitor exceeds the regulated voltage, the collector of the fourth NPN transistor Q10 of the capacitor switching unit outputs a negative level to the relay K, the relay K is disconnected, the start capacitor control circuit 140 is disconnected, and the motor works on the running capacitor.

[0070] Furthermore, after the starting capacitor is disconnected from the auxiliary winding of the motor, the starting capacitor will have overcurrent, overvoltage and overheat shock problems due to frequent motor starting, which greatly reduces the service life of the starting capacitor. This design adds a fast discharge function for the starting capacitor. When the starting capacitor is disconnected, the discharge unit of the charge and discharge regulation circuit quickly discharges the starting capacitor, reducing the risk of the starting capacitor being impacted by the motor starting again.

[0071] The starting capacitor discharge can be calculated using the following formula: (4) Among them, E is the full-charge voltage of the starting capacitor, V is the voltage value on the capacitor when the starting capacitor is in the disconnected state, C is the capacitance value of the starting capacitor, and r is the resistance value of the negative winding of the motor. When the starting capacitor capacitance is discharged from the full voltage E to 1 / 3E, the discharge time t of the starting capacitor is obtained by calculation. According to the discharge time t being 1.1R1C, the resistance value of the discharge resistor R1 in the selected discharge unit is calculated.

[0072] Step 4: Motor temperature detection: During the operation of the motor, the motor temperature needs to be detected. When the motor temperature is too high, the operating capacitor circuit is controlled to be disconnected to protect the motor from being damaged by overheating.

[0073] In this step, the motor temperature is detected in real time. If the motor temperature exceeds the limit, the forward and reverse contactors will control the motor to stop running. The brake is locked and the motor stops rotating.

[0074] The integrated single-phase motor control system provided by the present invention can flexibly design the on-off control and discharge process of the starting capacitor according to the working parameters of the motor, such as power and operation requirements. Combined with the calculation of the capacity of the starting capacitor and the running capacitor, the disconnection time point of the starting capacitor can be accurately controlled to improve the motor starting efficiency and reduce the damage in the motor starting process. At the same time, the present invention can detect the temperature of the motor in real time, and when the motor temperature exceeds the specified temperature, quickly control the motor to stop running, avoiding damage caused by overheating of the motor.

[0075] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0076] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated single-phase motor control system, characterized in that: include: A start signal input terminal, a steering signal input terminal, a voltage comparison circuit, a charge and discharge adjustment circuit, a charging capacitor, a start capacitor control circuit and a motor steering control circuit, wherein the start signal input terminal is respectively connected to the input terminals of the voltage comparison circuit and the motor steering control circuit, the output terminal of the motor steering control circuit is connected to the input terminal of the charge and discharge adjustment circuit, the output terminal of the charge and discharge adjustment circuit is respectively connected to one terminal of the charging capacitor and the input terminal of the voltage comparison circuit, the other terminal of the charging capacitor is grounded, the output terminal of the voltage comparison circuit is connected to the start capacitor control circuit, and the start capacitor control circuit is connected to the single-phase motor; The charge-discharge regulating circuit is used to charge the charging capacitor according to the motor steering signal output by the motor steering control circuit, and input the voltage used to charge the charging capacitor into the voltage comparison circuit in real time, wherein the resistance value of the charge-discharge regulating circuit is set according to the power of the motor and the weight of the load; The voltage comparison circuit is used to generate a regulated voltage after receiving a start signal, and compare the regulated voltage with the voltage of the charging capacitor. When the voltage of the charging capacitor is greater than the regulated voltage, the start capacitor control circuit is turned off to keep the motor running normally.

2. The integrated single-phase motor control system according to claim 1, characterized in that: The voltage comparison circuit comprises: a first voltage stabilizing unit, a second voltage stabilizing unit, a voltage comparison unit, and a capacitor switching unit; The input end of the first voltage stabilizing unit is connected to the start signal input end, the output end of the first voltage stabilizing unit is connected to the input end of the voltage comparison unit, and the first voltage stabilizing unit is used to generate a regulated voltage according to the received external voltage, and input the regulated voltage to the voltage comparison unit; The input end of the second voltage stabilizing unit is connected to the voltage input end; the output end of the second voltage stabilizing unit is connected to the input end of the voltage comparison unit, and the second voltage stabilizing unit is used to receive the power supply voltage input from the voltage input end, and provide a constant working voltage and working current for the voltage comparison unit to ensure that the voltage comparison unit works in a stable state; The two input ends of the voltage comparison unit are respectively connected to the output ends of the first voltage stabilizing unit and the charge and discharge regulating circuit, and the output end of the voltage comparison unit is connected to the input end of the capacitor switching unit, for comparing the received voltage of the charging capacitor with the stabilizing voltage, and outputting voltage control signals of different directions to the capacitor switching unit, so that the capacitor switching unit controls the shutdown and connection of the startup capacitor control circuit according to the received voltage control signal.

3. The integrated single-phase motor control system according to claim 2, characterized in that: The received voltage of the charging capacitor is compared with the regulated voltage. When the voltage of the charging capacitor is less than the regulated voltage, a positive voltage control signal is output to the capacitor switching unit so that the capacitor switching unit controls the starting capacitor control circuit to remain on and keep charging the charging capacitor; when the voltage of the charging capacitor is greater than the regulated voltage, a negative voltage control signal is output to the capacitor switching unit so that the capacitor switching unit controls the starting capacitor control circuit to be turned off.

4. The integrated single-phase motor control system according to claim 2 or 3, characterized in that: The first voltage stabilizing unit includes: a first resistor and a first voltage stabilizing tube; One end of the first resistor is connected to the start signal input end, and the connection point between the other end of the first resistor and the first voltage regulator is the output end of the first voltage regulator unit, the output end is connected to the input end of the voltage comparison unit, and the other end of the first voltage regulator is grounded; when the start signal input end inputs the start voltage, the first resistor and the first voltage regulator are used as a reference voltage for comparing the charging voltage of the charging capacitor; wherein the voltage value of the voltage regulator can be adjusted according to actual needs by adjusting the first voltage regulator.

5. The integrated single-phase motor control system according to claim 4, characterized in that: The voltage comparison unit includes: a first PNP type transistor, a second PNP type transistor, a third PNP type transistor, a fourth PNP type transistor, a first NPN type transistor, and a second NPN type transistor; The base of the first PNP transistor is connected to the output end of the first voltage stabilizing unit as the positive input end of the voltage comparison unit, and the emitter of the first PNP transistor is connected to the first voltage stabilizing branch and the base of the second PNP transistor respectively; The emitter of the second PNP transistor is connected to the emitter of the second voltage stabilizing branch and the third PNP transistor respectively, and the collector of the second PNP transistor is connected to the collector of the first NPN transistor; The base of the third PNP transistor is connected to the emitter of the fourth PNP transistor, and the base of the fourth PNP transistor serves as a negative input terminal of the voltage comparison unit, and is used to be connected to one end of the charging capacitor; the collector of the third PNP transistor and the collector of the second NPN transistor are connected together as an output terminal of the voltage comparison unit, and are used to be connected to the input terminal of the capacitor switching unit; The base of the first NPN transistor is connected to the base of the second NPN transistor, and the emitters of the first PNP transistor, the fourth PNP transistor, the first NPN transistor and the second NPN transistor are grounded respectively.

6. The integrated single-phase motor control system according to claim 4, characterized in that: The capacitor switching unit includes: a third NPN transistor and a fourth NPN transistor; The base of the third NPN transistor is used as the input end of the capacitor switching unit and is connected to the output end of the voltage comparison unit. The emitter of the third NPN transistor and the emitter of the fourth NPN transistor are grounded respectively; the collector of the third NPN transistor is connected to the base of the fourth NPN transistor; The collector of the fourth NPN transistor serves as the output end of the capacitor switching unit and is used to be connected to the startup capacitor control circuit.

7. The integrated single-phase motor control system according to claim 1, characterized in that: The charge and discharge regulation circuit comprises: a charging unit, the charging unit is connected to the charging capacitor and is used to charge the charging capacitor, the charging unit comprises: a jumper terminal and a plurality of resistance branches; the jumper terminal comprises a plurality of output pins, each of the output pins is connected to a resistance branch; Each of the resistance branches is formed by a resistor and a voltage stabilizing diode connected in series; By adjusting the output pin of the jumper terminal to select a suitable resistance branch to form a charging circuit with the charging capacitor, the charging time of the charging capacitor is adjusted; wherein, the charging time of the charging capacitor needs to be greater than the charging time of the starting capacitor.

8. The integrated single-phase motor control system according to claim 7, characterized in that: According to the following formula, the charging time of the charging capacitor is adjusted; ； Wherein, t is the charging time of the charging capacitor, R is the resistance of the selected charging resistor, C01 is the capacitance of the charging capacitor, V1 is the regulated voltage input to the voltage comparison unit, V0 is the initial voltage value on the charging capacitor, and Vt is the voltage value on the charging capacitor at time t.

9. The integrated single-phase motor control system according to claim 7, characterized in that: The charge and discharge regulation circuit also includes a discharge unit, which is connected to the starting capacitor control circuit and is used to form a discharge loop with the starting capacitor in the starting capacitor control circuit when the starting capacitor control circuit is in an off state, so as to quickly discharge the starting capacitor to prevent the starting capacitor from overcurrent, overvoltage and overheating shock.

10. The integrated single-phase motor control system according to claim 1, characterized in that: The starting capacitor control circuit comprises: a dual-circuit normally open relay, a starting capacitor and a running capacitor; The dual-circuit normally open relay is connected between the wiring terminals of the motor, the starting capacitor is connected between the wiring terminals of the motor, and the running capacitor is connected between the wiring terminals of the motor.

11. The integrated single-phase motor control system according to claim 10, characterized in that: The dual-circuit normally-open relay comprises: a first normally-open contact and a second normally-open contact; The first normally open contact corresponds to the forward start-up process of the motor, and the second normally open contact corresponds to the reverse start-up process of the motor; When the motor steering control circuit needs to control the motor to run forward, when the charging voltage is less than the regulated voltage, the two-way normally open relay is energized, the normally open contact of the first normally open contact is closed, the starting capacitor control circuit is connected, and the starting capacitor and the running capacitor are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the first normally open contact is disconnected, the starting capacitor control circuit is disconnected, and the motor is operated by the running capacitor to ensure the forward operation of the motor; When the motor steering control circuit needs to control the motor to reverse operation, when the charging voltage is less than the regulated voltage, the dual-circuit normally open relay is energized, the normally open contact of the second normally open contact is closed, the starting capacitor control circuit is turned on, and the starting capacitor and the running capacitor are connected in parallel to increase the starting torque of the motor; and when the charging voltage is greater than the regulated voltage, the second normally open contact is disconnected, the starting capacitor control circuit is disconnected, and the motor is operated by the running capacitor to ensure the reverse operation of the motor.

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