Energy-saving device of three-phase alternating-current asynchronous motor

Abstract

The invention provides an energy-saving device of a three-phase alternating-current asynchronous motor, which relates to the technical field of motor energy conservation and comprises an acquisition control module and an adjustment module, the acquisition control module is connected with the adjustment module and is used for acquiring a power factor signal of the motor in real time, generating an adjustment signal according to the real-time load change condition of the motor and the power factor signal of the motor, and sending the adjustment signal to the adjustment module; the adjusting signal comprises a voltage adjusting value and a current adjusting value of the motor; and the adjusting module is connected with the motor and is used for adjusting the input voltage and the input current of the motor according to the adjusting signal. According to the technical scheme provided by the invention, the energy consumption of the motor can be adjusted in real time along with the load change, the energy loss of the motor in the operation process can be effectively reduced, effective energy conservation and stable control of the energy consumption of the motor are realized, the energy loss of the motor is reduced, and the energy-saving effect of the motor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor energy saving, and particularly to an energy-saving device for a three-phase AC asynchronous motor. Background Art

[0002] Three-phase AC asynchronous motors occupy an important position in industrial production due to their high efficiency and wide application fields. However, with the increasing growth of energy consumption, the energy-saving problem of motors has become particularly important. When the motor load fails to reach the rated load, the power factor of the motor is relatively low, and the proportion of active power is relatively low, resulting in a great waste of energy.

[0003] Traditional motor energy-saving solutions usually focus on adjusting the working state of the motor or improving the structure of the motor, but the control of energy loss during the operation of the motor is not fine enough. For example, in phase control technology products, the energy-saving effect is not obvious when the power factor is relatively high or the motor power is relatively large, and the response speed of the energy-saving system is slow when the motor load changes greatly; for example, in variable frequency technology products, since the motor speed is reduced, the output power of the motor is reduced, and the energy saving per unit energy consumption cannot be truly achieved. Summary of the Invention

[0004] The present invention is completed in order to at least partially solve the technical problem that the existing motor energy-saving solutions are not fine enough in controlling the energy loss during the operation of the motor.

[0005] The present invention provides an energy-saving device for a three-phase AC asynchronous motor, including: an acquisition control module and an adjustment module; the acquisition control module is connected to the adjustment module, and is used to obtain the power factor signal of the motor in real time, generate an adjustment signal according to the real-time load change condition of the motor and the power factor signal of the motor, and send the adjustment signal to the adjustment module, where the adjustment signal includes the voltage adjustment value and the current adjustment value of the motor; the adjustment module is connected to the motor, and is used to adjust the input voltage and input current of the motor according to the adjustment signal.

[0006] Optionally, the acquisition control module includes: a signal detector, a signal adjustment circuit, and a high-frequency response circuit; one input terminal of the signal detector is connected to the phase wire of the motor, the other input terminal of the signal detector is connected to the motor wire, and the output terminal of the signal detector is connected to one input terminal of the signal adjustment circuit, which is used to collect the voltage and current of the motor in real time, generate a power factor signal according to the phase difference between the voltage and current of the motor, and send the power factor signal to the signal adjustment circuit; the input terminal of the high-frequency response circuit is connected to the motor wire, and the output terminal of the high-frequency response circuit is connected to the other input terminal of the signal adjustment circuit, which is used to sense the load change of the motor in real time, and in response to sensing that the load of the motor has changed, generate a load change signal and send the load change signal to the signal adjustment circuit; the output terminal of the signal adjustment circuit is connected to the adjustment module, which is used to adjust the power factor signal according to the load change signal, generate a first control signal as the adjustment signal, and send the adjustment signal to the adjustment module.

[0007] Optionally, the high-frequency response circuit includes: an operational amplifier U1, a diode D2, and a charge and discharge circuit; the non-inverting and inverting input terminals of the operational amplifier U1 are respectively connected to the motor wire, the output terminal of the operational amplifier U1 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the signal adjustment circuit through the charge and discharge circuit.

[0008] Optionally, the charge and discharge circuit includes: a capacitor C2 and a resistor R12; the capacitor C2 is connected in parallel with the resistor R12, one connection point of the two is grounded, and the other connection point of the two is respectively connected to the anode of the diode D2 and the signal adjustment circuit; wherein, in response to the high-frequency response circuit sensing that the load of the motor has changed, the operational amplifier U1 outputs a negative pulse and charges the capacitor C2 to the peak value through the diode D2 until the capacitor C2 is not applied with voltage, and the resistor R12 discharges the capacitor C2 to weaken the charge in the capacitor C2 to a preset value.

[0009] Optionally, the high-frequency response circuit further includes: a first resistor voltage dividing circuit; the non-inverting and inverting input terminals of the operational amplifier U1 are respectively connected to the motor wire through the first resistor voltage dividing circuit.

[0010] Optionally, the signal adjustment circuit includes: an operational amplifier U2; the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the signal detector, the non-inverting input terminal of the operational amplifier U2 is grounded, and the output terminal of the operational amplifier U2 is used as the output terminal of the signal adjustment circuit and is respectively connected to the high-frequency response circuit and the adjustment module.

[0011] Optionally, the signal adjustment circuit further includes: a feedback network circuit; the output terminal of the operational amplifier U2 is connected to the high-frequency response circuit through the feedback network circuit.

[0012] Optionally, the acquisition control module further includes: a pulse generator, a comparator, and a gate circuit; an input end of the pulse generator is connected to a phase line of the motor, an output end of the pulse generator is connected to an input end of the comparator, and is configured to generate a pulse signal and send the pulse signal to the comparator; an output end of the signal adjustment circuit is connected to the other input end of the comparator, and is configured to send the first control signal to the comparator; an output end of the comparator is connected to an input end of the gate circuit, and is configured to compare the first control signal and the pulse signal to generate a second control signal and send the second control signal to the gate circuit; an output end of the gate circuit is connected to the adjustment module, and sends the second control signal as the adjustment signal to the adjustment module, and is configured to control an on-time of the adjustment module according to the pulse signal included in the second control signal, and control the adjustment module to adjust an input voltage and an input current of the motor according to the first control signal included in the second control signal.

[0013] Optionally, the high-frequency response circuit further includes: a triode Q2 and a triode Q3; an output end of the gate circuit is further respectively connected to a base of the triode Q2 and a base of the triode Q3, emitters of the triode Q2 and the triode Q3 are both grounded, a collector of the triode Q2 is connected to an inverting input end of an operational amplifier U1, and a collector of the triode Q3 is connected to a non-inverting input end of the operational amplifier U1; the gate circuit is further configured to control the triode Q2 to conduct in response to a positive output of the gate circuit, and control the triode Q3 to conduct in response to a negative output of the gate circuit.

[0014] Optionally, the high-frequency response circuit further includes: a resistor R7 and a resistor R9; one end of the resistor R7 is connected to the base of the triode Q2, and the other end of the resistor R7 is connected to the output end of the gate circuit; one end of the resistor R9 is connected to the base of the triode Q3, and the other end of the resistor R9 is connected to the output end of the gate circuit;

[0015] and / or,

[0016] The high-frequency response circuit further includes: a resistor R6, a resistor R8, a resistor R10, and a resistor R11; one end of the resistor R6 is connected to a motor wire, and the other end of the resistor R6 is connected to the collector of the triode Q2; one end of the resistor R10 is connected to the collector of the triode Q2, and the other end of the resistor R10 is connected to the inverting input end of the operational amplifier U1; one end of the resistor R8 is connected to the motor wire, and the other end of the resistor R8 is respectively connected to the collector of the triode Q3 and the non-inverting input end of the operational amplifier U1; one end of the resistor R11 is connected to the non-inverting input end of the operational amplifier U1, and the other end of the resistor R11 is grounded.

[0017] Optionally, the gate circuit includes: a triode Q1; the base of the triode Q1 is connected to the output end of the comparator as the input end of the gate circuit, the emitter of the triode Q1 is grounded, and the collector of the triode Q1 is connected to the adjustment module as the output end of the gate circuit.

[0018] Optionally, the acquisition control module further includes: a signal control circuit; the input end of the signal control circuit is connected to the output end of the gate circuit, and the output end of the signal control circuit is connected to the input end of the adjustment module; the signal control circuit is further connected to the signal adjustment circuit, and is configured to generate the adjustment signal according to the second control signal and send the adjustment signal to the adjustment module, and is further configured to send a blocking control signal to the signal adjustment circuit when entering the non-start state according to the second control signal, so that the signal adjustment circuit stops working triggered by the blocking control signal, and send a start control signal to the signal adjustment circuit when entering the start state according to the second control signal, so that the signal adjustment circuit starts to work triggered by the start control signal.

[0019] Optionally, the signal adjustment circuit includes: an operational amplifier U2, a triode Q4, and a potentiometer R15; the inverting input end of the operational amplifier U2 is connected to the output end of the signal detector, the non-inverting input end of the operational amplifier U2 is grounded, and the output end of the operational amplifier U2 is connected to the output end of the high-frequency response circuit and the other input end of the comparator as the output end of the signal adjustment circuit; the base of the triode Q4 is connected to the signal control circuit, the emitter of the triode Q4 is grounded, and the collector of the triode Q4 is connected to the output end of the high-frequency response circuit and the output end of the operational amplifier U2 respectively; the potentiometer R15 is connected to the output end of the high-frequency response circuit and the collector of the triode Q4 respectively; the signal control circuit is specifically configured to send the blocking control signal to the base of the triode Q4 to make the triode Q4 conduct, or send the start control signal to the base of the triode Q4 to make the triode Q4 non-conduct.

[0020] Optionally, the signal control circuit includes: an operational amplifier U3, an operational amplifier U4, a triode Q5, and a potentiometer R22; the inverting input end of the operational amplifier U3 is connected to the potentiometer R22, the non-inverting input end of the operational amplifier U3 is grounded, the output end of the operational amplifier U3 is connected to the output end of the gate circuit and the collector of the triode Q5 respectively, and the emitter of the triode Q5 is grounded; the inverting input end of the operational amplifier U4 is connected to the inverting input end of the operational amplifier U3, the non-inverting input end of the operational amplifier U4 is connected to the input end of the adjustment module, and the output end of the operational amplifier U4 is connected to the base of the triode Q5; the output end of the operational amplifier U4 is further connected to the signal adjustment circuit for sending the blocking control signal or the start control signal to the signal adjustment circuit.

[0021] Optionally, the signal control circuit further includes: a second resistor voltage division circuit; the non-inverting input terminal of operational amplifier U4 is connected to the input terminal of the adjustment module through the second resistor voltage division circuit.

[0022] The technical solution provided by the present invention may include the following beneficial effects:

[0023] The energy-saving device for a three-phase AC asynchronous motor provided by the present invention, the acquisition control module generates an adjustment signal according to the real-time load change situation of the motor and the power factor signal of the motor and sends it to the adjustment module. The adjustment module adjusts the input voltage and input current of the motor according to the adjustment signal, so that the motor energy consumption is adjusted in real time with the load change, which can effectively reduce the energy loss during the operation of the motor, realize the effective energy saving and stable control of the motor energy consumption, reduce the energy loss of the motor, and improve the energy-saving effect of the motor.

[0024] Other features and advantages of the present invention will be described in the following description, and part of them will be obvious from the description, or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained through the structures specifically pointed out in the description, claims and drawings. Description of the Drawings

[0025] The drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the description. They are used together with the embodiments of the present invention to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

[0026] Figure 1 It is a structural block diagram of an energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention;

[0027] Figure 2 It is a structural block diagram of another energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention;

[0028] Figure 3 It is a structural block diagram of yet another energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention;

[0029] Figure 4 It is a structural block diagram of still another energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention;

[0030] Figure 5 It is a circuit structure diagram of still another energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention.

[0031] In the figure: 100 - Acquisition control module; 101 - Signal detector; 102 - Signal adjustment circuit; 103 - High-frequency response circuit; 104 - Pulse generator; 105 - Comparator; 106 - Gate circuit; 107 - Signal control circuit; 200 - Adjustment module; a - Charge and discharge circuit; b - First resistor voltage division circuit; c - Feedback network circuit; d - Second resistor voltage division circuit; M - Motor. Specific embodiments

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not used to limit the present invention.

[0033] It should be noted that the orientation or positional relationship indicated by various orientation terms is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. in the description and claims of the present invention are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. Moreover, without conflict, the embodiments in the present invention and the features in the embodiments can be arbitrarily combined with each other. Those of ordinary skill in the art should understand that the drawings provided herein are for illustrative purposes only, and the drawings are not necessarily drawn to scale. When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be an intermediate element.

[0034] In some related technologies, the response speed of the motor energy-saving system is slow and insufficient to meet the needs of rapid changes in motor load. This makes it easy for the motor energy-saving technology to have a situation of untimely response when the motor load changes greatly, resulting in motor jitter, stalling, or even burning. In other related technologies, the motor energy-saving system achieves energy saving by reducing the output power of the motor, and does not truly achieve effective savings in the unit energy consumption of the motor.

[0035] To solve the above problems, the present invention provides an energy-saving device for a three-phase AC asynchronous motor, which can greatly improve the response speed of motor energy saving, meet the stable control and effective energy saving of the motor under different load conditions, and can also effectively save the unit energy consumption of the motor without changing the motor speed and working conditions. The following is a detailed description through specific embodiments.

[0036] Figure 1 It is a structural block diagram of an energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention. As Figure 1As shown, the energy-saving device of the three-phase AC asynchronous motor includes: an acquisition control module 100 and an adjustment module 200. The motor in this embodiment refers to an electric motor.

[0037] Among them, the acquisition control module 100 is connected to the adjustment module 200, and is used to obtain the power factor signal of the motor M in real time, generate an adjustment signal according to the real-time load change situation of the motor M and the power factor signal of the motor M, and send the adjustment signal to the adjustment module 200. The adjustment signal includes the voltage adjustment value and the current adjustment value of the motor M. The adjustment module 200 is connected to the motor M, and is used to adjust the input voltage and input current of the motor M according to the adjustment signal.

[0038] In this embodiment, the acquisition control module generates an adjustment signal according to the real-time load change situation of the motor and the power factor signal of the motor and sends it to the adjustment module. The adjustment module adjusts the input voltage and input current of the motor according to the adjustment signal, so that the motor energy consumption is adjusted in real time with the load change, which can effectively reduce the energy loss during the operation of the motor, realize the effective energy saving and stable control of the motor energy consumption, reduce the energy loss of the motor, and improve the energy-saving effect of the motor.

[0039] During the operation of the motor, when the load of the motor decreases, the acquisition control module will detect in real time that the power factor decreases accordingly. The acquisition control module generates a corresponding adjustment signal according to the decreased power factor, and reduces the input voltage and input current of the motor through the adjustment module to achieve energy consumption savings of the motor. When the load of the motor increases, the acquisition control module will detect in real time that the power factor increases. The control module generates a corresponding adjustment signal according to the increased power factor, and increases the input voltage and input current of the motor through the adjustment module, so as to ensure the stable operation of the motor.

[0040] Figure 2 It is the structural block diagram of another energy-saving device of the three-phase AC asynchronous motor provided by the embodiment of the present invention. As Figure 2 shown, the energy-saving device of the three-phase AC asynchronous motor includes: an acquisition control module 100 and an adjustment module 200. The acquisition control module 100 includes a signal detector 101, a signal adjustment circuit 102 and a high-frequency response circuit 103.

[0041] In this embodiment, the acquisition control module uses a unique acquisition control circuit to collect the voltage and current of the motor in real time, and generates a power factor signal based on the phase difference between the voltage and current of the motor. Specifically, the cosine (cosΦ) of the phase difference (Φ) between the voltage and current is called the power factor, thereby obtaining relevant energy consumption data. The acquisition control module generates an adjustment signal including a voltage adjustment value and a current adjustment value according to the real-time load change of the motor and sends it to the adjustment module in real time. The adjustment module then adjusts the input voltage and input current of the motor according to the voltage adjustment value and the current adjustment value, so that the motor energy consumption is adjusted in real time with the load change, thereby improving the energy-saving effect of the motor and the response speed of the motor energy-saving device by precisely controlling the operating state of the motor.

[0042] Specifically, one input terminal of the signal detector 101 is connected to the phase wire of the motor M, and the other input terminal of the signal detector 101 is connected to the motor wire of the motor M. The output terminal of the signal detector 101 is connected to one input terminal of the signal adjustment circuit 102, which is used to collect the voltage and current of the motor M in real time, generate a power factor signal based on the phase difference between the voltage and current of the motor M, and send the power factor signal to the signal adjustment circuit 102. Among them, the phase wire of the motor M refers to the wire for transmitting electric energy, which is used to transmit the electric energy of the power supply to the motor M. The three-phase AC motor is connected to the three-phase power supply through three phase wires (A, B, C), and each phase wire transmits a phase voltage. The motor wire of the motor M refers to the winding wire inside the motor, which is part of the internal winding of the motor and is used to form the magnetic field and armature circuit of the motor M.

[0043] The signal detector 101 includes two input terminals and one output terminal. One input terminal is connected to the phase wire of the motor M, the other input terminal is connected to the motor wire of the motor M, and the output terminal is connected to the signal adjustment circuit 102, which is used to collect (measure) the input electrical signals of the motor M in real time, including voltage signals and current signals, and provide an output signal proportional to the phase difference between the voltage and current. This signal is the power factor signal. The signal detector 101 provides the power factor signal to the signal adjustment circuit 102.

[0044] Specifically, the input terminal of the high-frequency response circuit 103 is connected to the motor wire of the motor M, and the output terminal of the high-frequency response circuit 103 is connected to the other input terminal of the signal adjustment circuit 102, which is used to sense the load change of the motor M in real time. In response to sensing that the load of the motor M has changed, a load change signal is generated and sent to the signal adjustment circuit 102.

[0045] Among them, the high-frequency response circuit collects electrical signals from the input end of the motor M, senses the load change of the motor according to the collected electrical signals, and the output end of the high-frequency response circuit is connected to the signal adjustment circuit, which is used to generate a load change signal and send it to the signal adjustment circuit when it senses that the load of the motor changes. Moreover, the high-frequency response circuit can instantaneously perform rapid operations when it senses that the load of the motor changes, generate a corresponding load change signal and send it to the signal adjustment circuit, so that the signal adjustment circuit can timely adjust the power factor signal of the motor M.

[0046] Specifically, the output end of the signal adjustment circuit 102 is connected to the adjustment module 200, which is used to adjust the power factor signal according to the load change signal, generate a first control signal as an adjustment signal, and send the adjustment signal to the adjustment module 200.

[0047] Among them, the signal adjustment circuit includes two input ends and one output end. One input end is connected to the signal detector, the other input end is connected to the high-frequency response circuit, and the output end is connected to the adjustment module. After receiving the load change signal output by the high-frequency response circuit, the signal adjustment circuit immediately adjusts the power factor signal of the motor M and outputs a corresponding adjustment signal to the adjustment module, so that the adjustment module can timely adjust the input voltage and input current of the motor M.

[0048] In this embodiment, the high-frequency response circuit can quickly detect the sudden change of the load of the motor M, effectively improving the response speed of the motor energy-saving device. The response speed of the motor energy-saving device is increased by hundreds of times compared with the previous motor energy-saving products, realizing the stable control and effective energy saving of the motor energy-saving products.

[0049] In a specific implementation manner, the high-frequency response circuit 103 includes: an operational amplifier U1, a diode D2, and a charge and discharge circuit a. Among them, the in-phase and anti-phase input ends of the operational amplifier U1 are respectively connected to the motor wires of the motor M, the output end of the operational amplifier U1 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the signal adjustment circuit 102 through the charge and discharge circuit a.

[0050] In this embodiment, since the output terminal of the operational amplifier U1 is connected to the cathode of the diode D2, the positive output of the operational amplifier U1 is blocked by the diode D2, and only the negative output of the operational amplifier U1 can pass through the diode D2. In practical applications, when the motor M is suddenly loaded, the negative voltage increases instantaneously. Since the negative peak is close to zero in the motor M, the sudden change in the load of the motor M will cause an increase in the induced electromotive force, and the generated electrical signal can be amplified in the high-frequency response circuit, thereby effectively improving the effectiveness of its induction. Moreover, since there is no resistor between the output terminal of the operational amplifier U1 and the charge-discharge circuit, the charge-discharge circuit a can be filled instantaneously through the operational amplifier U1 and the diode D2. Through such a design, the rapid change in the load of the motor M can be sensed instantaneously by the high-frequency response circuit, thereby generating a load change signal and sending it to the signal adjustment circuit, so that the signal adjustment circuit adjusts the power factor signal according to the load change signal and generates a corresponding adjustment signal.

[0051] In a specific embodiment, the charge-discharge circuit a includes: a capacitor C2 and a resistor R12. The capacitor C2 is connected in parallel with the resistor R12. One connection point of the two is grounded, and the other connection point of the two is respectively connected to the anode of the diode D2 and the signal adjustment circuit 102.

[0052] Among them, in response to the high-frequency response circuit 103 sensing a change in the load of the motor M, the operational amplifier U1 outputs a negative pulse and charges the capacitor C2 to the peak value through the diode D2 until the capacitor C2 is not applied with voltage, and the resistor R12 discharges the capacitor C2 so that the charge in the capacitor C2 weakens to a preset value.

[0053] In this embodiment, the negative pulse output from the operational amplifier U1 passes through the diode D2. Since there is no resistor in the output of the operational amplifier U1, the capacitor C2 can be charged to the peak value instantaneously, thereby instantaneously sensing the load change of the motor, generating a load change signal and sending it to the signal adjustment circuit so that the signal adjustment circuit receives the load change signal; when the signal adjustment circuit responds to the load change of the motor (generates a corresponding control signal according to the load change situation to control the input voltage and input current of the motor), the capacitor C2 is not applied with voltage. At this time, the capacitor C2 can discharge through the parallel resistor R12, so that the charge in the capacitor C2 quickly weakens to the value when it can accept the next suddenly applied load, and then the high-frequency response circuit can sense the next change in the motor load in real time.

[0054] In a specific embodiment, the high-frequency response circuit 103 further includes: a first resistor voltage-dividing circuit b. The in-phase and anti-phase input terminals of the operational amplifier U1 are respectively connected to the motor wires of the motor M through the first resistor voltage-dividing circuit b.

[0055] Specifically, the first resistor voltage division circuit b includes: resistor R4 and resistor R5. Wherein, one end of resistor R4 is connected to the motor wire of motor M, the other end of resistor R4 is connected to one end of resistor R5, the other end of resistor R5 is grounded, and the connection point of resistor R4 and resistor R5 is also connected to the non-inverting input terminal and the inverting input terminal of operational amplifier U1 respectively.

[0056] In this embodiment, the first resistor voltage division circuit b can provide a stable reference voltage for operational amplifier U1, can also adjust the level of the input signal of operational amplifier U1 to a range suitable for the operational amplifier to process, and can also adjust the input voltage of operational amplifier U1, thereby controlling the operating point of operational amplifier U1.

[0057] In a specific embodiment, the signal adjustment circuit 102 includes: operational amplifier U2. The inverting input terminal of operational amplifier U2 is connected to the output terminal of the signal detector 101, the non-inverting input terminal of operational amplifier U2 is grounded, and the output terminal of operational amplifier U2 is used as the output terminal of the signal adjustment circuit 102 and is connected to the high-frequency response circuit 103 and the adjustment module 200 respectively.

[0058] In this embodiment, operational amplifier U2 adjusts the power factor signal of motor M output by the signal detector according to the load change signal output by the high-frequency response circuit and outputs a corresponding adjustment signal to the adjustment module 200.

[0059] In a specific embodiment, the signal adjustment circuit 102 further includes: a feedback network circuit c. The output terminal of operational amplifier U2 is connected to the high-frequency response circuit 103 through the feedback network circuit c. Correspondingly, one end of the feedback network circuit c is connected to the output terminal of the high-frequency response circuit 103, and the other end of the feedback network circuit c is connected to the output terminal of operational amplifier U2.

[0060] Specifically, the feedback network circuit c includes: resistor R18, resistor R19, resistor R20, capacitor C3, capacitor C4 and capacitor C5. Wherein, the feedback network circuit c is a parallel circuit, which is composed of three parallel branches. The first parallel branch includes capacitor C5, the second parallel branch includes resistor R20 and capacitor C4 connected in series, the third parallel branch includes resistor R18 and resistor R19 connected in series, and capacitor C3 with one end connected to the connection point of resistor R18 and resistor R19 and the other end grounded. A common connection point of these three parallel branches is used as one end of the feedback network circuit c and is connected to the output terminal of the high-frequency response circuit 103, and another common connection point of these three parallel branches is used as the other end of the feedback network circuit c and is connected to the output terminal of operational amplifier U2.

[0061] In this embodiment, the output terminal of the operational amplifier U2 is connected to the feedback network circuit c, which can stabilize the operating point of the operational amplifier U2, reduce the influence on the circuit caused by temperature changes or component parameter changes, improve the frequency response of the operational amplifier U2, enable it to have better performance within the required frequency range, reduce the non-linear distortion of the operational amplifier U2, improve the signal fidelity, and increase the input impedance of the operational amplifier U2 and reduce its output impedance, making it easier to match with the front and rear stage circuits.

[0062] In the related art, the schemes for controlling the voltage and current of the motor through the power factor all adopt the method of mutual inductor sampling, resulting in inaccurate sampling data of the system and slow system response speed, making the related energy-saving products unable to perform stable control under the condition of large motor load changes, and easily causing situations such as traffic jams and motor damage.

[0063] In this embodiment, through the collaborative work of the signal detector, signal adjustment circuit and high-frequency response circuit, and by adopting a unique acquisition control circuit, the motor energy consumption related data such as the voltage, current and power factor of the motor are collected in real time, and the load change of the motor is sensed in real time. According to the motor load change, the input voltage and input current of the motor are adjusted in real time, greatly improving the data accuracy as the basis for energy-saving control and the response speed of the energy-saving device, filling the gaps in technology and products of the motor energy-saving products under the condition of large motor load changes. At the same time, the energy-saving device has high compatibility and can be combined with related energy consumption software for application, providing accurate basic energy consumption data for the energy consumption management and control system.

[0064] Figure 3 It is a structural block diagram of another energy-saving device for a three-phase AC asynchronous motor provided by an embodiment of the present invention. As Figure 3 shown, the energy-saving device for the three-phase AC asynchronous motor includes: an acquisition control module 100 and an adjustment module 200. The acquisition control module 100 includes a signal detector 101, a signal adjustment circuit 102, a high-frequency response circuit 103, a pulse generator 104, a comparator 105 and a gate circuit 106. The pulse generator 104, the comparator 105 and the gate circuit 106 are electrically connected in sequence. Among them, the circuit structures and working principles of the signal detector 101, the signal adjustment circuit 102 and the high-frequency response circuit 103 can be referred to the previous embodiment.

[0065] Specifically, the input end of the pulse generator 104 is connected to the phase wire of the motor M, and the output end of the pulse generator 104 is connected to one input end of the comparator 105, which is used to generate a pulse signal and send the pulse signal to the comparator 105. The output end of the signal adjustment circuit 102 is connected to the other input end of the comparator 105, which is used to send the first control signal to the comparator 105. The output end of the comparator 105 is connected to the input end of the gate circuit 106, which is used to compare the first control signal and the pulse signal to generate a second control signal and send the second control signal to the gate circuit 106. The output end of the gate circuit 106 is connected to the adjustment module 200, and the second control signal is sent to the adjustment module 200 as an adjustment signal, which is used to control the on-time of the adjustment module 200 according to the pulse signal included in the second control signal, and control the adjustment module 200 to adjust the input voltage and input current of the motor M according to the first control signal included in the second control signal.

[0066] In this embodiment, the signal adjustment circuit adjusts the power factor signal according to the load change signal to generate a first control signal and sends the first control signal to the comparator. The pulse signal generated by the pulse generator is also sent to the comparator. The comparator compares the first control signal and the pulse signal to generate a second control signal and sends the second control signal to the gate circuit.

[0067] The gate circuit controls the adjustment module to adjust the input voltage and input current of the motor M according to the first control signal included in the second control signal.

[0068] In addition, as an electronic switch, the gate circuit can affect the on-time of the adjustment module. Since the on / off of the gate circuit is controlled by the pulse signal included in the second control signal, the gate circuit can also control the on-time of the adjustment module through the pulse signal included in the second control signal, and the on-time of the adjustment module follows the period of the pulse signal included in the second control signal. And the on-time of the adjustment module follows the pulse period, so the on-time of the adjustment module can be adjusted by adjusting the pulse period, so as to accurately control the input voltage and input current of the motor, realize the fine adjustment of the motor power, and thus realize the accurate control of the motor energy consumption.

[0069] In a specific embodiment, the high-frequency response circuit 103 includes: an operational amplifier U1, a diode D2, a charge and discharge circuit a, a triode Q2, and a triode Q3. Among them, the circuit structures and connection relationships of the operational amplifier U1, the diode D2, and the charge and discharge circuit a are as described in the previous embodiment, and will not be elaborated here.

[0070] The output terminals of the gate circuit 106 are also respectively connected to the bases of the triode Q2 and the triode Q3. The emitters of the triode Q2 and the triode Q3 are both grounded. The collector of the triode Q2 is connected to the inverting input terminal of the operational amplifier U1, and the collector of the triode Q3 is connected to the non-inverting input terminal of the operational amplifier U1. The gate circuit 106 is further configured to control the triode Q2 to conduct in response to the output of the gate circuit 106 being positive, and control the triode Q3 to conduct in response to the output of the gate circuit 106 being negative.

[0071] In this embodiment, when the output of the gate circuit is positive, the triode Q2 is controlled to conduct, thereby preventing any signal from reaching the inverting input terminal of the operational amplifier U1; when the output of the gate circuit is negative, the triode Q3 is controlled to conduct, thereby preventing any signal from reaching the non-inverting input terminal of the operational amplifier U1.

[0072] In a specific embodiment, the high-frequency response circuit 103 further includes: a resistor R7 and a resistor R9. One end of the resistor R7 is connected to the base of the triode Q2, and the other end of the resistor R7 is connected to the output terminal of the gate circuit; one end of the resistor R9 is connected to the base of the triode Q3, and the other end of the resistor R9 is connected to the output terminal of the gate circuit.

[0073] In this embodiment, by connecting the resistor R7 to the base of the triode Q2 and connecting the resistor R9 to the base of the triode Q3, functions such as current limiting protection, providing a bias voltage, preventing misoperation, stabilizing the operating point, and suppressing noise can be achieved.

[0074] In a specific embodiment, the high-frequency response circuit 103 further includes: a resistor R6, a resistor R8, a resistor R10, and a resistor R11. One end of the resistor R6 is connected to the motor wire of the motor M, and the other end of the resistor R6 is connected to the collector of the triode Q2; one end of the resistor R10 is connected to the collector of the triode Q2, and the other end of the resistor R10 is connected to the inverting input terminal of the operational amplifier U1; one end of the resistor R8 is connected to the motor wire of the motor M, and the other end of the resistor R8 is respectively connected to the collector of the triode Q3 and the non-inverting input terminal of the operational amplifier U1; one end of the resistor R11 is connected to the non-inverting input terminal of the operational amplifier U1, and the other end of the resistor R11 is grounded.

[0075] In this embodiment, it is preferable that the resistances of the resistor R6, the resistor R8, the resistor R10, and the resistor R11 are the same. Thus, the gain of the operational amplifier U1 is the same for the inputs to its non-inverting input terminal and inverting input terminal.

[0076] In a specific embodiment, the gate circuit 106 includes: a triode Q1. The base of the triode Q1 is connected to the output terminal of the comparator as the input terminal of the gate circuit. The emitter of the triode Q1 is grounded, and the collector of the triode Q1 is connected to the adjustment module as the output terminal of the gate circuit.

[0077] In this embodiment, the gate circuit uses a triode to implement the NOT gate function, and has the advantages of high input impedance, low output impedance, high switching speed, good temperature stability, easy integration, low cost, and high reliability.

[0078] In a specific embodiment, the gate circuit 106 further includes: a diode D1 and a capacitor C1. Among them, the anode of the diode D1 is connected to the collector of the triode Q1, the cathode of the diode D2 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is also connected to the collector of the triode Q1.

[0079] Furthermore, the gate circuit 106 further includes: a resistor R2 and a resistor R3. The diode D1 is connected to the capacitor C1 through the resistor R2 and the resistor R3. Specifically, the anode of the diode D1 is connected to the collector of the triode Q1, the cathode of the diode D2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is also connected to the collector of the triode Q1, that is, the diode D1, the resistor R2, the resistor R3, and the capacitor C1 are connected in series in sequence.

[0080] Figure 4 This is a structural block diagram of another energy-saving device for a three-phase AC induction motor provided by the embodiment of the present invention. As Figure 4 shown, the energy-saving device for the three-phase AC induction motor includes: an acquisition control module 100 and an adjustment module 200. The acquisition control module 100 includes a signal detector 101, a signal adjustment circuit 102, a high-frequency response circuit 103, a pulse generator 104, a comparator 105, a gate circuit 106, and a signal control circuit 107. The pulse generator 104, the comparator 105, the gate circuit 106, and the signal control circuit 107 are electrically connected in sequence. Among them, for the circuit structures and working principles of the signal detector 101, the signal adjustment circuit 102, the high-frequency response circuit 103, the pulse generator 104, the comparator 105, and the gate circuit 106, refer to the previous two embodiments.

[0081] Specifically, the input end of the signal control circuit 107 is connected to the output end of the gate circuit 106, the output end of the signal control circuit 107 is connected to the input end of the adjustment module 200, and the output end of the adjustment module 200 is connected to the input end of the motor M. The signal control circuit 107 is also connected to the signal adjustment circuit 102. The signal control circuit is used to generate an adjustment signal according to the second control signal and send the adjustment signal to the adjustment module 200; the signal control circuit is also used to send a blocking control signal to the signal adjustment circuit 102 when entering the non-start state according to the second control signal, so that the signal adjustment circuit 102 is triggered by the blocking control signal to stop working, and send a start control signal to the signal adjustment circuit 102 when entering the start state according to the second control signal, so that the signal adjustment circuit 102 is triggered by the start control signal to start working.

[0082] In this embodiment, after the signal control circuit receives the second control signal sent by the comparator through the gate circuit, it generates and outputs an adjustment signal, and the adjustment module controls the input voltage and input current of the motor according to the adjustment signal.

[0083] In addition, to ensure that the motor M is "not turned on" when the signal control circuit is not working, in the state where the signal control circuit is not started, the signal control circuit sends an electrical signal of "blocking control" to the signal adjustment circuit to make the signal adjustment circuit not work. Correspondingly, to ensure that the motor M is "turned on" when the signal control circuit is working, in the state where the signal control circuit is started, the signal control circuit sends an electrical signal of "starting control" to the signal adjustment circuit to make the signal adjustment circuit work.

[0084] In a specific embodiment, the signal adjustment circuit 102 includes: an operational amplifier U2, a triode Q4, and a potentiometer R15. Among them, the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the signal detector 101, the non-inverting input terminal of the operational amplifier U2 is grounded, and the output terminal of the operational amplifier U2 is used as the output terminal of the signal adjustment circuit 102 and is respectively connected to the output terminal of the high-frequency response circuit 103 and the other input terminal of the comparator 105. The base of the triode Q4 is connected to the signal control circuit 107, the emitter of the triode Q4 is grounded, and the collector of the triode Q4 is respectively connected to the output terminal of the high-frequency response circuit 103 and the output terminal of the operational amplifier U2. The potentiometer R15 is respectively connected to the output terminal of the high-frequency response circuit 103 and the collector of the triode Q4. The signal control circuit 107 is specifically configured to send a blocking control signal to the base of the triode Q4 to make the triode Q4 conduct, or send a starting control signal to the base of the triode Q4 to make the triode Q4 non-conduct.

[0085] In this embodiment, the way for the signal control circuit to control the signal adjustment circuit to work or not work is as follows: the signal control circuit outputs an electrical signal of "blocking control" to the base of the triode Q4 in the signal adjustment circuit to make the triode Q4 conduct, and the potentiometer R15 is short-circuited, then the signal adjustment circuit stops working; the signal control circuit outputs an electrical signal of "starting control" to the base of the triode Q4 in the signal adjustment circuit to make the triode Q4 turn off, then the signal adjustment circuit starts to work.

[0086] In a specific embodiment, the signal control circuit 107 includes: an operational amplifier U3, an operational amplifier U4, a triode Q5, and a potentiometer R22. The inverting input terminal of the operational amplifier U3 is connected to the potentiometer R22, the non-inverting input terminal of the operational amplifier U3 is grounded, the output terminal of the operational amplifier U3 is respectively connected to the output terminal of the gate circuit 106 and the collector of the triode Q5. The collector of the triode Q5 is also connected to the signal adjustment circuit 102, specifically to the output terminal of the operational amplifier U2 of the signal adjustment circuit 102. The emitter of the triode Q5 is grounded. The inverting input terminal of the operational amplifier U4 is connected to the inverting input terminal of the operational amplifier U3, the non-inverting input terminal of the operational amplifier U4 is connected to the input terminal of the adjustment module 200, and the output terminal of the operational amplifier U4 is connected to the base of the triode Q5. The output terminal of the operational amplifier U4 is also connected to the signal adjustment circuit 102, specifically to the base of the triode Q4 of the signal adjustment circuit 102, for sending the stop control signal or the start control signal to the signal adjustment circuit 102.

[0087] In this embodiment, the start state of the signal control circuit also follows the pulse period output by the comparator, so as to control the working state of the signal adjustment circuit.

[0088] In a specific embodiment, the signal control circuit 107 further includes: a second resistor voltage dividing circuit d. The non-inverting input terminal of the operational amplifier U4 is connected to the input terminal of the adjustment module 200 through the second resistor voltage dividing circuit d.

[0089] Specifically, the second resistor voltage dividing circuit d includes: a resistor R28 and a resistor R29. Wherein, one end of the resistor R28 is connected to the input terminal of the adjustment module 200, the other end of the resistor R28 is respectively connected to one end of the resistor R29 and the non-inverting input terminal of the operational amplifier U4, and the other end of the resistor R29 is grounded.

[0090] In this embodiment, the second resistor voltage dividing circuit d can provide a stable reference voltage for the operational amplifier U4 and the operational amplifier U3, can also adjust the level of the input signals of the operational amplifier U4 and the operational amplifier U3 to a range suitable for operational amplifier processing, and can also adjust the input voltages of the operational amplifier U4 and the operational amplifier U3, so as to control the operating points of the operational amplifier U4 and the operational amplifier U3.

[0091] Figure 5 This is the circuit structure diagram of another energy-saving device for a three-phase AC asynchronous motor provided by the embodiment of the present invention. As Figure 5 shown, the energy-saving device for the three-phase AC asynchronous motor includes: an acquisition control module 100 and an adjustment module 200. The acquisition control module 100 includes a signal detector 101, a signal adjustment circuit 102, a high-frequency response circuit 103, a pulse generator 104, a comparator 105, a gate circuit 106, and a signal control circuit 107.

[0092] Among them, the gate circuit 106 includes a triode Q1.

[0093] The base of the triode Q1 is electrically connected to the comparator 105 through the resistor R1. The collector of the triode Q1 is respectively electrically connected to the diode D1 and the capacitor C1. The emitter of the triode Q1 is grounded. The diode D1 is sequentially electrically connected to the capacitor C1 through the resistors R2 and R3.

[0094] The gate circuit 106 is an electronic switch that can adjust and control the output signal of the circuit to the adjustment module 200, thereby affecting the on-time of the adjustment module 200; and the on / off of the gate circuit 106 is controlled by the output pulse of the comparator 105. Therefore, the on-time of the adjustment module 200 follows the period of the pulse output by the comparator 105.

[0095] The signal adjustment circuit 102 includes a potentiometer R15, a triode Q4, a feedback network circuit c, and an operational amplifier U2.

[0096] The collector of the triode Q4 is connected to the resistor R17. The emitter of the triode Q4 is grounded. The base of the triode Q4 is electrically connected to the signal control circuit 107. The collector of the triode Q4 is also connected to the high-frequency response circuit 103. The collector of the triode Q4 is also connected to the potentiometer R15 through the resistor R16.

[0097] The feedback network circuit c is composed of resistors R18, R19, R20 and capacitors C3, C4, C5. One end of the feedback network circuit c is connected to the collector of the triode Q4 through the resistor R17. The other end of the feedback network circuit c is connected to the output terminal of the operational amplifier U2. One end of the feedback network circuit c is also connected to the signal control circuit 107.

[0098] The non-inverting input terminal of the operational amplifier U2 is grounded through the resistor R21. The inverting input terminal of the operational amplifier U2 is connected to the signal detector 101. The output terminal of the operational amplifier U2 is connected to the comparator 105.

[0099] The signal control circuit includes a potentiometer R22, operational amplifiers U3, U4, and a triode Q5.

[0100] The inverting input terminal of the operational amplifier U3 is connected to the potentiometer R22 through the resistor R23. The non-inverting input terminal of the operational amplifier U3 is grounded. The inverting input terminal of the operational amplifier U3 is also connected to the inverting input terminal of the operational amplifier U4 through the capacitor C6.

[0101] The non-inverting input terminal of the operational amplifier U4 is connected to the adjustment module 200 through the second resistor voltage division circuit d. The output terminal of the operational amplifier U4 is connected to the signal adjustment circuit 102 through the resistor R30.

[0102] The base of the triode Q5 is connected to the output terminal of the operational amplifier U4 through the resistor R31. The collector of the triode Q5 is connected to the output terminal of the operational amplifier U3 through the resistor R24, and the emitter of the triode Q5 is grounded. The collector of the triode Q5 is also connected to the gate circuit 106. The collector of the triode Q5 is also connected to the signal adjustment circuit 102 through the resistor R25. The connection point of the resistor R24 and the resistor R25 is connected to one end of the resistor R26, and the other end of the resistor R26 is connected to the potentiometer R27.

[0103] To ensure that the motor M does not "turn on" when the signal control circuit 107 is not working, in the unstarted state, the signal control circuit 107 is used to provide a "blocking control" electrical signal to the signal adjustment circuit 102 to make the signal adjustment circuit 102 not work. This is achieved by the signal control circuit 107 outputting an electrical signal to the base of the PNP triode Q4 to make the triode Q4 conduct, and the potentiometer R15 is short-circuited.

[0104] The high-frequency response circuit includes the triode Q2, the triode Q3, the diode D2, and the operational amplifier U1.

[0105] The base of the triode Q2 and the base of the triode Q3 are respectively connected through the resistors R7 and R9, and the connection point of the resistors R7 and R9 is connected to the gate circuit 106. The collectors of the triode Q2 and the triode Q3 are respectively connected through the resistors R6 and R8, and are also connected to the motor wire of the motor M through the first resistor voltage division circuit a. The emitters of the triode Q2 and the triode Q3 are grounded.

[0106] The non-inverting input terminal of the operational amplifier U1 is connected to the collector of the triode Q3. The non-inverting input terminal of the operational amplifier U1 is also grounded through the resistor R11. The inverting input terminal of the operational amplifier U1 is connected to the collector of the triode Q2 through the resistor R10, and the output terminal of the operational amplifier U1 is connected to the diode D2. The output terminal of the operational amplifier U1 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the charge and discharge circuit a.

[0107] The charge and discharge circuit a includes a capacitor C2 and a resistor R12 connected in parallel. One connection point of the capacitor C2 and the resistor R12 is connected to the anode of the diode D2, and the other connection point of the capacitor C2 and the resistor R12 is grounded. That is, the anode of the diode D2 is respectively connected to the capacitor C2 and the resistor R12, and the capacitor C2 and the resistor R12 are grounded. The other connection point of the capacitor C2 and the resistor R12 is connected to the signal adjustment circuit 102 through the resistor R13, the capacitor C2', and the resistor R14. Specifically, the resistor R13 is in parallel with the capacitor C2'. One connection point of the two is connected to the anode of the diode D2, and the other connection point of the two is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the signal adjustment circuit 102.

[0108] The output of the gate circuit 106 is connected to the base of the triode Q2 through the resistor R7 and to the base of the triode Q3 through the resistor R9. When the output of the gate circuit 106 is positive, it controls the triode Q2 to conduct, thereby preventing any signal from reaching the inverting input terminal of the operational amplifier U1; when the output of the gate circuit 106 is negative, it controls the triode Q3 to conduct, thereby preventing any signal from reaching the non-inverting input terminal of the operational amplifier U1. The values of the resistors R6, R8, R10, and R11 are the same. Therefore, the gain of the operational amplifier U1 is the same for the inputs to its non-inverting and inverting input terminals.

[0109] The positive output of the operational amplifier U1 is blocked by the diode D2, and the diode D2 only conducts through the negative output of the operational amplifier U1; when the motor M is suddenly loaded, this negative voltage increases instantaneously. Since the negative peak is close to zero in the motor M, the sudden change in the motor load causes an increase in the induced electromotive force. These signals can be amplified in the high-frequency response circuit 103, thereby improving the effectiveness of its load signal perception. The negative pulse from the operational amplifier U1 passes through the diode D2. Since there is no resistor at the output of the operational amplifier U1, the capacitor C2 can be charged to the peak value instantaneously. Through such a design, a rapid change in the load will be sensed by the high-frequency response circuit 103 instantaneously, and a signal is generated and sent to the signal adjustment circuit 102, enabling the signal adjustment circuit 102 to respond to the load change in a timely manner. When the signal adjustment circuit 102 responds to the load change, the capacitor C2 is not applied with voltage, and at the same time, the capacitor C2 is immediately discharged by the parallel resistor R12, and the charge rapidly weakens to a value that the capacitor C2 can accept for the next sudden application of the load.

[0110] Since the high-frequency response circuit 103 can perform rapid operations instantaneously, the input signal is sent into the control system along with a gain signal, thereby improving the stability of the system.

[0111] The input terminal of the adjustment module 200 is connected to the signal control circuit 107, and the output terminal of the adjustment module 200 is connected to the motor M. The voltage and current at the input terminal of the motor M are adjusted in real time through the control signal issued by the signal control circuit 107 to achieve greater energy conservation and stable control.

[0112] The energy-saving device for a three-phase AC asynchronous motor provided by the embodiment of the present invention, wherein the acquisition control module collects relevant energy consumption data such as the voltage, current, and power factor of the motor in real time through a unique acquisition control circuit, and in combination with the adjustment module, adjusts the input voltage and current of the motor in real time and dynamically according to the real-time load change situation of the motor, so as to achieve real-time adjustment of the motor energy consumption and energy-saving effect, and realize real-time optimization of the energy consumption.

[0113] Specifically, the signal detector measures the current and voltage of the motor in real time and provides an output signal (i.e., power factor signal) proportional to the phase difference between the voltage and current. The signal adjustment circuit adjusts the power factor signal and outputs a control signal. The signal control circuit generates an adjustment signal based on the control signal, and the adjustment module controls the input voltage and current of the motor according to the adjustment signal.

[0114] The high-frequency response circuit can instantaneously sense the rapid changes in the load and, through the signal adjustment circuit, quickly and timely respond to the load changes, improving the response speed and stability of the system. The high-frequency response circuit quickly responds to the load changes through negative pulse signals and realizes the rapid transmission of signals and the improvement of system stability through the charge and discharge mechanism of the capacitor. By quickly detecting the sudden changes in the motor load through the high-frequency response circuit, the response speed of the motor energy-saving device is increased by hundreds of times compared with previous products, achieving stable control and effective energy saving.

[0115] The gate circuit controls the on-time of the adjustment module through the pulses output by the comparator. The on-time of the adjustment module follows the pulse period output by the comparator, thereby achieving precise control of the motor energy consumption.

[0116] The signal control circuit provides an electrical signal of "blocking control" in the unstarted state, making the signal adjustment circuit inoperative and ensuring that the motor does not "turn on" when the signal control circuit is not working.

[0117] The adjustment module adjusts the voltage and current at the input end of the motor in real time through the control signal sent by the signal control circuit, achieving greater energy savings and stable control.

[0118] In summary, the motor energy-saving device described in the present invention can more accurately obtain the motor operation data during the motor operation process, and more accurately adjust the input voltage and input current of the motor according to the actual operation conditions of the motor, thereby providing a more refined energy consumption control strategy to achieve the best energy-saving effect of the motor under different loads, realizing greater energy savings, and improving the response speed to sudden loads.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy-saving device for a three-phase AC asynchronous motor, characterized in that: include: An acquisition control module and an adjustment module; the acquisition control module is connected to the adjustment module and is used to acquire the power factor signal of the motor in real time, generate an adjustment signal according to the real-time load change of the motor and the power factor signal of the motor, and send the adjustment signal to the adjustment module, wherein the adjustment signal includes the voltage adjustment value and the current adjustment value of the motor; the adjustment module is connected to the motor and is used to adjust the input voltage and input current of the motor according to the adjustment signal.

2. The energy-saving device for a three-phase AC asynchronous motor according to claim 1, characterized in that: The acquisition control module includes: a signal detector, a signal adjustment circuit and a high-frequency response circuit; one input end of the signal detector is connected to the phase line of the motor, the other input end of the signal detector is connected to the motor line, and the output end of the signal detector is connected to an input end of the signal adjustment circuit, which is used to collect the voltage and current of the motor in real time, generate a power factor signal according to the phase difference between the voltage and current of the motor, and send the power factor signal to the signal adjustment circuit; the input end of the high-frequency response circuit is connected to the motor line, and the output end of the high-frequency response circuit is connected to the other input end of the signal adjustment circuit, which is used to sense the load change of the motor in real time, and in response to sensing the load change of the motor, generate a load change signal and send the load change signal to the signal adjustment circuit; the output end of the signal adjustment circuit is connected to the adjustment module, which is used to adjust the power factor signal according to the load change signal, generate a first control signal as the adjustment signal, and send the adjustment signal to the adjustment module.

3. The energy-saving device for a three-phase AC asynchronous motor according to claim 2, characterized in that: The high-frequency response circuit includes: an operational amplifier U1, a diode D2 and a charge-discharge circuit; the in-phase and inverting input terminals of the operational amplifier U1 are respectively connected to the motor lines, the output terminal of the operational amplifier U1 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the signal adjustment circuit through the charge-discharge circuit.

4. The energy-saving device for a three-phase AC asynchronous motor according to claim 3, characterized in that: The charging and discharging circuit includes: a capacitor C2 and a resistor R12; the capacitor C2 and the resistor R12 are connected in parallel, one of the connection points between the two is grounded, and the other connection points between the two are respectively connected to the anode of the diode D2 and the signal adjustment circuit; wherein, in response to the high-frequency reaction circuit sensing the change in the load of the motor, the operational amplifier U1 outputs a negative pulse and charges the capacitor C2 to a peak value through the diode D2 until no voltage is applied to the capacitor C2, and the resistor R12 discharges the capacitor C2 to reduce the charge in the capacitor C2 to a preset value.

5. The energy-saving device for a three-phase AC asynchronous motor according to claim 3, characterized in that: The high-frequency response circuit also includes: a first resistor voltage divider circuit; the in-phase and inverting input terminals of the operational amplifier U1 are respectively connected to the motor line through the first resistor voltage divider circuit.

6. The energy-saving device for a three-phase AC asynchronous motor according to claim 2, characterized in that: The signal adjustment circuit includes: an operational amplifier U2; the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the signal detector, the non-inverting input terminal of the operational amplifier U2 is grounded, and the output terminal of the operational amplifier U2 is connected to the high-frequency response circuit and the adjustment module as the output terminal of the signal adjustment circuit.

7. The energy-saving device for a three-phase AC asynchronous motor according to claim 6, characterized in that: The signal adjustment circuit further includes: a feedback network circuit; the output end of the operational amplifier U2 is connected to the high-frequency response circuit through the feedback network circuit.

8. The energy-saving device for a three-phase AC asynchronous motor according to claim 3, characterized in that: The acquisition control module also includes: a pulse generator, a comparator and a gate circuit; the input end of the pulse generator is connected to the phase line of the motor, and the output end of the pulse generator is connected to an input end of the comparator, which is used to generate a pulse signal and send the pulse signal to the comparator; the output end of the signal adjustment circuit is connected to the other input end of the comparator, which is used to send the first control signal to the comparator; the output end of the comparator is connected to the input end of the gate circuit, which is used to compare the first control signal and the pulse signal to generate a second control signal, and send the second control signal to the gate circuit; the output end of the gate circuit is connected to the adjustment module, and the second control signal is sent to the adjustment module as the adjustment signal, which is used to control the opening time of the adjustment module according to the pulse signal contained in the second control signal, and control the adjustment module to adjust the input voltage and input current of the motor according to the first control signal contained in the second control signal.

9. The energy-saving device for a three-phase AC asynchronous motor according to claim 8, characterized in that: The high-frequency response circuit also includes: a transistor Q2 and a transistor Q3; the output end of the gate circuit is also connected to the base of the transistor Q2 and the base of the transistor Q3 respectively, the emitter of the transistor Q2 and the emitter of the transistor Q3 are both grounded, the collector of the transistor Q2 is connected to the inverting input end of the operational amplifier U1, and the collector of the transistor Q3 is connected to the non-inverting input end of the operational amplifier U1; the gate circuit is also used to control the transistor Q2 to be turned on in response to the output of the gate circuit being positive, and to control the transistor Q3 to be turned on in response to the output of the gate circuit being negative.

10. The energy-saving device for a three-phase AC asynchronous motor according to claim 9, characterized in that: The high frequency response circuit further includes: a resistor R7 and a resistor R9; one end of the resistor R7 is connected to the base of the transistor Q2, and the other end of the resistor R7 is connected to the output end of the gate circuit; one end of the resistor R9 is connected to the base of the transistor Q3, and the other end of the resistor R9 is connected to the output end of the gate circuit; and / or, The high-frequency response circuit also includes: a resistor R6, a resistor R8, a resistor R10 and a resistor R11; one end of the resistor R6 is connected to the motor line, and the other end of the resistor R6 is connected to the collector of the transistor Q2; one end of the resistor R10 is connected to the collector of the transistor Q2, and the other end of the resistor R10 is connected to the inverting input terminal of the operational amplifier U1; one end of the resistor R8 is connected to the motor line, and the other end of the resistor R8 is respectively connected to the collector of the transistor Q3 and the non-inverting input terminal of the operational amplifier U1; one end of the resistor R11 is connected to the non-inverting input terminal of the operational amplifier U1, and the other end of the resistor R11 is grounded.

11. The energy-saving device for a three-phase AC asynchronous motor according to claim 8, characterized in that: The gate circuit includes: a transistor Q1; the base of the transistor Q1 is connected to the output end of the comparator as the input end of the gate circuit, the emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 is connected to the adjustment module as the output end of the gate circuit.

12. The energy-saving device for a three-phase AC asynchronous motor according to claim 8, characterized in that: The acquisition control module also includes: a signal control circuit; the input end of the signal control circuit is connected to the output end of the gate circuit, and the output end of the signal control circuit is connected to the input end of the adjustment module; the signal control circuit is also connected to the signal adjustment circuit, and is used to generate the adjustment signal according to the second control signal, and send the adjustment signal to the adjustment module, and is also used to send a blocking control signal to the signal adjustment circuit when the second control signal enters a non-start state, so that the signal adjustment circuit stops working when triggered by the blocking control signal, and send a starting control signal to the signal adjustment circuit when the second control signal enters a starting state, so that the signal adjustment circuit starts working when triggered by the starting control signal.

13. The energy-saving device for a three-phase AC asynchronous motor according to claim 12, characterized in that: The signal adjustment circuit includes: an operational amplifier U2, a transistor Q4 and a potentiometer R15; the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the signal detector, the non-inverting input terminal of the operational amplifier U2 is grounded, and the output terminal of the operational amplifier U2 is connected to the output terminal of the high-frequency reaction circuit and the other input terminal of the comparator as the output terminal of the signal adjustment circuit; the base of the transistor Q4 is connected to the signal control circuit, the emitter of the transistor Q4 is grounded, and the collector of the transistor Q4 is connected to the output terminal of the high-frequency reaction circuit and the output terminal of the operational amplifier U2 respectively; the potentiometer R15 is connected to the output terminal of the high-frequency reaction circuit and the collector of the transistor Q4 respectively; the signal control circuit is specifically used to send the blocking control signal to the base of the transistor Q4 to turn on the transistor Q4, or send the start control signal to the base of the transistor Q4 to turn off the transistor Q4.

14. The energy-saving device for a three-phase AC asynchronous motor according to claim 12, characterized in that: The signal control circuit includes: an operational amplifier U3, an operational amplifier U4, a transistor Q5 and a potentiometer R22; the inverting input terminal of the operational amplifier U3 is connected to the potentiometer R22, the non-inverting input terminal of the operational amplifier U3 is grounded, the output terminal of the operational amplifier U3 is respectively connected to the output terminal of the gate circuit and the collector of the transistor Q5, and the emitter of the transistor Q5 is grounded; the inverting input terminal of the operational amplifier U4 is connected to the inverting input terminal of the operational amplifier U3, the non-inverting input terminal of the operational amplifier U4 is connected to the input terminal of the adjustment module, and the output terminal of the operational amplifier U4 is connected to the base of the transistor Q5; the output terminal of the operational amplifier U4 is also connected to the signal adjustment circuit, and is used to send the blocking control signal or the starting control signal to the signal adjustment circuit.

15. The energy-saving device for a three-phase AC asynchronous motor according to claim 14, characterized in that: The signal control circuit further includes: a second resistor voltage divider circuit; the in-phase input terminal of the operational amplifier U4 is connected to the input terminal of the adjustment module through the second resistor voltage divider circuit.

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