Motor control system, control method and motor system

Abstract

This invention proposes a motor control system, control method, and motor system. The motor control system includes a motor drive circuit and a load control circuit. The motor drive circuit has a first input terminal, a second input terminal, a first output terminal, a second output terminal, and a ground potential terminal. The motor drive circuit is used to convert AC power from an AC power source into chopped AC power before applying it to the motor. The motor drive circuit includes a chopper circuit. The load control circuit includes a first thyristor and a thyristor drive circuit. The first terminal of the first thyristor is coupled to a first load, and the thyristor drive circuit is coupled to the gate of the first thyristor. The load control circuit is used to control the on / off state of the power supply circuit in which the first load is located. The motor control system, control method, and motor system proposed in this invention effectively simplify the power supply configuration of the motor control system and solve the problem of isolated communication, realize efficient, quiet, and stepless speed regulation of the motor, and simplify the load control circuit of the first load.

Description

Technical Field

[0001] This invention belongs to the field of electronic circuit technology, and relates to a control circuit technology, particularly to a motor control system, control method, and motor system. Background Technology

[0002] Fans occupy a very important position in the home appliance industry. Traditional household electric fans generally use unidirectional AC asynchronous motors and employ mechanical switch tap speed control or thyristor chopper speed control. However, tap speed control is inefficient, produces noticeable noise at low speeds, and cannot provide deep speed adjustment. While thyristor chopper speed control can solve the problem of wide-range speed adjustment to some extent, it also introduces electromagnetic noise. The bridgeless fan light driver circuit solution provides a direct AC / AC converter (DAAC) single-phase motor drive topology circuit, which can effectively solve many problems of single-phase motor efficiency, noise, and speed control. Specifically, direct AC / AC conversion means that the drive circuit is directly connected to the AC power supply output, converting the AC power output into chopped AC power, which is then used to drive the motor.

[0003] In specific household appliance applications, such as some fan-type appliances, thyristors are often required to drive loads that only have two states: on and off. Specifically, in a floor fan, in addition to the main motor controlling the fan's rotation, a oscillating motor is also needed. This oscillating motor uses a thyristor to control the on / off state of its power supply circuit. Similarly, a fan-shaped light also requires a thyristor to control the on / off state of the power supply circuit for the light panel. Since the gate of these thyristors and the DAAC topology cannot share a common ground, an additional isolated power supply is required. For example... Figure 1 As shown, the DAAC topology circuit includes two half-bridges. The first and second input terminals of the DAAC topology circuit are coupled to the power supply Vac, respectively. The first and second output terminals of the DAAC topology circuit are coupled to the motor M, respectively. The first terminal of the on / off load RL is coupled to the first terminal of the thyristor T1', the second terminal of the on / off load RL is coupled to the second input terminal of the DAAC topology circuit, and the second terminal of the thyristor T1' is coupled to the first input terminal of the DAAC topology circuit. Figure 1 As can be seen from the existing scheme, the gate of the thyristor T1' cannot share a common ground with the DAAC topology circuit. In the existing technology, an additional isolation power supply is required to drive the thyristor. In addition, isolated signals need to be handled between the two ground systems, which not only increases cost but also increases system complexity.

[0004] In view of this, there is a need to provide a new structure or control method to solve the aforementioned technical problems. Summary of the Invention

[0005] To address at least some of the aforementioned problems, this invention proposes a motor control system, a control method, and a motor system. This invention effectively simplifies the power supply configuration of the motor control system and solves the problem of isolated communication, achieving efficient, quiet, and stepless speed regulation of the motor, and simplifies the load control circuit of the first load.

[0006] One embodiment of the present invention discloses a motor control system, the motor control system comprising:

[0007] A motor drive circuit has a first input terminal, a second input terminal, a first output terminal, a second output terminal, and a ground potential terminal; the first and second input terminals are used to couple to an AC power supply, and the first and second output terminals are used to couple to a motor; the motor drive circuit converts the AC power from the AC power supply into chopped AC power and applies it to the motor to drive the motor; the motor drive circuit includes a chopper circuit, which includes two half-bridges; and

[0008] A load control circuit includes a first thyristor and a thyristor drive circuit. The first terminal of the first thyristor is coupled to a first load, and the thyristor drive circuit is coupled to the gate of the first thyristor. The load control circuit controls the on / off state of the power supply circuit in which the first load is located.

[0009] The second terminal of the first thyristor is coupled to the first input terminal of the motor drive circuit, and the second input terminal of the motor drive circuit is used to couple to the first load; or, the second terminal of the first thyristor is coupled to the second input terminal of the motor drive circuit, and the first input terminal of the motor drive circuit is used to couple to the first load.

[0010] In one embodiment of the present invention, the thyristor driving circuit includes a fifth switch, which is used to control the switching state of the first thyristor.

[0011] In one embodiment of the present invention, the thyristor driving circuit includes:

[0012] Auxiliary power supply;

[0013] The fifth switch has its first terminal coupled to the auxiliary power supply;

[0014] The first capacitor has its first terminal coupled to the second terminal of the fifth switch, and its second terminal coupled to the second terminal of the first thyristor.

[0015] A first resistor, the first end of which is coupled to the first end of a first capacitor, and the second end of which is coupled to the gate of a first thyristor; and

[0016] The fifth diode is coupled between the auxiliary power supply and the first capacitor. The anode of the fifth diode is coupled to the auxiliary power supply, and the cathode of the fifth diode is coupled to the first terminal of the first capacitor.

[0017] In one embodiment of the present invention, the thyristor driving circuit further includes:

[0018] A synchronous control circuit is used to control the first thyristor to be in the on state when the voltage of the AC power supply is in a set region near the zero crossing point, and / or to control the first thyristor to be in the off state when the enable signal is in the first state; wherein the enable signal is used to control the switching state of the first thyristor.

[0019] In one embodiment of the present invention, the thyristor driving circuit further includes:

[0020] The trigger has a first input terminal coupled to an enable signal terminal to obtain an enable signal for controlling the switching state of the first thyristor, a second input terminal coupled to a zero-crossing detection signal terminal to obtain a zero-crossing detection signal of the AC power supply, and an output terminal coupled to the control terminal of a fifth switch. It is used to control the first thyristor to be in the on state when the enable signal is in the first state and to control the first thyristor to be in the off state when the enable signal is in the second state, within a set region near the zero-crossing point of the AC power supply.

[0021] In one embodiment of the present invention, the trigger is a D trigger, the D input terminal of the D trigger is coupled to the enable signal terminal, the clock signal input terminal of the D trigger is coupled to the zero-crossing detection signal terminal, and the output terminal of the D trigger is coupled to the control terminal of the fifth switch.

[0022] In one embodiment of the present invention, the fifth switch is a low-voltage transistor or a controller output port with current driving capability.

[0023] In one embodiment of the present invention, the load control circuit includes at least two thyristors, including a first thyristor and a second thyristor. The first end of the second thyristor is used to couple to a second load, and the second end of the second thyristor is coupled to the second end of the first thyristor. The thyristor drive circuit is coupled to the gate of the second thyristor. The load control circuit is also used to control the on / off state of the power supply circuit in which the second load is located.

[0024] In one embodiment of the present invention, the thyristor driving circuit further includes:

[0025] The sixth switch has its first terminal coupled to the auxiliary power supply;

[0026] The second capacitor has its first terminal coupled to the second terminal of the sixth switch, and its second terminal coupled to the second terminal of the second thyristor.

[0027] The second resistor has its first end coupled to the first end of the second capacitor and its second end coupled to the gate of the second thyristor; and

[0028] The sixth diode is coupled between the auxiliary power supply and the second capacitor. The anode of the sixth diode is coupled to the auxiliary power supply, and the cathode of the sixth diode is coupled to the first terminal of the second capacitor.

[0029] An embodiment of the present invention also discloses a motor system, which includes a motor, a first load, and a motor control system as described in any of the preceding claims. The first end of the motor is coupled to the first output terminal of a motor drive circuit, the second end of the motor is coupled to the second output terminal of the motor drive circuit, the first end of the first load is coupled to a first thyristor, and the second end of the first load is coupled to an AC power supply.

[0030] An embodiment of the present invention also discloses a control method for a motor control system. The motor control system includes a motor drive circuit and a load control circuit. The motor drive circuit includes a chopper circuit, which includes two half-bridges. The load control circuit is used to control the on / off state of the power supply circuit where the first load is located. The control method includes:

[0031] The alternating current (AC) from the AC power supply is converted into chopped AC current using a chopper circuit and then applied to the motor to drive it.

[0032] The on / off state of the power supply circuit of the first load is controlled by the load control circuit, so as to control the working state of the first load.

[0033] In one embodiment of the present invention, the load control circuit includes a first thyristor and a thyristor driving circuit. The first thyristor is coupled to a first load. The thyristor driving circuit includes a fifth switch, which is used to control the switching state of the first thyristor. The control method includes controlling the switching state of the fifth switch to control the operating state of the first load.

[0034] In one embodiment of the present invention, the two half-bridges are a first half-bridge and a second half-bridge, the first half-bridge is coupled to a first thyristor, and the control method includes: controlling the first half-bridge to be directly connected when the AC power supply is in the negative half-cycle.

[0035] This invention proposes a motor control system, a control method, and a motor system. The motor control system includes a motor drive circuit and a load control circuit. The first and second input terminals of the motor drive circuit are coupled to an AC power supply, and the first and second output terminals of the motor drive circuit are coupled to a motor. The motor drive circuit converts the AC power from the AC power supply into chopped AC power and applies it to the motor to drive the motor. The motor drive circuit includes a chopper circuit, which comprises two half-bridges. The load control circuit includes a first thyristor and a thyristor drive circuit. The first terminal of the first thyristor is coupled to a first load, and the thyristor drive circuit is coupled to the gate of the first thyristor. The load control circuit controls the on / off state of the power supply circuit containing the first load. Alternatively, the second terminal of the first thyristor is coupled to the first input terminal of the motor drive circuit, and the second input terminal of the motor drive circuit is coupled to the first load; or, the second terminal of the first thyristor is coupled to the second input terminal of the motor drive circuit, and the first input terminal of the motor drive circuit is coupled to the first load. The present invention proposes a motor control system, control method, and motor system, which effectively simplifies the power supply configuration of the motor control system and solves the problem of isolated communication, realizes efficient and quiet stepless speed regulation of the motor, and simplifies the load control circuit of the first load. Attached Figure Description

[0036] Figure 1 A circuit diagram of a prior art motor control system is shown;

[0037] Figure 2 A circuit diagram of a motor system according to an embodiment of the present invention is shown;

[0038] Figure 3 A circuit diagram of a motor system according to another embodiment of the present invention is shown;

[0039] Figure 4 A circuit diagram of a motor system according to yet another embodiment of the present invention is shown;

[0040] Figure 5 A circuit diagram of a first load according to an embodiment of the present invention is shown. Detailed Implementation

[0041] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0043] The description in this section pertains to only a few typical embodiments, and the present invention is not limited to the scope of the embodiments described. Substitution of identical or similar prior art methods with some technical features in the embodiments is also within the scope of the description and protection of this invention.

[0044] The term "coupled" or "connected" in the instruction manual includes both direct and indirect connections. An indirect connection is a connection made through an intermediate medium, such as a connection made through an electrically conductive medium, which may have parasitic inductance or capacitance. An indirect connection may also include connections made through other active or passive devices to achieve the same or similar functional purpose, such as connections made through circuits or components such as switches or follower circuits.

[0045] An embodiment of this invention discloses a motor control system, which includes a motor drive circuit and a load control circuit. The motor drive circuit has a first input terminal, a second input terminal, a first output terminal, a second output terminal, and a ground potential terminal. The first input terminal of the motor drive circuit is coupled to a first terminal of an AC power supply, the second input terminal of the motor drive circuit is coupled to a second terminal of the AC power supply, the first output terminal of the motor drive circuit is coupled to a first terminal of the motor, and the second output terminal of the motor drive circuit is coupled to a second terminal of the motor. The motor drive circuit is used to convert the AC power from the AC power supply into chopped AC power and then apply it to the motor, thereby controlling the motor's operating state. This invention, by adjusting the duty cycle of the chopped AC power, can achieve stepless speed regulation of the motor, unlike conventional gear speed regulation. When the duty cycle is 0, the motor stops working. When the duty cycle is greater than 0, the motor works. In this embodiment of the invention, the motor drive circuit includes a chopper circuit, which includes two half-bridges.

[0046] Furthermore, the load control circuit includes a first thyristor and a thyristor drive circuit. A first terminal of the first thyristor is coupled to a first load, and the thyristor drive circuit is coupled to the gate of the first thyristor. The load control circuit controls the on / off state of the power supply circuit in which the first load is located. In one embodiment, a second terminal of the first thyristor is coupled to a first input terminal of a motor drive circuit, and the second input terminal of the motor drive circuit is coupled to the first load. In another embodiment, a second terminal of the first thyristor is coupled to a second input terminal of the motor drive circuit, and the first input terminal of the motor drive circuit is coupled to the first load.

[0047] This invention can effectively solve the common ground problem of motor drive circuit and thyristor drive circuit, effectively simplify the power supply configuration of motor control system and solve the problem of isolated communication. It can eliminate one isolation power supply and the communication processing circuit of two non-common ground systems, realize efficient and quiet stepless speed regulation of motor, and simplify the load control circuit of the first load.

[0048] In one embodiment of the present invention, such as Figure 2As shown, the motor system includes a motor M, a first load RL1, and a motor control system. The motor control system includes a motor drive circuit 11 and a load control circuit 12. The motor drive circuit 11 has a first input terminal, a second input terminal, a first output terminal, a second output terminal, and a ground potential terminal. The first input terminal of the motor drive circuit 11 is coupled to the first terminal of the AC power supply Vac, and the second input terminal of the motor drive circuit 11 is coupled to the second terminal of the AC power supply Vac. The first output terminal of the motor drive circuit 11 is coupled to the first terminal of the motor M, and the second output terminal of the motor drive circuit 11 is coupled to the second terminal of the motor M. The motor drive circuit 11 is used to convert the AC power from the AC power supply Vac into chopped AC power and then apply it to the motor M, thereby controlling the operation of the motor M. The motor drive circuit 11 includes a chopper circuit, which includes two half-bridges, namely a first half-bridge and a second half-bridge. The first half-bridge includes a first switch Q1 and a second switch Q2, and the second half-bridge includes a third switch Q3 and a fourth switch Q4. In one embodiment of the present invention, the motor is a single-phase induction motor or other single-phase asynchronous motor after capacitor compensation.

[0049] In such Figure 2 In this embodiment, the load control circuit 12 is used to control the on / off state of the power supply circuit where the first load RL1 is located. The load control circuit 12 includes a first thyristor T1 and a thyristor drive circuit. The output terminal of the thyristor drive circuit is coupled to the gate of the first thyristor T1, and the thyristor drive circuit is used to control the switching state of the first thyristor T1. The switching state of the first thyristor T1 includes an on state and an off state. In this embodiment, the first terminal of the first thyristor T1 is coupled to the first load RL1, the second terminal of the first thyristor T1 is coupled to the first input terminal of the motor drive circuit 11, and the second input terminal of the motor drive circuit 11 is coupled to the second terminal of the first load RL1.

[0050] In one embodiment of the present invention, the thyristor driving circuit includes a fifth switch Q5, which controls the switching state of the first thyristor T1. When the fifth switch Q5 is in the on state, it controls the first thyristor T1 to turn on, thereby controlling the on / off state of the power supply circuit where the first load RL1 is located to be in the on state, and the first load RL1 operates. When the fifth switch Q5 is in the off state, it controls the first thyristor T1 to turn off, thereby controlling the on / off state of the power supply circuit where the first load RL1 is located to be in the off state, and the first load RL1 stops operating. In a specific embodiment of the present invention, the fifth switch Q5 is a low-voltage transistor or a controller output port (i.e., a controller I / O port) with current driving capability. In a first state, the controller output port outputs a driving current to control the first thyristor to turn on; in a second state, the controller output port does not output a driving current or outputs a current less than that capable of driving the first thyristor to control the first thyristor to turn off.

[0051] In another embodiment of the invention, such as Figure 2 As shown, the thyristor drive circuit includes an auxiliary power supply Vaux, a fifth switch Q5, a first capacitor C1, a first resistor R1, and a fifth diode D5. The auxiliary power supply Vaux shares a common ground with the motor drive circuit 11. In this embodiment, the auxiliary power supply Vaux is a voltage source providing voltage Vaux. The first terminal of the fifth switch Q5 is coupled to the auxiliary power supply Vaux. The first terminal of the first capacitor C1 is coupled to the second terminal of the fifth switch Q5, and the second terminal of the first capacitor C1 is coupled to the second terminal of the first thyristor T1. The first terminal of the first resistor R1 is coupled to the first terminal of the first capacitor C1, and the second terminal of the first resistor R1 is coupled to the gate of the first thyristor T1. The fifth diode D5 is coupled between the auxiliary power supply Vaux and the first capacitor C1. The fifth switch Q5 is also connected in series between the auxiliary power supply Vaux and the first capacitor C1. The anode of the fifth diode D5 is coupled to the positive terminal of the auxiliary power supply Vaux, and the cathode of the fifth diode D5 is coupled to the first terminal of the first capacitor C1. That is, there are two connection relationships in the above case. In a specific embodiment, as shown... Figure 2 As shown, the anode of the fifth diode D5 is coupled to the second terminal of the fifth switch Q5, and the cathode of the fifth diode D5 is coupled to the first terminal of the first capacitor C1. In another specific embodiment, the anode of the fifth diode D5 is coupled to the positive terminal of the auxiliary power supply Vaux, and the cathode of the fifth diode D5 is coupled to the first terminal of the fifth switch Q5.

[0052] In such Figure 2In this embodiment, the thyristor drive circuit adopts a capacitor bootstrap drive principle. Specifically, to control the first load RL1 to work, the first thyristor T1 needs to be turned on, and the thyristor drive circuit will control the fifth switch Q5 to turn on. Here, it can be defined that when the AC power supply voltage direction points towards the first switch Q1, the AC power supply is in the positive half-cycle; when the AC power supply voltage direction points towards the third switch Q3, the AC power supply is in the negative half-cycle. When the AC power supply is in the negative half-cycle, the motor drive circuit 11 controls the first switch Q1 and the second switch Q2 to turn on, and the terminal potential of the second terminal of the first thyristor T1 is pulled down to the terminal potential of the ground terminal of the motor drive circuit. At this time, if the fifth switch is on, the fifth diode D5 conducts, the first capacitor C1 is charged, and the gate of the first thyristor T1 is triggered through the first resistor R1. When the AC power supply is in the positive half-cycle, the terminal potential of the second terminal of the first thyristor T1 is raised to a high voltage, and the fifth diode D5 is in the off state. The first capacitor C1 uses its remaining charge to supply the first resistor R1, which can still trigger the first thyristor T1 to be in the on state. To control the first thyristor T1 to be turned off, the fifth switch Q5 can be turned off. After the last turn-on cycle, the first thyristor T1 remains in the off state because there is no gate trigger signal. In the embodiment of the present invention, the motor drive circuit is not affected by the thyristor drive circuit. By controlling the switching states of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4, the AC power from the AC power supply is converted into chopped AC power and applied to the motor, thereby realizing the speed control of the motor.

[0053] In one embodiment of the present invention, when the motor drive circuit controls the motor to work, when the AC power supply Vac is in the positive half-cycle, the motor drive circuit 11 controls the third switch Q3 and the fourth switch Q4 to be turned on, the first switch Q1 performs a switching action with a first duty cycle, and the switching action of the second switch Q2 is complementary to the switching action of the first switch Q1; and when the AC power supply Vac is in the negative half-cycle, the motor drive circuit 11 controls the first switch Q1 and the second switch Q2 to be turned on, the third switch Q3 performs a switching action with a first duty cycle, and the switching action of the fourth switch is complementary to the switching action of the third switch.

[0054] In one specific embodiment, when the motor drive circuit controls the motor to stop working, the motor drive circuit controls the first switch Q1 and the third switch Q3 to turn off, and the second switch Q2 and the fourth switch Q4 to turn on. Therefore, the first load only operates for half a power frequency cycle. In another specific embodiment, when the AC current of the AC power supply Vac is in the positive half-cycle, the motor drive circuit 11 controls the first switch Q1 to turn off, and the second switch Q2, the third switch Q3, and the fourth switch Q4 to turn on. When the AC current of the AC power supply Vac is in the negative half-cycle, the motor drive circuit 11 controls the third switch Q3 to turn off, and the first switch Q1, the second switch Q2, and the fourth switch Q4 to turn on. Therefore, the first load can operate for the entire power frequency cycle. In one embodiment of the present invention, the first switch Q1 includes a first body diode D1 connected in parallel. The anode of the first body diode D1 is coupled to the first output terminal of the motor drive circuit, and the cathode of the first body diode D1 is coupled to the first input terminal of the motor drive circuit. The second switch Q2 includes a second body diode D2 connected in parallel. The anode of the second body diode D2 is grounded, and the cathode of the second body diode D2 is connected to the first output terminal of the motor drive circuit. The third switch Q3 includes a third body diode D3 connected in parallel. The anode of the third body diode D3 is connected to the second output terminal of the motor drive circuit, and the cathode of the third body diode D3 is connected to the second input terminal of the motor drive circuit. The fourth switch Q4 includes a fourth body diode D4 connected in parallel. The anode of the fourth body diode D4 is grounded, and the cathode of the fourth body diode D4 is connected to the second output terminal of the motor drive circuit. In another embodiment, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, and the fifth switch Q5 can be one of the following transistors: a metal-oxide-semiconductor field-effect transistor (MOSFET), a junction field-effect transistor (JFET), and an insulated-gate bipolar field-effect transistor (IGBT). In a specific embodiment, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 may each include a parasitic body diode. In another specific embodiment, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 may each be connected in parallel with discrete diodes.

[0055] In one embodiment of the present invention, the thyristor driving circuit further includes a synchronization control circuit. The synchronization control circuit is configured to control the first thyristor to be in an on-state when the enable signal is in a first state, and to control the first thyristor to be in an off-state when the enable signal is in a second state, provided that the voltage of the AC power supply is within a set region near a zero-crossing point. The enable signal is used to control the switching state of the first thyristor. Wherein, when the enable signal is in the first state, the first thyristor meets one of the conditions for being on; when the enable signal is in the second state, the first thyristor meets one of the conditions for being off. In another embodiment, the synchronization control circuit is configured to control the first thyristor to be in an on-state when the enable signal is in a first state, provided that the voltage of the AC power supply is within a set region near a zero-crossing point. In yet another embodiment, the synchronization control circuit is configured to control the first thyristor to be in an off-state when the enable signal is in a second state, provided that the voltage of the AC power supply is within a set region near a zero-crossing point.

[0056] In one embodiment of the present invention, the thyristor driving circuit further includes a trigger. A first input terminal of the trigger is coupled to an enable signal terminal, which provides an enable signal to control the switching state of the first thyristor. A second input terminal of the trigger is coupled to a zero-crossing detection signal terminal to obtain a zero-crossing detection signal of the AC power supply. The output terminal of the trigger is coupled to the control terminal of a fifth switch. The trigger is used to control the first thyristor to be in an on-state when the enable signal is in a first state, and to control the first thyristor to be in an off-state when the enable signal is in a second state, provided that the voltage of the AC power supply is within a set region near the zero-crossing point. In a specific embodiment, the trigger is used to control the first thyristor to be in an on-state when the enable signal is in a first state, and to control the first thyristor to be in an off-state when the enable signal is in a second state, provided the voltage of the AC power supply is at the zero-crossing point. Specifically, when the enable signal is in a first state (e.g., high level), the first thyristor meets one of the conditions for being on; when the enable signal is in a second state (e.g., low level), the first thyristor meets one of the conditions for being off.

[0057] In specific embodiments of the present invention, such as Figure 4As shown, the thyristor drive circuit includes a trigger, specifically a D trigger. The D input of the D trigger is coupled to the enable signal terminal to receive the enable signal of the first thyristor. The clock signal input of the D trigger receives the zero-crossing detection signal SYNC from the AC power supply Vac. The output of the D trigger is coupled to the control terminal of the fifth switch. The zero-crossing detection signal SYNC serves as the clock signal of the D trigger to synchronize the enable signal of the first thyristor, thereby controlling the switching state of the fifth switch Q5. When the first load is a diode-capacitor rectifier load, during startup, if the input AC power supply voltage and the voltage of the large capacitor of the first load do not match, a large current surge may occur, damaging the first thyristor. Therefore, through synchronization processing, soft starting is achieved, ensuring that the first thyristor is triggered and turned on near the zero-crossing point of the AC power supply, avoiding surge current phenomena. Figure 5 As shown, in one embodiment of the present invention, the diode-capacitor type rectifier load includes a seventh diode D7, an eighth diode D8, a ninth diode D9, a tenth diode D10, a third capacitor C3, and a load RL1'. The anode of the seventh diode D7 is coupled to the first terminal of the diode-capacitor type rectifier load, and the cathode of the seventh diode D7 is coupled to the cathode of the ninth diode D9. The anode of the eighth diode D8 is coupled to the anode of the tenth diode D10, and the cathode of the eighth diode D8 is coupled to the first terminal of the diode-capacitor type rectifier load. The anode of the ninth diode D9 is coupled to the second terminal of the diode-capacitor type rectifier load, and the cathode of the tenth diode D10 is coupled to the second terminal of the diode-capacitor type rectifier load. The first terminal of the third capacitor C3 is coupled to the cathode of the ninth diode D9, and the second terminal of the third capacitor C3 is coupled to the anode of the tenth diode D10. The first terminal of the load RL1' is coupled to the first terminal of the third capacitor C3, and the second terminal of the load RL1' is coupled to the second terminal of the third capacitor C3.

[0058] In one embodiment of the present invention, a load control circuit can be used to drive at least two loads respectively. The load control circuit includes a thyristor drive circuit and at least two thyristors. The thyristor drive circuit is coupled to each of the at least two thyristors respectively, and is used to control the switching state of each of the at least two thyristors respectively. The at least two thyristors include a first thyristor and a second thyristor. The load control circuit controls the on / off state of the power supply circuit of the first load by controlling the switching state of the first thyristor, and controls the on / off state of the power supply circuit of the second load by controlling the switching state of the second thyristor, and so on. The circuit connection relationship of the first thyristor can be referred to... Figure 2The embodiments described herein will not be repeated here. The first terminal of the second thyristor is coupled to the second load, the second terminal of the second thyristor is coupled to the second terminal of the first thyristor, and the thyristor drive circuit is coupled to the gate of the second thyristor. In another embodiment, the load control circuit further includes a third thyristor, the first terminal of the third thyristor is coupled to the third load, the second terminal of the third thyristor is coupled to the second terminal of the first thyristor, and the thyristor drive circuit is coupled to the gate of the third thyristor.

[0059] In one embodiment of the present invention, such as Figure 3 As shown, the motor system includes a motor M, a first load RL1, a second load RL2, and a motor control system. The motor control system includes a motor drive circuit and a load control circuit. The load control circuit controls the on / off state of the power supply circuit containing the first load and the power supply circuit containing the second load. The load control circuit includes a first thyristor T1, a second thyristor T2, and a thyristor drive circuit. The first terminal of the first thyristor T1 is coupled to the first terminal of the first load RL1, and the second terminal of the first thyristor T1 is coupled to the first input terminal of the motor control system. The second terminal of the first load RL1 is coupled to the second input terminal of the motor control system. The first terminal of the second thyristor T2 is coupled to the first terminal of the second load RL2, and the second terminal of the second thyristor T2 is coupled to the second terminal of the first thyristor T1. The second terminal of the second load RL2 is coupled to the second input terminal of the motor control system. The thyristor drive circuit has two output terminals: a first output terminal and a second output terminal. The first output terminal of the thyristor drive circuit is coupled to the gate of the first thyristor T1, and the second output terminal of the thyristor drive circuit is coupled to the gate of the second thyristor T2. The thyristor drive circuit is used to control the switching states of the first thyristor T1 and the second thyristor T2 respectively, thereby controlling the working states of the first load and the second load respectively.

[0060] In a specific embodiment, the thyristor driving circuit includes an auxiliary power supply Vaux, a fifth switch Q5, a first capacitor C1, a first resistor R1, a fifth diode D5, a sixth switch Q6, a second capacitor C2, a second resistor R2, and a sixth diode D6. The positive terminal of the auxiliary power supply Vaux is coupled to the first terminals of the fifth switch Q5 and the sixth switch Q6, respectively. The second terminal of the fifth switch Q5 is coupled to the anode of the fifth diode D5, the cathode of the fifth diode D5 is coupled to the first terminal of the first capacitor C1, the second terminal of the first capacitor C1 is coupled to the second terminal of the first thyristor T1, the first terminal of the first resistor R1 is coupled to the first terminal of the first capacitor C1, and the second terminal of the first resistor R1 is coupled to the gate of the first thyristor T1. The second terminal of the sixth switch Q6 is coupled to the anode of the sixth diode D6, the cathode of the sixth diode D6 is coupled to the first terminal of the second capacitor C2, the second terminal of the second capacitor C2 is coupled to the second terminal of the second thyristor T2, the first terminal of the second resistor R2 is coupled to the first terminal of the second capacitor C2, and the second terminal of the second resistor R2 is coupled to the gate of the second thyristor T2.

[0061] In another embodiment of the present invention, the thyristor driving circuit includes an auxiliary power supply Vaux, a fifth switch Q5, a first capacitor C1, a first resistor R1, a fifth diode D5, a sixth switch Q6, a second capacitor C2, a second resistor R2, and a sixth diode D6. The auxiliary power supply Vaux may include a first auxiliary power supply Vaux1 and a second auxiliary power supply Vaux2. The positive terminal of the first auxiliary power supply Vaux1 is coupled to the first terminal of the fifth switch Q5, and the positive terminal of the second auxiliary power supply Vaux2 is coupled to the first terminal of the sixth switch Q6. The second terminal of the fifth switch Q5 is coupled to the anode of the fifth diode D5, the cathode of the fifth diode D5 is coupled to the first terminal of the first capacitor C1, the second terminal of the first capacitor C1 is coupled to the second terminal of the first thyristor T1, the first terminal of the first resistor R1 is coupled to the first terminal of the first capacitor C1, and the second terminal of the first capacitor R1 is coupled to the gate of the first thyristor T1. The second terminal of the sixth switch Q6 is coupled to the anode of the sixth diode D6, the cathode of the sixth diode D6 is coupled to the first terminal of the second capacitor C2, the second terminal of the second capacitor C2 is coupled to the second terminal of the second thyristor T2, the first terminal of the second resistor R2 is coupled to the first terminal of the second capacitor C2, and the second terminal of the second resistor R2 is coupled to the gate of the second thyristor T2.

[0062] One embodiment of the present invention also discloses a motor system, which includes a motor, a first load, and a motor control system as described above. The motor is coupled to a first output terminal and a second output terminal of a motor drive circuit, and the first load is coupled to a first thyristor and an AC power supply. In one specific embodiment, a first terminal of the first load is coupled to a first terminal of the first thyristor, a second terminal of the first load is coupled to a second terminal of the AC power supply, and the second terminal of the AC power supply is coupled to a second input terminal of the motor drive circuit. In another specific embodiment, a first terminal of the first load is coupled to a first terminal of the first thyristor, a second terminal of the first load is coupled to a first terminal of the AC power supply, and the first terminal of the AC power supply is coupled to a first input terminal of the motor drive circuit.

[0063] An embodiment of the present invention also discloses a control method for a motor control system, wherein the motor control system includes a motor drive circuit and a load control circuit, the motor drive circuit includes a chopper circuit including two half-bridges, and the load control circuit is used to control the on / off state of the power supply circuit of the first load, and the control method for the motor control system includes:

[0064] The alternating current (AC) from the AC power supply is converted into chopped AC current using a chopper circuit and then applied to the motor to drive it.

[0065] The on / off state of the power supply circuit of the first load is controlled by the load control circuit, so as to control the working state of the first load.

[0066] The steps of obtaining the chopped AC power and applying it to the motor, and the steps of the load control circuit controlling the on / off state of the power supply circuit of the first load, are not sequential.

[0067] In one embodiment of the present invention, the load control circuit includes a first thyristor and a thyristor driving circuit. The first thyristor is coupled to a first load. The thyristor driving circuit includes a fifth switch, which is used to control the switching state of the first thyristor. The control method includes controlling the switching state of the fifth switch to control the operating state of the first load.

[0068] In one embodiment of the present invention, the first load can be one of the following: a lamp panel, a heating wire, a claw-pole motor, or a single-phase asynchronous motor. The first load operates when the first thyristor is in the on state and stops operating when the first thyristor is in the off state. Similarly, the second load can also be one of the following: a lamp panel, a heating wire, a claw-pole motor, or a single-phase asynchronous motor.

[0069] In another embodiment of the present invention, the two half-bridges are a first half-bridge and a second half-bridge, respectively. The first half-bridge is coupled to the second terminal of a first thyristor, and the first terminal of the first thyristor is coupled to the first terminal of a first load. The control method includes controlling the first half-bridge to shoot-through when the AC power supply is in the negative half-cycle. The purpose of this shoot-through is to pull the terminal potential of the second terminal of the first thyristor down to the terminal potential of the ground terminal of the motor drive circuit. At this time, in such a case... Figure 2 In one embodiment, if the fifth switch is in the ON state, the fifth diode conducts, the first capacitor is charged, and the gate of the first thyristor is triggered through the first resistor, thus controlling the first thyristor to conduct and thereby controlling the first load to work. In a specific embodiment, the first half-bridge includes a first switching transistor and a second switching transistor. When the motor drive circuit controls the motor to stop working, during the negative half-cycle of the AC power supply, both the first and second switching transistors are controlled to turn on.

[0070] The above description and application of the present invention are illustrative and not intended to limit the scope of the invention to the above embodiments. The effects or advantages described in the embodiments may not be apparent in experimental cases due to uncertainties in specific conditions and parameters, and are not intended to limit the embodiments. Variations and modifications of the embodiments disclosed herein are possible, and various substitutions and equivalents of the components in the embodiments are well known to those skilled in the art. It should be understood by those skilled in the art that the present invention can be implemented in other forms, structures, arrangements, proportions, and with other components, materials, and parts without departing from the spirit or essential characteristics of the invention. Other variations and modifications can be made to the embodiments disclosed herein without departing from the scope and spirit of the invention.

Claims

1. An electric motor control system, characterized by, The motor control system comprises: A motor drive circuit having a first input end, a second input end, a first output end, a second output end and a ground potential end; the first input end and the second input end are used to couple an AC power supply, and the first output end and the second output end are used to couple a motor; the motor drive circuit is used to convert the AC power of the AC power supply into chopped AC power and then load it to the motor to drive the motor to work; the motor drive circuit comprises a chopping circuit, and the chopping circuit comprises two half-bridges; and A load control circuit comprising a first thyristor and a thyristor drive circuit, a first end of the first thyristor being used to couple a first load, and the thyristor drive circuit being coupled to a gate of the first thyristor; the load control circuit is used to control the on-off state of a power supply loop in which the first load is located; the thyristor drive circuit comprises an auxiliary power supply, a fifth switch, a first capacitor, a first resistor and a fifth diode; a first end of the fifth switch is coupled to the auxiliary power supply; a first end of the first capacitor is coupled to a second end of the fifth switch, and a second end of the first capacitor is coupled to a second end of the first thyristor; a first end of the first resistor is coupled to the first end of the first capacitor, and a second end of the first resistor is coupled to the gate of the first thyristor; the fifth diode is coupled between the auxiliary power supply and the first capacitor, an anode of the fifth diode is coupled to the auxiliary power supply, and a cathode of the fifth diode is coupled to the first end of the first capacitor; wherein The second end of the first thyristor is coupled to the first input end of the motor drive circuit, and the second input end of the motor drive circuit is used to couple the first load; or the second end of the first thyristor is coupled to the second input end of the motor drive circuit, and the first input end of the motor drive circuit is used to couple the first load.

2. The motor control system of claim 1, wherein, The thyristor drive circuit further comprises: A synchronization control circuit used to control the first thyristor to be in an on state when an enable signal is in a first state and / or to be in an off state when the enable signal is in a second state when a voltage of the AC power supply is in a set region near a zero-crossing point; wherein the enable signal is used to control the switching state of the first thyristor.

3. The motor control system of claim 1, wherein, The thyristor drive circuit further comprises: A flip-flop having a first input end coupled to an enable signal end to obtain the enable signal used to control the switching state of the first thyristor, a second input end coupled to a zero-crossing detection signal end to obtain a zero-crossing detection signal of the AC power supply, and an output end coupled to a control end of the fifth switch and used to control the first thyristor to be in an on state when the enable signal is in a first state and / or to be in an off state when the enable signal is in a second state when the voltage of the AC power supply is in a set region near a zero-crossing point.

4. The motor control system of claim 3, wherein, The flip-flop is a D flip-flop, a D input end of the D flip-flop is coupled to the enable signal end, a clock signal input end of the D flip-flop is coupled to the zero-crossing detection signal end, and an output end of the D flip-flop is coupled to the control end of the fifth switch.

5. The motor control system of claim 1, wherein, The fifth switch is a low-voltage transistor or a controller output port having a current driving capability.

6. The motor control system of claim 1, wherein, The load control circuit includes at least two thyristors, the at least two thyristors including a first thyristor and a second thyristor, a first end of the second thyristor being configured to be coupled to a second load, a second end of the second thyristor being coupled to a second end of the first thyristor, the thyristor drive circuit being coupled to a gate of the second thyristor, the load control circuit being further configured to control a turn-on / off state of a power supply loop in which the second load is located.

7. The motor control system of claim 6, wherein, The thyristor drive circuit further includes: a sixth switch having a first end coupled to the auxiliary power supply; a second capacitor having a first end coupled to a second end of the sixth switch and a second end coupled to the second end of the second thyristor; a second resistor having a first end coupled to the first end of the second capacitor and a second end coupled to the gate of the second thyristor; and a sixth diode coupled between the auxiliary power supply and the second capacitor, an anode of the sixth diode being coupled to the auxiliary power supply, and a cathode of the sixth diode being coupled to the first end of the second capacitor.

8. An electric motor system characterized by, The motor system includes a motor, a first load, and the motor control system according to any one of claims 1-7, a first end of the motor being coupled to a first output of the motor drive circuit, a second end of the motor being coupled to a second output of the motor drive circuit, a first end of the first load being coupled to the first thyristor, and a second end of the first load being coupled to the AC power supply.

9. A control method for controlling the motor control system according to claim 1, characterized by, The motor control system includes a motor drive circuit and a load control circuit, the motor drive circuit including a chopper circuit, the chopper circuit including two half-bridges, the load control circuit being configured to control a turn-on / off state of a power supply loop in which a first load is located, the control method including: converting AC power of the AC power supply into chopped AC power via the chopper circuit and loading the chopped AC power to the motor to drive the motor to work; and controlling the turn-on / off state of the power supply loop in which the first load is located via the load control circuit to control a working state of the first load.

10. The control method according to claim 9, characterized by, The load control circuit includes a first thyristor and a thyristor drive circuit, the first thyristor being coupled to a first load, the thyristor drive circuit including a fifth switch, the fifth switch being configured to control a switching state of the first thyristor; The control method includes: controlling the switching state of the fifth switch to thereby control the working state of the first load.

11. The control method according to claim 10, characterized by, The two half-bridges are a first half-bridge and a second half-bridge, the first half-bridge being coupled to the first thyristor, the control method including: controlling the first half-bridge to be directly turned on when the AC power of the AC power supply is in a negative half cycle.

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