A forward and reverse rotation module based on zero-crossing detection control

Abstract

This invention discloses a forward / reverse control module based on zero-crossing detection control, comprising a power supply circuit, an interlock delay circuit, a drive circuit, a switching circuit, a detection circuit, and a control unit. The drive circuit is connected in series between the interlock delay circuit and the switching circuit, and the switching circuit is connected in series between the load power supply and the winding terminals of the motor. The signal input terminal of the detection circuit is connected to the switching circuit. The control unit is connected to the interlock delay circuit to detect the presence of a forward rotation signal and / or a reverse rotation signal. The control unit is connected to the drive circuit through the detection circuit, and outputs a braking signal to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to conduct according to the braking signal, thereby realizing forward / reverse control and braking control of the motor. This invention combines forward / reverse control and braking functions without the need for additional braking components. It allows for adjustment of braking time and force, and features a simple braking structure, excellent performance, and high reliability.

Description

Technical Field

[0001] This invention relates to the field of three-phase motor forward and reverse rotation control technology, and in particular to a forward and reverse rotation module based on zero-crossing detection control. Background Technology

[0002] A three-phase motor is an AC motor driven by alternating current. The principle of three-phase motor rotation is as follows: When three-phase electricity is applied to the motor, the stator generates a rotating magnetic field under the influence of the three-phase electricity. This magnetic field creates a relative cutting motion with the rotor, inducing an electromotive force and generating an inductive current in the rotor conductors. The current-carrying rotor conductors experience an electromagnetic force in the magnetic field, forming an electromagnetic torque that drives the rotor to rotate. The direction of rotor rotation is related to the direction of the magnetic field, which in turn is related to the phase sequence of the three-phase electricity. By switching the phase sequence of the three-phase power supply, the direction of motor rotation can be controlled. A three-phase motor forward / reverse module can be used to switch the three-phase power sequence, thereby controlling the direction of motor rotation.

[0003] If three-phase electricity is replaced with direct current, the magnetic field generated by the motor stator will be a constant magnetic field, which will hinder the rotation of the motor rotor, thus creating a braking effect.

[0004] Currently, most forward and reverse rotation modules used for three-phase motor control can only control the forward and reverse rotation of three-phase motors. Their main components are interlocking delay circuits, optocoupler isolation circuits, and power component circuits. If braking is required, reverse braking or an external braking assembly is typically used. However, reverse braking has lower accuracy and is prone to failure to stop or over-braking leading to reverse rotation. External braking assemblies are more complex and expensive.

[0005] Some forward and reverse rotation modules have braking functions. For example, CN201820080042.4, "A Three-Phase Motor Forward and Reverse Rotation Controller with DC Braking," can achieve good braking performance. However, the control circuit is complex and costly. This solution uses a three-phase power supply rectified into DC power by diodes, and then controlled by IGBTs using PWM to keep the current through the motor constant, creating a constant magnetic field inside the motor to prevent rotation and achieve a braking effect. Because braking and forward / reverse rotation are independent and cannot work simultaneously, they need to be separated by a switch, placing high demands on the product's control timing.

[0006] In view of this, the inventors have developed a forward and reverse rotation module based on zero-crossing detection control, which has forward and reverse rotation control function and braking function. Summary of the Invention

[0007] The purpose of this invention is to provide a forward and reverse rotation module based on zero-crossing detection and control. By adding a braking function to a conventional forward and reverse rotation module, the module can have both forward and reverse rotation control and braking functions without the need for additional braking components. The braking time and force can be adjusted, and it features a simple braking structure, excellent braking performance, and high reliability.

[0008] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0009] A forward and reverse rotation module based on zero-crossing detection and control includes a power supply circuit, an interlock delay circuit, a drive circuit, a switching circuit, a detection circuit, and a control unit.

[0010] The interlock delay circuit has a forward rotation signal input terminal and a reverse rotation signal input terminal. The drive circuit is connected in series between the interlock delay circuit and the switching circuit. The switching circuit is connected in series between the load power supply and the winding assembly terminal of the motor, forming a forward and reverse rotation power supply control circuit for the motor.

[0011] The signal input terminal of the detection circuit is connected to the switching circuit to detect the zero-crossing signal of the load power supply and the positive and negative direction information of the input voltage of the load power supply.

[0012] The control unit is connected to an interlock delay circuit to detect the presence of a forward rotation signal and / or a reverse rotation signal. The control unit is also connected to the drive circuit through the detection circuit. When a zero-crossing signal of the load power supply is detected and there is no forward rotation signal or reverse rotation signal, the control unit outputs a braking signal to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to conduct according to the braking signal, so as to form a rectifier circuit that rectifies the AC power input of the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power.

[0013] Furthermore, the interlock delay circuit includes a forward rotation output terminal F_S, a forward rotation interlock output terminal F_L, a reverse rotation output terminal R_S, and a reverse rotation interlock output terminal R_L; the drive circuit includes drive switches T1, T3, and T5, as well as interlock switches T2 and T4; the switch circuit includes a first switch K1 connected between the load power output line L1 and the winding group terminal U, a second switch K2 connected between the load power output line L2 and the winding group terminal U, a third switch K3 connected between the load power output line L1 and the winding group terminal V, a fourth switch K4 connected between the load power output line L2 and the winding group terminal V, and a fifth switch K5 connected between the load power output line L3 and the winding group terminal W.

[0014] The forward output terminal F_S is connected in sequence to drive switch T1, optocoupler PX1 and optocoupler PX4; the forward interlock output terminal F_L is connected in sequence to interlock switch T4 and drive switch T3; the reverse output terminal R_S is connected in sequence to drive switch T3, optocoupler PX2 and optocoupler PX3; the reverse interlock output terminal R_L is connected in sequence to interlock switch T2 and drive switch T1; the forward output terminal F_S is also connected in sequence to drive switch T5 and optocoupler PX5; the reverse output terminal R_S is also connected in sequence to drive switch T5 and optocoupler PX5.

[0015] When the forward output terminal F_S outputs a high level, the activated drive switch T1 controls the first switch K1 and the fourth switch K4 to conduct through optocouplers PX1 and PX4 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate forward; when the reverse output terminal R_S outputs a high level, the activated drive switch T3 controls the second switch K2 and the third switch K3 to conduct through optocouplers PX2 and PX3 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate in reverse.

[0016] When the forward interlock output terminal F_L outputs a high level, the interlock switch T4 is turned on and the drive switch T3 is turned off; or when the reverse interlock output terminal R_L outputs a high level, the interlock switch T2 is turned on and the drive switch T1 is turned off, thus achieving interlocking.

[0017] Furthermore, the detection circuit employs zero-crossing detection and polarity protection circuitry, and the control unit employs logic control circuitry;

[0018] The zero-crossing detection and polarity protection circuit includes optocouplers P2, P3, and P4. The input terminal of optocoupler P2 is connected to the load power output line L1. The input terminal of optocoupler P3 is connected in series with the input terminal of optocoupler P2 and then connected to the load power output line L2. Optocoupler P4 is connected in anti-parallel with optocouplers P2 and P3. The signal output terminal of optocoupler P2 is connected to the logic control circuit. The signal output terminal of the logic control circuit is connected to drive switch T3 through optocoupler P3 and to drive switch T1 through optocoupler P4.

[0019] When the control unit outputs a braking signal, if the voltage of the load power output line L1 is greater than that of the load power output line L2, the braking signal is output to the drive circuit through the optocoupler P3, controlling the drive switch T3 to turn on, thereby controlling the second switch K2 and the third switch K3 to turn on, and the first switch K1 and the fourth switch K4 to turn off, so that the second switch K2, the third switch K3, the winding group terminal U, and the winding group terminal V form a first current loop; if the voltage of the load power output line L2 is greater than that of the load power output line L1, the braking signal is output to the drive circuit through the optocoupler P4, controlling the drive switch T1 to turn on, thereby controlling the first switch K1 and the fourth switch K4 to turn on, and the second switch K2 and the third switch K3 to turn off, so that the first switch K1, the fourth switch K4, the winding group terminal U, and the winding group terminal V form a second current loop.

[0020] Furthermore, the drive switches T1, T3, T5, T2, and T4 all employ switching transistors or MOSFETs.

[0021] Furthermore, the module also includes a step-down circuit connected in series between the power supply circuit output and the interlock delay circuit input.

[0022] After adopting the above scheme, the overall principle of the present invention to realize forward and reverse rotation control and braking function is as follows:

[0023] The interlock delay circuit is used to receive forward and / or reverse signals, the detection circuit detects the zero-crossing signal of the load power supply and the positive and negative direction information of the input voltage of the load power supply; the control unit detects whether the interlock delay circuit has forward and / or reverse signals.

[0024] When the control unit detects a zero-crossing signal from the load power supply and there are no forward or reverse signals in the interlock delay circuit, the control unit issues a braking signal. The drive circuit responds to the braking signal and drives the corresponding switch in the switching circuit to conduct, thereby achieving forward / reverse control and braking control of the motor. Specifically, when the corresponding switch in the drive circuit is on, the forward / reverse power supply control loop can be switched to a DC loop to form a rectifier circuit that converts the AC power input from the load power supply into DC power, causing the motor to brake due to the constant-direction magnetic field generated by the DC power.

[0025] When the control unit detects a forward or reverse signal from the interlock delay circuit, it does not issue a braking signal. Instead, the interlock delay circuit directly outputs a forward / reverse control command to the drive circuit based on the forward or reverse signal. The drive circuit then controls the corresponding switch in the switching circuit to turn on, allowing the forward / reverse power supply control loop to be switched to forward / reverse, thus achieving forward / reverse control.

[0026] When the control unit detects that the interlock delay circuit has forward and reverse signals, it does not issue a braking signal. Instead, the interlock delay circuit directly outputs the interlock control command based on the forward and reverse signals. The drive circuit cannot drive the switch in the control switch circuit to conduct, thus achieving interlocking.

[0027] The present invention has the following beneficial effects:

[0028] I. This invention detects the zero-crossing signal of the load power supply and the positive and negative direction information of the input voltage of the load power supply through a detection circuit, and detects the presence of forward and / or reverse rotation signals through an interlock delay circuit. By combining the zero-crossing signal of the load power supply and the forward and / or reverse rotation signals, it determines whether the braking conditions are met. When braking is required, the control unit sends a braking signal to the drive module. The drive module controls the current direction of the forward and reverse power supply control circuit by controlling the on and off of the corresponding power switches in the control switching circuit, thereby realizing the rectification of AC power and forming a non-rotating magnetic field on the motor rotor, thereby hindering the rotation of the motor rotor and forming a braking effect.

[0029] Second, since the braking signal is provided by the module's control unit, the braking force and duration can be adjusted by issuing the braking signal or controlling the corresponding time.

[0030] Third, the forward and reverse rotation module of the present invention does not require the use of the complex structure of existing forward and reverse rotation control and DC braking circuits. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other modifications can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the forward and reverse rotation module circuit structure based on zero-crossing detection control according to an embodiment of the present invention;

[0033] Label Explanation

[0034] Power supply circuit 10, interlock delay circuit 20, drive circuit 30, switch circuit 40, detection circuit 50, control unit 60, and step-down circuit 70. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 As shown in the figure, an embodiment of the present invention discloses a forward and reverse rotation module based on zero-crossing detection control, including a power supply circuit 10, an interlock delay circuit 20, a drive circuit 30, a switch circuit 40, a detection circuit 50, and a control unit 60.

[0037] The interlock delay circuit 20 has a forward rotation signal input terminal F+ and a reverse rotation signal input terminal R+. The drive circuit 30 is connected in series between the interlock delay circuit 20 and the switching circuit 40. The switching circuit 40 is connected in series between the load power supply and the winding group terminals of the motor, forming a forward and reverse rotation power supply control circuit for the motor. The winding group terminals of the motor M generally have three terminals: winding group terminal U, winding group terminal V, and winding group terminal W. In this embodiment, the interlock delay circuit 20 includes a forward rotation output terminal F_S, a forward rotation interlock output terminal F_L, a reverse rotation output terminal R_S, and a reverse rotation interlock output terminal R_L. The drive circuit 30 includes drive switches T1, T3, and T5, as well as interlock switches T2 and T4; the switch circuit 40 includes a first switch K1 connected between the load power output line L1 and the winding group terminal U, a second switch K2 connected between the load power output line L2 and the winding group terminal U, a third switch K3 connected between the load power output line L1 and the winding group terminal V, a fourth switch K4 connected between the load power output line L2 and the winding group terminal V, and a fifth switch K5 connected between the load power output line L3 and the winding group terminal W.

[0038] In this embodiment, the forward output terminal F_S is connected in sequence to drive switch T1, optocoupler PX1 and optocoupler PX4, the forward interlock output terminal F_L is connected in sequence to interlock switch T4 and drive switch T3, the reverse output terminal R_S is connected in sequence to drive switch T3, optocoupler PX2 and optocoupler PX3, the reverse interlock output terminal R_L is connected in sequence to interlock switch T2 and drive switch T1, the forward output terminal F_S is also connected in sequence to drive switch T5 and optocoupler PX5, and the reverse output terminal R_S is also connected in sequence to drive switch T5 and optocoupler PX5.

[0039] Based on the above circuit structure, the forward and reverse rotation control and interlocking principle implemented by the forward and reverse mounting module of the present invention are as follows:

[0040] When the interlock delay circuit 20 receives the forward rotation signal, when the forward rotation output terminal F_S outputs a high level, the activated drive switch T1 controls the first switch K1 and the fourth switch K4 to be activated through optocoupler PX1 and optocoupler PX4 respectively, and the activated drive switch T5 controls the fifth switch K5 to be activated through optocoupler PX5, and the motor rotates forward.

[0041] When the interlock delay circuit 20 receives the reversal signal, when the reversal output terminal R_S outputs a high level, the activated drive switch T3 controls the second switch K2 and the third switch K3 to be activated through optocoupler PX2 and optocoupler PX3 respectively, and the activated drive switch T5 controls the fifth switch K5 to be activated through optocoupler PX5, and the motor reverses.

[0042] When the interlock delay circuit 20 receives the forward rotation signal and the reverse rotation signal, the forward rotation interlock output terminal F_L outputs a high level, the interlock switch T4 is turned on, and the drive switch T3 is turned off. Alternatively, when the reverse rotation interlock output terminal R_L outputs a high level, the interlock switch T2 is turned on, and the drive switch T1 is turned off, thus achieving interlocking.

[0043] The signal input terminal of the detection circuit 50 is connected to the switching circuit 40 to detect the zero-crossing signal of the load power supply and the positive and negative direction information of the input voltage of the load power supply.

[0044] The control unit 60 is connected to the interlock delay circuit 20 to detect the presence of a forward rotation signal and / or a reverse rotation signal. The control unit 60 is also connected to the drive circuit 30 through the detection circuit 50. When a zero-crossing signal of the load power supply is detected and there is no forward rotation signal or reverse rotation signal, the control unit 60 outputs a braking signal to the drive circuit 30. The drive circuit 30 drives the corresponding switch in the switching circuit 40 to conduct according to the braking signal, so as to form a rectifier circuit that rectifies the AC power input of the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power.

[0045] In this embodiment, preferably, the detection circuit 50 adopts a zero-crossing detection and polarity protection circuit, and the control unit 60 adopts a logic control circuit. The logic control circuit preferably adopts a PIC12F683 microcontroller to realize logic control.

[0046] The zero-crossing detection and polarity protection circuit includes optocouplers P2, P3, and P4. The input terminal of optocoupler P2 is connected to the load power output line L1. The input terminal of optocoupler P3 is connected in series with the input terminal of optocoupler P2 and then connected to the load power output line L2. Optocoupler P4 is connected in anti-parallel with optocouplers P2 and P3. The signal output terminal of optocoupler P2 is connected to the logic control circuit. The signal output terminal of the logic control circuit is connected to drive switch T3 through optocoupler P3 and to drive switch T1 through optocoupler P4. Optocouplers P3 and P4 are used to ensure the correct braking control timing and avoid timing problems that could lead to burnout.

[0047] Based on the above circuit structure, the braking principle of the forward and reverse rotation module in this embodiment is as follows: When the control unit 60 outputs a braking signal, if the detection circuit 50 detects that the voltage of the load power output line L1 is greater than that of the load power output line L2, the braking signal is output to the drive circuit 30 through the optocoupler P3, controlling the drive switch T3 to turn on, thereby controlling the second switch K2 and the third switch K3 to turn on, and the first switch K1 and the fourth switch K4 to turn off, so that the second switch K2, the third switch K3, the winding group terminal U, and the winding group terminal V form a first current loop; if the voltage of the load power output line L2 is greater than that of the load power output line L1, the braking signal is output to the drive circuit 30 through the optocoupler P4, controlling the drive switch T1 to turn on, thereby controlling the first switch K1 and the fourth switch K4 to turn on, and the second switch K2 and the third switch K3 to turn off, so that the first switch K1, the fourth switch K4, the winding group terminal U, and the winding group terminal V form a second current loop. Regardless of whether the voltage of the load power output line L1 or the voltage of the load power output line L2 is greater, the winding group terminal U maintains a positive voltage and the winding group terminal V maintains a negative voltage. That is, in both the first current loop and the second circuit loop, the winding group terminal U is positive and the winding group terminal V is negative. This voltage causes the motor rotor to generate a constant magnetic field with an unchanged direction, thereby suppressing the motor rotation and producing a braking effect. This control process can also prevent the forward switch (first switch K1, fourth switch K4) and the reverse switch (second switch K2, third switch K3) from being turned on at the same time, realizing the interlock protection function and preventing the components from burning out.

[0048] As a further preferred embodiment, the drive switch T1, drive switch T3, drive switch T5, interlock switch T2, and interlock switch T4 can all be switching transistors or MOSFETs.

[0049] As a further preferred embodiment, the above-mentioned forward and reverse module also includes a step-down circuit 70 connected in series between the output terminal of the power supply circuit 10 and the input terminal of the interlock delay circuit 20. The switching circuit 40 may also include a capacitor and a varistor. The capacitor may also be a RC circuit to protect the power switch.

[0050] The embodiments described above do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments should be included within the scope of protection of this technical solution.

Claims

1. A forward and reverse rotation module based on zero-crossing detection control, characterized in that: It includes power supply circuit, interlock delay circuit, drive circuit, switching circuit, detection circuit, and control unit; The interlock delay circuit has a forward rotation signal input terminal and a reverse rotation signal input terminal. The drive circuit is connected in series between the interlock delay circuit and the switching circuit. The switching circuit is connected in series between the load power supply and the winding assembly terminal of the motor, forming a forward and reverse rotation power supply control circuit for the motor. The signal input terminal of the detection circuit is connected to the load power supply to detect the zero-crossing signal of the load power supply and the positive and negative direction information of the input voltage of the load power supply. The control unit is connected to an interlock delay circuit to detect the presence of a forward rotation signal and / or a reverse rotation signal. The control unit is also connected to the drive circuit through the detection circuit. When a zero-crossing signal of the load power supply is detected and there is no forward rotation signal or reverse rotation signal, the control unit outputs a braking signal to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to conduct according to the braking signal, so as to form a rectifier circuit that rectifies the AC power input of the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power. The detection circuit employs zero-crossing detection and polarity protection circuitry, and the control unit employs logic control circuitry. The zero-crossing detection and polarity protection circuit includes optocouplers P2, P3, and P4. The input terminal of optocoupler P2 is connected to the load power output line L1. The input terminal of optocoupler P3 is connected in series with the input terminal of optocoupler P2 and then connected to the load power output line L2. Optocoupler P4 is connected in anti-parallel with optocouplers P2 and P3. The signal output terminal of optocoupler P2 is connected to the logic control circuit. The signal output terminal of the logic control circuit is connected to drive switch T3 through optocoupler P3 and to drive switch T1 through optocoupler P4. When the control unit outputs a braking signal, if the voltage of the load power output line L1 is greater than that of the load power output line L2, the braking signal is output to the drive circuit through the optocoupler P3, controlling the drive switch T3 to turn on, and then controlling the second switch K2 and the third switch K3 to turn on, while the first switch K1 and the fourth switch K4 are turned off, thus forming a first current loop with the second switch K2, the third switch K3, the winding group terminal U, and the winding group terminal V. If the voltage of the load power output line L2 is greater than that of the load power output line L1, the braking signal is output to the drive circuit through the optocoupler P4, controlling the drive switch T1 to turn on, and then controlling the first switch K1 and the fourth switch K4 to turn on, while the second switch K2 and the third switch K3 are turned off, thus forming a second current loop with the first switch K1, the fourth switch K4, the winding group terminal U, and the winding group terminal V.

2. The forward and reverse rotation module based on zero-crossing detection control as described in claim 1, characterized in that: The interlocking delay circuit includes a forward rotation output terminal F_S, a forward rotation interlocking output terminal F_L, a reverse rotation output terminal R_S, and a reverse rotation interlocking output terminal R_L. The driving circuit includes driving switches T1, T3, and T5, as well as interlocking switches T2 and T4. The switching circuit includes a first switch K1 connected between the load power output line L1 and the winding group terminal U, a second switch K2 connected between the load power output line L2 and the winding group terminal U, a third switch K3 connected between the load power output line L1 and the winding group terminal V, a fourth switch K4 connected between the load power output line L2 and the winding group terminal V, and a fifth switch K5 connected between the load power output line L3 and the winding group terminal W. The forward rotation output terminal F_S is connected in sequence to drive switch T1, optocoupler PX1 and optocoupler PX4; the forward rotation interlock output terminal F_L is connected in sequence to interlock switch T4 and drive switch T3; the reverse rotation output terminal R_S is connected in sequence to drive switch T3, optocoupler PX2 and optocoupler PX3; the reverse rotation interlock output terminal R_L is connected in sequence to interlock switch T2 and drive switch T1; the forward rotation output terminal F_S is also connected in sequence to drive switch T5 and optocoupler PX5; the reverse rotation output terminal R_S is also connected in sequence to drive switch T5 and optocoupler PX5. When the forward output terminal F_S outputs a high level, the activated drive switch T1 controls the first switch K1 and the fourth switch K4 to conduct through optocouplers PX1 and PX4 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate forward; when the reverse output terminal R_S outputs a high level, the activated drive switch T3 controls the second switch K2 and the third switch K3 to conduct through optocouplers PX2 and PX3 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate in reverse. When the forward interlock output terminal F_L outputs a high level, the interlock switch T4 is turned on and the drive switch T3 is turned off; or when the reverse interlock output terminal R_L outputs a high level, the interlock switch T2 is turned on and the drive switch T1 is turned off, thus achieving interlocking.

3. The forward and reverse rotation module based on zero-crossing detection control as described in claim 2, characterized in that: The drive switches T1, T3, T5, T2, and T4 all use switching transistors or MOSFETs.

4. The forward and reverse rotation module based on zero-crossing detection control as described in claim 1, characterized in that: The module also includes a step-down circuit connected in series between the output of the power supply circuit and the input of the interlock delay circuit.

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