Three-phase motor control circuit based on relay
阅读说明：本技术 一种基于继电器的三相电机控制电路 (Three-phase motor control circuit based on relay ) 是由 罗海军 马瑜 王晋萱 张建龙 沈斌斌 沈雨婷 于 2020-06-23 设计创作，主要内容包括：本发明公开的一种基于继电器的三相电机控制电路,用于控制三相交流电机,三相四线制供电端的火线U接继电器一的引脚5,火线V接继电器二和继电器三的引脚5,火线W接继电器二和继电器三的引脚6；继电器一、继电器二和继电器三的引脚3分别连接至三相交流电机的A、B、C三相输入端,继电器二的引脚4连接至三相交流电机的C相输入端,继电器三的引脚4连接至三相交流电机的B相输入端；继电器一、继电器二和继电器三的引脚7、引脚8均与驱动板电连接,驱动板与控制器电连接,用于接收继电器通断的控制信号。本发明能有效地实现弱电间的互相通信和信号传输,从而转强电控制为弱电控制,提高了系统的安全性和操控性。(The invention discloses a three-phase motor control circuit based on a relay, which is used for controlling a three-phase alternating current motor, wherein a live wire U of a three-phase four-wire system power supply end is connected with a pin 5 of a first relay, a live wire V is connected with a pin 5 of a second relay and a pin 6 of a third relay, and a live wire W is connected with a pin 6 of the second relay and a pin 6 of the third relay; pins 3 of the relay I, the relay II and the relay III are respectively connected to A, B, C three-phase input ends of the three-phase alternating current motor, pins 4 of the relay II are connected to C-phase input ends of the three-phase alternating current motor, and pins 4 of the relay III are connected to B-phase input ends of the three-phase alternating current motor; pins 7 and 8 of the relay I, the relay II and the relay III are electrically connected with a driving plate, and the driving plate is electrically connected with a controller and used for receiving control signals for on-off of the relays. The invention can effectively realize the intercommunication and signal transmission between weak current, thereby switching strong current control into weak current control and improving the safety and the controllability of the system.)
1. A three-phase motor control circuit based on a relay is used for controlling a three-phase alternating current motor and is characterized by comprising a controller, a first relay, a second relay, a third relay and a drive board; wherein the content of the first and second substances,
the first relay, the second relay and the third relay adopt the same type of relay, a pin 3 and a pin 4 of the relay are movable contacts, a pin 5 and a pin 6 are armature connection points, and a pin 7 and a pin 8 are control circuit connection points;
a live wire U at the three-phase four-wire power supply end is connected with a pin 5 of a first relay, a live wire V is connected with a pin 5 of a second relay and a pin 6 of a third relay, and a live wire W is connected with a pin 6 of the second relay and the pin 6 of the third relay;
pins 3 of the first relay, the second relay and the third relay are respectively connected to A, B, C three-phase input ends of the three-phase alternating current motor, pins 4 of the second relay are connected to C-phase input ends of the three-phase alternating current motor, and pins 4 of the third relay are connected to B-phase input ends of the three-phase alternating current motor;
and pins 7 and 8 of the first relay, the second relay and the third relay are electrically connected with the driving plate, and the driving plate is electrically connected with the controller and used for receiving a control signal for switching on and off the relays.
2. The relay-based three-phase motor control circuit according to claim 1, wherein indicator lamps are respectively connected in series between a zero line N of the three-phase four-wire system power supply end and the input ends of the A phase, the B phase and the C phase of the three-phase alternating current motor.
3. The relay-based three-phase motor control circuit according to claim 1, wherein pins 1 and 2 of the relay I, the relay II and the relay III are static contacts; a first indicator lamp is connected in series on a path connecting a zero line N of the three-phase four-wire system power supply end with a pin 1 of a first relay; a second indicator lamp is connected in series between the pin 1 and the pin 2 of the second relay; and a third indicator light is connected in series between the pin 1 and the pin 2 of the third relay.
4. The relay-based three-phase motor control circuit as claimed in claim 3, wherein the phase sequence of the second relay and the phase sequence of the third relay are opposite, and under the normal working condition of the first relay, the on-off of the second relay and the third relay are changed to realize the forward and reverse rotation of the three-phase alternating current motor.
5. The relay-based three-phase motor control circuit according to claim 1, wherein the driving board is provided with two relay driving circuit interfaces for the first relay, the second relay and the third relay respectively, and is electrically connected with a pin 7 and a pin 8 respectively; the driving board is provided with control signal interfaces corresponding to the first relay, the second relay and the third relay, and is electrically connected with the controller.
6. The relay-based three-phase motor control circuit according to claim 3, further comprising a frequency converter having an A-phase input, a B-phase input, and a C-phase input corresponding to three phases of the three-phase AC motor A, B, C, and an A-phase output, a B-phase output, and a C-phase output;
the A-phase output end, the B-phase output end and the C-phase output end are respectively and correspondingly connected with the A, B, C three-phase input end of the three-phase alternating current motor;
the phase A input end, the phase B input end and the phase C input end are connected with pins 3 of the relay I, the relay II and the relay III;
the phase B input end is also connected with a pin 4 of the relay 3;
the C-phase input end is also connected with a pin 4 of the relay 2.
Technical Field
The invention belongs to the technical field of three-phase motor control, and relates to a three-phase motor control circuit based on a relay.
Background
At present, most of motor control circuits control the starting, stopping and positive and negative rotation of an alternating current motor in a manner of strong electric control such as a contactor change-over switch. Fig. 1 is a wiring diagram of a normal and reverse rotation self-locking control circuit of a common three-phase alternating current motor. The wiring diagram ensures that when one contactor is energized, the other contactor is not energized by its auxiliary normally closed contact. The 'strong-strong' control has higher potential safety hazard, so that a user needs to be vigilant and careful when operating.
Therefore, it is an urgent technical problem to be solved by those skilled in the art to provide a three-phase motor control circuit which controls a strong current through a weak current and realizes the start-stop and forward and reverse rotation of a three-phase motor based on a relay, thereby improving the safety and controllability of operation.
Disclosure of Invention
Aiming at the current research situation and the existing problems, the invention provides a control mode of a three-phase alternating current motor based on a relay, which can effectively realize the intercommunication and signal transmission between weak currents, thereby switching strong current control into weak current control and improving the safety and the controllability of a system.
The specific scheme for achieving the purpose is as follows:
a three-phase motor control circuit based on a relay is used for controlling a three-phase alternating current motor and comprises a controller, a first relay, a second relay, a third relay and a drive board; wherein the content of the first and second substances,
the first relay, the second relay and the third relay adopt the same type of relay, a
a live wire U at the three-phase four-wire power supply end is connected with a
and
Preferably, indicator lights are respectively connected in series between the zero line N of the three-phase four-wire system power supply end and the input ends of the a phase, the B phase and the C phase of the three-phase alternating current motor.
Preferably, the
Preferably, the phase sequence of the second relay is opposite to that of the third relay, and under the condition that the first relay normally works, the on-off of the second relay and the third relay is changed to realize the forward and reverse rotation of the three-phase alternating-current motor.
Preferably, the driving board is a relay driving circuit interface in which two paths are respectively allocated to the relay I, the relay II and the relay III, and the driving board is respectively and electrically connected with the
Preferably, the present invention further comprises a frequency converter having an a-phase input, a B-phase input, and a C-phase input corresponding to three phases of the three-phase ac motor A, B, C, and an a-phase output, a B-phase output, and a C-phase output;
the A-phase output end, the B-phase output end and the C-phase output end are respectively and correspondingly connected with the A, B, C three-phase input end of the three-phase alternating current motor;
the phase A input end, the phase B input end and the phase C input end are connected with
the phase B input end is also connected with a pin 4 of the
the C-phase input end is also connected with a pin 4 of the relay 2.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a three-phase motor control circuit based on a relay, which designs a control circuit for controlling strong current by weak current through a high-power relay, realizes communication and signal transmission between the weak current, realizes the start-stop and positive and negative rotation work of the three-phase motor by the weak current, utilizes a weak current controller such as a single chip microcomputer and the like to complete the operation control of the three-phase motor, realizes the control of the working states of the three-phase motor such as start-stop, positive and negative rotation and the like under the absolute safe voltage of a human body, improves the safety and the controllability of the system, and provides powerful technical support for the intelligent control in the fields of industry, agriculture and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only embodiments of the invention, and that for a person skilled in the art, other drawings can be obtained from the provided drawings without inventive effort.
FIG. 1 is a wiring diagram of a positive and negative rotation self-locking control circuit of a prior three-phase AC motor;
fig. 2 is a logic circuit diagram of a three-phase motor control circuit based on a relay according to an embodiment of the present invention;
fig. 3 is a logic circuit diagram of a three-phase motor control circuit based on a relay according to a second embodiment of the present invention;
FIG. 4 is a pin diagram of Relay one, Relay two, and Relay three of the present invention;
fig. 5 is a pin diagram of the driving board of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a three-phase motor control circuit based on a relay, which comprises a controller, a relay I1, a relay II 2, a relay III 3 and a drive board 4. The relay I1, the relay II 2 and the relay III 3 adopt the same type of relay, referring to a relay pin diagram provided in the attached figure 4, the
A live wire U at the three-phase four-wire power supply end is connected with a
The working principle of the three-phase alternating current motor is as follows: when a three-phase power supply is connected into the stator winding, the stator winding can generate a rotating magnetic field. The direction of rotation of the rotating magnetic field is related to the phase sequence of the current in the winding. The phase sequence U, V, W is arranged clockwise, the magnetic field rotates clockwise, if any two of the three power lines are reversed, the phase sequence will change, the magnetic field rotates counterclockwise, and the three-phase motor will be reversed. The invention realizes the control of starting, stopping and positive and negative rotation of the three-phase alternating current motor by utilizing the high-power relay HHC 71A. The driving board 4 is provided with two relay driving circuit interfaces for the relay I1, the relay II 2 and the relay III 3 respectively, and is electrically connected with the
Referring to fig. 5, which is a pin diagram of a driving board, the driving board has 38 pins, and 01-24 two-by-two sets of
Referring to the first embodiment, a logic circuit for starting and stopping of the three-phase motor based on relay control is provided, and the second embodiment provides a logic circuit for forward and reverse rotation of the three-phase motor based on relay control.