Motor control circuit of pulverizer

Abstract

The utility model discloses a motor control circuit of a pulverizer, which relates to the field of motors and comprises a motor working module used for a three-phase motor to receive three-phase alternating current to work; the direct current acquisition module is used for converting single-phase alternating current into direct current as working voltage and supplying power to the positive and negative rotation control module and the rotating speed control module; the positive and negative rotation control module is used for controlling a switch of the motor working module through a relay to control positive and negative rotation of the three-phase motor; the rotating speed control module is used for controlling the current flowing size of the three-phase motor in unit time by controlling the duty ratio of the output PWM signal so as to control the rotating speed of the three-phase motor; the beneficial effects of the utility model are that the positive and negative rotation control module is used to control the positive and negative rotation of the three-phase motor, the rotation speed control module is used to control the rotation speed of the three-phase motor, and the positive and negative rotation control module and the rotation speed control module are simple in structure and low in cost, and meet the working requirements of the three-phase motor.

Description

Technical Field

[0001] The utility model relates to the field of motors, in particular to a motor control circuit for a pulverizer. Background Art

[0002] The working principle of the crusher is to use high-speed rotating blades or hammers to impact, shear, crush and rub the material, turning the material from large blocks or solids into smaller particles.

[0003] Existing three-phase motor control is often based on frequency converters, but frequency converters are large and expensive. For some small crushers, the use of frequency converters is too wasteful and needs to be improved. Utility Model Content

[0004] The purpose of the present utility model is to provide a motor control circuit for a pulverizer to solve the problems raised in the above background technology.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A motor control circuit for a pulverizer, comprising:

[0007] Motor working module, used for three-phase motor to receive three-phase AC power to work;

[0008] The DC acquisition module is used to convert single-phase AC power into DC power as the working voltage to power the forward and reverse control module and the speed control module;

[0009] The forward and reverse control module is used to control the switch of the motor working module through the relay to control the forward and reverse rotation of the three-phase motor;

[0010] The speed control module is used to control the current flowing through the three-phase motor per unit time by controlling the duty cycle of the output PWM signal, thereby controlling the speed of the three-phase motor;

[0011] The motor working module is connected to the DC acquisition module, the DC acquisition module is connected to the forward and reverse control module and the speed control module, the forward and reverse control module is connected to the motor working module, and the speed control module is connected to the motor working module.

[0012] As a further solution of the present invention: the motor working module includes a bidirectional thyristor Z1, a bidirectional thyristor Z2, a bidirectional thyristor Z3, a switch S1, a switch S2, a switch S3, a switch S4, a switch S5, a switch S6, and a three-phase motor M, the positive pole of the bidirectional thyristor Z1 is connected to the live wire L3, the negative pole of the bidirectional thyristor Z1 is connected to one end of the switch S1 and one end of the switch S6, the control pole of the bidirectional thyristor Z1 is connected to the speed control module, the positive pole of the bidirectional thyristor Z2 is connected to the live wire L2, the negative pole of the bidirectional thyristor Z2 is connected to one end of the switch S2, and the switch S 5, the control electrode of the bidirectional thyristor Z2 is connected to the speed control module, the positive electrode of the bidirectional thyristor Z3 is connected to the live wire L1, the negative electrode of the bidirectional thyristor Z3 is connected to one end of the switch S3 and one end of the switch S4, the control electrode of the bidirectional thyristor Z3 is connected to the speed control module, the other end of the switch S1 is connected to the other end of the switch S4 and the first end of the three-phase motor M, the other end of the switch S2 is connected to the other end of the switch S5 and the second end of the three-phase motor M, the other end of the switch S3 is connected to the other end of the switch S6 and the third end of the three-phase motor M, and the fourth end of the three-phase motor M is grounded.

[0013] As a further solution of the present invention: the DC acquisition module includes a transformer W, a rectifier T, a capacitor C1, an inductor L4, a resistor R1, a resistor R2, and a switch S1. One end of the input end of the transformer W is connected to any live wire, and the other end of the input end of the transformer W is connected to the neutral wire N. One end of the output end of the transformer W is connected to the first end of the rectifier T, the other end of the output end of the transformer W is connected to the third end of the rectifier T, the second end of the rectifier T is grounded, the fourth end of the rectifier T is connected to one end of the capacitor C1 and one end of the inductor L4, the other end of the capacitor C1 is grounded, the other end of the inductor L4 is connected to one end of the resistor R1 and one end of the resistor R2, the other end of the resistor R1 is grounded, the other end of the resistor R2 is connected to one end of the switch S1, and the other end of the switch S1 is connected to the forward and reverse control module and the speed control module.

[0014] As a further solution of the present invention: the forward and reverse control module includes a switch S2, a diode D1, and a relay J1. The cathode of the diode D1 is connected to one end of the relay J1 and one end of the switch S2. The other end of the switch S2 is connected to the DC acquisition module. The anode of the diode D1 is grounded, and the other end of the relay J1 is grounded.

[0015] As a further solution of the present utility model: the speed control module includes an inverter U1, an inverter U2, a resistor R3, a potentiometer RP1, a diode D2, a diode D3, and a capacitor C2. The power supply end of the inverter U1 is connected to the power supply end of the inverter U2 and the DC acquisition module. The input end of the inverter U1 is connected to the cathode of the diode D2, one end of the capacitor C2, and the positive electrode of the diode D3. The other end of the capacitor C2 is grounded. The cathode of the diode D3 is connected to one end of the potentiometer RP1. The positive electrode of the diode D2 is connected to the other end of the potentiometer RP1. The sliding end of the potentiometer RP1 is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the output end of the inverter U1 and the input end of the inverter U2. The output end of the inverter U2 is connected to the motor working module.

[0016] Compared with the existing technology, the beneficial effects of the present invention are: the present invention controls the forward and reverse rotation of the three-phase motor through the forward and reverse control module, and controls the speed of the three-phase motor through the speed control module. The forward and reverse control module and the speed control module have simple structures and low prices, and meet the working requirements of the three-phase motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The schematic diagram of the motor control circuit of a pulverizer.

[0018] Figure 2 The present invention is a circuit diagram of a motor control circuit of a pulverizer.

[0019] Figure 3 Schematic diagram of the internal structure of the rectifier T. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] See also Figure 1 , a motor control circuit for a pulverizer, comprising:

[0022] Motor working module, used for three-phase motor to receive three-phase AC power to work;

[0023] The DC acquisition module is used to convert single-phase AC power into DC power as the working voltage to power the forward and reverse control module and the speed control module;

[0024] The forward and reverse control module is used to control the switch of the motor working module through the relay to control the forward and reverse rotation of the three-phase motor;

[0025] The speed control module is used to control the current flowing through the three-phase motor per unit time by controlling the duty cycle of the output PWM signal, thereby controlling the speed of the three-phase motor;

[0026] The motor working module is connected to the DC acquisition module, the DC acquisition module is connected to the forward and reverse control module and the speed control module, the forward and reverse control module is connected to the motor working module, and the speed control module is connected to the motor working module.

[0027] In this example: See Figure 2 The motor working module includes a bidirectional thyristor Z1, a bidirectional thyristor Z2, a bidirectional thyristor Z3, a switch S1, a switch S2, a switch S3, a switch S4, a switch S5, a switch S6, and a three-phase motor M. The positive pole of the bidirectional thyristor Z1 is connected to the live wire L3, the negative pole of the bidirectional thyristor Z1 is connected to one end of the switch S1 and one end of the switch S6, the control pole of the bidirectional thyristor Z1 is connected to the speed control module, the positive pole of the bidirectional thyristor Z2 is connected to the live wire L2, the negative pole of the bidirectional thyristor Z2 is connected to one end of the switch S2 and one end of the switch S5, and the bidirectional The control electrode of the thyristor Z2 is connected to the speed control module, the positive electrode of the bidirectional thyristor Z3 is connected to the live wire L1, the negative electrode of the bidirectional thyristor Z3 is connected to one end of the switch S3 and one end of the switch S4, the control electrode of the bidirectional thyristor Z3 is connected to the speed control module, the other end of the switch S1 is connected to the other end of the switch S4 and the first end of the three-phase motor M, the other end of the switch S2 is connected to the other end of the switch S5 and the second end of the three-phase motor M, the other end of the switch S3 is connected to the other end of the switch S6 and the third end of the three-phase motor M, and the fourth end of the three-phase motor M is grounded.

[0028] Three-phase AC power is input, passes through bidirectional thyristors Z1, Z2, and Z3, and then passes through switches S1, S2, and S3 (or switches S4, S5, and S6) to power a three-phase motor M. The speed of the three-phase motor is controlled by the conduction frequency of the bidirectional thyristors Z1, Z2, and Z3. Forward and reverse rotation is achieved by the closing conditions of the switch group of switches S1, S2, and S3 and the switch group of switches S4, S5, and S6. When the switch group of switches S1, S2, and S3 is closed, the rotation direction of the three-phase motor M is opposite to the rotation direction of the three-phase motor M when the switch group of switches S4, S5, and S6 is closed.

[0029] In this example: See Figure 2 and Figure 3The DC acquisition module includes a transformer W, a rectifier T, a capacitor C1, an inductor L4, a resistor R1, a resistor R2, and a switch S1. One end of the input end of the transformer W is connected to any live wire, and the other end of the input end of the transformer W is connected to the neutral wire N. One end of the output end of the transformer W is connected to the first end of the rectifier T, the other end of the output end of the transformer W is connected to the third end of the rectifier T, the second end of the rectifier T is grounded, the fourth end of the rectifier T is connected to one end of the capacitor C1 and one end of the inductor L4, the other end of the capacitor C1 is grounded, the other end of the inductor L4 is connected to one end of the resistor R1 and one end of the resistor R2, the other end of the resistor R1 is grounded, the other end of the resistor R2 is connected to one end of the switch S1, and the other end of the switch S1 is connected to the forward and reverse control module and the speed control module.

[0030] The rectifier T is composed of a bridge rectifier circuit. Two diodes are connected in series to form a diode string, and two diode strings are connected in parallel to form a bridge rectifier circuit.

[0031] After the single-phase AC power is input, it is stepped down by transformer W, converted into DC power by rectifier T, and converted into smooth DC power by capacitor C1, inductor L4, and resistor R1. Switch S1 is a manual switch to control whether to power the subsequent circuit.

[0032] In this example: See Figure 2 The forward and reverse control module includes a switch S2, a diode D1, and a relay J1. The cathode of the diode D1 is connected to one end of the relay J1 and one end of the switch S2. The other end of the switch S2 is connected to the DC acquisition module. The anode of the diode D1 is grounded, and the other end of the relay J1 is grounded.

[0033] Whether the switch S2 is closed controls whether the relay J1 is working. When the relay J1 is not working, the switches S1, S2, and S3 are closed, and the switches S4, S5, and S6 are open. When the relay J1 is working, the switches S1, S2, and S3 are open, and the switches S4, S5, and S6 are closed.

[0034] In this example: See Figure 2 The speed control module includes an inverter U1, an inverter U2, a resistor R3, a potentiometer RP1, a diode D2, a diode D3, and a capacitor C2. The power supply end of the inverter U1 is connected to the power supply end of the inverter U2 and the DC acquisition module. The input end of the inverter U1 is connected to the cathode of the diode D2, one end of the capacitor C2, and the anode of the diode D3. The other end of the capacitor C2 is grounded. The cathode of the diode D3 is connected to one end of the potentiometer RP1, the anode of the diode D2 is connected to the other end of the potentiometer RP1, the sliding end of the potentiometer RP1 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the output end of the inverter U1 and the input end of the inverter U2, and the output end of the inverter U2 is connected to the motor working module.

[0035] Initially, there is no voltage on capacitor C2, the input end of inverter U1 is at a low level, and inverter U1 outputs a high level. Capacitor C2 is charged through resistor R3, the left side of the sliding end of potentiometer RP1, and diode D2. When capacitor C2 becomes a high level, inverter U1 outputs a low level, and capacitor C2 is discharged through diode D3, the right side of the sliding end of potentiometer RP1, and resistor R3, and becomes a low level again. This cycle repeats, forming a square wave signal at the output end of inverter U1. After being inverted by inverter U2, a PWM signal is output to control the conduction state of bidirectional thyristors Z1, Z2, and Z3.

[0036] The working principle of the present utility model is as follows: the motor working module is used for the three-phase motor to receive three-phase alternating current for operation; the DC acquisition module is used to convert single-phase alternating current into direct current as the working voltage to supply power to the forward and reverse control module and the speed control module; the forward and reverse control module is used to control the switch of the motor working module through a relay to control the forward and reverse rotation of the three-phase motor; the speed control module is used to control the current flowing through the three-phase motor per unit time by controlling the duty cycle of the output PWM signal, thereby controlling the speed of the three-phase motor.

[0037] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive.

[0038] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A motor control circuit for a pulverizer, characterized in that: The motor control circuit of the pulverizer includes: Motor working module, used for three-phase motor to receive three-phase AC power to work; The DC acquisition module is used to convert single-phase AC power into DC power as the working voltage to power the forward and reverse control module and the speed control module; The forward and reverse control module is used to control the switch of the motor working module through the relay to control the forward and reverse rotation of the three-phase motor; The speed control module is used to control the current flowing through the three-phase motor per unit time by controlling the duty cycle of the output PWM signal, thereby controlling the speed of the three-phase motor; The motor working module is connected to the DC acquisition module, the DC acquisition module is connected to the forward and reverse control module and the speed control module, the forward and reverse control module is connected to the motor working module, and the speed control module is connected to the motor working module.

2. The motor control circuit of the pulverizer according to claim 1, characterized in that: The motor working module includes a bidirectional thyristor Z1, a bidirectional thyristor Z2, a bidirectional thyristor Z3, a switch S1, a switch S2, a switch S3, a switch S4, a switch S5, a switch S6, and a three-phase motor M. The positive pole of the bidirectional thyristor Z1 is connected to the live wire L3, the negative pole of the bidirectional thyristor Z1 is connected to one end of the switch S1 and one end of the switch S6, the control pole of the bidirectional thyristor Z1 is connected to the speed control module, the positive pole of the bidirectional thyristor Z2 is connected to the live wire L2, the negative pole of the bidirectional thyristor Z2 is connected to one end of the switch S2 and one end of the switch S5, and the bidirectional thyristor Z1 is connected to the speed control module. The control electrode of the thyristor Z2 is connected to the speed control module, the positive electrode of the bidirectional thyristor Z3 is connected to the live wire L1, the negative electrode of the bidirectional thyristor Z3 is connected to one end of the switch S3 and one end of the switch S4, the control electrode of the bidirectional thyristor Z3 is connected to the speed control module, the other end of the switch S1 is connected to the other end of the switch S4 and the first end of the three-phase motor M, the other end of the switch S2 is connected to the other end of the switch S5 and the second end of the three-phase motor M, the other end of the switch S3 is connected to the other end of the switch S6 and the third end of the three-phase motor M, and the fourth end of the three-phase motor M is grounded.

3. The motor control circuit of the pulverizer according to claim 1, characterized in that: The DC acquisition module includes a transformer W, a rectifier T, a capacitor C1, an inductor L4, a resistor R1, a resistor R2, and a switch S1. One end of the input end of the transformer W is connected to any live wire, and the other end of the input end of the transformer W is connected to the neutral wire N. One end of the output end of the transformer W is connected to the first end of the rectifier T, the other end of the output end of the transformer W is connected to the third end of the rectifier T, the second end of the rectifier T is grounded, the fourth end of the rectifier T is connected to one end of the capacitor C1 and one end of the inductor L4, the other end of the capacitor C1 is grounded, the other end of the inductor L4 is connected to one end of the resistor R1 and one end of the resistor R2, the other end of the resistor R1 is grounded, the other end of the resistor R2 is connected to one end of the switch S1, and the other end of the switch S1 is connected to the forward and reverse control module and the speed control module.

4. The motor control circuit of the pulverizer according to claim 2, characterized in that: The forward and reverse control module includes a switch S2, a diode D1, and a relay J1. The cathode of the diode D1 is connected to one end of the relay J1 and one end of the switch S2. The other end of the switch S2 is connected to the DC acquisition module. The anode of the diode D1 is grounded, and the other end of the relay J1 is grounded.

5. The motor control circuit of the pulverizer according to claim 2, characterized in that: The speed control module includes an inverter U1, an inverter U2, a resistor R3, a potentiometer RP1, a diode D2, a diode D3, and a capacitor C2. The power supply end of the inverter U1 is connected to the power supply end of the inverter U2 and the DC acquisition module. The input end of the inverter U1 is connected to the cathode of the diode D2, one end of the capacitor C2, and the anode of the diode D3. The other end of the capacitor C2 is grounded. The cathode of the diode D3 is connected to one end of the potentiometer RP1. The anode of the diode D2 is connected to the other end of the potentiometer RP1. The sliding end of the potentiometer RP1 is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the output end of the inverter U1 and the input end of the inverter U2. The output end of the inverter U2 is connected to the motor working module.

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