Series motor control circuit

Abstract

The utility model provides a series motor control circuit, which is used for controlling a series motor composed of an excitation winding L1 and an armature winding L2, and comprises a rectifier bridge used for rectifying the excitation winding L1 or the armature winding L2; the power H-bridge circuit comprises four semiconductor power devices, and the semiconductor power devices are used for controlling the direction of current flowing through the excitation winding L1 and the armature winding L2 so as to realize forward rotation, reverse rotation and braking of the series motor; and the central processing controller is used for generating a PWM (Pulse Width Modulation) signal and controlling the on and off of the four semiconductor power devices through a gate control driving circuit. According to the series motor control circuit, the rectifier bridge, the power H-bridge circuit and the central processing controller are integrated, so that efficient control over a series motor composed of the excitation winding L1 and the armature winding L2 is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor control circuit technical field, in particular to a series excited motor control circuit. BACKGROUND

[0002] Single-phase series excited motor is named because of the series connection of armature winding and excitation winding. The motor belongs to AC and DC dual-purpose motor, which can work with AC power supply or DC power supply. Single-phase series excited motor has high speed, large starting torque, small size, light weight, non-stall and wide voltage range, so it is widely used in various applications such as household appliances, tools and industrial equipment.

[0003] The traditional DC brush series excited motor control method mainly includes two kinds. One is to realize polarity switching through external commutating contactor. This method switches the power polarity of armature winding or excitation winding through external commutating contactor to realize the control of motor rotating direction. The controller uses semiconductor power devices to realize chopper speed regulation. This method has mechanical fatigue problem due to the use of mechanical contactor, which affects the stability and reliability of the system. When the current is switched by the contact, arc will be generated, which will cause the contact ablation and sticking phenomenon, seriously affecting the reliability and service life of the controller.

[0004] The other is to use electronic commutation parallel continuous diode. This method replaces the above-mentioned commutating contactor with electronic commutation and parallel continuous diode at the other end of the winding. In this way, polarity switching can be realized without using mechanical contactor. However, in order to realize fast brake control, additional complex control circuit is needed, which not only increases the cost, but also makes the controller larger in size, reduces the integration and efficiency of the system. TECHNICAL SOLUTION

[0005] In view of the above-mentioned defects of the prior art, the purpose of the utility model is to provide a series excited motor control circuit, which solves the problems of low reliability and high cost of the controller in the prior art.

[0006] In order to achieve the above-mentioned purpose and other related purposes, the utility model provides the following technical scheme:

[0007] A series excited motor control circuit for controlling a series excited motor composed of an excitation winding L1 and an armature winding L2, comprising a rectifier bridge for rectifying the excitation winding L1 or the armature winding L2; a power H-bridge circuit comprising four semiconductor power devices for controlling the current direction flowing through the excitation winding L1 and the armature winding L2 to realize the forward rotation, reverse rotation and braking of the series excited motor; a central processing controller for generating a PWM signal and controlling the conduction and turn-off of the four semiconductor power devices through a gate drive circuit.

[0008] To achieve the above technical solutions, the series excited motor control circuit integrates the rectifier bridge, the power H-bridge circuit and the central processing controller (MCU), realizes the efficient control of the series excited motor composed of the excitation winding L1 and the armature winding L2, the rectifier bridge is composed of four diodes D1, D2, D3 and D4 to ensure that the current direction in the armature winding L2 is always consistent, the central processing controller generates a PWM signal and controls the conduction and turn-off of the four power devices through a gate drive circuit, which can realize the forward rotation, reverse rotation and braking of the motor, increase the control flexibility of the motor, and can realize the real-time regulation and control of the motor operating state, and accurately control the speed and torque of the motor.

[0009] In an embodiment of the utility model, four semiconductor power devices are Q1, Q2, Q3 and Q4 respectively; the rectifier bridge is composed of four diodes D1, D2, D3 and D4.

[0010] To achieve the above technical solutions, the rectifier bridge is composed of four diodes D1, D2, D3 and D4, which is used for rectifying the excitation winding L1 or the armature winding L2 to ensure the consistency of the current.

[0011] In an embodiment of the utility model, when Q1 and Q4 are turned on and Q2 and Q3 are turned off, the series excited motor rotates forward, and the current flowing out of the positive electrode of the power supply passes through Q1, the excitation winding L1, diode D4, the armature winding L2, diode D2, Q4 in turn and then flows into the negative electrode of the power supply.

[0012] To achieve the above technical solutions, when Q1 and Q4 are turned on and Q2 and Q3 are turned off, the current direction in the excitation winding L1 and the armature winding L2 makes the series excited motor generate a positive torque, which causes the series excited motor to rotate forward, and by accurately controlling the current direction, the electromagnetic interference generated during the operation of the motor can be reduced, and the stability of the whole system can be improved.

[0013] In an embodiment of the utility model, when Q2 and Q3 are turned on and Q1 and Q4 are turned off, the series excited motor reverses, and the current flowing out of the positive electrode of the power supply passes through Q3, diode D3, the armature winding L2, diode D1, the excitation winding L1, Q2 in turn and then flows into the negative electrode of the power supply.

[0014] The above technical solution is realized, when the Q2 and the Q3 are turned on, and the Q1 and the Q4 are turned off, the motor generates a reverse torque, causing the motor to reverse. By using the PWM signal generated by the central processing controller, the speed and position of the motor can be accurately controlled by adjusting the on time of Q2 and Q3.

[0015] In an embodiment of the present application, when the Q2 and the Q4 are turned on, and the Q1 and the Q3 are turned off, the series excited motor executes a short circuit braking mode.

[0016] The above technical solution is realized, when the Q2 and the Q4 are turned on, and the Q1 and the Q3 are turned off, the H bridge circuit short circuits the field winding L1 and the armature winding L2, forming a low impedance path. Since the field winding L1 and the armature winding L2 are shorted together, the reverse electromotive force generated by the motor cannot effectively drive the current to flow outward, but is forced to circulate internally, generating heat and consuming kinetic energy, thereby rapidly decelerating or stopping the motor.

[0017] In an embodiment of the present application, when the Q1 and the Q3 are turned on, and the Q2 and the Q4 are turned off, the series excited motor executes a short circuit braking mode.

[0018] The above technical solution is realized, when the Q1 and the Q3 are turned on, and the Q2 and the Q4 are turned off, the H bridge circuit short circuits the field winding L1 and the armature winding L2, forming a low impedance path. The short circuit braking mode can provide a powerful braking torque in an instant, making the motor stop quickly, especially suitable for applications that require rapid braking.

[0019] In an embodiment of the present application, when the Q1, Q2, Q3, and Q4 are all turned off, the series excited motor executes an energy feedback braking mode.

[0020] The above technical solution is realized, in this mode, the motor continues to rotate due to inertia, and in the energy feedback braking mode, the series excited motor operates as a generator, converting mechanical energy into electrical energy. This electrical energy can be fed back to the power grid or energy storage system through an inverter or other power electronic devices, improving energy utilization efficiency.

[0021] In an embodiment of the present application, the semiconductor power device is one or more of MOSFET, IGBT, GTO, IGCT, thyristor or triode.

[0022] The above technical solution is realized, by allowing the use of different types of semiconductor power devices, this design can adapt to a wide range of power levels and application requirements, from low power to super high power applications can find the right solution.

[0023] The serially excited motor control circuit has the following beneficial effects: the serially excited motor control circuit integrates the rectifier bridge, the power H-bridge circuit and the central processing controller, realizes high-efficiency control of the serially excited motor composed of the field winding L1 and the armature winding L2, avoids mechanical wear and tear problems caused by the traditional reversing contactor through full-electronic control, greatly improves the stability and reliability of the system, rectifies the field winding L1 or the armature winding L2, the current flows through different bridge arms in the serially excited forward and reverse rotation control, the internal diodes work alternately, the single diode is prevented from being damaged due to long-time continuous work, the work load of each diode is ensured to be evenly shared, and the durability and reliability are enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The circuit schematic diagram of the utility model is shown. DETAILED DESCRIPTION

[0025] The following specific embodiments illustrate the implementation of the utility model, and those skilled in the art can easily understand other advantages and effects of the utility model from the disclosed content of the specification. It should be noted that the following examples and features in the examples can be combined with each other without conflict.

[0026] Please refer to Figure 1 The utility model provides a kind of serially excited motor control circuit, for controlling the serially excited motor composed of field winding L1 and armature winding L2, comprising: rectifier bridge, for rectifying the field winding L1 or armature winding L2;Power H-bridge circuit, including four semiconductor power devices, the semiconductor power device is used to control the current direction flowing through field winding L1 and armature winding L2, to realize the positive rotation, reverse rotation and braking of serially excited motor;Central processing controller is used to generate PWM signal, and the conduction of four semiconductor power devices is controlled by gate drive circuit and shutdown.

[0027] The serially excited motor control circuit integrates the rectifier bridge, the power H-bridge circuit and the central processing controller (MCU), realizes high-efficiency control of the serially excited motor composed of the field winding L1 and the armature winding L2;The rectifier bridge is composed of four diodes D1, D2, D3, D4 to ensure that the current direction in the armature winding L2 is always consistent;The central processing controller generates PWM signal, and the conduction of four power devices is controlled by gate drive circuit and shutdown, which can realize the positive rotation, reverse rotation and braking of motor, increase the control flexibility of motor, and can real-time regulate and control the running state of motor, accurately control the speed and torque of motor.

[0028] Four semiconductor power devices are Q1, Q2, Q3 and Q4 respectively; the rectifier bridge is composed of four diodes D1, D2, D3 and D4, which is used for rectifying the excitation winding L1 or the armature winding L2 to ensure the consistency of the current.

[0029] When Q1 and Q4 are turned on and Q2 and Q3 are turned off, the series excited motor rotates forward, and the current flowing out of the positive pole of the power supply passes through Q1, the excitation winding L1, the diode D4, the armature winding L2, the diode D2, Q4 in turn, and then flows into the negative pole of the power supply.

[0030] When Q1 and Q4 are turned on and Q2 and Q3 are turned off, the current directions in the excitation winding L1 and the armature winding L2 make the series excited motor generate a positive torque, resulting in the forward rotation of the series excited motor. By accurately controlling the current flow direction, the electromagnetic interference generated during the operation of the motor can be reduced, and the stability of the entire system can be improved.

[0031] When Q2 and Q3 are turned on and Q1 and Q4 are turned off, the series excited motor reverses, and the current flowing out of the positive pole of the power supply passes through Q3, the diode D3, the armature winding L2, the diode D1, the excitation winding L1, Q2 in turn, and then flows into the negative pole of the power supply. When Q2 and Q3 are turned on and Q1 and Q4 are turned off, the motor generates a reverse torque, resulting in the reverse rotation of the motor. By using the PWM signal generated by the central processing controller, the speed and position of the motor can be accurately controlled by adjusting the on time of Q2 and Q3.

[0032] When Q2 and Q4 are turned on and Q1 and Q3 are turned off, the series excited motor executes the short-circuit braking mode. When Q2 and Q4 are turned on and Q1 and Q3 are turned off, the H-bridge circuit short-circuits the excitation winding L1 and the armature winding L2, forming a low-impedance path. Since the excitation winding L1 and the armature winding L2 are short-circuited together, the reverse electromotive force generated by the motor cannot effectively drive the current to flow outward, but is forced to circulate internally, generating heat and consuming kinetic energy, thereby rapidly decelerating or stopping the motor.

[0033] When Q1 and Q3 are turned on and Q2 and Q4 are turned off, the series excited motor executes the short-circuit braking mode. When Q1 and Q3 are turned on and Q2 and Q4 are turned off, the H-bridge circuit short-circuits the excitation winding L1 and the armature winding L2, forming a low-impedance path. The short-circuit braking mode can provide a powerful braking torque in an instant, making the motor stop quickly, and is particularly suitable for applications that require rapid braking.

[0034] When Q1, Q2, Q3, Q4 are all off, the series excited motor executes energy feedback braking mode. In this mode, the motor continues to rotate due to inertia, and in the energy feedback braking mode, the series excited motor operates as a generator to convert mechanical energy into electrical energy; this electrical energy can be fed back to the power grid or energy storage system through the inverter or other power electronic devices, improving energy utilization efficiency.

[0035] The semiconductor power device is one or more of MOSFET, IGBT, GTO, IGCT, thyristor or triode.

[0036] By allowing the use of different types of semiconductor power devices, the design can adapt to a wide range of power levels and application requirements, from low power to ultra-high power applications.

[0037] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. All equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical concept disclosed by the present application should still be covered by the claims of the present application.

Claims

1. A series motor control circuit for controlling a series motor consisting of a field winding L1 and an armature winding L2, characterized in that, include: A rectifier bridge is used to rectify the excitation winding L1 or the armature winding L2; The power H-bridge circuit includes four semiconductor power devices, which are used to control the direction of the current flowing through the excitation winding L1 and the armature winding L2, so as to realize the forward rotation, reverse rotation and braking of the series motor. The central processing controller is used to generate PWM signals and control the on and off of the four semiconductor power devices through a gating drive circuit.

2. The series motor control circuit according to claim 1, characterized in that: The four semiconductor power devices are Q1, Q2, Q3, and Q4, respectively. The rectifier bridge consists of four diodes, D1, D2, D3, and D4.

3. The series motor control circuit according to claim 2, characterized in that: When Q1 and Q4 are turned on and Q2 and Q3 are turned off, the series motor rotates in the forward direction. The current flowing out of the positive terminal of the power supply passes through Q1, excitation winding L1, diode D4, armature winding L2, diode D2, Q4 in sequence, and then flows into the negative terminal of the power supply.

4. The series motor control circuit according to claim 2, characterized in that: When Q2 and Q3 are turned on and Q1 and Q4 are turned off, the series motor reverses direction. The current flowing out of the positive terminal of the power supply passes through Q3, diode D3, armature winding L2, diode D1, excitation winding L1, and Q2 in sequence, and then flows into the negative terminal of the power supply.

5. A series motor control circuit according to claim 2, characterized in that: When Q2 and Q4 are turned on and Q1 and Q3 are turned off, the series motor executes a short-circuit braking mode.

6. The series motor control circuit according to claim 2, characterized in that: When Q1 and Q3 are turned on and Q2 and Q4 are turned off, the series motor performs short-circuit braking mode.

7. A series motor control circuit according to claim 2, characterized in that: When Q1, Q2, Q3, and Q4 are all turned off, the series motor executes the energy feedback braking mode.

8. The series motor control circuit according to claim 1, characterized in that: The semiconductor power device is one or more of MOSFET, IGBT, GTO, IGCT, thyristor or transistor.

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