Motor pump boost voltage bleeder circuit and motor control circuit

Abstract

The utility model discloses a motor pumping voltage bleeder circuit and a motor control circuit, comprising a current-limiting resistor R1 and a TVS tube, one end of the current-limiting resistor R1 is connected with the TVS tube, the other end of the current-limiting resistor R1 is connected with a DC bus end, and the other end of the TVS tube is grounded. When the bus voltage Ub is smaller than the maximum working voltage Vrwm of the TVS tube, the TVS tube is in a high-resistance state; when the bus voltage Ub is larger than the breakdown voltage Vbr of the TVS tube, the TVS tube changes from high impedance to low impedance at the speed of ps level and absorbs instantaneous large pulse power, pumping voltage of the bus voltage Ub is rapidly discharged through the TVS tube, electric energy is converted into heat energy, and therefore the voltage is clamped to a preset level, use of devices is reduced, cost is effectively reduced, and the service life of the TVS tube is prolonged. And due to the quick response characteristic, the problem that the device is easy to burn down is effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of motor control, and more specifically to a motor pump boost voltage discharge circuit and a motor control circuit. Background Art

[0002] In the motor speed control system, when the motor slows down or stops suddenly, the motor will be in a power generation state. The energy generated will be fed back to the DC bus terminal, and the bus voltage will continue to rise. If the bus voltage is not suppressed, overvoltage damage will be caused to the filter capacitors and power devices on the bus.

[0003] At present, the solution to this problem is usually to use a voltage sampling circuit to transmit the voltage signal to the single-chip microcomputer through the AD conversion chip. After the single-chip microcomputer processes it, it controls the MOS tube switch and discharges the pump-up voltage through the power resistor. However, it has the following disadvantages:

[0004] 1. Many components are required, and the cost is high;

[0005] 2. Software processing is required, and the response is slow, which may result in failure to discharge the pump-up voltage in time, thereby burning the device. Utility Model Content

[0006] In order to overcome the deficiencies of the prior art, the utility model provides a motor pump-up voltage discharge circuit to solve the problem that the voltage sampling circuit has a slow response speed and is prone to device burnout due to failure to discharge the pump-up voltage in time.

[0007] The technical solution of the utility model is as follows: a motor pump boost voltage discharge circuit, including a current limiting resistor R1 and a TVS tube, one end of the current limiting resistor R1 is connected to the TVS tube, the other end of the current limiting resistor R1 is connected to the DC bus terminal, and the other end of the TVS tube is grounded.

[0008] Furthermore, the TVS tube is a unidirectional TVS tube.

[0009] In addition, the utility model also provides a motor control circuit, including the above-mentioned motor pump voltage discharge circuit and the main control circuit, the main control circuit includes a power supply BT1, a three-phase motor MT1, a MOS tube Q1, a MOS tube Q2, a MOS tube Q3, a MOS tube Q4, a MOS tube Q5, and a MOS tube Q6, the D pole of the MOS tube Q1, the D pole of the MOS tube Q2, and the D pole of the MOS tube Q3 are all connected to the bus voltage Ub, the positive pole of the power supply BT1 is connected to the bus voltage Ub through an electronic switch, the S pole of the MOS tube Q4, the S pole of the MOS tube Q5 The S pole of the MOS tube Q3 and the S pole of the MOS tube Q6 are both connected to the negative pole of the power supply BT1, the S pole of the MOS tube Q1 and the D pole of the MOS tube Q4 are connected to the A phase line of the three-phase motor MT1, the S pole of the MOS tube Q2 and the D pole of the MOS tube Q5 are connected to the B phase line of the three-phase motor MT1, the S pole of the MOS tube Q3 and the D pole of the MOS tube Q6 are connected to the C phase line of the three-phase motor MT1, one end of the motor pump-up voltage discharge circuit is connected to the bus voltage Ub, and the other end of the motor pump-up voltage discharge circuit is connected to the negative pole of the power supply BT1.

[0010] Furthermore, it also includes a capacitor C1, one end of the capacitor C1 is connected to the bus voltage Ub, and the other end of the capacitor C1 is connected to the negative electrode of the power supply BT1.

[0011] Furthermore, the MOS transistor Q1 , the MOS transistor Q2 , the MOS transistor Q3 , the MOS transistor Q4 , the MOS transistor Q5 , and the MOS transistor Q6 are all N-channel MOS transistors.

[0012] Furthermore, the electronic switch is a diode D1, the positive electrode of the power supply BT1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the bus voltage Ub.

[0013] Furthermore, a controller driving circuit is included, and the G poles of the MOS tube Q1, the G pole of the MOS tube Q2, the G pole of the MOS tube Q3, the G pole of the MOS tube Q4, the G pole of the MOS tube Q5 and the G pole of the MOS tube Q6 are all connected to the controller driving circuit.

[0014] The utility model according to the above scheme has the following beneficial effects: a motor pump-up voltage discharge circuit, including a current limiting resistor R1 and a TVS tube, one end of the current limiting resistor R1 is connected to the TVS tube, the other end of the current limiting resistor R1 is connected to the DC bus terminal, and the other end of the TVS tube is grounded. When the motor decelerates or stops suddenly, the motor is in a power generation state, and the energy generated by it will be fed back to the DC bus terminal, and the bus voltage Ub at the DC bus terminal continues to rise; when the bus voltage Ub is less than the maximum working voltage Vrwm of the TVS tube, the TVS tube is in a high impedance state; when the bus voltage Ub is greater than the breakdown voltage Vbr of the TVS tube, the TVS tube changes from high impedance to low impedance at a speed of ps level, absorbing instantaneous large pulse power, and the pump-up voltage of the bus voltage Ub is quickly discharged through the TVS tube, so that the electrical energy is converted into heat energy, thereby clamping the voltage to a predetermined level. Secondly, as electrical energy is continuously converted into thermal energy, the bus voltage Ub gradually decreases. When the bus voltage Ub is less than the maximum operating voltage Vrwm of the TVS tube, the TVS tube returns to a high-resistance state, which not only reduces the use of devices and effectively reduces costs, but also effectively solves the problem of devices being easily burned due to its fast response characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a structural schematic diagram of a motor pump boost voltage discharge circuit in an embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure of a motor control circuit in an embodiment of the utility model; DETAILED DESCRIPTION

[0018] The following detailed description and drawings of the embodiments of the present invention are used to illustrate the principle of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the embodiments described.

[0019] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0020] See also Figure 1As shown, an embodiment of the utility model provides a motor pump boost voltage discharge circuit, including a current limiting resistor R1 and a TVS tube, one end of the current limiting resistor R1 is connected to the TVS tube, the other end of the current limiting resistor R1 is connected to the DC bus terminal, and the other end of the TVS tube is grounded.

[0021] The present invention provides a motor pump boost voltage discharge circuit, and its specific working principle is as follows:

[0022] When the motor decelerates or stops suddenly, the motor is in a power generation state. At this time, the energy generated by the motor cannot be consumed by the external load, so this energy will be fed back to the DC bus end, and the bus voltage Ub at the DC bus end continues to rise; when the bus voltage Ub is less than the maximum operating voltage Vrwm of the TVS tube, the TVS tube is in a high-impedance state and will not have a significant impact on the circuit. It can be considered to be in a non-conducting state. At this time, the TVS tube is equivalent to a disconnected switch and does not participate in the voltage discharge. When the bus voltage Ub is greater than the breakdown voltage Vbr of the TVS tube, the TVS tube changes from a high impedance state to a low impedance state at a speed of ps (picoseconds, i.e., within a very short time), so that the TVS tube can quickly absorb the instantaneous large pulse power generated in the circuit, thereby effectively discharging the pumped-up voltage of the bus voltage Ub. During the discharge process, the electrical energy is converted into heat energy by the TVS tube and dissipated in the circuit; thereby, the bus voltage Ub is clamped at a predetermined level, avoiding the risk of device burning caused by excessive voltage. As the electrical energy is continuously converted into heat energy and dissipated through the TVS tube, the bus voltage Ub gradually decreases. When the bus voltage Ub is reduced again to less than the maximum operating voltage Vrwm of the TVS tube, the TVS tube returns to a high impedance state and no longer participates in the voltage discharge. Compared with the traditional solution of controlling MOS tube switches and discharging the pump-up voltage through power resistors, the motor pump-up voltage discharge circuit provided by the embodiment of the utility model not only reduces the use of devices and effectively reduces costs, but also does not require software processing, so that it has a fast response characteristic and effectively solves the problem of devices being easily burned.

[0023] Preferably, the TVS tube is a unidirectional TVS tube. In this embodiment, a unidirectional TVS tube is used as a voltage discharge element. The unidirectional TVS tube can accurately control the discharge direction of the voltage, effectively avoid circuit failure and device damage caused by voltage feedback, and significantly improve the safety and stability of the circuit. When the motor decelerates or stops suddenly, the energy generated by the motor will be fed back to the DC bus terminal, and the bus voltage Ub continues to rise. The unidirectional TVS tube can quickly respond and absorb instantaneous large pulse power, and discharge the excessive voltage, thereby protecting other devices in the circuit. Secondly, the fast response characteristics of the unidirectional TVS tube help to reduce the heat loss caused by excessive voltage in the circuit. Specifically, when the bus voltage Ub exceeds the breakdown voltage of the unidirectional TVS tube, the unidirectional TVS tube can change from a high impedance state to a low impedance state at a speed of picoseconds, and quickly discharge the voltage, thereby reducing the time the voltage stays in the circuit, reducing the heat generated by excessive voltage, and effectively reducing the risk of circuit failure and device burning caused by excessive voltage, making the circuit more stable and reliable during long-term operation, and extending the service life of the circuit. In addition, the use of unidirectional TVS tubes also reduces the cost and complexity of the circuit. Due to its fast response and automatic switching characteristics, unidirectional TVS tubes can complete the voltage discharge without the need for external control, reducing additional control circuits and devices. This not only reduces the cost of the circuit, but also simplifies the design and manufacturing process of the circuit.

[0024] In addition, the utility model also provides a motor control circuit, see Figure 2 As shown, the motor control circuit includes the above-mentioned motor pump voltage discharge circuit and the main control circuit, the main control circuit includes a power supply BT1, a three-phase motor MT1, a MOS tube Q1, a MOS tube Q2, a MOS tube Q3, a MOS tube Q4, a MOS tube Q5, and a MOS tube Q6, the D pole of the MOS tube Q1, the D pole of the MOS tube Q2, and the D pole of the MOS tube Q3 are all connected to the bus voltage Ub, the positive pole of the power supply BT1 is connected to the bus voltage Ub through an electronic switch, the S pole of the MOS tube Q4, the S pole of the MOS tube Q5 The S pole and the S pole of MOS tube Q6 are both connected to the negative pole of the power supply BT1, the S pole of MOS tube Q1 and the D pole of MOS tube Q4 are connected to the A phase line of the three-phase motor MT1, the S pole of MOS tube Q2 and the D pole of MOS tube Q5 are connected to the B phase line of the three-phase motor MT1, the S pole of MOS tube Q3 and the D pole of MOS tube Q6 are connected to the C phase line of the three-phase motor MT1, one end of the motor pump-up voltage discharge circuit is connected to the bus voltage Ub, and the other end of the motor pump-up voltage discharge circuit is connected to the negative pole of the power supply BT1.

[0025] Furthermore, it also includes a capacitor C1, one end of the capacitor C1 is connected to the bus voltage Ub, and the other end of the capacitor C1 is connected to the negative electrode of the power supply BT1.

[0026] Furthermore, the MOS transistor Q1 , the MOS transistor Q2 , the MOS transistor Q3 , the MOS transistor Q4 , the MOS transistor Q5 , and the MOS transistor Q6 are all N-channel MOS transistors.

[0027] Furthermore, the electronic switch is a diode D1, the positive electrode of the power source BT1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the bus voltage Ub.

[0028] Furthermore, a controller driving circuit is also included, and the G pole of MOS tube Q1, the G pole of MOS tube Q2, the G pole of MOS tube Q3, the G pole of MOS tube Q4, the G pole of MOS tube Q5 and the G pole of MOS tube Q6 are all connected to the controller driving circuit. Specifically, the controller driving circuit converts the control signal of the single-chip microcomputer into a signal that can drive the motor controller, ensuring that the motor controller can receive accurate control instructions, and then control the operating state of the motor. It is worth mentioning that the controller driving circuit in this embodiment is a common motor controller driving circuit in the field, so it will not be repeated here.

[0029] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the utility model.

[0030] The above is an exemplary description of the utility model patent in conjunction with the accompanying drawings. It is obvious that the implementation of the utility model patent is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the utility model patent, or the concept and technical solution of the utility model patent are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A motor pump boost voltage discharge circuit, characterized in that: It includes a current limiting resistor R1 and a TVS tube, one end of the current limiting resistor R1 is connected to the TVS tube, the other end of the current limiting resistor R1 is connected to a DC bus terminal, and the other end of the TVS tube is grounded.

2. A motor pump boost voltage discharge circuit as claimed in claim 1, characterized in that: The TVS tube is a unidirectional TVS tube.

3. A motor control circuit, characterized in that: The invention comprises a motor pump boost voltage discharge circuit and a main control circuit as described in any one of claims 1 to 2, wherein the main control circuit comprises a power supply BT1, a three-phase motor MT1, a MOS tube Q1, a MOS tube Q2, a MOS tube Q3, a MOS tube Q4, a MOS tube Q5, and a MOS tube Q6, wherein the D pole of the MOS tube Q1, the D pole of the MOS tube Q2, and the D pole of the MOS tube Q3 are all connected to a bus voltage Ub, the positive pole of the power supply BT1 is connected to the bus voltage Ub through an electronic switch, and the S pole of the MOS tube Q4, the S pole of the MOS tube Q5, and the M The S pole of the OS tube Q6 is connected to the negative pole of the power supply BT1, the S pole of the MOS tube Q1 and the D pole of the MOS tube Q4 are connected to the A phase line of the three-phase motor MT1, the S pole of the MOS tube Q2 and the D pole of the MOS tube Q5 are connected to the B phase line of the three-phase motor MT1, the S pole of the MOS tube Q3 and the D pole of the MOS tube Q6 are connected to the C phase line of the three-phase motor MT1, one end of the motor pump-up voltage discharge circuit is connected to the bus voltage Ub, and the other end of the motor pump-up voltage discharge circuit is connected to the negative pole of the power supply BT1.

4. A motor control circuit as claimed in claim 3, characterized in that: It also includes a capacitor C1, one end of the capacitor C1 is connected to the bus voltage Ub, and the other end of the capacitor C1 is connected to the negative electrode of the power supply BT1.

5. A motor control circuit as claimed in claim 3, characterized in that: The MOS transistor Q1 , the MOS transistor Q2 , the MOS transistor Q3 , the MOS transistor Q4 , the MOS transistor Q5 , and the MOS transistor Q6 are all N-channel MOS transistors.

6. A motor control circuit as claimed in claim 3, characterized in that: The electronic switch is a diode D1, the positive electrode of the power source BT1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the bus voltage Ub.

7. A motor control circuit as claimed in claim 3, characterized in that: It also includes a controller driving circuit, and the G poles of the MOS tube Q1, the G poles of the MOS tube Q2, the G poles of the MOS tube Q3, the G poles of the MOS tube Q4, the G poles of the MOS tube Q5 and the G poles of the MOS tube Q6 are all connected to the controller driving circuit.

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