High-power servo driving device and servo control system

Abstract

The utility model discloses a high-power servo driving device and a high-power servo control system.The driving device comprises a rectifying circuit, a fuse protector, a buffer circuit, a filter circuit, an inverter circuit, a control circuit and a current protection circuit, the input end of the rectifying circuit is connected with a three-phase power source, and the output end of the rectifying circuit is connected with the input end of the buffer circuit; the buffer circuit is used for converting alternating current into direct current, the output end of the buffer circuit is connected with the input end of the filter circuit, the output end of the filter circuit is connected with the input end of the inverter circuit, the fuse is connected between the rectifying circuit and the filter circuit, and the control circuit is respectively connected with the buffer circuit and the inverter circuit. The current protection circuit at least comprises a first current protection circuit and a second current protection circuit; through various current protection circuits, input power grid faults caused by overcurrent faults of the servo driving device are effectively prevented, and some losses caused by poor protection are prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of servo control, and particularly relates to a high-power servo drive device and a servo control system. Background Art

[0002] Liquid-cooled servo motors are widely used due to their low noise and high cooling efficiency, such as servo motors for electric vehicle drives, injection molding machines, die-casting machines, etc. However, when current high-power servo drivers malfunction, the impact is significant. For example, a short-circuit fault may cause a power outage in the entire industrial area. Currently, the main solution is to detect the short-circuit condition of the upper and lower bridges of the detection module for protection. The disadvantage of this method is that it can only provide protection in most cases and cannot provide protection for some special cases. Summary of the Utility Model

[0003] In view of the above technical problems, the utility model provides a high-power servo drive device and a servo control system, which can achieve multi-channel protection.

[0004] The first embodiment of the utility model provides a high-power servo drive device, which includes a rectifier circuit, a fuse, a buffer circuit, a filter circuit, an inverter circuit, a control circuit, and a current protection circuit. The input end of the rectifier circuit is connected to a three-phase power supply, and the output end is connected to the input end of the buffer circuit, which is used to convert alternating current into direct current. The output end of the buffer circuit is connected to the input end of the filter circuit, and the output end of the filter circuit is connected to the input end of the inverter circuit. The fuse is connected between the rectifier circuit and the filter circuit. The control circuit is respectively connected to the buffer circuit, the inverter circuit, and the current protection circuit. The current protection circuit at least includes a first current protection circuit and a second current protection circuit.

[0005] Optionally, the inverter circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm includes transistors Q1, Q3, and Q5, and the lower bridge arm includes transistors Q2, Q4, and Q6. The three-phase output end of the inverter circuit is connected to a servo motor to supply power to the servo motor.

[0006] Optionally, the first current protection circuit is used to detect the saturation voltage drop of the upper bridge arm and the lower bridge arm, and transmit the detected voltage signal to the control circuit.

[0007] Optionally, the second overcurrent protection circuit includes a first current sensor, a second current sensor, and a third current sensor. The first current sensor, the second current sensor, and the third current sensor respectively detect the currents of the three-phase output ends. When the currents of the three-phase output ends are greater than a first preset current, the control circuit stops outputting.

[0008] Optionally, the current protection circuit further includes a third current protection circuit, which includes a fourth current sensor for detecting the bus current flowing through the fuse and transmitting it to the control circuit for overcurrent protection.

[0009] Optionally, the buffer circuit includes a resistor R1 and a DC contactor K1. The resistor R1 is connected in parallel with the normally open contact of the DC contactor K1 and then connected between the rectifier circuit and the filter circuit.

[0010] Optionally, the filter circuit includes a filter capacitor C1. One end of the filter capacitor C1 is connected to one end of the resistor R1 and the DC contactor K1, and the other end of the filter capacitor C1 is connected to the input end of the inverter circuit.

[0011] Optionally, the filter capacitor C1 uses a non-polar film DC support capacitor for filtering.

[0012] Optionally, the rectifier circuit is a bridge rectifier circuit, including an upper bridge arm and a lower bridge arm. The upper bridge arm includes diodes D1, D3, and D5, and the lower bridge arm includes diodes D2, D4, and D6.

[0013] The second embodiment of the present invention provides a high-power servo control system, including a servo motor and the high-power servo drive device described in any one of the above.

[0014] In the technical solution provided by the embodiment of the present invention, it includes a first current protection circuit, a second current protection circuit, a third current protection circuit, and a fourth current protection circuit. Compared with the prior art, through the four current protection circuits, this application effectively prevents the input power grid from failing due to the overcurrent fault of the servo drive device and prevents some losses caused by insufficient protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a circuit schematic diagram of a high-power servo drive device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a 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 those skilled in the art without creative efforts belong to the protection scope of the present invention.

[0017] It should be noted that when an element is described as "connected" or "linked" to another element, it can be directly connected to the other element, or there may be one or more intermediate elements therebetween. The serial numbers assigned to the components in this article, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning.

[0018] Please refer to Figure 1 Shown in the figure is a high-power servo drive device of the present application, including a rectifier circuit 1, a fuse F1, a buffer circuit 2, a filter circuit 3, an inverter circuit 4, a control circuit 5 and a current protection circuit. The input end of the rectifier circuit 1 is connected to a three-phase power supply, and the output end is connected to the input end of the buffer circuit 2, for converting alternating current into direct current. The output end of the buffer circuit 2 is connected to the input end of the filter circuit 3, the output end of the filter circuit 3 is connected to the input end of the inverter circuit 4, the fuse F1 is connected between the rectifier circuit 1 and the filter circuit 3, the control circuit 5 is respectively connected to the buffer circuit 2, the inverter circuit 4 and the current protection circuit, and the current protection circuit at least includes a first current protection circuit and a second current protection circuit.

[0019] In the present utility model, the rectifier circuit 1 is a bridge rectifier circuit, including six diodes D1 to D6. The diodes on the upper bridge arm are D1, D3, and D5, and the diodes on the lower bridge arm are D2, D4, and D6, for rectifying the three-phase AC input R, S, T into DC. Among them, the positive electrode of diode D1 is connected to the negative electrode of diode D2 to form a bridge arm, the positive electrode of diode D3 is connected to the negative electrode of diode D4 to form a bridge arm, and the positive electrode of diode D5 is connected to the negative electrode of diode D6 to form a bridge arm. In the present utility model, the rectifier circuit 1 can also be a full-wave rectifier circuit, a half-wave rectifier circuit, etc., as long as it can convert the three-phase AC input from the AC power supply into DC output. The embodiments of the present utility model do not make any limitation thereto.

[0020] The inverter circuit 4 includes six transistors, transistors Q1, Q2, Q3, Q4, Q5, and Q6. Among them, the collectors of the three transistors Q1, Q3, and Q5 on the upper bridge arm are connected to the positive busbar, the emitters of the three transistors Q1, Q3, and Q5 are connected to the collectors of the three transistors Q2, Q4, and Q6 on the lower bridge arm, the emitters of the three transistors Q2, Q4, and Q6 on the lower bridge arm are connected to the negative busbar, and the emitters of the transistors Q2, Q4, and Q6 are connected to one end of the first capacitor C1. The inverter circuit works in the order set by the CPU under the action of six-way gate drive (UH\UL, VH\VL, WH\WL), and converts direct current into three-phase alternating current (U, V, W) for the three-phase motor to work.

[0021] The transistor in the present utility model can be a MOS transistor, a bipolar junction transistor or an IGBT, etc., as long as it can be turned on and off under the control of the control unit, and there is an anti-parallel diode in the power device. The embodiments of the present utility model do not make any limitations in this regard.

[0022] The buffer circuit 2 includes a resistor R1 and a DC contactor K1. The resistor R1 is connected in parallel with the normally open contact of the DC contactor K1 and then connected between the rectifier circuit 1 and the filter circuit 3. The filter circuit 3 includes a filter capacitor C1. One end of the resistor R1 is connected to the output end of the rectifier circuit 1, and the other end is respectively connected to the DC contactor K1 and one end of the filter capacitor C1. The other end of the filter capacitor C1 is connected to the output end of the rectifier circuit 1 through a fuse F1, and the other end of the filter capacitor C1 is also connected to the emitters of the transistors Q2, Q4 and Q6. The present utility model protects the components in the motor drive device through the buffer circuit 2 to prevent the components in the motor drive device from being burned out by the instantaneous large current when powered on. Specifically, the resistor R1 is a current-limiting resistor. The current-limiting resistor R1 limits the charging current flowing through the rectifier bridge and the filter capacitor C1 during the power-on process to prevent the filter capacitor C1 from being damaged by excessive current surge at the moment of starting to charge. When the voltage across the filter capacitor C1 reaches the normal working voltage, the current-limiting resistor R1 is short-circuited by the DC contactor K1 connected in parallel with it to avoid excessive power consumption of the resistor R1.

[0023] In the present utility model, the filter capacitor C1 uses a non-polar film DC support capacitor for filtering. Compared with the traditional use of electrolytic capacitors for filtering, since the withstand voltage of electrolytic capacitors is limited, in order to achieve a higher withstand voltage, it is necessary to connect capacitors in series to achieve the purpose of high withstand voltage. The non-polar film DC support capacitor adopted in the present utility model has a high withstand voltage, good temperature characteristics, and can withstand a large ripple current. Therefore, it does not require series connection and a balancing resistor to balance the voltage, requires fewer filter capacitors, has a simple structure, and thus has a small volume. At the same time, it reduces the hardware cost, reduces the system loss, and improves the power density of the system.

[0024] The filtered DC power supply is used as the input of the inverter circuit. The control circuit 5 controls by driving and detecting the six transistors Q1~Q6 of the inverter circuit to supply an AC output U, V, W with adjustable frequency and voltage to the load, and the AC output voltage drives the servo motor to work.

[0025] The control circuit 5 of the present utility model includes a control unit, a drive and overcurrent detection control unit. The control unit is respectively connected to the DC contactor K1 and the drive and overcurrent detection control unit. The drive and overcurrent detection control unit is connected to the inverter circuit. The first current protection circuit is used to detect the saturation voltage drop of the upper and lower bridge arms of the inverter circuit and transmit the detected voltage signal to the control unit for processing to achieve the purpose of controlling the output current.

[0026] The second overcurrent protection circuit includes a first current sensor hall1, a second current sensor hall2, and a third current sensor hall3. The first current sensor hall1, the second current sensor hall2, and the third current sensor hall3 respectively detect the currents of the three-phase output terminals U, V, and W. When the current of the three-phase output terminal is greater than the first preset current, the control circuit stops outputting to perform overcurrent protection.

[0027] The current protection circuit further includes a third current protection circuit. The third current protection circuit includes a fourth current sensor hall4. The fourth current sensor hall4 is used to detect the bus current flowing through the fuse F1 and transmit it to the control unit. When the current is too large, the control unit has no current output, thereby performing overcurrent protection.

[0028] The fuse F1 of the present invention serves as the fourth current protection circuit. When the bus current reaches the melting point of the fuse, the fuse melts, and the main circuit of the driving device is opened. Therefore, the driving device has no output current, achieving the purpose of short-circuit protection of the driving device.

[0029] The present invention also provides a high-power liquid-cooled servo control system, including a servo motor, and further including the high-power servo driving device described in any one of the above embodiments.

[0030] The present invention effectively prevents the input power grid failure caused by the overcurrent fault of the servo driving device through four current protection circuits, and prevents some losses caused by insufficient protection.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-power servo drive device, characterized in that, It includes a rectifier circuit, a fuse, a buffer circuit, a filter circuit, an inverter circuit, a control circuit and a current protection circuit. The input end of the rectifier circuit is connected to a three-phase power supply, and the output end is connected to the input end of the buffer circuit, which is used to convert alternating current into direct current. The output end of the buffer circuit is connected to the input end of the filter circuit, and the output end of the filter circuit is connected to the input end of the inverter circuit. The fuse is connected between the rectifier circuit and the filter circuit. The control circuit is respectively connected to the buffer circuit, the inverter circuit and the current protection circuit. The current protection circuit at least includes a first current protection circuit and a second current protection circuit.

2. The high-power servo drive device according to claim 1, characterized in that, The inverter circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm includes transistors Q1, Q3 and Q5, and the lower bridge arm includes transistors Q2, Q4 and Q6. The three-phase output end of the inverter circuit is connected to a servo motor to supply power to the servo motor.

3. The high-power servo drive device according to claim 2, wherein The first current protection circuit is used to detect the saturation voltage drop of the upper bridge arm and the lower bridge arm and transmit the detected voltage signal to the control circuit.

4. The high-power servo drive device according to claim 2, characterized in that The second current protection circuit includes a first current sensor, a second current sensor and a third current sensor. The first current sensor, the second current sensor and the third current sensor respectively detect the currents at the three-phase output ends. When the currents at the three-phase output ends are greater than a first preset current, the control circuit stops outputting.

5. The high-power servo drive device according to claim 2, wherein The current protection circuit further includes a third current protection circuit. The third current protection circuit includes a fourth current sensor, which is used to detect the bus current flowing through the fuse and transmit it to the control circuit for overcurrent protection.

6. The high-power servo drive device according to claim 1, wherein The buffer circuit includes a resistor R1 and a DC contactor K1. The resistor R1 is connected in parallel with the normally open contact of the DC contactor K1 and then connected between the rectifier circuit and the filter circuit.

7. The high-power servo drive device according to claim 6, characterized in that, The filter circuit includes a filter capacitor C1. One end of the filter capacitor C1 is connected to one end of the resistor R1 and the DC contactor K1, and the other end of the filter capacitor C1 is connected to the input end of the inverter circuit.

8. The high-power servo drive device according to claim 7, characterized in that, The filter capacitor C1 uses a non-polar film DC support capacitor for filtering.

9. The high-power servo drive device according to claim 1, wherein The rectifier circuit is a bridge rectifier circuit, including an upper bridge arm and a lower bridge arm. The upper bridge arm includes diodes D1, D3 and D5, and the lower bridge arm includes diodes D2, D4 and D6.

10. A high-power liquid-cooled servo control system, including a servo motor, characterized in that, It also includes the high-power servo drive device according to any one of the above claims 1-9.

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