CN114678838A - Alternating current drive protection circuit and device - Google Patents

Alternating current drive protection circuit and device Download PDF

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Publication number
CN114678838A
CN114678838A CN202210436850.0A CN202210436850A CN114678838A CN 114678838 A CN114678838 A CN 114678838A CN 202210436850 A CN202210436850 A CN 202210436850A CN 114678838 A CN114678838 A CN 114678838A
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CN
China
Prior art keywords
circuit
voltage
rectifying
motor
protection
Prior art date
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Pending
Application number
CN202210436850.0A
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Chinese (zh)
Inventor
万小兵
石建军
苗立晓
程国醒
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SHENZHEN HUACHENG INDUSTRIAL CONTROL CO LTD
Original Assignee
SHENZHEN HUACHENG INDUSTRIAL CONTROL CO LTD
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SHENZHEN HUACHENG INDUSTRIAL CONTROL CO LTD filed Critical SHENZHEN HUACHENG INDUSTRIAL CONTROL CO LTD
Priority to CN202210436850.0A priority Critical patent/CN114678838A/en
Publication of CN114678838A publication Critical patent/CN114678838A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/122—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters
    • H02H7/1225—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters responsive to internal faults, e.g. shoot-through
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/34—Snubber circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
    • H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
    • H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
    • H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
    • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
    • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Stopping Of Electric Motors (AREA)
  • Inverter Devices (AREA)

Abstract

The invention relates to an alternating current drive protection circuit and a device, wherein the circuit comprises a power circuit, a rectifying brake circuit, an inverter circuit, an MCU control circuit, a voltage detection circuit and a motor, wherein the power circuit is used for providing alternating current voltage; the rectifying brake circuit is used for rectifying the alternating voltage and then converting the alternating voltage into direct voltage; the inverter circuit is used for inverting and converting the direct-current voltage into a multi-phase alternating-current voltage and then driving the motor to work; the voltage detection circuit is used for detecting voltage change in the rectifying brake circuit; the MCU control circuit is used for controlling the on-off condition of the power supply circuit by using the MCU according to the voltage change. The relay is added, so that when the inverter unit has a fault, the relay and the diode can be controlled to be disconnected simultaneously to achieve the purpose of protection, and meanwhile, the relay is connected with the starting buffer resistor in series, so that a low-current relay can be used, the extra cost is very low, and the purpose of protection is achieved.

Description

Alternating current drive protection circuit and device
Technical Field
The invention relates to the technical field of alternating current servo drive protection, in particular to an alternating current drive protection circuit and device.
Background
Currently, in the main circuit diagram of a universal single-phase or three-phase motor driver (including a frequency converter, such as fig. 1; a servo driver, such as fig. 2; a brushless direct current driver, such as fig. 3), three-phase or single-phase alternating current is rectified by a rectifier bridge and then becomes direct current, and an energy storage filtering link consisting of a C1 electrolytic capacitor and a C2 electrolytic capacitor is charged through a charging buffer network consisting of a resistor R1 and a contactor (relay) RLY1, and then is supplied to a motor through an inverter link consisting of 6 IGBTs, so that the motor is driven to operate. The charging buffer network formed by the R1 and the RLY1 can be placed on a DC + bus and can also be placed on a DC-bus. Because the motor runs with acceleration and deceleration, the energy generated in deceleration can be fed back to the direct current (DC +, DC-) bus, and at the moment, the brake IGBT can open the external energy consumption brake resistor R2 to discharge the redundant energy so as to protect the direct current bus device in the working range.
During operation of the drive, for various reasons, it is not possible to avoid a failure of the internal single device, and when a single device fails, it is generally required that no fire or safety accident be caused, thus requiring safety precautions for all single failures.
The prior art scheme has the following defects:
1, as shown in fig. 1, the current technical solution is provided with a motor side U V W short circuit function, that is, when a driver is connected with a short circuit between any two phase wires of a U V W of a motor or the motor is internally short-circuited, protection between U V W can be achieved through detection and protection, but if the motor U V W is short-circuited to the ground, as shown in fig. 1, detection can only be performed through LM3, and then an external signal is given by a control loop to cut off an incoming line R S T power supply, as shown in fig. 2 and fig. 3, protection needs other modes, such as tripping protection of an incoming line leakage switch;
2, after a single device of the IGBT1 of fig. 1VT1 and fig. 23 fails and is damaged (for example, a short circuit is caused by a pin mounted in a chip type), the external braking resistor may be always turned on to cause heating and fire, and there is no better way to protect the inside of the driver of fig. 1-3, which only depends on external protection;
3 when the inverter IGBT is failed and short-circuited, the direct current DC + DC-is in a short-circuit state, if the relay RLY1 is in a pull-in state, the RST input is short-circuited, the external part needs to be reliably protected, and when the RLY1 is in a disconnection state, the internal slow starting resistor R1 generates heat, which may cause fire, and the current frequency converter or the servo driver can only depend on external circuit protection or no protection.
In summary, the driver in the prior art can only rely on external circuit protection or no protection, and therefore, it is urgently needed to find a scheme that can implement driving protection without relying on external circuit.
Disclosure of Invention
Therefore, there is a need to provide an ac driving protection circuit and apparatus, which can solve the technical problem that the driver can only depend on external circuit for protection or no protection.
The invention provides an alternating current drive protection circuit, comprising:
the motor brake system comprises a power circuit, a rectifying brake circuit, an inverter circuit, an MCU control circuit, a voltage detection circuit and a motor, wherein the power circuit, the rectifying brake circuit and the inverter circuit are sequentially and electrically connected with the motor;
the power supply circuit is used for providing alternating voltage;
the rectifying brake circuit is used for rectifying the alternating voltage and then converting the alternating voltage into direct voltage;
the inverter circuit is used for inverting and converting the direct-current voltage into a multi-phase alternating-current voltage and then driving the motor to work;
the voltage detection circuit is used for detecting voltage change in the rectifying brake circuit or the inverter circuit;
and the MCU control circuit is used for controlling the on-off condition of the power supply circuit by using the MCU according to the voltage change.
Preferably, the power circuit is a three-phase ac circuit, and the three-phase ports are an R terminal, an S terminal, and a T terminal, respectively.
Preferably, the rectifying brake circuit comprises a rectifying circuit and a brake circuit; the rectifier circuit comprises diodes D16, D17, D18, D20, D21 and D22, and the brake circuit comprises an IGBT tube M7, a diode D23 and an external brake resistor R;
the D17 and D21 are connected into an R terminal voltage, the D16 and D20 are connected into an S terminal voltage, and the D18 and D22 are connected into a T terminal voltage;
the diode D23 is connected in parallel with the external brake resistor R and then connected in series with the IGBT tube M7.
Preferably, the rectifying brake circuit further comprises a buffer circuit, wherein the buffer circuit comprises a relay RLY1, a diode D19 and a buffer resistor RA; the RLY1 is connected in series with RA and then connected in parallel with the diode D19.
Preferably, the voltage detection circuit comprises resistors R155 and R156 and a thyristor Q18, and the resistor R155, the thyristor Q18 and the thyristor Q156 are all connected in series.
Preferably, the voltage detection circuit is a thyristor detection circuit.
Preferably, the inverter circuit comprises 6 IGBT tubes M1, M2, M3, M4, M5 and M6, and two of the 6 IGBT tubes respectively provide three-phase alternating-current voltage for the motor to drive the motor to work.
The invention provides an alternating current drive protection device, which comprises the alternating current drive protection circuit.
The invention has the beneficial effects that: the relay is added, so that when the inverter unit has a fault, the relay and the diode can be controlled to be disconnected simultaneously to achieve the purpose of protection, and meanwhile, the relay is connected with the starting buffer resistor in series, so that a low-current relay can be used, the extra cost is very low, and the purpose of protection is achieved.
Drawings
FIG. 1 is a diagram of a main circuit of a frequency converter drive in a prior art motor drive;
FIG. 2 is a main circuit diagram of a servo driver in a motor driver according to the prior art;
FIG. 3 is a diagram of a main circuit of a brushless DC motor in a motor driver according to the prior art;
FIG. 4 is a circuit diagram of an embodiment of an AC driving protection circuit according to the present invention;
FIG. 5 is a schematic circuit diagram of an alternate embodiment of the AC drive protection circuit according to the present invention;
FIG. 6 is a schematic circuit diagram of an alternate current driving protection circuit according to another embodiment of the present invention;
FIG. 7 is a schematic circuit diagram of an embodiment of a partial circuit in the AC driving protection circuit according to the present invention;
fig. 8 is a schematic circuit diagram of another embodiment of a partial circuit in the ac driving protection circuit according to the present invention.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
As shown in fig. 4, an embodiment of the present invention provides an ac driving protection circuit, including:
the brake control system comprises a power supply circuit 10, a rectifying brake circuit 20, an inverter circuit 30, an MCU control circuit 40, a voltage detection circuit 50 and a motor 60, wherein the power supply circuit 10, the rectifying brake circuit 20, the inverter circuit 30 and the motor 60 are sequentially and electrically connected, the MCU control circuit 40 is electrically connected with the power supply circuit 10 and the rectifying brake circuit 20, and the voltage control circuit 50 is electrically connected with the rectifying brake circuit 20, the MCU control circuit 40 and the inverter circuit 30;
the power supply circuit 10 is used for supplying alternating voltage;
the rectifying brake circuit 20 is configured to rectify the ac voltage and convert the rectified ac voltage into a dc voltage;
the inverter circuit 30 is configured to invert the dc voltage into a multi-phase ac voltage and drive the motor 60 to work;
the voltage detection circuit 40 is used for detecting voltage change in the rectifying brake circuit or the inverter circuit;
the MCU control circuit 50 is used for controlling the on-off condition of the power supply circuit by using the MCU according to the voltage change.
In a normal state, when the power supply circuit 10 supplies a power supply voltage, generally three-phase power, the power supply voltage is converted into a dc voltage by the rectifying brake circuit 20, and after a voltage and current buffering process is performed, the inverter circuit 30 inverts and converts the dc voltage into ac three-phase power, thereby driving the motor 60 to operate. However, when the actual motor works, when a fault is encountered, such as a motor side three-phase U vw short circuit, an inverter circuit fault, etc., which may cause a driver short circuit damage, the present invention uses the on-off state switching of the diode/thyristor to consume heat caused by the short circuit by setting the voltage detection circuit 50 to detect a voltage change (such as a sudden increase of a voltage drop) in the rectifying brake circuit or the inverter circuit, and further may feed back the voltage change in the rectifying brake circuit or the inverter circuit to the MUC control circuit 40 to control the on-off of the power supply circuit 10.
As a preferred embodiment, please refer to fig. 5, fig. 5 is a schematic circuit diagram of an alternate embodiment of the ac driving protection circuit provided in the present invention, in which the power circuit (i.e., the starting power) is a three-phase ac circuit, and the three-phase ports are an R terminal, an S terminal and a T terminal, respectively. In this embodiment, the voltage detection circuit is a thyristor detection circuit.
Further, the rectifying brake circuit (i.e., rectifying brake portion) includes a rectifying circuit and a brake circuit; the rectifier circuit comprises diodes D16, D17, D18, D20, D21 and D22, and the brake circuit comprises an IGBT tube M7, a diode D23 and an external brake resistor R;
the D17 and D21 are connected to the R terminal voltage, the D16 and D20 are connected to the S terminal voltage, and the D18 and D22 are connected to the T terminal voltage, specifically, the rectifying circuit is a bridge type rectifying circuit;
the diode D23 is connected in parallel with the external brake resistor R and then connected in series with the IGBT tube M7.
As a preferred embodiment, the rectifying brake circuit further comprises a snubber circuit, the snubber circuit comprises a relay RLY1, a diode D19, and a snubber resistor RA; the RLY1 is connected in series with RA and then connected in parallel with the diode D19.
Specifically, the buffer circuit is the core content of the invention, the invention can simultaneously control the RLY1 and the D19 controllable silicon to be switched off when the inverter unit has a fault by adding the RLY1, so as to achieve the purpose of protection, and meanwhile, the RLY1 is connected in series with the starting buffer resistor RA, so that a small-current relay can be used, the additional cost is very small, and the purpose of protection is achieved.
It should be noted that D19 in fig. 5 is a turn-off thyristor, the gate signal of D19 is positive during normal operation, D19 operates normally, and when a fault occurs, the control signal of relay RLY1 and the control signal of gate of D19 are cut off at the same time, so that the power failure of the back-stage unit can be ensured, and the protection purpose is achieved.
As a preferred embodiment, the inverter circuit comprises 6 IGBT transistors M1, M2, M3, M4, M5 and M6, and two of the 6 IGBT transistors respectively provide three-phase alternating-current voltage for the motor to drive the motor to operate.
Further, referring to fig. 6, fig. 6 is a schematic circuit diagram of another embodiment of the ac driving protection circuit according to the present invention. In this embodiment, the rectifying brake part and the inverter unit may be integrated, or the inverter unit may be separated, and a plurality of inverter units may be connected in parallel (common bus technology), so that the whole machine may be protected.
To further explain how the driving circuit is protected when the inverter unit has a fault, please refer to fig. 7-8, fig. 7 is a schematic circuit diagram of an embodiment of a part of circuits in the ac driving protection circuit provided by the present invention, fig. 8 is a schematic circuit diagram of another embodiment of a part of circuits in the ac driving protection circuit provided by the present invention, and neither of the schematic circuit diagrams includes an inverter circuit and a motor.
In the present embodiment, the snubber circuit includes a relay RLY1, a diode D19, and a snubber resistor RA; the RLY1 is connected in series with RA and then connected in parallel with the diode D19.
The voltage detection circuit comprises resistors R155 and R156 and a thyristor Q18, and the resistor R155, the thyristor Q18 and the thyristor R156 are all connected in series.
Looking at the circuit at point CD, point C and point D are the anode and cathode of the D19-diode, and during normal operation, the gate of D19 is open. The voltage between CDs is changed along with the flowing current, the maximum voltage drop between CDs in normal operation can be within a certain range, such as within 1.5V, when short circuit or later stage fault occurs, because the current suddenly becomes larger, the voltage drop between CDs can increase, so that whether short circuit occurs or not can be judged by detecting the voltage between CDs (the judgment needs to be combined with the control sequence of starting MCU), the scheme circuit is simple, the cost is lower, no power consumption is generated, the method for detecting the voltage between CDs has a technical point to be overcome, namely the circuit needs to be switched during starting or after protection, the voltage between CDs is specifically detected, as shown in FIG. 8, R155 can be sampled from a graph, when the R155 resistance voltage is more than a certain value, Q18 in the graph can be closed, the circuit can be protected, or an automatic range switching circuit (mature circuit-universal circuit of multimeter is used, and belongs to a universal circuit in the measurement industry, not described in detail herein). The difference between the circuit and the measurement industry is that only one low voltage needs to be detected as a reference, and the precision requirement is not high.
The embodiment of the invention also provides an alternating current driving protection device which comprises an alternating current driving protection circuit, and on the basis of the alternating current driving protection circuit, the implementation process of the alternating current driving protection device is similar to that of the alternating current driving protection circuit, and the implementation process is not repeated herein.
In summary, the ac driving protection device provided by the present invention has the following beneficial effects:
the invention has the beneficial effects that: the relay is added, so that when the inverter unit has a fault, the relay and the diode can be controlled to be disconnected simultaneously to achieve the purpose of protection, and meanwhile, the relay is connected with the starting buffer resistor in series, so that a low-current relay can be used, the extra cost is very low, and the purpose of protection is achieved.
In summary, the preferred embodiments of the present invention are described, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention shall be covered by the scope of the present invention.

Claims (8)

1. An ac drive protection circuit, comprising: the motor braking system comprises a power circuit, a rectifying braking circuit, an inverter circuit, an MCU control circuit, a voltage detection circuit and a motor, wherein the power circuit, the rectifying braking circuit and the inverter circuit are sequentially and electrically connected with the motor;
the power supply circuit is used for providing alternating voltage;
the rectifying brake circuit is used for rectifying the alternating voltage and then converting the alternating voltage into direct voltage;
the inverter circuit is used for inverting and converting the direct-current voltage into a multi-phase alternating-current voltage and then driving the motor to work;
the voltage detection circuit is used for detecting voltage change in the rectifying brake circuit or the inverter circuit;
and the MCU control circuit is used for controlling the on-off condition of the power supply circuit by using the MCU according to the voltage change.
2. The ac driving protection circuit according to claim 1, wherein the power circuit is a three-phase ac circuit, and the three-phase ports are an R terminal, an S terminal, and a T terminal, respectively.
3. The ac drive protection circuit of claim 2, wherein the rectifying braking circuit comprises a rectifying circuit and a braking circuit; the braking circuit comprises an IGBT tube M7, a diode D23 and an external braking resistor R, and is characterized in that the rectifying circuit comprises diodes D16, D17, D18, D20, D21 and D22;
the D17 and D21 are connected into an R terminal voltage, the D16 and D20 are connected into an S terminal voltage, and the D18 and D22 are connected into a T terminal voltage;
the diode D23 is connected in parallel with the external brake resistor R and then connected in series with the IGBT tube M7.
4. The ac driven protection circuit of claim 3, wherein the rectifying brake circuit further comprises a snubber circuit comprising relay RLY1, diode D19, and snubber resistor RA; the RLY1 is connected in series with RA and then connected in parallel with the diode D19.
5. The AC drive protection circuit of claim 4, wherein the voltage detection circuit comprises resistors R155, R156 and a thyristor Q18, and the resistors R155, the thyristors Q18 and R156 are all connected in series.
6. The ac driving protection circuit of claim 1, wherein the voltage detection circuit is a thyristor detection circuit.
7. The ac driving protection circuit according to claim 1, wherein the inverter circuit comprises 6 IGBT transistors M1, M2, M3, M4, M5 and M6, and two groups of the 6 IGBT transistors respectively provide three-phase ac voltage for the motor to drive the motor to operate.
8. An ac drive protection device comprising the ac drive protection circuit according to any one of claims 1 to 7.
CN202210436850.0A 2022-04-14 2022-04-14 Alternating current drive protection circuit and device Pending CN114678838A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210436850.0A CN114678838A (en) 2022-04-14 2022-04-14 Alternating current drive protection circuit and device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210436850.0A CN114678838A (en) 2022-04-14 2022-04-14 Alternating current drive protection circuit and device

Publications (1)

Publication Number Publication Date
CN114678838A true CN114678838A (en) 2022-06-28

Family

ID=82080502

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210436850.0A Pending CN114678838A (en) 2022-04-14 2022-04-14 Alternating current drive protection circuit and device

Country Status (1)

Country Link
CN (1) CN114678838A (en)

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