Drive power voltage detection circuit for power device in frequency converter and frequency converter

Abstract

The application provides a driving power supply voltage detection circuit for a power device in a frequency converter and the frequency converter, which is applied to the technical field of power electronics, and the circuit comprises a sampling circuit, a reference circuit and a verification circuit. The sampling circuit samples the power supply voltage of a driving circuit and outputs a sampling voltage. The reference circuit is used for outputting a reference voltage. The verification circuit is connected with the sampling circuit and the reference circuit respectively. In response to the sampling voltage being less than the reference voltage, the verification circuit outputs a first detection signal. In response to the sampling voltage being greater than the reference voltage, the verification circuit outputs a second detection signal. The sampling voltage is positively correlated with the power supply voltage. The sampling voltage can accurately reflect the size of the power supply voltage. In this way, the circuit can output different detection voltages to represent the detection result of the power supply voltage, thereby providing a reference basis for the control of the power supply voltage of the driving circuit, and further ensuring the efficient and reliable switching on-off state of the power device, and meeting the actual application requirements.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a drive power supply voltage detection circuit for power devices in a frequency converter and a frequency converter. Background Technology

[0002] In practical applications, a drive circuit needs to be set between the MCU (Microcontroller Unit) and power devices such as IGBT (Insulated Gate Bipolar Transistor) and MOSFET (Metal-Oxide Semiconductor Field Effect Transistor). The drive circuit is equipped with a drive power supply. The power supply voltage provided by the drive power supply enables the drive circuit to work and provides drive signals to control the conduction state of the power devices.

[0003] The power supply voltage of the drive circuit directly affects the working performance of the power device: if the power supply voltage is too high, the power device will turn on too quickly, causing voltage fluctuations; if the power supply voltage is too low, it will reduce the turn-on speed of the power device, increase the power device losses, and thus lead to an increase in the junction temperature of the power device, affecting the service life of the power device.

[0004] Based on the above, how to detect the power supply voltage of the drive circuit and ensure that the power devices switch on and off efficiently and reliably has become one of the technical problems that urgently need to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, this application aims to provide a drive power supply voltage detection circuit and a frequency converter for power devices in a frequency converter, which detects the power supply voltage of the drive circuit and ensures efficient and reliable switching conduction state of the power devices.

[0006] In a first aspect, this application provides a drive power supply voltage detection circuit for power devices in a frequency converter, comprising:

[0007] A sampling circuit, connected to the output terminal of the drive circuit of the power device, is used to sample the power supply voltage of the drive circuit and output a sampled voltage, wherein the sampled voltage is positively correlated with the power supply voltage of the drive circuit.

[0008] A reference circuit is used to receive the first operating voltage generated by the auxiliary power supply of the frequency converter and output a reference voltage.

[0009] A verification circuit is connected to the output terminals of the sampling circuit and the reference circuit, respectively.

[0010] In response to the sampling voltage being less than the reference voltage, the verification circuit outputs a first detection signal;

[0011] In response to the sampling voltage being greater than the reference voltage, the verification circuit outputs a second detection signal.

[0012] In one optional implementation, the sampling circuit includes: a first sampling resistor and a second sampling resistor, wherein,

[0013] One end of the first sampling resistor is used to receive the power supply voltage, and the other end of the first sampling resistor is connected to one end of the second sampling resistor;

[0014] The other end of the second sampling resistor is grounded;

[0015] The connection point between the first sampling resistor and the second sampling resistor serves as the output terminal of the sampling circuit.

[0016] In one optional implementation, the reference circuit includes: a protection resistor and a reference voltage generation module, wherein,

[0017] One end of the protection resistor receives the first operating voltage, and the other end of the protection resistor is connected to the reference voltage generation module. The first operating voltage is used to drive the reference voltage generation module to operate.

[0018] The reference voltage generation module is used to output the reference voltage.

[0019] In one optional implementation, the verification circuit includes: a comparator, wherein,

[0020] The inverting input of the comparator is connected to the output of the sampling circuit, the non-inverting input of the comparator is connected to the output of the reference circuit, and the output of the comparator serves as the output of the verification circuit.

[0021] In an optional embodiment, the voltage detection circuit provided in the first aspect of this application further includes: a preprocessing circuit, wherein,

[0022] The preprocessing circuit includes: a pull-up resistor, an optocoupler, and a pull-down resistor, wherein...

[0023] One end of the pull-up resistor is used to receive the first operating voltage, and the other end of the pull-up resistor is connected to the first end of the input side of the optocoupler;

[0024] The second terminal on the input side of the optocoupler is connected to the output terminal of the verification circuit;

[0025] The first terminal of the output side of the optocoupler receives the second operating voltage, and the second terminal of the output side of the optocoupler is connected to one end of the pull-down resistor, while the other end of the pull-down resistor is grounded.

[0026] The connection point between the optocoupler and the pull-down resistor serves as the output terminal of the preprocessing circuit.

[0027] The preprocessing circuit is used to convert the first detection signal into a first target signal, or to convert the second detection signal into a second target signal.

[0028] In one optional implementation, the voltage detection circuit provided in the first aspect of this application further includes: a control module, wherein,

[0029] The control module is connected to the output terminal of the preprocessing circuit;

[0030] The control module is configured to output an alarm signal in response to the received first target signal.

[0031] In one alternative implementation, the control module is the microcontroller of the frequency converter.

[0032] Secondly, this application provides a frequency converter, including: an inverter circuit, a drive circuit, a control module, and a drive power supply voltage detection circuit as provided in any embodiment of the first aspect of this application, wherein...

[0033] The inverter circuit includes power devices;

[0034] The output terminal of the drive circuit is connected to the control terminal of the power device, and outputs a drive signal to the power device.

[0035] The drive power supply voltage detection circuit is connected to the drive circuit, detects the power supply voltage of the drive circuit, and outputs a signal to the control module.

[0036] When the control module detects that the sampled voltage is lower than the reference voltage, it outputs an alarm signal.

[0037] Thirdly, this application provides a drive power supply voltage detection circuit for power devices in a frequency converter, comprising:

[0038] A sampling circuit, connected to the drive circuit of the power device, is used to sample the power supply voltage of the drive circuit and output a sampled voltage, wherein the sampled voltage is positively correlated with the power supply voltage of the drive circuit.

[0039] The reference circuit includes a series-connected protection resistor and a TL431 reference voltage chip, which is used to receive the first operating voltage generated by the auxiliary power supply of the inverter and output a reference voltage.

[0040] Comparator, its

[0041] The inverting input terminal is connected to the output terminal of the sampling circuit to receive the sampled voltage;

[0042] The positive input terminal is connected to the output terminal of the reference circuit to receive the reference voltage.

[0043] The output terminal is used to output the comparison result between the applied voltage and the reference voltage;

[0044] An optocoupler, wherein the light-emitting diode on the primary side is connected to the first operating voltage and the output terminal of the comparator respectively, and the secondary side is connected to the microcontroller of the frequency converter;

[0045] In response to a high-level signal from the comparator indicating that the sampled voltage is less than the reference voltage, the LED on the primary side of the optocoupler is de-conductive, the secondary side outputs a low level to the microcontroller, and the microcontroller outputs an alarm signal.

[0046] Based on the above, the drive power supply voltage detection circuit provided in this application includes a sampling circuit, a reference circuit, and a verification circuit. The sampling circuit is connected to the drive circuit of the power device, samples the drive power supply voltage of the drive circuit, and outputs a sampled voltage. The reference circuit receives the first operating voltage generated by the auxiliary power supply of the inverter and outputs a reference voltage. The verification circuit is connected to the output terminals of the sampling circuit and the reference circuit respectively. In response to the sampled voltage being less than the reference voltage, the verification circuit outputs a first detection signal; correspondingly, in response to the sampled voltage being greater than the reference voltage, the verification circuit outputs a second detection signal. The sampled voltage is positively correlated with the power supply voltage; therefore, the sampled voltage can accurately reflect the magnitude of the power supply voltage. With this configuration, the drive power supply voltage detection circuit provided in this application can characterize the detection result of the power supply voltage by outputting different detection voltages, providing a reference for the control of the drive circuit, thereby ensuring the efficient and reliable switching of the power device's conduction state and meeting the needs of practical applications. Furthermore, the introduction of the reference circuit improves the detection accuracy, provides good thermal stability, and can generate a stable reference voltage for the verification circuit. The circuit structure is simple, the overall cost is low, and it occupies relatively few resources of the control module, thus significantly improving the overall performance of the inverter. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a structural block diagram of a voltage detection circuit provided in an embodiment of the present invention.

[0049] Figure 2 This is a circuit topology diagram of a voltage detection circuit provided in an embodiment of this utility model.

[0050] Figure 3 This is a structural block diagram of another voltage detection circuit provided in this embodiment of the present invention.

[0051] Figure 4 This is a circuit topology diagram of another voltage detection circuit provided in this embodiment of the present invention. Detailed Implementation

[0052] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] As mentioned earlier, the magnitude of the driving power supply voltage directly affects the operating performance of power devices: if the power supply voltage is too high, the power devices will turn on too quickly, causing voltage fluctuations; if the power supply voltage is too low, it will reduce the turn-on speed of the power devices, increase the power device losses, and consequently lead to an increase in the junction temperature of the power devices, affecting their service life. Therefore, how to detect the power supply voltage of the driving circuit to ensure that the power devices switch on and off efficiently and reliably has become one of the technical problems that urgently need to be solved by those skilled in the art.

[0054] This application provides a drive power supply voltage detection circuit, which uses a low-cost and stable simple circuit to detect the power supply voltage of the drive circuit of the power device in the frequency converter with high precision. This provides a reference for controlling the drive circuit to output a stable drive signal, thereby ensuring that the power device switches the conduction state efficiently and reliably, and meeting the needs of practical applications.

[0055] Based on the above, see Figure 1 The driving power supply voltage detection circuit provided in this application embodiment includes: a sampling circuit 10, a reference circuit 20, and a verification circuit 30.

[0056] Specifically, in combination Figure 1As shown, the input terminal of the drive circuit is connected to the drive power supply, which provides a power supply voltage Vc to the drive circuit. The output terminal of the drive circuit is connected to the control terminal of the power device (which can be the gate of an IGBT or MOSFET). Driven by the power supply voltage, the drive circuit outputs a drive signal, which in turn drives the power device to turn on or off. Based on this, the sampling terminal of the sampling circuit 10 is connected to the drive circuit to sample the power supply voltage Vc of the drive circuit and output a corresponding sampling voltage. To accurately reflect the magnitude of the power supply voltage, the sampling voltage output by the sampling circuit 10 is positively correlated with the power supply voltage Vc of the drive circuit; that is, the larger the power supply voltage Vc, the larger the sampling voltage, and the smaller the power supply voltage Vc, the smaller the sampling voltage will be.

[0057] The reference circuit 20 is used to receive the first operating voltage generated by the auxiliary power supply of the frequency converter (not shown in the figure) and provide a reference voltage. In practical applications, the reference circuit 20 can be implemented in various ways, which will be elaborated in subsequent embodiments and will not be described in detail here.

[0058] The verification circuit 30 has a first input terminal, a second input terminal, and an output terminal. Figure 1 (shown as Out in the middle), combined Figure 1 As shown, the first input terminal of the verification circuit 30 is connected to the output terminal of the sampling circuit 10, receiving the sampling voltage output by the sampling circuit 10. The second input terminal of the verification circuit 30 is connected to the output terminal of the reference circuit 20, receiving the reference voltage output by the reference circuit 20. The verification circuit 30 compares the magnitude of the sampling voltage with the reference voltage. When the sampling voltage is less than the reference voltage, the verification circuit 30 outputs a first detection signal, such as a high level, indicating that the power supply voltage of the driving power supply is lower than the standard voltage. Correspondingly, when the sampling voltage is greater than the reference voltage, the verification circuit 30 outputs a second detection signal, such as a low level, indicating that the power supply voltage of the driving power supply meets the standard voltage.

[0059] It should be noted that, based on the foregoing, the sampling voltage fed back by the sampling circuit 10 is positively correlated with the power supply voltage, and there is a certain proportional relationship between the two. The verification circuit 30 outputs a detection voltage based on the relationship between the sampling voltage and the reference voltage. In order to accurately measure the actual situation of the power supply voltage, the reference voltage output by the reference circuit 20 should also be positively correlated with the standard power supply voltage of the drive circuit. Moreover, the proportional relationship between the reference voltage and the aforementioned standard power supply voltage should be the same as or similar to the proportional relationship between the sampling voltage and the power supply voltage. Only with this setting can the relationship between the sampling voltage and the reference voltage accurately reflect the relationship between the actual power supply voltage obtained by the drive circuit and the standard power supply voltage. Therefore, in practical applications, it is necessary to configure the reference voltage output by the reference circuit 20 and the proportional relationship of the sampling circuit 10 in converting the power supply voltage of the drive circuit into the sampling voltage, based on the above content. As for the specific values ​​of the above proportional relationship and the reference voltage, they can be set according to the actual application requirements, and this application does not impose specific limitations on them.

[0060] In summary, the sampling circuit in the drive power supply voltage detection circuit provided in this embodiment samples the power supply voltage of the drive circuit and outputs a sampled voltage. The reference circuit outputs a reference voltage. In response to the sampled voltage being less than the reference voltage, the verification circuit outputs a first detection signal. In response to the sampled voltage being greater than the reference voltage, the verification circuit outputs a second detection signal. The sampled voltage is positively correlated with the power supply voltage, and the sampled voltage can accurately reflect the magnitude of the power supply voltage. With this configuration, the drive power supply voltage detection circuit provided in this application can provide detection results characterizing the power supply voltage, providing a reference for the control of the drive circuit, thereby ensuring the efficient and reliable switching of the power device's conduction state and meeting the needs of practical applications.

[0061] Furthermore, the introduction of the reference circuit improves detection accuracy and thermal stability, generates a stable reference voltage for the verification circuit, has a simple circuit structure, low overall cost, and occupies relatively few control module resources, thus significantly improving the overall performance of the frequency converter.

[0062] Further, see Figure 2 As shown, in the driving power supply voltage detection circuit provided in this embodiment, the sampling circuit 10 includes a first sampling resistor R1 and a second sampling resistor R2, the reference circuit 20 includes a protection resistor R3 and a reference voltage generation module 210, and the verification circuit 30 includes a comparator U1.

[0063] Combination Figure 2 As shown, one end of the first sampling resistor R1 serves as the sampling terminal of the sampling circuit 10, connected to the driving circuit to receive the power supply voltage Vc. The other end of the first sampling resistor R1 is connected to one end of the second sampling resistor R2, and the other end of the second sampling resistor R2 is grounded. This connection relationship is consistent with the aforementioned... Figure 2As shown, the first sampling circuit R1 and the second sampling resistor R2 are connected in series to form a voltage divider circuit. The connection point of the first sampling resistor R1 and the second sampling resistor R2 serves as the output terminal of the sampling circuit 10, used to output the sampling voltage. It can be understood that the conversion ratio between the sampling voltage and the power supply voltage, that is, the voltage division ratio of the voltage divider circuit formed by the first sampling circuit R1 and the second sampling resistor R2, is specifically the ratio of R2 / (R1+R2).

[0064] In the reference circuit 20, one end of the protection resistor R3 receives the first operating voltage Vcc1, and the other end of the protection resistor R3 is connected to the reference voltage generation module 210. The reference voltage generation module 210 operates under the drive of the first operating voltage Vcc1 and outputs a reference voltage. The first operating voltage Vcc1 is the voltage generated by the auxiliary power supply (e.g., a switching power supply) in the frequency converter. In practical applications, the specific values ​​of the first operating voltage Vcc1 and the protection resistor R3 need to be selected based on the operating parameters of the reference voltage generation module 210 to meet the normal operating requirements of the reference voltage generation module 210. This application does not limit the specific values ​​of the first operating voltage Vcc1 and the protection resistor R3.

[0065] In one optional implementation, the reference voltage generation module 210 can be implemented using a TL431 reference voltage chip, fully utilizing the excellent performance of the TL431 reference voltage chip to provide a highly stable and accurate reference voltage. Of course, the reference voltage generation module 210 can also be implemented in other ways, which will not be detailed here.

[0066] The verification circuit 30 is implemented based on comparator U1, combined with Figure 2 As shown, the inverting input of comparator U1 serves as the first input of the verification circuit 30 and is connected to the output of the sampling circuit 10 to receive the sampled voltage. The non-inverting input of comparator U1 serves as the second input of the verification circuit 30 and is connected to the output of the reference circuit 20 to receive the reference voltage. The output of comparator U1 serves as the output of the verification circuit, and is shown as Out in the figure.

[0067] The following is combined with Figure 2 The circuit topology shown in this application details the voltage detection circuit provided in the embodiment of the application, and the process of detecting the power supply voltage of the drive circuit.

[0068] The driving circuit receives the power supply voltage Vc. The sampling circuit 10 divides the power supply voltage Vc according to the voltage division ratio of the first sampling resistor R1 and the second sampling resistor R2, and outputs the corresponding sampling voltage. The reference voltage generation module 210 operates under the drive of the first operating voltage Vcc1 and outputs a reference voltage. The comparator U1 compares the magnitude of the obtained reference voltage with the sampling voltage. When the sampling voltage is less than the reference voltage, the output pin of the comparator U1 is at a high level, i.e., the first detection signal. Conversely, when the sampling voltage is greater than the reference voltage, the output pin of the comparator U1 is at a low level, i.e., the second detection signal.

[0069] It is understandable that in practical applications, control modules such as MCUs have certain format requirements for input information. Only information that meets the recognition requirements of the control module can be effectively read and recognized by the control module. Based on this, this application provides another voltage detection circuit, see [link to relevant documentation]. Figure 3 As shown, compared to the voltage detection circuit provided in the previous embodiment, the voltage detection circuit provided in this embodiment further includes a preprocessing circuit 40 and a control module 50.

[0070] Combination Figure 3 As shown, the input terminal of the preprocessing circuit 40 is connected to the output terminal of the verification circuit 30, and receives the first detection signal or the second detection signal output by the verification circuit 30. Based on this, the preprocessing circuit 40 is used to convert the obtained first detection signal into a first target signal, or to convert the obtained second detection signal into a second target signal.

[0071] It is understood that the drive power supply voltage detection circuit provided in the foregoing embodiments includes a dedicated control module. This configuration can improve the detection efficiency of the drive power supply voltage detection circuit, but it will also increase the overall cost of the voltage detection circuit to some extent. Based on this, in another optional embodiment, the control module 50 can be a microcontroller inside the frequency converter, that is, the above-mentioned functions of the control module 50 are integrated into the microcontroller of the frequency converter. This configuration can reduce the number of microcontrollers and reduce the overall cost of the circuit. Of course, the control module 50 can also have other implementations, which will not be listed here. In practical applications, it can be determined based on the actual application scenario of the drive power supply voltage detection circuit.

[0072] Furthermore, embodiments of this application provide another drive power supply voltage detection circuit, see [link to relevant documentation]. Figure 4 As shown, in the driving power supply voltage detection circuit provided in this application embodiment, the preprocessing circuit 40 includes a pull-up resistor R4, a pull-down resistor R5, and an optocoupler U2.

[0073] Combination Figure 4As shown, one end of the pull-up resistor R4 is used to receive the first working voltage Vcc1, and the other end of the pull-up resistor R4 is connected to one end of the input side of the optocoupler U2. The other end of the input side of the optocoupler U2 serves as the input terminal of the preprocessing circuit 40 and is connected to the output terminal of the verification circuit 30 to receive the first detection signal or the second detection signal output by the verification circuit 30. One end of the output side of the optocoupler U2 receives the second working voltage Vcc2, and the other end of the output side of the optocoupler U2 is connected to one end of the pull-down resistor R5. The other end of the pull-down resistor R5 is grounded, and the connection point between the optocoupler U2 and the pull-down resistor R5 serves as the output terminal of the preprocessing circuit 40 and is connected to the control module 50.

[0074] As for the specific implementation of other related circuits in the drive power supply voltage detection circuit and their interconnections, please refer to the relevant content of the foregoing embodiments, which will not be repeated here.

[0075] Following the previous example, when the verification circuit 30 outputs the first detection signal (i.e., a high level), the input side of the optocoupler U2 is turned off, and its internal LED does not emit light. The output side of the optocoupler U2 is also turned off. The output level of the optocoupler U2 is pulled down to a low level through the pull-down resistor R5, i.e., the first target signal is output to the control module 50. The control module 50 responds to the obtained first target signal and determines that the power supply voltage of the driving power supply is less than the standard power supply voltage and cannot meet the working requirements of the driving circuit. As an optional implementation, the control module 50 can output an alarm signal to prompt the user that the driving power supply is abnormal. Correspondingly, when the verification circuit 30 outputs the second detection signal (i.e., a low level), the input side (primary side) of the optocoupler U2 is turned on, and its internal LED emits light. The output side of the optocoupler U2 is also turned on. The second working voltage Vcc2 forms a closed loop through the output side of the optocoupler U2 and the pull-down resistor R5, and a voltage is generated across the pull-down resistor R5, i.e., the second target signal is output (i.e., the secondary side of the optocoupler outputs a high level). The control module 50, in response to the received second target signal, determines that the power supply voltage of the drive power supply is normal and meets the operating requirements of the drive circuit. The specific processes by which the verification circuit 30 outputs the first and second detection signals can be referred to the relevant content in the foregoing embodiments, and will not be repeated here.

[0076] Based on the above, it can be understood that when the verification circuit 30 outputs the second detection signal, the second target signal is related to the second working voltage Vcc2. Therefore, the specific value of the second working voltage should be based on the fact that the control module 50 can accurately identify it. This application does not limit the specific value of the second working voltage.

[0077] Compared to the power supply voltage detection scheme based on linear isolation optocouplers and analog signal acquisition in related technologies, the driving power supply voltage detection circuit provided in this application has a simple circuit structure, can complete the detection using ordinary optocouplers, is less affected by ambient temperature, has low cost, and high detection accuracy. Moreover, it ultimately only provides a high-level or low-level switching signal to the control module, effectively solving the problem of related technologies occupying a large amount of computing resources of the control module.

[0078] This application also provides a frequency converter, including: an inverter circuit, a drive circuit, a control module, and a drive power supply voltage detection circuit provided in any of the foregoing embodiments, wherein...

[0079] Inverter circuits include power devices;

[0080] The output terminal of the drive circuit is connected to the control terminal of the power device, and outputs a drive signal to the power device;

[0081] The drive power supply voltage detection circuit is connected to the drive circuit, detects the power supply voltage of the drive circuit and outputs a signal to the control module.

[0082] When the control module detects that the sampled voltage is lower than the reference voltage, it outputs an alarm signal.

[0083] Of course, the drive power supply voltage detection circuit provided in this application can also be applied to other power electronic devices that drive power devices through drive circuits, such as servo drives, etc., which will not be described in detail here.

[0084] Based on the above, this application also provides a drive power supply voltage detection circuit for power devices in a frequency converter, comprising:

[0085] The sampling circuit is connected to the drive circuit of the power device. It is used to sample the power supply voltage of the drive circuit and output the sampled voltage. The sampled voltage is positively correlated with the power supply voltage of the drive circuit.

[0086] The reference circuit, including a series-connected protection resistor and a TL431 reference voltage chip, is used to receive the first operating voltage generated by the auxiliary power supply of the frequency converter and output a reference voltage.

[0087] Comparator, its

[0088] The inverting input terminal is connected to the output terminal of the sampling circuit to receive the sampled voltage;

[0089] The positive input terminal is connected to the output terminal of the reference circuit to receive the reference voltage;

[0090] The output terminal is used to output the comparison result between the applied voltage and the reference voltage;

[0091] An optocoupler, in which the light-emitting diodes on the primary side are connected to the first operating voltage and the output of the comparator respectively, and the secondary side is connected to the microcontroller of the frequency converter;

[0092] In response to a high-level signal from the comparator indicating that the sampled voltage is less than the reference voltage, the LED on the primary side of the optocoupler is de-conductive, and the secondary side outputs a low level to the microcontroller, which then outputs an alarm signal.

[0093] Those skilled in the art will understand that the contents disclosed herein can be varied and modified in many ways. For example, the various devices or components described above can be implemented in hardware, or in software, firmware, or a combination of some or all of the three.

[0094] Furthermore, while this disclosure makes various references to certain elements of systems according to embodiments of this disclosure, any number of different elements may be used and operated on clients and / or servers. Elements are merely illustrative, and different aspects of the system and method may use different elements.

[0095] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in a common dictionary should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0096] The foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined by the claims. It should be understood that the foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

Claims

1. A drive power supply voltage detection circuit for power devices in a frequency converter, characterized in that, include: A sampling circuit, connected to the drive circuit of the power device, is used to sample the power supply voltage of the drive circuit and output a sampled voltage, wherein the sampled voltage is positively correlated with the power supply voltage of the drive circuit. A reference circuit is used to receive the first operating voltage generated by the auxiliary power supply of the frequency converter and output a reference voltage. A verification circuit is connected to the output terminals of the sampling circuit and the reference circuit, respectively. In response to the sampling voltage being less than the reference voltage, the verification circuit outputs a first detection signal; In response to the sampling voltage being greater than the reference voltage, the verification circuit outputs a second detection signal.

2. The driving power supply voltage detection circuit according to claim 1, characterized in that, The sampling circuit includes: a first sampling resistor and a second sampling resistor, wherein, One end of the first sampling resistor is used to receive the power supply voltage, and the other end of the first sampling resistor is connected to one end of the second sampling resistor; The other end of the second sampling resistor is grounded; The connection point between the first sampling resistor and the second sampling resistor serves as the output terminal of the sampling circuit.

3. The driving power supply voltage detection circuit according to claim 1, characterized in that, The reference circuit includes: a protection resistor and a reference voltage generation module, wherein, One end of the protection resistor receives the first operating voltage, and the other end of the protection resistor is connected to the reference voltage generation module. The first operating voltage is used to drive the reference voltage generation module to operate. The reference voltage generation module is used to output the reference voltage.

4. The drive power supply voltage detection circuit according to claim 1, characterized in that, The verification circuit includes: a comparator, wherein, The inverting input of the comparator is connected to the output of the sampling circuit, the non-inverting input of the comparator is connected to the output of the reference circuit, and the output of the comparator serves as the output of the verification circuit.

5. The drive power supply voltage detection circuit according to any one of claims 1 to 4, characterized in that, Also includes: Preprocessing circuit, wherein, The preprocessing circuit includes: a pull-up resistor, an optocoupler, and a pull-down resistor, wherein... One end of the pull-up resistor is used to receive the first operating voltage, and the other end of the pull-up resistor is connected to the first end of the input side of the optocoupler; The second terminal on the input side of the optocoupler is connected to the output terminal of the verification circuit; The first terminal of the output side of the optocoupler receives the second operating voltage, and the second terminal of the output side of the optocoupler is connected to one end of the pull-down resistor, while the other end of the pull-down resistor is grounded. The connection point between the optocoupler and the pull-down resistor serves as the output terminal of the preprocessing circuit. The preprocessing circuit is used to convert the first detection signal into a first target signal, or to convert the second detection signal into a second target signal.

6. The drive power supply voltage detection circuit according to claim 5, characterized in that, Also includes: Control module, in which, The control module is connected to the output terminal of the preprocessing circuit; The control module is configured to output an alarm signal in response to the received first target signal.

7. The driving power supply voltage detection circuit according to claim 6, characterized in that, The control module is the microcontroller of the frequency converter.

8. A frequency converter, characterized in that, include: The inverter circuit, the drive circuit, the control module, and the drive power supply voltage detection circuit as described in any one of claims 1 to 7, wherein, The inverter circuit includes power devices; The output terminal of the drive circuit is connected to the control terminal of the power device, and outputs a drive signal to the power device. The drive power supply voltage detection circuit is connected to the drive circuit, detects the power supply voltage of the drive circuit, and outputs a signal to the control module. When the control module detects that the sampled voltage is lower than the reference voltage, it outputs an alarm signal.

9. A drive power supply voltage detection circuit for power devices in a frequency converter, characterized in that, include: A sampling circuit, connected to the drive circuit of the power device, is used to sample the power supply voltage of the drive circuit and output a sampled voltage, wherein the sampled voltage is positively correlated with the power supply voltage of the drive circuit. The reference circuit includes a series-connected protection resistor and a TL431 reference voltage chip, which is used to receive the first operating voltage generated by the auxiliary power supply of the inverter and output a reference voltage. Comparator, its The inverting input terminal is connected to the output terminal of the sampling circuit to receive the sampled voltage; The positive input terminal is connected to the output terminal of the reference circuit to receive the reference voltage. The output terminal is used to output the comparison result between the applied voltage and the reference voltage; An optocoupler, wherein the light-emitting diode on the primary side is connected to the first operating voltage and the output terminal of the comparator respectively, and the secondary side is connected to the microcontroller of the frequency converter; In response to a high-level signal from the comparator indicating that the sampled voltage is less than the reference voltage, the LED on the primary side of the optocoupler is de-conductive, the secondary side outputs a low level to the microcontroller, and the microcontroller outputs an alarm signal.

Images