Variable frequency board and electronic device

Abstract

The application discloses a frequency conversion board and electronic equipment, wherein, by embedding an operational amplifier in a current detection circuit of an intelligent power module, the target current flowing through a driving circuit can be detected by the operational amplifier in the intelligent power module, so as to obtain a current detection signal, and then the current detection signal is directly output to a controller, so that the controller can timely adjust a driving signal according to the current detection signal in real time, thereby adjusting the phase current amplitude of three-phase current. Compared with the related art, the operational amplifier is embedded in the intelligent power module, so that the external operational amplifier connected to the intelligent power module can be saved, the controller can use the specification without the need of connecting the operational amplifier or embedding the operational amplifier, and the circuit structure of the whole frequency conversion board is simpler.

Description

Technical Field

[0001] This application relates to frequency conversion technology, including but not limited to a frequency conversion board and electronic equipment. Background Technology

[0002] IPM (Intelligent Power Module) is a power drive product that combines power electronics and integrated circuit technology. With its advantages of high integration and high reliability, it has won an increasingly large market share. It is especially suitable for frequency converters and various inverter power supplies that drive motors. It is an ideal power electronic device for variable frequency speed control, metallurgical machinery, electric traction, servo drive, and variable frequency home appliances.

[0003] Because the IPM needs to output three-phase current to achieve power drive, in order to ensure the stability of the three-phase current, it is usually necessary to collect the current flowing through the IPM. However, since the current value flowing through the IPM does not match the detection range of the controller, the controller in related technologies usually needs to use an additional operational amplifier to realize the function of detecting the current flowing through the IPM, which undoubtedly increases the complexity of the circuit. Summary of the Invention

[0004] In view of this, the embodiments provided in this application can simplify the connection relationship of the circuit and reduce the complexity of the circuit.

[0005] In a first aspect, embodiments of this application provide a frequency converter board, comprising:

[0006] substrate;

[0007] A controller mounted on the substrate;

[0008] A voltage input circuit disposed on the substrate is used to convert the received AC signal into a DC signal and output the DC signal.

[0009] The intelligent power module mounted on the substrate includes a drive circuit and a current detection circuit. The control terminal of the drive circuit and the output terminal of the current detection circuit are electrically connected to the controller, respectively. The input terminal of the drive circuit is electrically connected to the output terminal of the voltage input circuit, and the input terminal of the current detection circuit is electrically connected to the first output terminal of the drive circuit. The drive circuit receives and outputs a three-phase current through a second output terminal based on the drive signal and the DC signal sent by the controller. The current detection circuit collects the target current flowing through the drive circuit through the first output terminal of the drive circuit, obtains a current detection signal, and outputs the current detection signal to the controller.

[0010] The current detection circuit includes an operational amplifier. The first input terminal of the operational amplifier is electrically connected to one end of the sampling resistor and the first output terminal of the driving circuit. The second input terminal of the operational amplifier is connected to the other end of the sampling resistor and ground. The output terminal of the operational amplifier is electrically connected to the controller. The current detection circuit is used to detect the target current through the operational amplifier to obtain the current detection signal.

[0011] In the aforementioned inverter board, by embedding an operational amplifier in the current detection circuit of the intelligent power module, the target current flowing through the drive circuit can be detected internally by the operational amplifier, thereby obtaining a current detection signal. This current detection signal is then directly output to the controller, allowing the controller to adjust the drive signal in real time based on the current detection signal, thereby adjusting the phase current amplitude of the three phases. Compared to related technologies, the intelligent power module of this application has an embedded operational amplifier, which saves the need for an external operational amplifier connected to the intelligent power module. The controller can also use a specification that does not require an operational amplifier or has an embedded operational amplifier, making the circuit structure of the entire inverter board simpler.

[0012] In some embodiments, the driving circuit includes multiple switching transistors, and the controller controls the switching transistors to turn on and off by outputting the driving signal, so that the driving circuit outputs the three-phase current; the material of the switching transistors is GaN.

[0013] Understandably, using GaN material for the switching transistors in the drive circuit can result in lower switching losses, enabling higher switching frequencies without generating more heat, thus improving the operating efficiency of the inverter board and reducing power consumption.

[0014] In some embodiments, the sampling resistor is integrated with the operational amplifier and the at least one switching transistor in the smart power module.

[0015] Understandably, integrating the sampling resistor, operational amplifier, and at least one switching transistor in the current detection circuit into the intelligent power module can save the additional sampling resistor connected to the current detection circuit, further reducing the complexity of the inverter board's circuit structure.

[0016] In some embodiments, the intelligent power module further includes a temperature detector. The input of the temperature detector collects the ambient temperature around the switching transistor, and the output of the temperature detector is electrically connected to the controller. The temperature detector is used to output a temperature signal to the controller so that the controller controls the intelligent power module to stop working when it detects that the ambient temperature around the switching transistor is greater than a temperature threshold.

[0017] Understandably, by integrating a temperature detector into the smart power module, the temperature detector can be placed closer to the switching transistor, allowing for more accurate acquisition of the ambient temperature around the switching transistor and preventing overheating damage to the smart power module.

[0018] In some embodiments, the intelligent power module further includes an overcurrent protector connected in series at the second output terminal of the drive circuit, which is used to disconnect the connection at the second output terminal of the drive circuit when the current value of the three-phase current is greater than the current threshold.

[0019] Understandably, by integrating an overcurrent protector into the intelligent power module, the need for an additional overcurrent protector connected to the second output terminal of the drive circuit can be eliminated. When the three-phase current output by the drive circuit exceeds the current threshold, the connection at the second output terminal of the drive circuit can be cut off in time, thereby achieving overcurrent protection for the intelligent power module and improving the operational stability of the inverter board.

[0020] In some embodiments, the intelligent power module further includes a voltage detection circuit. The input terminal of the voltage detection circuit is electrically connected to the second output terminal of the drive circuit, and the output terminal of the voltage detection circuit is electrically connected to the controller. The voltage detection circuit is used to detect the voltage value of the three-phase current and output a corresponding voltage detection signal to the controller so that the controller adjusts the duty cycle of the drive signal according to the voltage detection signal.

[0021] Understandably, by integrating a voltage detection circuit into the intelligent power module, when an abnormal voltage value of the three-phase current is detected by the voltage detection circuit, the conduction time of the switching transistors in the intelligent power module can be controlled in a timely manner, thereby controlling the waveform of the phase current more precisely, resulting in faster load response and a smoother output phase current waveform.

[0022] In some embodiments, the smart power module is packaged as a QFN surface mount package.

[0023] Understandably, by setting the intelligent power module as a QFN surface mount package, with the QFN surface mount fixed on the substrate of the inverter board, compared to the through-hole package in related technologies, the inverter board can be directly reflow soldered during production. The package size is smaller, which can reduce the area of ​​the substrate and thus reduce the size of the inverter board, achieving a more miniaturized inverter board.

[0024] In some embodiments, the inverter board further includes a power supply circuit, which includes an ACDC module and a DC-DC module. The input terminal of the ACDC module is electrically connected to the output terminal of the voltage input circuit, and the output terminal of the ACDC module is electrically connected to the input terminal of the DC-DC module. The output terminal of the DC-DC module is electrically connected to the controller to output a first power supply signal to the controller through the ACDC module and the DC-DC module. The output terminal of the ACDC module is also electrically connected to the intelligent power module to output a second power supply signal to the intelligent power module through the ACDC module. The voltage values ​​of the first power supply signal and the second power supply signal are different.

[0025] Understandably, by using ACDC and DCDC modules, the power supply circuit can further improve power efficiency and reduce the standby power consumption of the inverter board compared to the low-dropout regulator (LDO) in related technologies, thereby improving the overall operating efficiency of the inverter board and reducing power consumption.

[0026] In some embodiments, the frequency converter board further includes a communication circuit electrically connected to the controller, which is used to output parameter information sent by the controller to the host computer after establishing a communication connection with the host computer. The parameter information includes the current value of the target current.

[0027] Understandably, by setting up a communication circuit in the frequency converter board, the parameter information collected by the controller can be uploaded to the host computer in a timely manner, so that the host computer can make reasonable adjustments to the drive parameters of the intelligent power module based on the parameter information, thereby improving the operational stability of the frequency converter board.

[0028] Secondly, embodiments of this application provide an electronic device, including a compressor and a frequency converter board as described in the first aspect, wherein the compressor is electrically connected to the second output terminal of the drive circuit to drive the compressor to work through the three-phase current. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application.

[0030] Figure 1 This is a schematic diagram of the structure of the frequency converter board provided in the embodiments of this application;

[0031] Figure 2 This is a schematic diagram of the current detection circuit provided in an embodiment of this application;

[0032] Figure 3A schematic diagram of the implementation structure of the driving circuit provided in the embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the implementation structure of the current detection circuit provided in the embodiments of this application;

[0034] Figure 5 This is a schematic diagram of the structure of the intelligent power module provided in the embodiments of this application;

[0035] Figure 6 This is a schematic diagram of the structure of the intelligent power module provided in the embodiments of this application;

[0036] Figure 7 This is a schematic diagram of the structure of the intelligent power module provided in the embodiments of this application;

[0037] Figure 8 This is a schematic diagram of the structure of the intelligent power module provided in the embodiments of this application;

[0038] Figure 9 This is a schematic diagram of the voltage detection circuit provided in the embodiments of this application;

[0039] Figure 10 This is a schematic diagram of the power supply circuit provided in an embodiment of this application;

[0040] Figure 11 This is a schematic diagram of the structure of the intelligent power module provided in an embodiment of this application. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0043] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0044] It should be noted that the terms "first, second, third" used in the embodiments of this application are used to distinguish similar or different objects and do not represent a specific order of objects. It can be understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0045] Figure 1 This is a schematic diagram of a frequency converter board provided in an embodiment of this application. Figure 1 As shown, the frequency converter board may include:

[0046] substrate;

[0047] Controller 30 is mounted on the substrate;

[0048] A voltage input circuit 10 is disposed on the substrate;

[0049] The intelligent power module 20 mounted on the substrate includes a drive circuit 201 and a current detection circuit 202. The control terminal of the drive circuit 201 and the output terminal of the current detection circuit 202 are electrically connected to the controller 30, respectively. The input terminal of the drive circuit 201 is electrically connected to the output terminal of the voltage input circuit 10, and the input terminal of the current detection circuit 202 is electrically connected to the first output terminal of the drive circuit 201.

[0050] During the process of outputting three-phase current through the frequency converter board, the voltage input circuit 10 receives the AC signal, converts the AC signal into a DC signal, and outputs the DC signal to the intelligent power module 20. After receiving the DC signal, the drive circuit 201 in the intelligent power module 20 outputs the three-phase current through the second output terminal under the control of the controller 30. At the same time, the current detection circuit 202 will synchronously collect the target current flowing through the drive circuit 201 through the first output terminal, obtain the current detection signal, and output the current detection signal to the controller 30. The controller 30 can adjust the drive signal according to the current detection signal, so that the current value of the three-phase current conforms to the theoretical value.

[0051] Among them, such as Figure 2 As shown, the current detection circuit 202 includes an operational amplifier 2021. The first input terminal of the operational amplifier 2021 is electrically connected to one end of the sampling resistor 2022 and the first output terminal of the driving circuit 201, respectively. The second input terminal of the operational amplifier 2021 is connected to the other end of the sampling resistor 2022 and the ground terminal, respectively. The output terminal of the operational amplifier 2021 is electrically connected to the controller 30. The current detection circuit 202 is used to detect the target current through the operational amplifier 2021 to obtain a current detection signal.

[0052] During the process of obtaining the current detection signal in the current detection circuit 202, the first input terminal of the operational amplifier 2021 in the current detection signal receives the target current, the second input terminal of the operational amplifier 2021 is connected to the ground terminal, and the output terminal of the operational amplifier 2021 is electrically connected to the controller 30. Therefore, the operational amplifier 2021 can perform differential detection on the target current through the voltage difference between the first input terminal and the second input terminal to obtain the current detection signal, and output the current detection signal to the controller 30.

[0053] In some embodiments, the voltage input circuit 10 may include an AC input terminal and a rectifier circuit. The AC input terminal and the input terminal of the rectifier circuit are electrically connected, and the output terminal of the rectifier circuit is electrically connected to the input terminal of the drive circuit 201. The AC input terminal receives an AC signal, and the rectifier circuit converts the received AC signal into a DC signal and outputs the DC signal to the drive circuit 201. The AC input terminal may include a live wire connection terminal and a neutral wire connection terminal, and the rectifier circuit may be a full-bridge rectifier circuit or a half-bridge rectifier circuit.

[0054] In the aforementioned inverter board, by embedding an operational amplifier 2021 in the current detection circuit 202 of the intelligent power module 20, the three-phase current output by the drive circuit 201 can be detected by the operational amplifier 2021 to obtain a current detection signal. The current detection signal is then output to the controller 30, which allows the controller 30 to adjust the drive signal in real time based on the current detection signal, thereby adjusting the phase current amplitude of the three-phase current. Compared with related technologies, the intelligent power module 20 of this application has an operational amplifier 2021 built in, which can save the external operational amplifier 2021 that needs to be connected to the intelligent power module 20. The controller 30 can also use a specification that does not require the connection of the operational amplifier 2021 or has an internal operational amplifier 2021, making the circuit structure of the entire inverter board simpler.

[0055] In some embodiments, the smart power module 20 described above can be packaged as a QFN surface mount package.

[0056] Understandably, by setting the intelligent power module 20 to a QFN surface mount package, with the QFN surface mount fixed on the substrate of the inverter board, compared to the through-hole package in related technologies, the inverter board can be directly reflow soldered during production. The package size is smaller, which can reduce the area of ​​the substrate and thus reduce the size of the inverter board, achieving a more miniaturized inverter board.

[0057] In some embodiments, the drive circuit 201 may include three sets of switching transistors connected in parallel. The controller 30 is connected to the control terminals of the three sets of switching transistors respectively. When the drive circuit 201 is electrically connected to the compressor, the three sets of switching transistors correspond one-to-one with the three windings in the compressor. Each set of switching transistors includes an upper arm switching transistor near the positive input terminal and a lower arm switching transistor near the negative input terminal. One end of the winding is connected between the upper arm switching transistor and the lower arm switching transistor. The controller 30 controls the switching transistors to output three-phase current. The positive input terminal is, for example, the live wire connection terminal, and the negative input terminal is, for example, the neutral wire connection terminal.

[0058] For example, such as Figure 3 As shown, the drive circuit 201 may include a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a fifth switch Q5, and a sixth switch Q6. The windings include a first winding L1, a second winding L2, and a third winding L3. The drive terminals of the first switch Q1, second switch Q2, third switch Q3, fourth switch Q4, fifth switch Q5, and sixth switch Q6 are respectively connected to the controller 30. One end of the first switch Q1 is connected to the positive terminal, one end of the second switch Q2, and one end of the third switch Q6. One end of Q3 is connected, the other end of the first switch Q1 is connected to one end of the first winding L1 and one end of the fourth switch Q4, the other end of the second switch Q2 is connected to one end of the second winding L2 and one end of the fifth switch Q5, the other end of the third switch Q3 is connected to one end of the third winding L3 and one end of the sixth switch Q6, the other ends of the fourth switch Q4, the fifth switch Q5 and the sixth switch Q6 are also connected to the negative terminal, and the first winding L1, the second winding L2 and the third winding L3 are also connected in parallel with each other.

[0059] In this configuration, the first switch Q1 and the fourth switch Q4 are a pair of switches corresponding to the first winding L1, the second switch Q2 and the fifth switch Q5 are a pair of switches corresponding to the second winding L2, and the third switch Q3 and the sixth switch Q6 are a pair of switches corresponding to the third winding L3. The controller 30 controls the connection state of the three sets of switches to make the three windings form corresponding magnetic fields, thereby synthesizing a basic spatial vector of arbitrary size and direction. By combining the synthesized basic spatial vectors, a spatial vector of arbitrary direction can be synthesized, which can then drive the motor.

[0060] The switching transistors of the drive circuit 201 in the related technology are usually made of Si material and are DIP packaged for through-hole. The required substrate size is large, and it is inconvenient to route the through-hole. An external heat sink is required. If the temperature rise is high, the heat dissipation area of ​​the heat sink needs to be increased to enhance heat dissipation. Screws are required to fix the heat sink, and the assembly process is complicated.

[0061] In view of the above-mentioned technical problems, in this embodiment, the switching transistor is replaced with GaN instead of Si, which can effectively reduce the loss of the switching transistor, improve the operating efficiency of the drive circuit 201, improve the operating efficiency of the entire inverter board, reduce the heat loss of the inverter board, and thus improve the overall efficiency and reduce the power consumption of the entire machine. Furthermore, GaN material has lower losses and lower heat generation, eliminating the need for an external heat sink; heat dissipation can be achieved using the substrate itself, and the substrate temperature is more than 10°C lower than the original intelligent power module 20 with a heat sink, simplifying the production and installation process, improving production efficiency, and reducing production costs. Simultaneously, GaN material can support higher switching frequencies. By using the new intelligent power module 20, the inverter board can adjust the switching frequency to 20kHz via the controller 30, increasing the switching frequency of the inverter board, thereby improving the control efficiency of the compressor, resulting in a smoother sinusoidal current output, and reducing the overall noise of the compressor.

[0062] Understandably, setting the switching transistor in the drive circuit 201 to GaN material can result in lower switching losses, enabling higher switching frequencies without generating more heat, thus improving the operating efficiency of the inverter board and reducing power consumption.

[0063] Accordingly, based on Figure 3 The structure of the driving circuit 201 shown is as follows, and the structure of the current detection circuit 202 in this embodiment is as follows. Figure 4 As shown, one end of sampling resistor 2022 is connected to the output terminals of the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6, respectively, and the other end of sampling resistor 2022 is connected to ground. The first input terminal of operational amplifier 2021 is connected to one end of sampling resistor 2022, and the second input terminal of operational amplifier 2021 is connected to the other end of sampling resistor 2022 and ground. Therefore, when the fourth switch Q4, the fifth switch Q5, or the sixth switch Q6 is turned on, sampling resistor 2022 can collect the target current flowing through the fourth switch Q4, the fifth switch Q5, or the sixth switch Q6, and then the operational amplifier 2021 detects the target current to obtain a current detection signal.

[0064] In some embodiments, the sampling resistor 2022 can be integrated with the operational amplifier 2021 and the switching transistor in the smart power module 20.

[0065] It is understandable that integrating the sampling resistor 2022 in the current detection circuit 202 with the operational amplifier 2021 and at least one switching transistor in the intelligent power module 20 can save the additional sampling resistor 2022 connected to the current detection circuit 202, further reducing the complexity of the inverter board's circuit structure.

[0066] In some embodiments, the sampling resistor 2022 can be disposed on the substrate and independently of the location of the smart power module 20. That is, when the smart power module 20 is an independent chip package, the smart power module 20 has a connection terminal for connecting the sampling resistor 2022. Thus, technicians can set the device parameters of the sampling resistor 2022 according to the operating parameters of the compressor connected to the inverter board, and then solder the corresponding sampling resistor 2022 to the corresponding position on the substrate, so that the sampling resistor 2022 matches the operating parameters of the compressor.

[0067] For example, such as Figure 5 As shown, taking the intelligent power module 20 as an independent chip package as an example, the intelligent power module 20 includes a first output terminal OUTA, a second output terminal OUTB, a third output terminal OUTC, a fourth output terminal IU, a fifth output terminal IV, a sixth output terminal IW, a first input terminal AMPIN+, a second input terminal AMPIN-, and a seventh output terminal AMPOUT. The first output terminal OUTA, the second output terminal OUTB, and the third output terminal OUTC are used to output the U-phase current, the V-phase current, and the W-phase current, respectively. The fourth output terminal IU is used to output the target current IU flowing through the fourth switch Q4. The fifth output terminal IV is used to output the target current IV flowing through the fifth switch Q5. The sixth output terminal IW is used to output the target current IW flowing through the sixth switch Q6. The fourth output terminal IU, the fifth output terminal IV, and the sixth output terminal IW are connected in parallel to one end of the sampling resistor R, and then connected to the first input terminal AMPIN+. The other end of the sampling resistor R is connected to the ground terminal and the second input terminal AMPIN-, respectively. The seventh output terminal AMPOUT is connected to the input terminal of the controller 30.

[0068] The operational amplifier 2021 in the intelligent power module 20 amplifies the voltage difference between the two connection terminals AMPIN+ and AMPIN-, and then outputs the corresponding current detection signal through the seventh output terminal AMPOUT, which is then transmitted to the controller 30.

[0069] Understandably, placing the sampling resistor 2022 independently from the intelligent power module 20 in the frequency converter board allows technicians to easily modify the device parameters of the sampling resistor 2022, thereby adapting it to the operating parameters of different compressors and improving compatibility.

[0070] In some of these embodiments, such as Figure 6As shown, the intelligent power module 20 may also include a temperature detector 203. The input terminal of the temperature detector 203 collects the ambient temperature around the switching transistor, and the output terminal of the temperature detector 203 is electrically connected to the controller 30. The temperature detector 203 is used to output a temperature signal to the controller 30 so that the controller 30 controls the intelligent power module 20 to stop working when it detects that the ambient temperature around the switching transistor is greater than the temperature threshold.

[0071] The temperature detector 203 can be a thermistor, such as a positive temperature coefficient (PTC) thermistor or a negative temperature coefficient (NTC) thermistor. When the ambient temperature around the switching transistor rises, the resistance of the thermistor will also change. The controller 30 can obtain the corresponding temperature signal by calculating the resistance of the thermistor.

[0072] Understandably, by integrating a temperature detector 203 into the intelligent power module 20, the temperature detector 203 can be placed closer to the switching transistor, allowing for more accurate acquisition of the ambient temperature around the switching transistor and preventing overheating damage to the intelligent power module 20.

[0073] In some of these embodiments, such as Figure 7 As shown, the intelligent power module 20 may also include an overcurrent protector 204, which is connected in series at the second output terminal of the drive circuit 201 and is used to disconnect the connection at the output terminal of the drive circuit 201 when the current value of the three-phase current is greater than the current threshold.

[0074] Among them, the overcurrent protector 204 is, for example, a fuse. Since the drive circuit 201 outputs three-phase current, including U-phase current, V-phase current and W-phase current, fuses can be set at the corresponding output terminals of U-phase, V-phase and W-phase to ensure current protection for the three-phase current.

[0075] It is understandable that by integrating the overcurrent protector 204 into the intelligent power module 20, the additional overcurrent protector 204 connected to the output terminal of the drive circuit 201 can be saved. When the current value of the three-phase current output by the drive circuit 201 is greater than the current threshold, the connection at the output terminal of the drive circuit 201 can be cut off in time, thereby realizing the overcurrent protection of the intelligent power module 20 and improving the operating stability of the frequency converter board.

[0076] In some of these embodiments, such as Figure 8As shown, the intelligent power module 20 also includes a voltage detection circuit 205. The input terminal of the voltage detection circuit 205 is electrically connected to the output terminal of the drive circuit 201, and the output terminal of the voltage detection circuit 205 is electrically connected to the controller 30. It is used to detect the voltage value of the three-phase current and output the corresponding voltage detection signal to the controller 30 so that the controller 30 adjusts the duty cycle of the drive signal according to the voltage detection signal.

[0077] Since the input terminal of the voltage detection circuit 205 is directly connected to the output terminal of the drive circuit 201, the voltage detection circuit 205 can include multiple series-connected voltage divider resistors. The controller 30 can obtain the voltage value after voltage division, and then calculate the voltage value of the three-phase current based on the voltage value after voltage division and the resistance values ​​of the multiple voltage divider resistors.

[0078] Since the drive circuit 201 includes three output currents, the voltage detection circuit 205 needs to detect the voltage of each of the three output currents separately. Therefore, the multiple series-connected voltage divider resistors can include a first series-connected voltage divider resistor, a second series-connected voltage divider resistor, and a third series-connected voltage divider resistor. The first series-connected voltage divider resistor is used to divide the voltage of one phase current, the second series-connected voltage divider resistor is used to divide the voltage of another phase current, and the third series-connected voltage divider resistor is used to divide the voltage of the last phase current, thereby ensuring that the controller 30 can detect the voltage value of each phase current.

[0079] The resistance values ​​of the voltage divider resistors mentioned above can be set by those skilled in the art according to actual conditions, and the embodiments of this application do not impose any restrictions.

[0080] For example, such as Figure 9As shown, the voltage detection circuit 205 may include a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, and a third capacitor C3. One end of the first resistor R1 is connected to the U-phase current output terminal of the drive circuit 201, and the other end of the first resistor R1 is connected to one end of the fourth resistor R4 and one end of the first capacitor C1, respectively. The other ends of the fourth resistor R4 and the first capacitor C1 are respectively connected to ground. One end of the second resistor R2 is connected to the V-phase current output terminal of the drive circuit 201, and the other end of the second resistor R2 is connected to one end of the fifth resistor R5 and one end of the second capacitor C2. The fifth resistor R5... The other end of the resistor R3 is connected to the ground terminal, the other end of the second capacitor C2 is connected to the W-phase current output terminal of the drive circuit 201, the other end of the third resistor R3 is connected to one end of the sixth resistor R6 and one end of the third capacitor C3, the other end of the sixth resistor R6 and the other end of the third capacitor C3 are connected to the ground terminal, the first voltage receiving terminal AD1 of the controller 30 is connected to the other end of the fourth resistor R4 and the other end of the first capacitor C1, the second voltage receiving terminal AD2 of the controller 30 is connected to the other end of the fifth resistor R5 and the other end of the second capacitor C2, and the third voltage receiving terminal AD3 of the controller 30 is connected to the other end of the sixth resistor R6 and the other end of the third capacitor C3.

[0081] Understandably, by integrating a voltage detection circuit 205 into the intelligent power module 20, when an abnormal voltage value of the three-phase current is detected by the voltage detection circuit 205, the conduction time of the switching transistor in the intelligent power module 20 can be controlled in a timely manner, thereby controlling the waveform of the phase current more precisely, resulting in faster load response and smoother output phase current waveform.

[0082] In some of these embodiments, such as Figure 10 As shown, the inverter board also includes a power supply circuit 40, which includes an ACCDC module 402 and a DCCDC module 401. The input terminal of the ACCDC module 402 is electrically connected to the output terminal of the voltage input circuit 10, and the output terminal of the ACCDC module 402 is electrically connected to the input terminal of the DCCDC module 401. The output terminal of the DCCDC module 401 is electrically connected to the controller 30 to output a first power supply signal to the controller 30 through the ACCDC module 402 and the DCCDC module 401. The output terminal of the ACCDC module 402 is also electrically connected to the intelligent power module 20 to output a second power supply signal to the intelligent power module 20 through the ACCDC module 402.

[0083] It should be understood that although the electrical signal output by the voltage input circuit 10 is a DC signal, there is still some ripple in the DC signal. In order to ensure the stable power supply of the controller 30 and the intelligent power module 20, in this embodiment, the power supply circuit 40 is configured to include an ACDC module 402 and a DCCDC module 401. First, the ACDC module 402 filters out the ripple in the DC signal output by the voltage input circuit 10 and outputs a second power supply signal to the intelligent power module 20. Then, the DC signal voltage value is further reduced by the DCCDC module 401 and a first power supply signal is output to the controller 30.

[0084] The circuit structures of the ACDC module 402 and the DCDC module 401 can adopt conventional ACDC and DCDC circuits in this field, which will not be described in detail here.

[0085] Understandably, by using the ACDC module 402 and the DC-DC module 401, the power supply circuit 40 can further improve power efficiency and reduce the standby power consumption of the inverter board compared to the low-dropout regulator (LDO) in related technologies, thereby improving the overall operating efficiency of the inverter board and reducing power consumption.

[0086] In some of these embodiments, such as Figure 11 As shown, the frequency converter board also includes a communication circuit 50, which is electrically connected to the controller 30. The communication circuit 50 is used to output the parameter information sent by the controller 30 to the host computer after establishing a communication connection with the host computer. The parameter information includes the current value of the target current.

[0087] The aforementioned parameter information may also include information such as the compressor speed, phase voltage and phase current of the three-phase current collected by the controller 30. The specific settings shall be made by those skilled in the art according to the actual situation, and the embodiments of this application do not impose any restrictions.

[0088] After obtaining the above parameter information, the host computer can calculate the compressor's start-stop ratio and then calculate the compressor's power consumption.

[0089] Understandably, by setting up a communication circuit 50 in the frequency converter board, the parameter information collected by the controller 30 can be uploaded to the host computer in a timely manner, so that the host computer can make reasonable adjustments to the drive parameters of the intelligent power module 20 based on the parameter information, thereby improving the operational stability of the frequency converter board.

[0090] Secondly, embodiments of this application provide an electronic device, including a compressor and a frequency converter board as described in the first aspect, wherein the compressor is electrically connected to the second output terminal of the drive circuit 201 to drive the compressor to work via three-phase current.

[0091] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0092] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0093] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0094] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network terminals. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0095] In addition, each functional module in the various embodiments of this application can be fully integrated into one processing terminal, or each module can be a separate terminal, or two or more modules can be integrated into one terminal; the integrated modules can be implemented in hardware or in the form of hardware plus software functional terminals.

[0096] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0097] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A frequency converter board, characterized in that, include: substrate; A controller mounted on the substrate; A voltage input circuit disposed on the substrate is used to convert the received AC signal into a DC signal and output the DC signal. The intelligent power module disposed on the substrate includes a driving circuit and a current detection circuit. The control terminal of the driving circuit and the output terminal of the current detection circuit are electrically connected to the controller, respectively. The input terminal of the driving circuit is electrically connected to the output terminal of the voltage input circuit, and the input terminal of the current detection circuit is electrically connected to the first output terminal of the driving circuit. The drive circuit is used to receive and output three-phase current through the second output terminal according to the drive signal sent by the controller and the DC signal; The current detection circuit is used to collect the target current flowing through the drive circuit via the first output terminal of the drive circuit, obtain a current detection signal, and output the current detection signal to the controller. The current detection circuit includes an operational amplifier. The first input terminal of the operational amplifier is electrically connected to one end of the sampling resistor and the first output terminal of the driving circuit. The second input terminal of the operational amplifier is connected to the other end of the sampling resistor and ground. The output terminal of the operational amplifier is electrically connected to the controller. The current detection circuit is used to detect the target current through the operational amplifier to obtain the current detection signal.

2. The frequency converter board as described in claim 1, characterized in that, The driving circuit includes multiple switching transistors, and the controller controls the switching transistors to turn on and off by outputting the driving signal, so that the driving circuit outputs the three-phase current; the material of the switching transistors is GaN.

3. The frequency converter board as described in claim 2, characterized in that, The sampling resistor is integrated with the operational amplifier and the switching transistor in the smart power module.

4. The frequency converter board as described in claim 2, characterized in that, The intelligent power module also includes a temperature detector. The input terminal of the temperature detector collects the ambient temperature around the switching transistor, and the output terminal of the temperature detector is electrically connected to the controller. The temperature detector is used to output a temperature signal to the controller so that when the controller detects that the ambient temperature around the switching transistor is greater than a temperature threshold, it controls the intelligent power module to stop working.

5. The frequency converter board as described in claim 1, characterized in that, The intelligent power module also includes an overcurrent protector connected in series at the second output terminal of the drive circuit, which is used to disconnect the connection at the second output terminal of the drive circuit when the current value of the three-phase current is greater than the current threshold.

6. The frequency converter board as described in claim 1, characterized in that, The intelligent power module further includes a voltage detection circuit. The input terminal of the voltage detection circuit is electrically connected to the second output terminal of the drive circuit, and the output terminal of the voltage detection circuit is electrically connected to the controller. The voltage detection circuit is used to detect the voltage value of the three-phase current and output a corresponding voltage detection signal to the controller so that the controller adjusts the duty cycle of the drive signal according to the voltage detection signal.

7. The frequency converter board as described in any one of claims 1-6, characterized in that, The intelligent power module is packaged in a QFN surface mount package.

8. The frequency converter board as described in claim 7, characterized in that, The inverter board also includes a power supply circuit, which comprises an ACDC module and a DC-DC module. The input terminal of the ACDC module is electrically connected to the output terminal of the voltage input circuit, and the output terminal of the ACDC module is electrically connected to the input terminal of the DC-DC module. The output terminal of the DC-DC module is electrically connected to the controller to output a first power supply signal to the controller through the ACDC module and the DC-DC module. The output terminal of the ACDC module is also electrically connected to the intelligent power module to output a second power supply signal to the intelligent power module through the ACDC module. The voltage values ​​of the first power supply signal and the second power supply signal are different.

9. The frequency converter board as described in claim 1, characterized in that, The frequency converter board also includes a communication circuit, which is electrically connected to the controller and is used to output the parameter information sent by the controller to the host computer after establishing a communication connection with the host computer. The parameter information includes the current value of the target current.

10. An electronic device comprising a compressor and a frequency converter board as described in any one of claims 1-9, wherein the compressor is electrically connected to a second output terminal of the drive circuit to drive the compressor to operate via the three-phase current.

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