Variable frequency controller and refrigeration device

Abstract

The invention discloses a variable-frequency controller and a refrigerating device, and relates to the technical field of variable-frequency control, and the variable-frequency controller comprises a power supply module, a control module and a 0-ohm resistor. The power supply module is used for carrying out voltage reduction and rectification on alternating current so as to supply power to the control module, and a 0-ohm resistor is arranged between the control module and the ground and is used for isolating the control module from the ground when electromagnetic interference exists. Therefore, the zero-ohm resistor is arranged between the control module and the ground, the reference ground of the control module is isolated from the ground when electromagnetic interference exists, the electromagnetic interference is effectively reduced, and normal operation of the refrigeration device is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of variable frequency control, and in particular to a variable frequency controller and a refrigeration device. Background Art

[0002] The motor is one of the core components of the refrigeration device. Its operating status directly affects the stability and reliability of the entire device. With the continuous development of refrigeration devices, the control of the motor has evolved from the previous fixed-frequency control motor to the variable-frequency control motor. However, the variable-frequency controller will generate a large amount of high-order harmonics and electromagnetic noise in the process of variable-frequency control of the motor, forming electromagnetic interference, which will cause serious harm to the circuit. The variable-frequency controller includes a power module and a control module. The control module includes a digital module, an analog module, a communication module, etc. The control module is powered by the power module. In the actual circuit, if the reference grounds of the analog module, the digital module, and the communication module are directly connected, the interference source may be transmitted through the ground. Please refer to Figure 1 As shown, Figure 1 The schematic diagram of the structure of a frequency conversion controller in the related technology; if the reference grounds of the analog module, digital module, and communication module are isolated from each other, there will be a voltage difference between the reference grounds of the three modules, which is easy to accumulate charge and cause static electricity. The above two solutions cannot effectively reduce electromagnetic interference, which may cause distortion of the output analog signal, digital signal, and collected data, resulting in abnormal operation of the refrigeration device. Summary of the invention

[0003] The object of the present invention is to provide a variable frequency controller and a refrigeration device, by setting a 0 ohm resistor between the control module and the ground, the reference ground of the control module is isolated from the ground when electromagnetic interference exists, thereby effectively reducing the electromagnetic interference and ensuring the normal operation of the refrigeration device.

[0004] In order to solve the above technical problems, the present invention provides a frequency conversion controller, comprising:

[0005] A power supply module, wherein the positive power supply terminal of the power supply module is connected to the alternating current, the output terminal is connected to the power supply terminal of the control module, the ground terminal is connected to the second end of the 0 ohm resistor, and the common terminal after connection is grounded, and is used to step down and rectify the alternating current to power the control module;

[0006] The control module, wherein a ground terminal of the control module is connected to a first end of the 0 ohm resistor;

[0007] The 0 ohm resistor is used to isolate the control module from the ground when electromagnetic interference exists.

[0008] Optionally, the control module includes a digital quantity module, an analog quantity module and a communication module, and the number of the 0 ohm resistors is 3, namely a first 0 ohm resistor, a second 0 ohm resistor and a third 0 ohm resistor;

[0009] The grounding end of the digital quantity module is grounded through the first 0-ohm resistor, the grounding end of the analog quantity module is grounded through the second 0-ohm resistor, and the grounding end of the communication module is grounded through the third 0-ohm resistor.

[0010] Optionally, also include:

[0011] A power isolation module, wherein a first end of the power isolation module is connected to an output end of the power module, and a second end of the power isolation module is connected to a power end of the control module.

[0012] Optionally, the control module includes a digital quantity module, an analog quantity module and a communication module, and the power isolation module is three transformers, the high-voltage sides of the three transformers are all connected to the output end of the power module, and the low-voltage sides of the three transformers are respectively connected to the power ends of the digital quantity module, the analog quantity module and the communication module.

[0013] Optionally, also include:

[0014] A filter module, wherein a first end of the filter module is connected to a common end of the power module and the 0 ohm resistor, and a second end of the filter module is grounded.

[0015] Optionally, the filtering module is a capacitor.

[0016] Optionally, also include:

[0017] A current sensor, connected to the output end of the power module, and used to collect the current value of the output end of the power module;

[0018] A switch, wherein a first end of the switch is connected to the output end of the power module, and a second end of the switch is connected to the power end of the control module, and is used to disconnect when the current value is greater than a preset current threshold.

[0019] Optionally, also include:

[0020] A switching module, wherein the multiple input terminals of the switching module are respectively connected to multiple AC power lines, and the output terminal is connected to the positive power terminal of the power module, and is used to switch to other AC power lines that are not powered off or out of power when one AC power line is powered off or out of power.

[0021] Optionally, also include:

[0022] An energy storage module, wherein a first end of the energy storage module is connected to an output end of the switching module, and a second end of the energy storage module is connected to a positive power supply end of the power supply module, and is used to store energy when current is output at the output end of the switching module, and output electric energy to the power supply module during the process of the switching module switching the alternating current.

[0023] To solve the above technical problems, the present invention further provides a refrigeration device, including a frequency converter and a motor, and also including the frequency converter controller as described above, wherein the frequency converter is connected to the motor and the frequency converter controller respectively.

[0024] The present application provides a variable frequency controller and a refrigeration device, the variable frequency controller includes a power module control module and a 0 ohm resistor. The power module is used to step down and rectify the AC power to power the control module, and a 0 ohm resistor is set between the control module and the ground, and the 0 ohm resistor is used to isolate the control module from the ground when electromagnetic interference exists. It can be seen that the present application sets a 0 ohm resistor between the control module and the ground, isolates the reference ground of the control module from the ground when electromagnetic interference exists, effectively reduces electromagnetic interference, and ensures the normal operation of the refrigeration device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a structural schematic diagram of a frequency conversion controller in the related art;

[0027] Figure 2 A schematic diagram of the structure of a frequency conversion controller provided by the present invention;

[0028] Figure 3 A schematic structural diagram of a specific frequency conversion controller provided by the present invention. DETAILED DESCRIPTION

[0029] The core of the present invention is to provide a variable frequency controller and a refrigeration device. By setting a 0 ohm resistor between the control module and the ground, the reference ground of the control module is isolated from the ground when electromagnetic interference exists, thereby effectively reducing the electromagnetic interference and ensuring the normal operation of the refrigeration device.

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The frequency converter includes a power module and a control module. The control module includes a digital module, an analog module, a communication module, etc. The control module is powered by the power module. In the actual circuit, if the reference grounds of the analog module, the digital module, and the communication module are directly connected, the interference source may be transmitted through the ground. Please refer to Figure 1 As shown, Figure 1 The schematic diagram of the structure of a frequency conversion controller in the related technology; if the reference grounds of the analog module, digital module, and communication module are isolated from each other, there will be a voltage difference between the reference grounds of the three modules, which is easy to accumulate charge and cause static electricity. The above two solutions cannot effectively reduce electromagnetic interference, which may cause distortion of the output analog signal, digital signal, and collected data, resulting in abnormal operation of the refrigeration device.

[0032] Please refer to Figure 2 As shown, Figure 2 A schematic structural diagram of a frequency conversion controller provided by the present invention.

[0033] The frequency conversion controller comprises:

[0034] A power module 1, wherein the positive power terminal V+ of the power module 1 is connected to the AC power, the output terminal is connected to the power terminal of the control module 2, the ground terminal GND1 is connected to the second end of the 0 ohm resistor R, and the common terminal after connection is grounded, for stepping down and rectifying the AC power to supply power to the control module 2;

[0035] A control module 2, wherein a ground terminal GND of the control module 2 is connected to a first end of a 0 ohm resistor R;

[0036] The 0 ohm resistor R is used to isolate the control module 2 from the earth PE when electromagnetic interference exists.

[0037] The frequency conversion controller includes a power supply module 1, a control module 2 and a 0 ohm resistor R. It should be noted that in the process of the frequency conversion controller performing frequency conversion control on the motor, the control module 2 in the frequency conversion controller requires a stable power supply to ensure its normal operation, and the control module 2 usually uses 24V DC power, while the power grid is generally 220V AC power. Therefore, in this embodiment, the power supply module 1 steps down and rectifies the 220V AC power, and converts it into the 24V DC power required by the control module 2 to ensure the normal operation of the control module 2.

[0038] Specifically, in order to reduce the electromagnetic interference generated during the frequency conversion control process, the electromagnetic interference includes but is not limited to high-frequency interference signals. In this embodiment, a 0-ohm resistor R is set between the reference ground of the control module 2 and the earth PE. The control module 2 includes but is not limited to a digital module, an analog module, and a communication module. The 0-ohm resistor R also has a certain resistance value, but the resistance value is very small. The resistance value of the 0-ohm resistor R can be 50mΩ. When there is no high-frequency interference signal, the 0-ohm resistor R is resistive, which is equivalent to directly connecting the reference grounds of the power module 1, the digital module, the analog module, and the communication module, thereby avoiding the isolation of the reference grounds of any two modules, forming a voltage difference, and generating static electricity. If there is a high-frequency interference signal, the 0-ohm resistor R becomes inductive, which is equivalent to a high-impedance state between the reference grounds of the power module 1, the digital module, the analog module, and the communication module and the earth PE. In this state, the reference grounds of the power module 1, the digital module, the analog module, and the communication module are disconnected from the earth PE and do not interfere with each other.

[0039] It can be seen that the present application sets a 0 ohm resistor R between the control module 2 and the earth PE, and isolates the reference ground of the control module 2 from the earth PE when electromagnetic interference exists, effectively reducing the electromagnetic interference and ensuring the normal operation of the refrigeration device.

[0040] Based on the above embodiments:

[0041] Please refer to Figure 3 As shown, Figure 3 A schematic structural diagram of a specific frequency conversion controller provided by the present invention.

[0042] As an optional embodiment, the control module 2 includes a digital quantity module 3, an analog quantity module 4 and a communication module 5, and there are three 0 ohm resistors R, namely a first 0 ohm resistor R1, a second 0 ohm resistor R2, and a third 0 ohm resistor R3;

[0043] The ground terminal GND2 of the digital module 3 is grounded through the first 0 ohm resistor R1 , the ground terminal GND3 of the analog module 4 is grounded through the second 0 ohm resistor R2 , and the ground terminal GND4 of the communication module 5 is grounded through the third 0 ohm resistor R3 .

[0044] Specifically, the control module 2 includes but is not limited to a digital quantity module 3, an analog quantity module 4 and a communication module 5. Different modules have different functions. Specifically, the digital quantity module 3 can receive a digital quantity signal and convert it into a signal that can be recognized by the frequency conversion controller, which is used to control the frequency converter to control the motor; the analog quantity module 4 can convert the analog quantity signal into a digital quantity signal so that the frequency conversion controller can recognize it, and can also convert the digital quantity signal into an analog quantity signal and output it to the frequency converter so that the frequency converter can adjust the speed of the motor, etc.; the communication module 5 is used to realize data exchange between the frequency converter and the host computer. For example, the host computer can send control instructions to the frequency converter through the communication module 5. The control instructions may include but are not limited to start, stop, and frequency setting. At the same time, the frequency converter can also feedback the operating status information to the host computer to realize remote monitoring and control.

[0045] Furthermore, considering that the reference ground between different modules is easily affected by electromagnetic interference, for example, the reference ground of the digital module 3 and the analog module 4 is in common ground, if the ground potential fluctuation of the digital signal may be transmitted to the reference ground of the analog module 4 through the earth PE, the analog signal is interfered with and the accuracy of the analog signal is affected, so a 0 ohm resistor R is set between the reference ground of each module of the control module 2 and the earth PE. Specifically, when there is no high-frequency interference signal, the 0 ohm resistor R is resistive, which is equivalent to directly connecting the reference grounds of the power module 1, the digital module 3, the analog module 4 and the communication module 5, avoiding the isolation of the reference grounds of any two modules, forming a voltage difference, and generating static electricity; if there is a high-frequency interference signal, the 0 ohm resistor R becomes inductive, which is equivalent to a high impedance state between the reference grounds of the power module 1, the digital module 3, the analog module 4 and the communication module 5 and the earth PE. In this state, the reference grounds of the power module 1, the digital module 3, the analog module 4 and the communication module 5 are equivalent to being disconnected from the earth PE and do not interfere with each other.

[0046] It can be seen that in this embodiment, a 0 ohm resistor R is set between the reference ground of each module of the control module 2 and the earth PE, namely the first 0 ohm resistor R1, the second 0 ohm resistor R2, and the third 0 ohm resistor R3, so that when electromagnetic interference exists, the 0 ohm resistor R can isolate the reference grounds of each module of the control module 2 and any two modules in the power module 1 from each other, thereby preventing the signals of each module from being electromagnetically interfered by the signals of other modules, thereby improving the accuracy of each signal.

[0047] As an optional embodiment, it also includes:

[0048] The power isolation module 6 has a first end connected to the output end of the power module 1 , and a second end connected to the power end of the control module 2 .

[0049] Specifically, considering that the electromagnetic interference signals of different modules in the control module 2 may be transmitted to other modules through the power lines of each module and interfere with the signals of other modules, a power isolation module 6 is set between the control module 2 and the power module 1 to block the electromagnetic interference signals of each module.

[0050] It can be seen that in this embodiment, a power isolation module 6 is provided between the control module 2 and the power module 1 to block the electromagnetic interference signals of each module, further reduce the electromagnetic interference, and ensure the normal operation of the refrigeration device.

[0051] As an optional embodiment, the control module 2 includes a digital quantity module 3, an analog quantity module 4 and a communication module 5, and the power isolation module 6 is three transformers, the high-voltage sides of the three transformers are all connected to the output end of the power module 1, and the low-voltage sides of the three transformers are respectively connected to the power supply ends of the digital quantity module 3, the analog quantity module 4 and the communication module 5.

[0052] This embodiment uses three transformers as the power isolation module 6 to achieve electrical isolation and prevent electromagnetic interference between different modules in the control module 2. In addition, considering that different modules in the control module 2 may require different voltages, the turns ratio of the secondary coil and the primary coil of the corresponding transformer can be adjusted according to the requirements of different modules to provide different voltages for each module.

[0053] It can be seen that this embodiment uses three transformers as the power isolation module 6 to block the electromagnetic interference signals of each module, and adjusts the turns ratio of the secondary coil and the primary coil of the corresponding transformer according to the requirements of each module to meet the functional requirements of each module.

[0054] As an optional embodiment, it also includes:

[0055] A filter module, wherein a first end of the filter module is connected to a common end of the power module 1 and a 0 ohm resistor R, and a second end of the filter module is grounded.

[0056] Specifically, in order to reduce noise interference and improve communication quality, in this embodiment, a filtering module is set between the common end of the power module 1 and the 0 ohm resistor R and the earth PE to filter out clutter. At the same time, the filtering module isolates the earth PE from the power module 1 and the control module 2, thereby preventing interference on the earth PE from flowing to the power module 1 and the control module 2.

[0057] It can be seen that in this embodiment, a filter module is set between the common end of the power module 1 and the 0 ohm resistor R and the earth PE, which can remove high-frequency noise and prevent interference on the earth PE from flowing to the power module 1 and the control module 2, thereby ensuring the normal operation of the refrigeration device.

[0058] As an optional embodiment, the filtering module is a capacitor C.

[0059] Specifically, this embodiment uses a capacitor C as a filtering module. The capacitor C can remove signals in a specific frequency band from the total signal, thereby filtering out signals in unnecessary frequency bands to improve signal quality and stability and reduce the impact of interference signals on communications.

[0060] It can be seen that the performance and stability of the frequency conversion controller are improved by using the capacitor C to remove the signal in a specific frequency band.

[0061] As an optional embodiment, it also includes:

[0062] A current sensor is connected to the output end of the power module 1 and is used to collect the current value of the output end of the power module 1;

[0063] A switch, wherein a first end of the switch is connected to the output end of the power module 1, and a second end of the switch is connected to the power end of the control module 2, and is used to disconnect when the current value is greater than a preset current threshold.

[0064] Specifically, in order to help analyze the load condition of the power module 1 or perform fault diagnosis and improve the stability and reliability of the frequency conversion controller, it is necessary to detect the current value at the output end of the power module 1 in real time. In this embodiment, a current sensor is set at the output end of the power module 1. When the current value collected by the current sensor is greater than the preset current threshold, the switch is disconnected and the power module 1 stops the control module 2 from supplying power.

[0065] It can be seen that in this embodiment, the switch is disconnected when the current value collected by the current sensor is greater than the preset current threshold, so as to avoid continuing to supply power to the control module 2 when the power module 1 is overloaded or the control module 2 fails, resulting in signal loss and / or component burning, thereby improving the stability and reliability of the frequency conversion controller.

[0066] As an optional embodiment, it also includes:

[0067] The switching module has multiple input terminals connected to multiple AC power supplies, and the output terminal is connected to the positive power supply terminal of the power supply module 1, so as to switch to other AC power supplies that are not cut off or out of power when one AC power supply is cut off or out of power.

[0068] Specifically, in this embodiment, in order to avoid the signal loss of the control module 2 due to power failure or power outage of one AC power line, affecting the subsequent monitoring and data analysis, and reducing the safety and reliability of the variable frequency control of the motor, this embodiment provides multiple AC powers for the power module 1. During normal operation, the switching module selects one AC power line to power the power module 1. When the AC power line fails or power outage occurs, the switching module switches from the AC power that has failed or power outage to other AC power that has not failed or power outage, so as to ensure that it can quickly switch to the backup power supply when the power is interrupted, thereby improving the safety and reliability of the variable frequency controller.

[0069] It can be seen that this embodiment provides multiple AC powers for the power module 1. During normal operation, the switching module selects one AC power to power the power module 1. When the AC power is cut off or out of power, the switching module can switch from the AC power that has been cut off or out of power to other AC power that has not been cut off or out of power, ensuring that the power module 1 continues to be powered, thereby improving the safety and reliability of the frequency conversion controller.

[0070] As an optional embodiment, it also includes:

[0071] An energy storage module, wherein the first end of the energy storage module is connected to the output end of the switching module, and the second end of the energy storage module is connected to the positive power supply end of the power supply module 1, and is used to store energy when there is current output at the output end of the switching module, and output electrical energy to the power supply module 1 during the process of the switching module switching alternating current.

[0072] Specifically, since switching time is required in the process of the switching module switching the AC power at the input end, in order to avoid the power module 1 being without power supply during the switching process, the present application sets an energy storage module between the switching module and the power module 1. Under normal working conditions, the energy storage module stores energy while the AC power supplies the power module 1. In the process of the switching module switching the AC power at the input end, the energy stored in the energy storage module can be used to power the power module 1, thereby avoiding the frequency conversion controller being without power supply and stopping operation during the AC switching process.

[0073] It can be seen that the present invention sets an energy storage module between the switching module and the power module 1, and the power module 1 can be powered by the energy stored in the energy storage module during the process of switching the AC power at the input end of the switching module, thereby preventing the frequency conversion controller from stopping due to lack of power supply during the AC power switching process.

[0074] The present invention further provides a refrigeration device, comprising a frequency converter and a motor, and also comprising the frequency converter controller as described above, wherein the frequency converter is connected to the motor and the frequency converter controller respectively.

[0075] Specifically, the frequency conversion controller controls the start and stop and speed of the motor by controlling the frequency converter, so as to ensure the normal operation of the refrigeration device. In addition, the introduction of a refrigeration device provided by the present invention refers to the embodiment of the frequency conversion controller, and the present invention will not be repeated here.

[0076] It can be seen that the present application sets a 0 ohm resistor R between the control module 2 and the earth PE, and isolates the reference ground of the control module 2 from the earth PE when electromagnetic interference exists, effectively reducing the electromagnetic interference and ensuring the normal operation of the refrigeration device.

[0077] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0078] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0079] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A frequency conversion controller, characterized in that: include: A power supply module, wherein the positive power supply terminal of the power supply module is connected to the alternating current, the output terminal is connected to the power supply terminal of the control module, the ground terminal is connected to the second end of the 0 ohm resistor, and the common terminal after connection is grounded, and is used to step down and rectify the alternating current to power the control module; The control module, wherein a ground terminal of the control module is connected to a first end of the 0 ohm resistor; The 0 ohm resistor is used to isolate the control module from the ground when electromagnetic interference exists.

2. The frequency conversion controller according to claim 1, characterized in that: The control module includes a digital quantity module, an analog quantity module and a communication module. The 0 ohm resistors are three, namely a first 0 ohm resistor, a second 0 ohm resistor and a third 0 ohm resistor; The grounding end of the digital quantity module is grounded through the first 0-ohm resistor, the grounding end of the analog quantity module is grounded through the second 0-ohm resistor, and the grounding end of the communication module is grounded through the third 0-ohm resistor.

3. The frequency conversion controller according to claim 1, characterized in that: Also includes: A power isolation module, wherein a first end of the power isolation module is connected to an output end of the power module, and a second end of the power isolation module is connected to a power end of the control module.

4. The frequency conversion controller according to claim 3, characterized in that: The control module includes a digital quantity module, an analog quantity module and a communication module. The power isolation module is three transformers. The high-voltage sides of the three transformers are connected to the output end of the power module, and the low-voltage sides of the three transformers are respectively connected to the power supply ends of the digital quantity module, the analog quantity module and the communication module.

5. The frequency conversion controller according to claim 1, characterized in that: Also includes: A filter module, wherein a first end of the filter module is connected to a common end of the power module and the 0 ohm resistor, and a second end of the filter module is grounded.

6. The frequency conversion controller according to claim 5, characterized in that: The filtering module is a capacitor.

7. The frequency conversion controller according to claim 1, characterized in that: Also includes: A current sensor, connected to the output end of the power module, and used to collect the current value of the output end of the power module; A switch, wherein a first end of the switch is connected to the output end of the power module, and a second end of the switch is connected to the power end of the control module, and is used to disconnect when the current value is greater than a preset current threshold.

8. The frequency conversion controller according to any one of claims 1 to 7, characterized in that: Also includes: A switching module, wherein the multiple input terminals of the switching module are respectively connected to multiple AC power lines, and the output terminal is connected to the positive power terminal of the power module, and is used to switch to other AC power lines that are not powered off or out of power when one AC power line is powered off or out of power.

9. The frequency conversion controller according to claim 8, characterized in that: Also includes: An energy storage module, wherein a first end of the energy storage module is connected to an output end of the switching module, and a second end of the energy storage module is connected to a positive power supply end of the power supply module, and is used to store energy when current is output at the output end of the switching module, and output electric energy to the power supply module during the process of the switching module switching the alternating current.

10. A refrigeration device, characterized in that: The invention comprises a frequency converter and a motor, and also comprises a frequency conversion controller as claimed in any one of claims 1 to 9, wherein the frequency converter is connected to the motor and the frequency conversion controller respectively.

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