Power supply circuit and variable-frequency electric appliance
By setting two power supply branches in the power supply circuit of the frequency converter and setting the reactor in the branch that only supplies voltage compressors, the increase in volume and cost caused by the heating of the reactor in the prior art is solved, and the problem of increasing volume and cost in the reactor is realized Lower cost and smaller volume reactor design.
Patent Information
- Application Number
- CN202411684480.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-02-18
AI Technical Summary
In the prior art, frequency conversion electrical appliances can only control the heating of the reactor by increasing the rated current of the reactor, resulting in increased device volume and cost.
A power supply circuit is designed, and two power supply branches are set up, one of which only supplies power to the compressor. The reactor is set in the power supply branch that supplies power to the compressor, so that the current flowing through the reactor is only the current of the compressor. The working current of the reactor is reduced, thereby reducing the heat generation of the reactor.
By reducing the working current of the reactor, the heating temperature of the reactor is reduced, the cost and volume increase caused by overheating of the reactor is avoided, and the temperature requirements of the frequency converter appliance are met.
Smart Images
Figure CN119483228A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electronic circuits, and in particular to a power supply circuit and a frequency conversion electrical appliance. Background Art
[0002] With the development of technology, frequency conversion technology is increasingly used in various electrical appliances. The working principle of frequency conversion technology is to provide different compressor speeds according to parameters such as ambient temperature, compartment temperature, and the difference between the actual compartment temperature and the design temperature, which can greatly reduce the power consumption of the whole machine and improve the energy consumption level. However, the introduction of frequency conversion technology will inevitably bring about electromagnetic interference problems inside electrical appliances, and will also have a great impact on harmonic currents. Due to the increase in the requirements for harmonic currents of frequency conversion electrical appliances, at present, in most cases, the method of inserting a reactor in series in the circuit is used to effectively suppress the harmonics of the frequency conversion. However, there are also certain problems with the series reactor, namely: since the reactor is connected in series in the circuit, the reactor body will generate heat due to the large current flowing through it, and the heating temperature of the reactor is closely related to the working current of the frequency conversion electrical appliance. The greater the load of the frequency conversion electrical appliance, the greater the working current will be, and the higher the temperature of the reactor will be.
[0003] Since the working current of small-volume or low-end variable-frequency electrical appliances is relatively small, the temperature rise of the reactor is not obvious. However, for large-volume or high-end variable-frequency electrical appliances, the compressor exhaust volume and power of large-volume variable-frequency electrical appliances are large, and the internal decorative lights of high-end variable-frequency electrical appliances are also large, so the working current increases, which requires increasing the rated current of the reactor to avoid the temperature of the reactor being too high when the variable-frequency electrical appliances are working. However, to increase the rated current of the reactor, it is necessary to increase the wire diameter of the reactor wire, which will inevitably increase the volume of the reactor and increase the cost of the controller.
[0004] With regard to the problem that in the prior art, variable frequency electrical appliances can only control the heating of the reactor by increasing the rated current of the reactor, which will lead to an increase in the size and cost of the device, no effective solution has been proposed so far. Summary of the invention
[0005] The embodiments of the present invention provide a power supply circuit and a variable frequency electrical appliance to solve the problem in the prior art that the variable frequency electrical appliance can only control the heating of the reactor by increasing the rated current of the reactor, which will lead to an increase in the size and cost of the device.
[0006] In order to solve the above technical problems, the present invention provides a power supply circuit, which is applied to a variable frequency electrical appliance with a compressor, and the power supply circuit comprises:
[0007] A discharge module, an input end of which is connected to a power source;
[0008] A first power supply branch, wherein the positive terminal of the input end is connected to the positive terminal of the output end of the discharge module, the negative terminal of the input end is connected to the negative terminal of the output end of the discharge module, and the output end is connected to the compressor;
[0009] A reactor, arranged between the positive terminal of the input end of the first power supply branch and the positive terminal of the output end of the discharge module;
[0010] The second power supply branch has a positive terminal at its input end connected to a positive terminal at the output end of the discharge module, a negative terminal at its input end connected to a negative terminal at the output end of the discharge module, and an output end connected to a main control load of the variable frequency electrical appliance.
[0011] Furthermore, the first power supply branch includes:
[0012] A first rectifier module, whose input end is connected to the discharge module and whose output end is connected to the BUCK power supply module;
[0013] The BUCK power module has an output end connected to the compressor.
[0014] Furthermore, the first power supply branch further includes:
[0015] The first filter module is arranged between the first rectifier module and the BUCK power supply module.
[0016] Furthermore, the second power supply branch includes:
[0017] A second rectifier module, whose input end is connected to the discharge module and whose output end is connected to the switch power supply module;
[0018] The switching power supply module has an output end connected to the main control load.
[0019] Furthermore, the second power supply branch further includes:
[0020] The second filtering module is arranged between the second rectifying module and the switching power supply module.
[0021] Furthermore, the second power supply branch further includes:
[0022] The step-down circuit has an input end connected to the switch power supply module, and an output end connected to the main control chip and the display panel respectively.
[0023] Furthermore, the power supply circuit further includes:
[0024] The absorption module is arranged between the discharge module and the power supply.
[0025] Furthermore, the power supply circuit further includes:
[0026] The frequency conversion module is arranged between the first power supply branch and the compressor.
[0027] The present invention also provides a variable frequency electrical appliance, comprising the above power supply circuit.
[0028] Furthermore, the variable frequency electrical appliances include at least one of the following: variable frequency electrical appliances with variable frequency, and variable frequency air conditioners.
[0029] By applying the technical solution of the present invention, two power supply branches are set, one of which only supplies power to the compressor, and the reactor is set in the power supply branch that supplies power to the compressor, so that the current flowing through the reactor is only the current of the compressor, reducing the working current of the reactor, thereby reducing the heating of the reactor. When the current of the main control load of the variable frequency electrical appliance is large, the reactor can also meet the temperature requirements. When manufacturing the device, selecting a reactor with a smaller rated current can also meet the temperature requirements, and there is no need to use a reactor with a larger rated current, which can reduce the occupied space of the device and reduce the device cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is a structural diagram of a power supply circuit of a variable frequency electrical appliance in the prior art;
[0031] Figure 2 is a structural diagram of a power supply circuit according to an embodiment of the present invention. DETAILED DESCRIPTION
[0032] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0033] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.
[0034] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.
[0035] It should be understood that, although the terms first, second, etc. may be used to describe the power supply branch in the embodiments of the present invention, these power supply branches should not be limited to these terms. These terms are only used to distinguish different power supply branches. For example, without departing from the scope of the embodiments of the present invention, the first power supply branch may also be referred to as the second power supply branch, and similarly, the second power supply branch may also be referred to as the first power supply branch.
[0036] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.
[0037] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.
[0038] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0039] Example 1
[0040] Figure 1 The structure diagram of the power supply circuit of the variable frequency electrical appliance in the prior art is as follows: Figure 1 As shown in the figure, the reactor is connected in series in the circuit. The reactor body will generate heat due to the large current flowing through it, and the heating temperature of the reactor is closely related to the working current of the variable frequency electrical appliance. The greater the load of the variable frequency electrical appliance, the greater the working current will be, and the higher the temperature of the reactor will be. Since the working current of small volume or low-grade variable frequency electrical appliances is relatively small, the temperature rise of the reactor is not obvious, but for large volume or high-grade variable frequency electrical appliances, large volume variable frequency electrical appliances, large compressor exhaust volume, large power, high-grade variable frequency electrical appliances, their internal decorative lights are also relatively large, so the working current increases, which requires increasing the rated current of the reactor to avoid the temperature of the reactor being too high when the variable frequency electrical appliance is working. However, to increase the rated current of the reactor, it is necessary to increase the wire diameter of the reactor wire, which will inevitably increase the volume of the reactor and increase the cost of the controller.
[0041] In view of the problem that the variable frequency electrical appliances in the prior art can only control the heating of the reactor by increasing the rated current of the reactor, which will lead to an increase in the size and cost of the device, this embodiment provides a power supply circuit, which is applied to the variable frequency electrical appliances with a compressor. Figure 2 is a structural diagram of a power supply circuit according to an embodiment of the present invention, such as Figure 2 As shown, the power supply circuit includes: a discharge module 1, whose input end is connected to a three-phase power supply; a first power supply branch 2, whose positive terminal at the input end is connected to the positive terminal at the output end of the discharge module, whose negative terminal at the input end is connected to the negative terminal at the output end of the discharge module, and whose output end is connected to a compressor 5; a reactor 3, which is arranged between the positive terminal at the input end of the first power supply branch 2 and the positive terminal at the output end of the discharge module 1; a second power supply branch 4, whose positive terminal at the input end is connected to the positive terminal at the output end of the discharge module 1, whose negative terminal at the input end is connected to the negative terminal at the output end of the discharge module 1, and whose output end is connected to the main control load of the variable frequency electrical appliance.
[0042] The power supply circuit of this embodiment is provided with two power supply branches, one of which is only for the compressor, and the reactor 3 is provided in the power supply branch for the compressor, so that the current flowing through the reactor 3 is only the current of the compressor, which reduces the working current of the reactor, thereby reducing the heating of the reactor. When the current of the main control load of the variable frequency electrical appliance is large, the reactor can also meet the temperature requirements. When manufacturing the device, the temperature requirements can be met by selecting a reactor with a smaller rated current, and there is no need to use a reactor with a larger rated current, which can reduce the occupied space of the device and reduce the device cost at the same time.
[0043] In order to achieve the type and voltage of electrical energy required to provide the compressor, such as Figure 2 As shown, the first power supply branch 2 includes: a first rectifier module 21, whose input end is connected to the discharge module 1, and whose output end is connected to the BUCK power module 22, for converting AC power into DC power. The output end of the BUCK power module 22 is connected to the compressor 5, for converting the DC voltage output by the first rectifier module 21 into the voltage value required by the compressor 5.
[0044] Since there may be clutter and harmonics in the voltage output by the first rectifier module 21, in order to filter out these clutter and harmonics, such as Figure 2 As shown, the first power supply branch 2 further includes: a first filter module 23 , which is arranged between the first rectifier module 21 and the BUCK power module 22 .
[0045] In order to achieve the power type and voltage required by the main control load, such as Figure 2As shown, the second power supply branch 4 includes: a second rectifier module 41, whose input end is connected to the discharge module 1, and whose output end is connected to the switching power supply module 42, which is used to convert AC power into DC power, and the output end of the switching power supply module 42 is connected to the main control load, which is used to convert the DC voltage output by the second rectifier module 41 into the voltage value required by the main control load.
[0046] Similarly, since there may be clutter and harmonics in the voltage output by the second rectifier module 22, in order to filter out these clutter and harmonics, Figure 2 As shown, the second power supply branch 4 further includes: a second filtering module 43 , which is arranged between the second rectifier module 41 and the switch power supply module 42 .
[0047] Since the main control chip and the display panel can only input a lower voltage, in order to convert a higher voltage into a lower voltage and avoid damage to the main control chip and the display panel, the second power supply branch 4 also includes: a step-down circuit 44, whose input end is connected to the switching power supply module, and whose output end is respectively connected to the main control chip and the display panel.
[0048] If a large current appears in the power supply circuit, it will cause device damage. To prevent device damage, absorption prevents voltage breakdown, buffers prevent current breakdown, keeps power devices away from dangerous working areas, improves reliability, and reduces (switching) device losses, or achieves a certain degree of soft switching, reduces instantaneous voltage and instantaneous current, reduces ringing, and improves EMI quality, such as Figure 2 As shown, the power supply circuit further includes: an absorption module 6, which is arranged between the discharge module 1 and the three-phase power supply.
[0049] To achieve variable frequency control, such as Figure 2 As shown, the power supply circuit further includes: a frequency conversion module 7 , which is arranged between the first power supply branch 2 and the compressor 5 .
[0050] In order to meet the new national standard requirements for harmonic current, a reactor will be connected in series in the power supply circuit to reduce harmonics. Figure 1 As shown in the figure, the AC power flows into the reactor through the discharge module, the reactor is connected in series in the circuit, and then two power supplies are output through the power supply module: one non-isolated +15V for the frequency conversion module to drive the compressor; the other +12V for the main control load.
[0051] Since the reactor is connected in series with the circuit, the magnitude of the current will directly affect the temperature of the reactor. The larger the current, the higher the temperature of the reactor, which may exceed the temperature rise of the reactor and burn the reactor.
[0052] The solution of the prior art is the solution currently adopted by most controllers, with a simple circuit and easy design. Since the working current of small-volume or low-end variable-frequency electrical appliances is relatively small, the temperature rise of the reactor is not obvious, but for variable-frequency electrical appliances with larger volumes or higher grades, the compressor exhaust volume of large-volume variable-frequency electrical appliances is larger, and the power is also larger. For high-end variable-frequency electrical appliances, more decorative lights, motors, dampers, surface light sources and other high-power main control loads will be added inside. As the main control load increases and the working current increases, it is necessary to increase the rated current of the reactor to avoid the temperature of the reactor being too high when the variable-frequency electrical appliances are working. However, when the rated current of the reactor is increased and the inductance remains unchanged, it is necessary to increase the wire diameter and frame size of the reactor wire, which will inevitably increase the volume and size of the reactor and increase the cost of the controller. However, the size and height of the controller have certain restrictions and cannot meet the design requirements.
[0053] In order to ensure that the temperature rise of the reactor meets the requirements when the frequency conversion electrical appliances work normally, so as to avoid the reactor from burning due to overheating, and at the same time meet the harmonic requirements of the frequency conversion electrical appliances, the circuit is improved as follows in this embodiment: after the AC power passes through the filtering module and the discharge module, it is divided into two paths, one path is directly rectified and filtered, and outputs +12V for the main control load to work; the other path passes through the reactor, then rectified and filtered, and passes through the BUCK power supply (AC to DC) to output +15V for the frequency conversion module to work and drive the compressor.
[0054] Since the harmonics of variable frequency electrical appliances are mainly generated by variable frequency compressors, the harmonics of variable frequency compressors can be reduced by reactors to meet the harmonic requirements of variable frequency electrical appliances. Comparing this embodiment with the prior art, in the prior art, in addition to the current of the frequency conversion module and the compressor, the current flowing through the reactor also includes the current of the main control load. When the current of the main control load is small, the temperature rise of the reactor will not be too high and can meet the requirements. However, when the main control load increases, the power increases, and the current of the main control load increases, the temperature rise of the reactor will be too high. In this embodiment, the current flowing through the reactor is only the current of the frequency conversion module and the compressor. The working power of the compressor is usually about 100W, and the working current is 0.5A~0.8A, while the rated current of ordinary reactors is above 2A. When the main control load is large, the temperature rise of the reactor will not increase, and there is no risk of the reactor temperature being too high and burning the reactor. By improving the power supply circuit, the problem of excessive reactor temperature is well solved. Compared with solving the heating problem of the reactor by increasing the rated current of the reactor, this method has lower cost and is easier to implement.
[0055] Example 2
[0056] This embodiment provides a variable frequency electrical appliance, including the power supply circuit of the above embodiment. In some embodiments of the present invention, the variable frequency electrical appliance includes at least one of the following: a variable frequency electrical appliance and a variable frequency air conditioner.
[0057] The circuit embodiments described above are merely illustrative, wherein the modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, i.e., they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.
[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A power supply circuit, applied to a variable frequency electrical appliance with a compressor, characterized in that: The power supply circuit comprises: A discharge module, an input end of which is connected to a power source; A first power supply branch, wherein the positive terminal of the input end is connected to the positive terminal of the output end of the discharge module, the negative terminal of the input end is connected to the negative terminal of the output end of the discharge module, and the output end is connected to the compressor; A reactor, arranged between the positive terminal of the input end of the first power supply branch and the positive terminal of the output end of the discharge module; The second power supply branch has a positive terminal at its input end connected to a positive terminal at the output end of the discharge module, a negative terminal at its input end connected to a negative terminal at the output end of the discharge module, and an output end connected to a main control load of the variable frequency electrical appliance.
2. The power supply circuit according to claim 1, characterized in that: The first power supply branch comprises: A first rectifier module, whose input end is connected to the discharge module and whose output end is connected to the BUCK power supply module; The BUCK power module has an output end connected to the compressor.
3. The power supply circuit according to claim 2, characterized in that: The first power supply branch further includes: The first filter module is arranged between the first rectifier module and the BUCK power supply module.
4. The power supply circuit according to claim 1, characterized in that: The second power supply branch comprises: A second rectifier module, whose input end is connected to the discharge module and whose output end is connected to the switch power supply module; The switching power supply module has an output end connected to the main control load.
5. The power supply circuit according to claim 4, characterized in that: The second power supply branch further includes: The second filtering module is arranged between the second rectifying module and the switching power supply module.
6. The power supply circuit according to claim 4, characterized in that: The second power supply branch further includes: The step-down circuit has an input end connected to the switch power supply module, and an output end connected to the main control chip and the display panel respectively.
7. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes: The absorption module is arranged between the discharge module and the power supply.
8. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes: The frequency conversion module is arranged between the first power supply branch and the compressor.
9. A variable frequency electrical appliance, characterized in that: A power supply circuit comprising the power supply circuit according to any one of claims 1 to 8.
10. The variable frequency electrical appliance according to claim 9, characterized in that: The variable frequency electrical appliances include at least one of the following: variable frequency electrical appliances and variable frequency air conditioners.