Harmonic control method and circuit, power supply circuit and electrical equipment

Abstract

The invention discloses a harmonic control method and circuit, a power supply circuit and electrical equipment. The harmonic control method is applied to a power supply circuit, the power supply circuit comprises a reactor input board, a rectifier, a PFC circuit and a variable frequency drive circuit, and the harmonic control method comprises the following steps: detecting a harmonic distortion value of current in the power supply circuit; and when the harmonic distortion value exceeds a preset threshold value, adjusting the duty ratio of a power switch tube in the PFC circuit, the switching frequency of the power switch tube and the reactance value of the reactor input board according to the harmonic distortion value so as to adjust the harmonic distortion value. According to the invention, the electrical equipment which does not meet the harmonic wave requirement can be rectified on the premise that the machine is not disassembled, so that the time and the labor cost are greatly saved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a harmonic control method, circuit, power supply circuit and electrical equipment. Background Art

[0002] A large number of switching power supplies and power switches are generally used in electrical equipment required for life. These switching power supplies and power switches improve the efficiency of electric energy utilization, but at the same time they also lead to the generation of harmonics. Harmonics are very harmful. On the one hand, the existence of harmonics increases the burden on the neutral line of the power grid. When the harmonics generated by a large number of nonlinear loads flow through the neutral line, the neutral line will be overloaded. In severe cases, the neutral line will be burned and cause a fire; on the other hand, harmonics increase the burden on the high-voltage capacitors of the power grid. The transformers of power grid users are generally connected to high-voltage capacitors to filter out high-frequency interference from the power grid, and high-frequency harmonics flowing through the capacitors will cause the temperature to rise or even explode. In addition, harmonic currents can also cause distortion of the voltage waveform of the power grid, thereby affecting the stable operation of other electrical equipment in the power grid. Therefore, electrical equipment needs to use special harmonic test instruments to test the size of harmonics during the development stage, and the equipment is rectified according to the test results so that the current harmonics meet the national standards. However, the harmonic test instrument can only test the current harmonics and cannot complete the rectification of the current harmonics. It is necessary to dismantle the machine for rectification and then retest it, which takes a lot of time and labor costs.

[0003] In the prior art, if electrical equipment fails harmonic testing during the development phase, it needs to be dismantled for rectification, which results in a lot of time and labor costs. No effective solution has been proposed so far. Summary of the invention

[0004] The embodiments of the present invention provide a harmonic control method, circuit, power supply circuit and electrical equipment to solve the problem in the prior art that if the harmonic test of electrical equipment fails during the development stage, the equipment needs to be dismantled and rectified, which results in a lot of time and labor costs.

[0005] In order to solve the above technical problems, the present invention provides a harmonic control method, which is applied to a power supply circuit, wherein the power supply circuit includes: a reactor input board, a rectifier, a PFC circuit and a variable frequency drive circuit. The harmonic control method includes:

[0006] detecting a harmonic distortion value of a current in the power circuit;

[0007] When the harmonic distortion value exceeds a preset threshold, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted according to the harmonic distortion value to adjust the harmonic distortion value.

[0008] Further, adjusting the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board according to the harmonic distortion value includes:

[0009] Controlling the duty cycle of the power switch tube to gradually increase according to a first preset step size, and / or controlling the switching frequency of the duty cycle of the power switch tube to gradually decrease according to a second preset step size;

[0010] When the harmonic distortion value in the current of the power circuit does not exceed a preset threshold, the adjustment of the duty cycle and the switching frequency is stopped.

[0011] Further, adjusting the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board according to the harmonic distortion value also includes:

[0012] After the duty cycle of the duty cycle of the power switch tube is controlled to be gradually increased according to the first preset step length, and / or the switching frequency of the duty cycle of the power switch tube is controlled to be gradually decreased according to the second preset step length, it is judged whether the following conditions are met: the duty cycle of the power switch tube reaches an upper limit value of the duty cycle and / or the switching frequency of the duty cycle of the power switch tube reaches a lower limit value of the switching frequency, and the harmonic distortion value still exceeds the preset threshold value;

[0013] If yes, the control stops adjusting the work duty cycle and / or the switching frequency, and adjusts the reactance value of the reactor input board until the harmonic distortion value does not exceed the preset threshold.

[0014] Further, adjusting the reactance value of the reactor input board until the harmonic distortion value does not exceed the preset threshold value includes:

[0015] Switching the reactors put into operation in the reactor input board in sequence, so that the reactance value of the reactor input board increases from the minimum value in sequence;

[0016] After each switching of the reactor into operation, determining whether the harmonic distortion value still exceeds the preset threshold;

[0017] If yes, continue switching the reactor to be put into operation until the harmonic distortion value does not exceed the preset threshold value;

[0018] If not, stop switching the reactor into operation.

[0019] Further, after the harmonic distortion value does not exceed the preset threshold, the method further includes:

[0020] The duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value are stored and displayed.

[0021] The present invention also provides a harmonic control circuit for implementing the above harmonic control method, the harmonic control circuit comprising:

[0022] A sampling resistor is provided between the reactor input board and the positive terminal of the rectifier;

[0023] A detection module, whose first input terminal and second input terminal are respectively connected to two ends of the sampling resistor, and is used to detect the harmonic distortion value of the current in the power supply circuit;

[0024] A control chip, whose input and output ends are connected to the detection module, and whose output end is connected to the control end of the power switch tube of the PFC circuit and the inductor input board, is used to adjust the duty cycle of the power switch tube, the switching frequency of the power switch tube, and the reactance value of the inductor input board according to the harmonic distortion value.

[0025] Furthermore, the reactor input board comprises:

[0026] at least two reactors with different reactance values;

[0027] The relay is a single-pole multi-throw relay, whose fixed contact is connected to the live wire of the mains, and whose moving contact is selectively connected to the reactor.

[0028] Furthermore, the detection module includes:

[0029] An operational amplifier, wherein the non-inverting input terminal thereof is connected between the sampling resistor and the reactor input board through a first resistor, the inverting input terminal thereof is connected between the sampling resistor and the positive terminal of the rectifier through a second resistor, the output terminal thereof is connected to its own non-inverting input terminal through a third resistor, and the output terminal thereof is also connected to the control chip.

[0030] Furthermore, the circuit further comprises:

[0031] A storage module, used for storing the duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value after the harmonic distortion value does not exceed the preset threshold value;

[0032] The display module is used to display the duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value after the harmonic distortion value does not exceed the preset threshold value.

[0033] The present invention also provides a power supply circuit, comprising the harmonic control circuit of the above embodiment.

[0034] The present invention also provides an electrical device, comprising the power supply circuit.

[0035] Furthermore, the electrical equipment includes at least one of the following:

[0036] Inverter air conditioner, inverter air conditioner, inverter compressor, inverter washing machine.

[0037] The present invention also provides a computer-readable storage medium on which a computer program is stored, and the program implements the above harmonic control method when executed by a processor.

[0038] The present invention also provides an electronic device, comprising:

[0039] one or more processors;

[0040] A storage device is used to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned harmonic control method.

[0041] By applying the technical solution of the present invention, the harmonic distortion value of the current in the power supply circuit is first detected by a detection module. When the harmonic distortion value exceeds a preset threshold, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted according to the harmonic distortion value to adjust the harmonic distortion value. This enables rectification of electrical equipment that does not meet the harmonic requirements without disassembling the equipment, thereby greatly saving time and labor costs. In addition, harmonic adjustment is performed through three parameters, namely, the duty cycle of the power switch tube, the switching frequency of the power switch tube, and the reactance value of the reactor input board. Harmonics are reduced by combining software and hardware, which can broaden the adjustment range of harmonics and ensure that the harmonic distortion value is within the required range. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of a harmonic control method according to an embodiment of the present invention;

[0043] Figure 2 is a structural diagram of a harmonic control circuit according to an embodiment of the present invention;

[0044] Figure 3 is a structural diagram of a reactor input board according to an embodiment of the present invention;

[0045] Figure 4 is a structural diagram of a detection module according to an embodiment of the present invention;

[0046] Figure 5 The figure is a schematic diagram of the hardware structure of an electronic device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] 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.

[0050] It should be understood that although the terms first, second, third, etc. may be used to describe resistors in embodiments of the present invention, these resistors should not be limited to these terms. These terms are only used to distinguish different resistors. For example, without departing from the scope of embodiments of the present invention, a first resistor may also be referred to as a second resistor, and similarly, a second resistor may also be referred to as a first resistor.

[0051] 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.

[0052] 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.

[0053] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0054] Example 1

[0055] Harmonics are extremely harmful. On the one hand, the existence of harmonics increases the burden on the neutral line of the power grid. When a large number of harmonics generated by nonlinear loads flow through the neutral line, the neutral line will be overloaded. In severe cases, the neutral line will be burned and cause a fire. On the other hand, harmonics increase the burden on the high-voltage capacitors of the power grid. The transformers of power grid users are generally connected to high-voltage capacitors to filter out high-frequency interference from the power grid, and high-frequency harmonics flowing through the capacitors will cause the temperature to rise or even explode. In addition, harmonic currents can also cause distortion of the grid voltage waveform, thereby affecting the stable operation of other electrical equipment in the power grid. Therefore, electrical equipment needs to be tested for harmonic size through special harmonic test instruments during the development stage, and the equipment needs to be rectified according to the test results so that the current harmonics meet the national standards. However, harmonic test instruments can only test current harmonics and cannot complete the rectification of current harmonics. After dismantling the machine for rectification, retesting is required, which takes a lot of time and labor costs.

[0056] In view of the problem in the prior art that in the development stage of electrical equipment, if the harmonic test fails, the equipment needs to be dismantled and rectified, which results in a lot of time and labor costs, this embodiment provides a harmonic control method, which is applied to a power supply circuit. The power supply circuit includes: a reactor input board, a rectifier, a PFC circuit, and a variable frequency drive circuit. The PFC circuit includes a power switch tube Q and an inductor L0. Figure 1 is a flow chart of a harmonic control method according to an embodiment of the present invention. Figure 1 As shown, the harmonic control method includes:

[0057] S101, detecting the harmonic distortion value of the current in the power supply circuit.

[0058] Specifically, the detection module is first controlled by a software program to sample the current within 0.2s in real time at a sampling interval of 1ms, and a waveform curve is fitted based on the sampled real-time current value. Due to the non-sinusoidal components contained in the current, these non-sinusoidal components can be decomposed into fundamental waves and harmonics. The calculation of harmonic current usually involves Fourier transform, which decomposes the non-sinusoidal wave into a superposition of a series of sine waves. The form of the Fourier series is:

[0059] i(t)=I1sin(2πf1t+φ1)+I2sin(2πf2t+φ2)+I3sin(2πf3t+φ3)+...Insin(2πfnt+φn);

[0060] Where i(t) is the function of the non-sinusoidal current changing with time t, I1 is the primary current, f1 is the first frequency, f2 is the second frequency, f3 is the third frequency, fn is the nth frequency, φ1 is the first phase angle, φ2 is the second phase angle, φ3 is the third phase angle, φn is the nth phase angle, I2 is the secondary current, I3 is the tertiary current, and so on, In is the nth current;

[0061] Extract each harmonic current and sum them to get the total harmonic distortion value THD:

[0062] THD=I12+I22+I32+I42+…In2; wherein, I12 is the first harmonic current, I22 is the second harmonic current, I32 is the third harmonic current, and In is the nth harmonic current.

[0063] S102, when the harmonic distortion value exceeds a preset threshold, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted according to the harmonic distortion value to adjust the harmonic distortion value.

[0064] The lower the duty cycle of the power switch tube, the more harmonics are generated; the higher the switching frequency of the power switch tube, the more differential harmonics are generated. The reactance value of the reactor input board will also affect the harmonic content. Therefore, the harmonic distortion value can be adjusted by adjusting the duty cycle of the power switch tube and the switching frequency of the power switch tube through software adjustment, and by changing the reactance value of the reactor input board through hardware adjustment.

[0065] The harmonic control method of this embodiment first detects the harmonic distortion value of the current in the power circuit through the detection module. When the harmonic distortion value exceeds the preset threshold, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted according to the harmonic distortion value to adjust the harmonic distortion value. This can realize rectification of electrical equipment that does not meet the harmonic requirements without disassembling the equipment, which greatly saves time and labor costs. In addition, harmonic adjustment is performed through the three parameters of the duty cycle of the power switch tube, the switching frequency of the power switch tube, and the reactance value of the reactor input board. Harmonics are reduced by combining software and hardware, which can broaden the adjustment range of harmonics and ensure that the harmonic distortion value is within the required range.

[0066] As mentioned above, the lower the duty cycle of the power switch tube, the more harmonics are generated; the higher the switching frequency of the power switch tube, the more harmonics are generated. Therefore, in order to reduce the harmonic distortion value, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted according to the harmonic distortion value, including: controlling the duty cycle of the power switch tube to gradually increase according to a first preset step size, and / or controlling the switching frequency of the duty cycle of the power switch tube to gradually decrease according to a second preset step size; until the harmonic distortion value in the current of the power supply circuit does not exceed the preset threshold value, stop adjusting the duty cycle and switching frequency.

[0067] Since the duty cycle and frequency of the power switch tube are limited, the duty cycle generally does not exceed 50%. However, when setting the upper and lower values ​​of the duty cycle, a certain margin should be left for safety reasons. For example, when the maximum duty cycle is 50%, the upper limit of the duty cycle can be set to 45%. If the duty cycle of the power switch tube reaches the upper limit, or the frequency of the power switch tube reaches the lower limit, but the harmonic distortion value still does not meet the requirements, it is necessary to continue to adjust the harmonics by adjusting the reactance value of the reactor input board. Therefore, the duty cycle of the power switch tube in the PFC circuit and the switching frequency of the power switch tube are adjusted according to the harmonic distortion value. , the reactance value of the inductor input board, and also include: after controlling the duty cycle of the duty cycle of the power switch tube to gradually increase according to the first preset step size, and / or controlling the switching frequency of the duty cycle of the power switch tube to gradually decrease according to the second preset step size, judging whether the following conditions are met: the duty cycle of the power switch tube reaches the upper limit value of the duty cycle and / or the switching frequency of the duty cycle of the power switch tube reaches the lower limit value of the switching frequency, and the harmonic distortion value still exceeds the preset threshold value; if so, controlling to stop adjusting the duty cycle and / or switching frequency of the power switch tube, and adjusting the reactance value of the inductor input board until the harmonic distortion value does not exceed the preset threshold value.

[0068] In order to facilitate users to understand the current parameters of the power supply circuit and to facilitate harmonic adjustment after subsequent harmonic changes, after the harmonic distortion value does not exceed the preset threshold, the above method also includes: storing and displaying the duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value of the inductor input board.

[0069] The above reactor input board includes: at least two reactors L1-Ln with different reactance values; a relay K, which is a single-pole multi-throw relay, whose fixed contact a is connected to the live wire L of the mains, and whose moving contact b is selectively connected to the reactor. By changing the position of the moving contact of the relay to switch different reactors, different reactance values ​​are obtained. Since the corresponding relationship between the reactance value and the harmonic distortion value is uncertain, it is necessary to start from the smallest reactance value, switch one by one, and finally determine the appropriate reactance value. Therefore, the reactance value of the reactor input board is adjusted until the harmonic distortion value does not exceed the preset threshold value, including: sequentially switching the reactors put into operation in the reactor input board, so that the reactance value of the reactor input board increases from the minimum value in sequence; after each switching of the reactor put into operation, judging whether the harmonic distortion value still exceeds the preset threshold value; if yes, continue to switch the reactor put into operation until the harmonic distortion value does not exceed the preset threshold value; if not, stop switching the reactor put into operation.

[0070] In summary, the harmonic control method of this embodiment is implemented in two ways. One is to adjust the duty cycle and frequency of the PWM controller signal on the PFC circuit through software, and the other is to change the reactance value of the reactor input board by switching the reactor put into the reactor input board on the neutral line or live line of the AC power through hardware.

[0071] After comparing the calculated total harmonic distortion value with the preset threshold, it is decided whether to perform harmonic rectification. If it exceeds the preset threshold, harmonic rectification is required. First, through software control, the duty cycle of the PWM control signal is increased to reduce the frequency of the PWM control signal, and then the total harmonic distortion value is calculated and compared until it is less than the above preset threshold. However, the duty cycle in the PFC circuit generally does not exceed 50%. When the duty cycle is increased to 45%, it is necessary to switch the hardware method to suppress harmonics. The control chip sends a control signal to control the relay on the reactor input board to switch different types of reactors. After each switching of the reactor, test whether the total harmonic distortion value meets the standard. After the rectification is completed, the duty cycle and frequency parameters of the PWM control signal of the power switch are displayed on the display module, as well as whether a reactor is added and the reactor value or model of the added reactor.

[0072] By applying the harmonic control method of this embodiment, electrical equipment can monitor and test the harmonic current generated by itself without the need for external testing instruments, and adjust the control parameters of its own PFC circuit according to the test or switch to reactors of different specifications to complete the rectification output rectification plan, greatly reducing the economic cost and time cost of development.

[0073] Example 2

[0074] This embodiment provides a harmonic control circuit for implementing the harmonic control method of the above embodiment. Figure 2 is a structural diagram of a harmonic control circuit according to an embodiment of the present invention, Figure 2 As shown, the harmonic control circuit includes:

[0075] The sampling resistor R0 is arranged between the reactor input board 1 and the positive terminal of the rectifier 2;

[0076] A detection module 10, whose first input terminal and second input terminal are respectively connected to two ends of a sampling resistor R0, and is used to detect the harmonic distortion value of the current in the power supply circuit;

[0077] The control chip 20 has its input and output ends connected to the detection module 10, and its output end is connected to the control end of the power switch tube Q of the PFC circuit and the inductor input board 1, and is used to adjust the duty cycle of the power switch tube Q, the switching frequency of the power switch tube Q, and the reactance value of the inductor input board 1 according to the harmonic distortion value.

[0078] Figure 3 : is a structural diagram of a reactor input board according to an embodiment of the present invention, Figure 3 As shown, the reactor input board 1 includes: at least two reactors L1-Ln with different reactance values; a relay K, which is a single-pole multi-throw relay, whose fixed contact a is connected to the live wire of the mains, and whose moving contact b is selectively connected to the reactor Ln.

[0079] Figure 4 is a structural diagram of a detection module according to an embodiment of the present invention, such as Figure 4 As shown, the detection module includes: an operational amplifier U, whose in-phase input terminal + is connected between the sampling resistor R0 and the inductor input board 1 through the first resistor R1, and whose inverting input terminal - is connected between the sampling resistor R0 and the positive terminal of the rectifier through the second resistor R2, and whose output terminal is connected to its own in-phase input terminal + through the third resistor R3, and whose output terminal is also connected to the above-mentioned control chip 20, and whose output terminal is also provided with a fourth resistor R4 and a first capacitor C1, forming an RC filtering structure to filter the signal output by the operational amplifier U.

[0080] In order to help users understand the current parameters of the power supply circuit and facilitate harmonic adjustment after subsequent harmonic changes, the above-mentioned harmonic control circuit also includes: a storage module (not shown in the figure), which is used to store the duty cycle of the power switch tube, the switching frequency of the switch tube and the reactance value after the harmonic distortion value does not exceed the preset threshold value; a display module 30, which is used to display the duty cycle of the power switch tube, the switching frequency of the switch tube and the reactance value after the harmonic distortion value does not exceed the preset threshold value.

[0081] Example 3

[0082] The present embodiment provides a power supply circuit, including the harmonic control circuit of the above embodiment, which is used to realize rectification of electrical equipment that does not meet the harmonic requirements without disassembling the equipment, thereby greatly saving time and labor costs. In addition, harmonic adjustment is performed through three parameters: the duty cycle of the power switch tube, the switching frequency of the power switch tube, and the reactance value of the reactor input board. Harmonics are reduced by combining software and hardware, which can broaden the harmonic adjustment range and ensure that the harmonic distortion value is within the required range.

[0083] Example 4

[0084] This embodiment provides an electrical device, including the power supply circuit of the above embodiment.

[0085] In some embodiments of the present invention, the electrical equipment includes at least one of the following: a variable frequency air conditioner, a variable frequency air conditioner, a variable frequency compressor, and a variable frequency washing machine.

[0086] Example 5

[0087] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the harmonic control method of the above embodiment is implemented.

[0088] Example 6

[0089] This embodiment provides an electronic device, including:

[0090] one or more processors;

[0091] A storage device is used to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the harmonic control method of the above embodiment.

[0092] Figure 5 FIG. 1 is a schematic diagram of the hardware structure of an electronic device provided according to an embodiment of the present invention. Figure 5 As shown, the electronic device includes:

[0093] One or more processors 510 and memory 520, Figure 5 A processor 510 is taken as an example.

[0094] The electronic device may further include: an input device 530 and an output device 540 .

[0095] The processor 510, the memory 520, the input device 530 and the output device 540 may be connected via a bus or other means. Figure 5 The example of connecting through bus is taken in the following.

[0096] The memory 520 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the harmonic control method in the embodiment of the present invention. The processor 510 executes various functional applications and data processing of the server by running the non-volatile software programs, instructions and modules stored in the memory 520, that is, the local magnification method based on the editable document in the above method embodiment is implemented.

[0097] The memory 520 may include a program storage area and a data storage area, wherein the program storage area may store an application required for operating the device and at least one function; the data storage area may store data created according to the use of the harmonic control method, etc. In addition, the memory 520 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0098] The input device 530 can receive input digital or character information and generate key signal input related to user settings and function control of the electronic device. The output device 540 can include a display device such as a display screen.

[0099] The one or more modules are stored in the memory 520, and when executed by the one or more processors 510, the harmonic control method in any of the above method embodiments is executed.

[0100] The electronic device product can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not described in detail in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0101] The electronic device of the embodiment of the present invention exists in various forms, including but not limited to:

[0102] (1) Mobile communication devices: These devices are characterized by their mobile communication functions and their main purpose is to provide voice and data communications. These terminals include: smart phones (such as iPhone), multimedia phones, functional phones, and low-end phones.

[0103] (2) Ultra-mobile personal computer devices: These devices fall into the category of personal computers, have computing and processing capabilities, and generally also have mobile Internet access features. These terminals include: PDA, MID and UMPC devices, such as iPad.

[0104] (3) Portable entertainment devices: These devices can display and play multimedia content. They include audio and video players (such as iPods), handheld game consoles, e-books, smart toys, and portable car navigation devices.

[0105] (4) Server: A device that provides computing services. The server consists of a processor, hard disk, memory, device bus, etc. The server is similar to a general computer architecture, but because it needs to provide highly reliable services, it has higher requirements in terms of processing power, stability, reliability, security, scalability, and manageability.

[0106] (5) Other electronic devices with data interaction functions, such as televisions, large-screen cars, etc.

[0107] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, 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 solution of this embodiment.

[0108] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0109] 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 harmonic control method, applied to a power supply circuit, the power supply circuit comprising: Reactor input board, rectifier, PFC circuit and variable frequency drive circuit, characterized in that the method comprises: detecting a harmonic distortion value of a current in the power circuit; When the harmonic distortion value exceeds a preset threshold, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted according to the harmonic distortion value to adjust the harmonic distortion value.

2. The method according to claim 1, characterized in that According to the harmonic distortion value, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted, including: Controlling the duty cycle of the power switch tube to gradually increase according to a first preset step size, and / or controlling the switching frequency of the duty cycle of the power switch tube to gradually decrease according to a second preset step size; When the harmonic distortion value in the current of the power circuit does not exceed a preset threshold, the adjustment of the duty cycle and the switching frequency is stopped.

3. The method according to claim 2, characterized in that According to the harmonic distortion value, the duty cycle of the power switch tube in the PFC circuit, the switching frequency of the power switch tube, and the reactance value of the reactor input board are adjusted, and the method further includes: After the duty cycle of the duty cycle of the power switch tube is controlled to be gradually increased according to the first preset step length, and / or the switching frequency of the duty cycle of the power switch tube is controlled to be gradually decreased according to the second preset step length, it is judged whether the following conditions are met: the duty cycle of the power switch tube reaches an upper limit value of the duty cycle and / or the switching frequency of the duty cycle of the power switch tube reaches a lower limit value of the switching frequency, and the harmonic distortion value still exceeds the preset threshold value; If yes, the control stops adjusting the work duty cycle and / or the switching frequency, and adjusts the reactance value of the reactor input board until the harmonic distortion value does not exceed the preset threshold.

4. The method according to claim 3, characterized in that Adjusting the reactance value of the reactor input board until the harmonic distortion value does not exceed the preset threshold value includes: Switching the reactors put into operation in the reactor input board in sequence, so that the reactance value of the reactor input board increases from the minimum value in sequence; After each switching of the reactor into operation, determining whether the harmonic distortion value still exceeds the preset threshold; If yes, continue switching the reactor to be put into operation until the harmonic distortion value does not exceed the preset threshold value; If not, stop switching the reactor into operation.

5. The method according to claim 3 or 4, characterized in that: After the harmonic distortion value does not exceed the preset threshold, the method further includes: The duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value are stored and displayed.

6. A harmonic control circuit, used to implement the harmonic control method according to any one of claims 1 to 5, characterized in that: The circuit comprises: A sampling resistor is provided between the reactor input board and the positive terminal of the rectifier; A detection module, whose first input terminal and second input terminal are respectively connected to two ends of the sampling resistor, and is used to detect the harmonic distortion value of the current in the power supply circuit; A control chip, whose input and output ends are connected to the detection module, and whose output end is connected to the control end of the power switch tube of the PFC circuit and the inductor input board, is used to adjust the duty cycle of the power switch tube, the switching frequency of the power switch tube, and the reactance value of the inductor input board according to the harmonic distortion value.

7. The circuit according to claim 6, characterized in that The reactor input board comprises: at least two reactors with different reactance values; The relay is a single-pole multi-throw relay, whose fixed contact is connected to the live wire of the mains, and whose moving contact is selectively connected to the reactor.

8. The circuit according to claim 6, characterized in that The detection module comprises: An operational amplifier, wherein the non-inverting input terminal thereof is connected between the sampling resistor and the reactor input board through a first resistor, the inverting input terminal thereof is connected between the sampling resistor and the positive terminal of the rectifier through a second resistor, the output terminal thereof is connected to its own non-inverting input terminal through a third resistor, and the output terminal thereof is also connected to the control chip.

9. The circuit according to claim 6, characterized in that The circuit further comprises: A storage module, used for storing the duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value after the harmonic distortion value does not exceed the preset threshold value; The display module is used to display the duty cycle of the power switch tube, the switching frequency of the power switch tube and the reactance value after the harmonic distortion value does not exceed the preset threshold value.

10. A power supply circuit, characterized in that: The harmonic control circuit comprises the harmonic control circuit as claimed in any one of claims 6 to 9.

11. An electrical device, characterized in that: The invention comprises the power supply circuit as claimed in claim 10.

12. The electrical device according to claim 11, characterized in that: The electrical equipment includes at least one of the following: Inverter air conditioner, inverter air conditioner, inverter compressor, inverter washing machine.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

14. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the one or more processors to implement the method according to any one of claims 1 to 5.

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