Harmonic suppression circuit, method and equipment

Abstract

The invention relates to the technical field of refrigeration devices, in particular to a harmonic suppression circuit, method and equipment. The harmonic suppression circuit comprises a power supply input end, a harmonic absorption module and a load, the power supply input end is used for providing voltage stabilization for a load in the harmonic suppression circuit; the harmonic wave absorption module comprises a first filter connected to a main loop and a second filter connected to a branch, and is used for eliminating harmonic waves in the harmonic wave treatment circuit through the first filter or through the first filter and the second filter according to the power of a load end; and the load is used for converting the electric energy provided by the power supply input into mechanical energy for equipment operation. According to the embodiment of the invention, the load power is identified, and when the load reaches half-load or above operating power, the second filter subjected to parameter modulation is connected to the harmonic suppression circuit, so that the total harmonic current distortion rate can be limited within a relatively small level.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration devices, and in particular to a harmonic control circuit, method and device. Background Art

[0002] With the development of technology, refrigeration equipment has gradually upgraded from fixed-frequency products to variable-frequency products. Although this can achieve energy-saving effects, the accompanying increase in harmonics and reactive power will cause serious damage to the circuit of the refrigeration equipment. The increase in harmonics in the circuit may cause the circuit breaker to malfunction, interfere with communication, and thus cause a series of problems such as abnormal operation of the system, and even cause fire. Therefore, more and more users require that when the refrigeration equipment is running at a power of more than half load, the total harmonic current distortion rate needs to be limited to a smaller level. For example, the total harmonic current distortion rate needs to be limited to less than 5%, and the power factor needs to be greater than 95% to protect the refrigeration equipment from damage and protect the life and property of the user. Summary of the invention

[0003] The embodiments of the present invention provide a harmonic control circuit, method and device to solve the problem in the prior art that the harmonic current distortion rate cannot be limited to a smaller level.

[0004] In a first aspect, an embodiment of the present invention provides a harmonic control circuit, comprising: a power input terminal, a harmonic absorption module and a load; The power input terminal is used to provide voltage stabilization for the load in the harmonic control circuit; The harmonic absorption module includes a first filter connected to the main circuit and a second filter connected to the branch circuit, and is used to eliminate harmonics in the harmonic control circuit through the first filter or through the first filter and the second filter according to the power at the load end; The load is used to convert the electrical energy provided by the power input end into mechanical energy for the operation of the equipment.

[0005] Optionally, the harmonic absorption module includes: a reactor and a capacitor; The first filter comprises a first reactance and a second reactance connected in series to the main circuit, and is used to individually eliminate harmonics in the harmonic control circuit when the operating power of the load is not higher than a first threshold value; The second filter comprises a high-order harmonic absorption reactance and a first capacitor connected in series to the branch, and is used to eliminate harmonics in the harmonic control circuit together with the first filter when the operating power of the load is higher than a first threshold; The first reactance, the second reactance, the inductance of the high-order harmonic absorption reactance, and the capacitance of the first capacitor are determined by the grid frequency and grid voltage at the power input end, and the power of the load.

[0006] Optionally, the harmonic absorption module further includes: a first air switch; The second filter is connected to the main circuit of the harmonic control circuit through the first air switch. When the load operating power is not higher than the first threshold, the first air switch is disconnected to cut the second filter out of the main circuit. When the load operating power is higher than the first threshold, the first air switch is closed to connect the second filter to the main circuit.

[0007] Optionally, the harmonic absorption module further includes: a resistance-capacitance absorption module; The RC absorption module is connected to the input end of the first filter in the main loop and is used to absorb high-order harmonics in the harmonic control circuit.

[0008] Optionally, the harmonic absorption module further includes: a third filter; The third filter is connected to the input end of the first filter in the main loop, and is used to filter out the interference signal generated by the load end in the harmonic control circuit.

[0009] Optionally, it also includes: power supply lightning arrester; The power supply lightning arrester is connected to the power supply input terminal through a second air switch to prevent damage to the internal components of the harmonic control circuit caused by external impact; Wherein, the second air switch is used to cut the power supply lightning arrester out of the harmonic control circuit after the power supply lightning arrester is damaged.

[0010] In a second aspect, an embodiment of the present invention provides a harmonic control method, including: determining the power of the load when the load operates at a regulated voltage provided by the power input terminal; When the power of the load is not higher than the first threshold, the harmonics in the harmonic control circuit are eliminated separately by the first filter in the harmonic absorption module; When the power of the load is higher than the first threshold, the harmonics in the harmonic control circuit are eliminated together by the first filter and the second filter in the harmonic absorption module.

[0011] Optionally, the method further includes: When it is determined that the power of the load is not higher than a first threshold, disconnecting the second filter from the harmonic control circuit by disconnecting the first air switch; When it is determined that the power of the load is higher than a first threshold, the second filter is connected to the harmonic control circuit by closing the first air switch.

[0012] In a third aspect, an embodiment of the present invention provides an electronic device, including: at least one processor and the harmonic suppression circuit according to any one of the first aspects; and at least one memory in communication with the processor, wherein: The memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute the method as described in any one of the second aspects.

[0013] In a fourth aspect, an embodiment of the present invention provides a storage medium, wherein the storage medium includes a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute any method described in the second aspect.

[0014] The embodiment of the present invention identifies the load power. When the load reaches the operating power of half load or above, the second filter after parameter modulation, that is, the high-order harmonic absorption reactance, the first capacitor and the resistance-capacitance absorption module are connected to the harmonic control circuit. It can not only control the harmonic current distortion rate below 5% and improve the power factor to above 0.95, but also suppress the impact current of the whole machine, protect the subsequent load, and avoid large impact current from causing damage to the load. At the same time, by adding a third filter to the main circuit, the high-frequency interference signal generated by the load itself can be filtered out to prevent the high-frequency interference signal from affecting the normal operation of the unit communication system and other equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 Shown is a schematic diagram of a harmonic control circuit provided in an embodiment of the present application; Figure 2 Shown is a circuit diagram of a specific harmonic control circuit provided in an embodiment of the present application; Figure 3 Shown is a flow chart of a harmonic control method provided in an embodiment of the present application; Figure 4 Shown is a schematic structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0018] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0019] With the continuous development of refrigeration device technology, users not only have certain requirements for the refrigeration effect of refrigeration devices, but also pay more and more attention to the energy-saving effect of refrigeration products. Refrigeration devices have gradually upgraded from early fixed-frequency products to variable-frequency products. Although energy-saving effects have been achieved, the accompanying increase in harmonics and reactive power will cause serious damage to the circuits of refrigeration devices.

[0020] The increase of harmonics in the circuit may cause the circuit breaker to malfunction, interfere with communication, and thus cause a series of problems such as abnormal operation of the system. In addition, harmonics will accelerate the aging of other components in the circuit and reduce their lifespan. Severe harmonics may even cause fires, endangering the safety of users' lives and property. In order to avoid serious economic losses caused by harmonics, more and more customers require that the total harmonic current distortion rate of refrigeration equipment should be less than 5% and the power factor should be greater than 95% when the refrigeration equipment is running at more than half load.

[0021] In the related art, the harmonic control method of the refrigeration device includes two methods: controlling by setting an active filter in the circuit of the refrigeration device or controlling by setting a passive filter.

[0022] In the existing treatment method using active filters, active filters are installed in the circuit of the refrigeration device to perform real-time harmonic compensation to eliminate the harmonics in the circuit. However, when the device is at maximum load, the compensation efficiency is only 85%, and the harmonic current distortion rate can only be controlled above 15%, which cannot meet the user's requirements.

[0023] At the same time, the interference generated by the active filter when controlling harmonics is very strong and difficult to handle, which may affect the normal operation of the refrigeration device's own communication system or other equipment. In addition, the front end of the active filter is not short-circuit protected. When the active filter is short-circuited, the refrigeration device will stop running, causing significant economic losses.

[0024] In the existing passive filter treatment method, capacitors, inductors and resistors are set in the circuit for filtering to eliminate harmonics in the circuit. However, this solution is large in size and high in cost, and can only filter fixed frequencies or fixed frequency segments. Moreover, the harmonic current distortion rate can only be controlled at around 35%, and the adaptability to the power grid is poor, and it cannot meet the requirements of users.

[0025] In this regard, an embodiment of the present invention provides a harmonic control circuit for solving the problem in the related art that the harmonic current distortion rate cannot be limited to a smaller level.

[0026] like Figure 1 , which is a schematic diagram of a harmonic control circuit provided by an embodiment of the present invention.

[0027] See also Figure 1 The harmonic control circuit includes a power input terminal 110, a harmonic absorption module 120 and a load 130.

[0028] The power input terminal 110 is used to provide voltage stabilization for the load connected to the back end of the harmonic control circuit. The power input terminal can usually be a power grid. The AC power input to the power input terminal is rectified by the inverter rectifier bridge and then output to the load through inversion to supply power to the load.

[0029] The load 120 is used to convert the electric energy provided by the power input end into mechanical energy for the operation of the refrigeration device. The load is usually a frequency converter, a power module, etc. The load end will generate harmonics during continuous operation, which will harm the circuit.

[0030] The harmonic absorption module 130 is connected between the power input terminal and the load, and is used to eliminate the harmonics generated by the load, such as the inverter, in the harmonic control circuit.

[0031] The harmonic absorption module specifically includes a first filter connected to the main circuit and a second filter connected to the branch. It is determined whether the second filter in the branch needs to be connected to the harmonic control circuit for harmonic elimination according to the different operating power at the load end. That is, according to the different operating power at the load end, it is selected to eliminate the harmonics in the harmonic control circuit alone through the first filter, or to eliminate the harmonics in the harmonic control circuit together through the first filter and the second filter.

[0032] Among them, when the power at the load end does not reach the preset first threshold, the harmonic content generated by the load is small, the harmonic current distortion rate is low, and the harmonic elimination can be performed by the first filter connected to the main circuit alone. When the power at the load end reaches the preset first threshold, the harmonic content generated by the load is large, and the harmonic current distortion rate is high. It is necessary to connect the second filter to the harmonic control circuit, and the first filter and the second filter are used together to eliminate the harmonics.

[0033] Generally, the first threshold is set to 50%, that is, when the load is not running or is lightly loaded, the harmonics in the harmonic absorption circuit are eliminated by the first filter alone; when the load is running at half load or at a higher power such as full power, the second filter in the branch is connected to the harmonic absorption circuit, and the harmonics are eliminated by the first filter and the second filter together.

[0034] In the first filter, a first reactance and a second reactance are specifically connected in series to the main circuit. Based on the inductance characteristics of the reactance, the reactance deployed in the main circuit can play a filtering role, and harmonics are suppressed. Specifically, the inductance of the first reactance and the second reactance in the first filter is modulated to achieve the purpose of suppressing harmonics and changing the power factor.

[0035] In the second filter, a high-order harmonic absorption reactance and a first capacitor are specifically connected in series to the branch. The high-order harmonic absorption reactance and the first capacitor are used to suppress high-frequency harmonics in the harmonic absorption circuit. Specifically, the inductance of the high-order harmonic absorption reactance and the capacitance value of the first capacitor in the second filter are modulated to achieve the purpose of suppressing harmonics and changing the power factor.

[0036] Specifically, the inductance of the first reactance and the second reactance in the first filter, the inductance of the high-order harmonic absorption reactance in the second filter, and the capacitance of the first capacitance method need to be actually configured according to refrigeration devices with different power supply systems. That is, the specific parameters of the first filter and the second filter are modulated according to the grid frequency and grid voltage at the power input end and the power of the load.

[0037] The second filter also includes a first air switch. The first air switch is connected to the front end of the branch, and the second filter is connected to the main circuit through the first air switch. When it is determined that the load operating power is not higher than the first threshold, the first air switch is disconnected, and the second filter is cut out of the main circuit; when it is determined that the load operating power is higher than the first threshold, the first air switch is closed, and the second filter is connected to the main circuit.

[0038] Among them, when the first air switch is disconnected, the second filter is cut out from the main circuit, and the capacitor in the second filter is not charged, thereby reducing the generation of reactive power in the harmonic control circuit.

[0039] In addition to the first filter and the second filter, the harmonic absorption module also includes a resistor-capacitor absorption module and a third filter.

[0040] The RC absorption module is connected to the input end of the first filter in the main circuit, and is used to absorb higher harmonics in the harmonic control circuit, and together with the first filter and the second filter, reduces the total harmonic current in the circuit to less than 5%.

[0041] The third filter is connected to the front end of the harmonic absorption circuit, that is, before the input end of the first filter in the main circuit, and is used to eliminate the interference signal generated by the load end in the harmonic control circuit to avoid the interference signal from affecting the communication system of the refrigeration device itself and other equipment and devices in the harmonic elimination circuit.

[0042] A power lightning arrester is also provided in the harmonic absorption circuit. The power lightning arrester is connected to the power input terminal through the second air switch to prevent external shocks such as lightning strikes and surges from damaging the internal components of the harmonic control circuit, such as the power input terminal, causing abnormal operation, affecting the operation of the entire machine, and causing significant economic losses. When the power lightning arrester fails, the failed power lightning arrester can be cut out of the harmonic control circuit through the second air switch.

[0043] The embodiment of the present invention identifies the load power. When the load reaches the operating power of half load or above, the second filter after parameter modulation, that is, the high-order harmonic absorption reactance, the first capacitor and the resistance-capacitance absorption module are connected to the harmonic control circuit. It can not only control the harmonic current distortion rate below 5% and improve the power factor to above 0.95, but also suppress the impact current of the whole machine, protect the subsequent load, and avoid large impact current from causing damage to the load. At the same time, by adding a third filter to the main circuit, the high-frequency interference signal generated by the load itself can be filtered out to prevent the high-frequency interference signal from affecting the normal operation of the unit communication system and other equipment.

[0044] like Figure 2 As shown, it is a circuit diagram of a specific harmonic control circuit provided by an embodiment of the present invention.

[0045] See also Figure 2 , the power input end is the power grid. The power grid is three-phase electricity, providing 380V AC input for the harmonic control circuit. After the refrigeration device switch is turned on, the refrigeration device is turned on, and the harmonic control circuit is turned on. The AC power output from the power grid is rectified by the inverter rectifier bridge, and then output to the load through inversion to supply power to the load. The load generates harmonics in the harmonic control circuit when it is running.

[0046] During the operation of the load, the power of the load is determined. When the load is lightly loaded, the first air switch is disconnected, and the first reactance and the second reactance deployed in the main circuit of the harmonic control circuit act as the first filter to eliminate the harmonics in the harmonic elimination circuit separately. When the power of the load reaches half load, the first air switch is closed, and the high-order harmonic absorption reactance and the first capacitor are connected to the harmonic control circuit as the second filter to suppress high-frequency harmonics, and cooperate with the resistance-capacitance absorption module to absorb high-order harmonics, and suppress the total harmonic current to less than 5%. In an embodiment of the present invention, the first reactance, the second reactance and the high-order harmonic absorption reactance are all set as chokes.

[0047] A third filter is set in the main circuit to eliminate the interference signal generated by the load. A power lightning arrester is set in the main circuit through the second air switch to prevent damage to the internal components of the refrigeration device caused by lightning surges and other impacts.

[0048] like Figure 3As shown in FIG. 1 , a flow chart of a harmonic control method provided by an embodiment of the present invention is shown. The method is applied to Figure 1 The harmonic control circuit shown in Figure 3 The specific steps of the method include: S301, when the load operates under the regulated voltage provided by the power input terminal, determine the power of the load.

[0049] S302, when the power of the load is not higher than the first threshold, the harmonics in the harmonic control circuit are eliminated separately by the first filter in the harmonic absorption module.

[0050] Specifically, the first threshold is set to 50% of the load power. When the load is not running or is running at a light load of no more than 50%, the harmonic content generated is small, the first air switch is disconnected, and the second filter is cut out of the harmonic control circuit. The capacitor in the second filter is no longer charged, reducing the generation of reactive power.

[0051] S303, when the power of the load is higher than the first threshold, the harmonics in the harmonic control circuit are eliminated by the first filter and the second filter in the harmonic absorption module.

[0052] Specifically, when the load operating power is higher than 50%, the first air switch is closed and the second filter is connected to the harmonic control circuit to participate in the harmonic control work to meet the requirement that the harmonic distortion current of the refrigeration device is less than 5% at half load or above.

[0053] Among them, the inductance of the first reactance and the second reactance in the first filter, the inductance of the high-order harmonic absorption reactance in the second filter and the capacitance of the first capacitance method need to be actually configured according to the refrigeration devices with different power supply systems. That is, the specific parameters of the first filter and the second filter are determined according to the grid frequency and grid voltage at the power input end and the power of the load.

[0054] The embodiment of the present invention identifies the load power. When the load reaches the operating power of half load or above, the second filter after parameter modulation, that is, the high-order harmonic absorption reactance, the first capacitor and the resistance-capacitance absorption module are connected to the harmonic control circuit. This can not only control the harmonic current distortion rate below 5% and improve the power factor to above 0.95, but also suppress the impact current of the whole machine, protect the subsequent load, and avoid damage to the load caused by large impact current.

[0055] Figure 4 Schematic diagram of the structure of an electronic device of this specification. The electronic device can be specifically provided with Figure 1 The refrigeration device with harmonic control circuit shown in FIG. Figure 4As shown, the electronic device may include at least one processor; and at least one memory communicatively connected to the processing unit, wherein: the memory stores program instructions that can be executed by the processing unit, and the processor calls the program instructions to execute the harmonic control method provided in this embodiment.

[0056] The electronic device can be a device capable of intelligently communicating with a user, such as a cloud server, and the specific form of the electronic device is not limited in the embodiments of this specification. It can be understood that the electronic device here is the machine mentioned in the method embodiment.

[0057] Figure 4 A block diagram of an exemplary electronic device suitable for implementing the embodiments of the present description is shown. Figure 4 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of this specification.

[0058] like Figure 4 As shown, the electronic device is in the form of a general computing device. The components of the electronic device may include but are not limited to: one or more processors 410, a communication interface 420, a memory 430, and a communication bus 440 connecting different system components (including the memory 430, the communication interface 420 and the processor 410).

[0059] The communication bus 440 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnection (PCI) bus.

[0060] Electronic devices typically include a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device, including volatile and non-volatile media, removable and non-removable media.

[0061] The memory 430 may include a computer system readable medium in the form of a volatile memory, such as a random access memory (RAM) and / or a cache memory. The electronic device may further include other removable / non-removable, volatile / non-volatile computer system storage media. The memory 430 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of each embodiment of the present specification.

[0062] A program / utility having a set (at least one) of program modules may be stored in memory 430, such program modules including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules generally perform the functions and / or methods of the embodiments described in this specification.

[0063] The processor 410 executes various functional applications and data processing by running the programs stored in the memory 430, such as implementing the harmonic control method provided in the embodiments shown in this specification.

[0064] An embodiment of the present specification provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions enable the computer to execute the harmonic control method provided by the embodiment shown in the present specification.

[0065] The above-mentioned non-transitory computer-readable storage medium may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (Read Only Memory; hereinafter referred to as: ROM), an erasable programmable read-only memory (Erasable Programmable Read Only Memory; hereinafter referred to as: EPROM) or flash memory, optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device.

[0066] Computer-readable signal media may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0067] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0068] Computer program code for performing the operations of this specification may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect through the Internet).

[0069] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0070] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this specification, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0071] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of this specification includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of this specification belong.

[0072] The word "if" as used herein 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.

[0073] It should be noted that the terminals involved in the embodiments of this specification may include but are not limited to personal computers (Personal Computer; hereinafter referred to as: PC), personal digital assistants (Personal Digital Assistant; hereinafter referred to as: PDA), wireless handheld devices, tablet computers (Tablet Computer), mobile phones, MP3 players, MP4 players, etc.

[0074] In the embodiments provided in this specification, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0075] In addition, each functional unit in each embodiment of this specification may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0076] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute some steps of the method described in each embodiment of this specification.

[0077] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.

Claims

1. A harmonic control circuit, characterized in that: include: Power input terminal, harmonic absorption module and load; The power input terminal is used to provide voltage stabilization for the load in the harmonic control circuit; The harmonic absorption module includes a first filter connected to the main circuit and a second filter connected to the branch circuit, and is used to eliminate harmonics in the harmonic control circuit through the first filter or through the first filter and the second filter according to the power at the load end; The load is used to convert the electrical energy provided by the power input end into mechanical energy for the operation of the equipment.

2. The circuit according to claim 1, characterized in that The harmonic absorption module includes: a reactor and a capacitor; The first filter comprises a first reactance and a second reactance connected in series to the main circuit, and is used to individually eliminate harmonics in the harmonic control circuit when the operating power of the load is not higher than a first threshold value; The second filter comprises a high-order harmonic absorption reactance and a first capacitor connected in series to the branch, and is used to eliminate harmonics in the harmonic control circuit together with the first filter when the operating power of the load is higher than a first threshold; The first reactance, the second reactance, the inductance of the high-order harmonic absorption reactance, and the capacitance of the first capacitor are determined by the grid frequency and grid voltage at the power input end, and the power of the load.

3. The circuit according to claim 1, characterized in that The harmonic absorption module further includes: a first air switch; The second filter is connected to the main circuit of the harmonic control circuit through the first air switch. When the load operating power is not higher than the first threshold, the first air switch is disconnected to cut the second filter out of the main circuit. When the load operating power is higher than the first threshold, the first air switch is closed to connect the second filter to the main circuit.

4. The circuit according to claim 1, characterized in that The harmonic absorption module also includes: a resistance-capacitance absorption module; The RC absorption module is connected to the input end of the first filter in the main loop and is used to absorb high-order harmonics in the harmonic control circuit.

5. The circuit according to claim 1, characterized in that The harmonic absorption module further includes: a third filter; The third filter is connected to the input end of the first filter in the main loop, and is used to filter out the interference signal generated by the load end in the harmonic control circuit.

6. The circuit according to claim 1, characterized in that Also includes: Power supply lightning arrester; The power supply lightning arrester is connected to the power supply input terminal through a second air switch to prevent damage to the internal components of the harmonic control circuit caused by external impact; Wherein, the second air switch is used to cut the power supply lightning arrester out of the harmonic control circuit after the power supply lightning arrester is damaged.

7. A harmonic control method, characterized in that: include: determining the power of the load when the load operates at a regulated voltage provided by the power input terminal; When the power of the load is not higher than the first threshold, the harmonics in the harmonic control circuit are eliminated separately by the first filter in the harmonic absorption module; When the power of the load is higher than the first threshold, the harmonics in the harmonic control circuit are eliminated together by the first filter and the second filter in the harmonic absorption module.

8. The method according to claim 7, characterized in that The method further comprises: When it is determined that the power of the load is not higher than a first threshold, disconnecting the second filter from the harmonic control circuit by disconnecting the first air switch; When it is determined that the power of the load is higher than a first threshold, the second filter is connected to the harmonic control circuit by closing the first air switch.

9. An electronic device, characterized in that: include: At least one processor and the harmonic control circuit according to any one of claims 1 to 6; as well as at least one memory in communication with the processor, wherein: The memory stores program instructions executable by the processor, and the processor can execute the method according to any one of claims 7 to 8 by calling the program instructions.

10. A storage medium, characterized in that: The storage medium includes a stored program, wherein when the program is executed, the device where the storage medium is located is controlled to execute the method according to any one of claims 7 to 8.

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