A circuit and method for detecting abnormal power supply frequency of electric equipment

Abstract

The present invention discloses a circuit and method for detecting abnormal power supply frequency of electrical equipment. The circuit includes: an XOR logic module, which is used to input a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal, and perform XOR logic processing to generate a sampling signal; wherein the duty cycle of the square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal; a difference detection module, whose input end is connected to the XOR logic module, which is used to convert the sampling signal into a DC signal and output it to a digital signal processor; the digital signal processor is used to determine whether the power supply frequency is abnormal according to the voltage value carried by the DC signal. Through the present invention, it is possible to avoid false alarms of power supply frequency abnormalities caused by interference spikes, and improve the accuracy of power supply frequency abnormality protection of electrical equipment.

Description

Technical Field

[0001] The present invention relates to the field of electronic power technology, and in particular to a circuit and method for detecting abnormal power supply frequency of electrical equipment. Background Art

[0002] Most induction heating equipment in factories adopts multiple equipment assembly line operation to form a product assembly line for induction heating welding process. Several induction heating equipment equipped with different induction coils are selected according to different welding workpieces and processes. Since the entire product assembly line will stop when one equipment stops working, the operation stability of several induction heating equipment working together must be very high. There are many industrial-grade electrical equipment in the factory, with high power and high load, which leads to many harmonic interferences in the factory power grid, poor power quality, and complex electromagnetic field environment around the induction heating equipment when it is working. At this time, the power supply frequency detection function of the induction heating equipment is affected, and some spikes caused by interference will be detected as frequency counts, which will cause the detected frequency to be higher than the actual frequency. When the power supply frequency does not actually increase but the detected frequency increases, the system will mistakenly perform power supply frequency abnormal protection. When this phenomenon occurs frequently, it will lead to a decrease in the operating stability of the induction heating equipment, especially when one of the several induction heating equipment that need to work together is shut down due to erroneous protection, and the entire production line cannot work. This brings about economic losses such as production stoppage, delay in construction period, and damage to workpieces.

[0003] There is currently no effective solution to the problem in the prior art that interference spikes cause the equipment to falsely report power supply frequency anomalies, which in turn leads to unnecessary shutdown of the entire production line. Summary of the invention

[0004] The embodiments of the present invention provide a circuit and method for detecting abnormal power supply frequency of an electrical device, so as to solve the problem in the prior art that interference spikes cause the device to falsely report abnormal power supply frequency, thereby causing unnecessary shutdown of the entire production line.

[0005] In order to solve the above technical problems, the present invention provides a circuit for detecting abnormal power supply frequency of an electric device, the circuit comprising:

[0006] An XOR logic module, used to input a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal, and perform XOR logic processing to generate a sampling signal; wherein the duty cycle of the square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal;

[0007] A difference detection module, whose input end is connected to the XOR logic module, is used to convert the sampled signal into a DC signal and output it to a digital signal processor;

[0008] The digital signal processor is used to determine whether the power supply frequency is abnormal according to the voltage value carried by the DC signal.

[0009] Furthermore, the XOR logic module includes:

[0010] An XOR gate chip, wherein a first pin thereof is connected to a first voltage source, one end of a second pin thereof inputs the power supply frequency detection signal, and the other end thereof is connected to a first input end of a first XOR gate element inside the XOR gate chip, one end of a third pin thereof inputs the square wave signal, and the other end thereof is connected to a second input end of the first XOR gate element, one end of a fourth pin thereof is connected to an output end of the first XOR gate element, and the other end thereof is connected to the difference detection module for outputting the sampling signal, and a fifth pin thereof is grounded;

[0011] A first capacitor has a first end connected between the first pin of the XOR gate chip and the first voltage source, and a second end connected to the ground.

[0012] Furthermore, the XOR gate chip further includes:

[0013] A sixth pin, one end of which is connected to the ground line for inputting a 0V voltage signal, and the other end of which is connected to the first input end of the second XOR gate element in the XOR gate chip;

[0014] A seventh pin, one end of which is input with the power supply frequency detection signal, and the other end of which is connected with the second input end of the second XOR gate element;

[0015] An eighth pin, one end of which is connected to the output end of the second XOR gate element, and the other end of which is connected to the second pin, and is used to output the power supply frequency detection signal processed by the second XOR gate element to the second pin.

[0016] Furthermore, the XOR gate chip further includes:

[0017] A ninth pin, one end of which is connected to the ground wire for inputting a 0V voltage signal, and the other end of which is connected to the first input end of the third XOR gate element in the XOR gate chip;

[0018] A tenth pin, one end of which is input with the square wave signal, and the other end is connected to the second input end of the third XOR gate element;

[0019] The eleventh pin has one end connected to the output end of the third XOR gate element and the other end connected to the third pin, and is used to output the square wave signal processed by the third XOR gate element to the third pin.

[0020] Furthermore, the difference detection module includes:

[0021] An optocoupler chip, wherein the first pin thereof is connected to the fourth pin of the XOR gate chip via a third resistor, the second pin thereof is grounded, the fourth resistor is connected between the first pin and the second pin of the optocoupler chip, the third pin thereof is grounded, the fourth pin is connected to the digital signal processor via a fifth resistor, and the fifth pin is connected to a second voltage source;

[0022] A second capacitor, a first end of which is connected between the fifth pin of the optical coupling chip and the second voltage source, and a second end of which is grounded;

[0023] A third capacitor has a first end connected between the fifth resistor and the digital signal processor, and a second end connected to the ground.

[0024] Furthermore, the circuit further comprises:

[0025] A voltage conversion module, whose input end respectively inputs the power supply frequency detection signal and the square wave signal, and whose output end is connected to the XOR logic module, is used to convert the voltage values ​​carried by the power supply frequency detection signal and the square wave signal and output them to the XOR gate chip.

[0026] Furthermore, the voltage conversion module includes:

[0027] A voltage conversion chip, wherein the first pin thereof is connected to a third voltage source, the second pin thereof inputs a power supply frequency detection signal, the third pin thereof inputs a square wave signal having the same frequency and phase as the power supply frequency detection signal, the fourth pin thereof is connected to the first end of the first resistor, the fifth pin thereof is connected to the first end of the second resistor, the second end of the first resistor and the second end of the second resistor are both grounded, the sixth pin thereof outputs the converted power supply frequency detection signal, and the seventh pin thereof outputs the converted square wave signal.

[0028] Furthermore, the digital signal processor is specifically used for:

[0029] Determining whether the voltage value carried by the DC signal is zero;

[0030] When the voltage value carried by the DC signal is zero, determining that the power supply frequency is normal;

[0031] When the voltage value carried by the DC signal is not zero, it is determined that the power supply frequency is abnormal.

[0032] The present invention also provides an electrical equipment, comprising the above-mentioned electrical equipment power supply frequency abnormality detection circuit.

[0033] Furthermore, the electrical equipment is an induction heating equipment.

[0034] The present invention also provides a method for detecting abnormal power supply frequency of an electric device, which is applied to the above-mentioned abnormal power supply frequency detection circuit, and the method comprises:

[0035] Acquire a DC signal generated based on a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal; wherein the DC signal is generated after the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal are logically processed and then converted, and the duty cycle of the square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal;

[0036] Whether the power supply frequency is abnormal is determined according to the voltage value carried by the DC signal.

[0037] Further, judging whether the power supply frequency is abnormal according to the voltage value carried by the DC signal includes:

[0038] Determining whether the voltage value carried by the DC signal is zero;

[0039] If yes, it is determined that the power supply frequency is normal;

[0040] If not, it is determined that the power supply frequency is abnormal.

[0041] Furthermore, before obtaining a DC signal generated based on the power supply frequency detection signal and a square wave signal having the same frequency and phase as the power supply frequency detection signal, the method further includes:

[0042] Determining whether the frequency of the power supply frequency detection signal is abnormal;

[0043] If not, directly determine that the power supply frequency is normal;

[0044] If yes, trigger acquisition of a DC signal generated based on the power supply frequency detection signal and a square wave signal having the same frequency and phase as the power supply frequency detection signal.

[0045] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned method for detecting abnormal power supply frequency of electrical equipment is implemented.

[0046] By applying the technical solution of the present invention, the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal are subjected to XOR logic processing through the XOR logic module to generate a sampling signal, and then the sampling signal is converted into a DC signal through the difference detection module and output to the digital signal processor, and finally the digital signal processor determines whether the power supply frequency is abnormal according to the voltage value carried by the DC signal. It can avoid the false alarm of power supply frequency abnormality caused by interference spikes and improve the accuracy of power supply frequency abnormality protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a structural block diagram of a circuit for detecting abnormal power supply frequency of an electric device according to an embodiment of the present invention;

[0048] Figure 2 is a structural diagram of an XOR logic module according to an embodiment of the present invention;

[0049] Figure 3 is a structural diagram of a difference detection module according to an embodiment of the present invention;

[0050] Figure 4 is a structural diagram of a voltage conversion module according to an embodiment of the present invention;

[0051] Figure 5 This is a flow chart of a method for detecting abnormal power supply frequency of an electric device according to an embodiment of the present invention;

[0052] Figure 6 The present invention is a flowchart of another method for detecting abnormal power supply frequency of an electrical device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] 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.

[0054] 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.

[0055] 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.

[0056] It should be understood that although the terms first, second, third, etc. may be used to describe XOR gate elements in embodiments of the present invention, these XOR gate elements should not be limited to these terms. These terms are only used to distinguish different XOR gate elements. For example, without departing from the scope of embodiments of the present invention, the first XOR gate element may also be referred to as the second XOR gate element, and similarly, the second XOR gate element may also be referred to as the first XOR gate element.

[0057] 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.

[0058] 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.

[0059] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0060] Example 1

[0061] This embodiment provides a circuit for detecting abnormal power supply frequency of an electric device. Figure 1 FIG. 1 is a structural block diagram of a circuit for detecting abnormal power supply frequency of an electric device according to an embodiment of the present invention. Figure 1 As shown, the above-mentioned power supply frequency abnormality detection circuit of the electrical equipment includes:

[0062] The XOR logic module 10 is used to input a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal, and perform XOR logic processing to generate a sampling signal; wherein the duty cycle of the above square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal. For example, if the duty cycle of the power supply voltage is 50% when the frequency is normal, then the duty cycle of the above square wave signal is also 50%.

[0063] The difference detection module 20 has an input end connected to the XOR logic module, which is used to convert the sampled signal into a DC signal and output it to the digital signal processor.

[0064] The digital signal processor 30 is used to determine whether the power supply frequency is abnormal according to the voltage value carried by the DC signal.

[0065] The power supply frequency abnormality detection circuit of the electric equipment of this embodiment performs XOR logic processing on the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal through the XOR logic module 10 to generate a sampling signal, and then converts the sampling signal into a DC signal through the difference detection module 20, outputs it to the digital signal processor, and finally determines whether the power supply frequency is abnormal according to the voltage value carried by the DC signal through the digital signal processor 30. It can avoid the false alarm of power supply frequency abnormality caused by interference spikes and improve the accuracy of power supply frequency abnormality protection.

[0066] Example 2

[0067] This embodiment provides another circuit for detecting abnormal power supply frequency of an electric device. Figure 2 is a structural diagram of an XOR logic module according to an embodiment of the present invention, such as Figure 2 As shown, the XOR logic module includes:

[0068] The XOR gate chip U1 has a first pin Vcc connected to a first voltage source, one end of its second pin 1A inputs a power supply frequency detection signal ZERO, and the other end is connected to a first input end of a first XOR gate element (not shown in the figure) inside the XOR gate chip U1, one end of its third pin 1B inputs a square wave signal PWM, and the other end is connected to a second input end of the first XOR gate element, one end of its fourth pin 1Y is connected to an output end of the first XOR gate element, and the other end is connected to a difference detection module 20 for outputting a sampling signal ADF, and its fifth pin GND is grounded; a first capacitor C1, a first end of which is connected between the first pin Vcc of the XOR gate chip U1 and the first voltage source, and a second end is grounded.

[0069] When the power supply frequency is abnormal and the abnormality is caused by an interference spike, the power supply frequency detection signal ZERO is always synchronized with the square wave signal PWM, and the sampling signal ADF is a signal carrying a voltage value of zero. When the power supply frequency is abnormal and the abnormality is caused by the frequency fluctuation of the power supply itself, the duty cycle of the power supply frequency detection signal ZERO will change, and the power supply frequency detection signal ZERO is no longer synchronized with the square wave signal PWM, and the sampling signal ADF is a square wave signal with a certain duty cycle.

[0070] Since the power supply frequency detection signal may not be a standard square wave waveform, in order to obtain a standard square wave waveform, the XOR gate chip U1 also includes: a sixth pin 2B, one end of which is connected to the ground wire for inputting a 0V voltage signal, and the other end is connected to the first input end of the second XOR gate element (not shown in the figure) in the XOR gate chip U1; a seventh pin 2A, one end of which inputs the power supply frequency detection signal ZERO, and the other end is connected to the second input end of the second XOR gate element; an eighth pin 2Y, one end of which is connected to the output end of the second XOR gate element, and the other end is connected to the second pin 1A, for outputting the power supply frequency detection signal processed by the second XOR gate element to the second pin 1A.

[0071] Similarly, the above-mentioned square wave signal may not be a standard square wave waveform. In order to obtain a standard square wave waveform, the above-mentioned XOR gate chip U1U1 also includes: a ninth pin 3A, one end of which is connected to the ground wire for inputting a 0V voltage signal, and the other end is connected to the first input end of the third XOR gate element in the XOR gate chip U1; a tenth pin 3B, one end of which inputs a square wave signal PWM, and the other end is connected to the second input end of the third XOR gate element (not shown in the figure); an eleventh pin 3Y, one end of which is connected to the output end of the third XOR gate element, and the other end is connected to the third pin 1B, for outputting the square wave signal processed by the third XOR gate element to the third pin 1B.

[0072] Figure 3 The structure diagram of a difference detection module according to an embodiment of the present invention, in order to realize the difference detection, the difference detection module includes: an optocoupler chip U2, whose first pin 1 is connected to the fourth pin 1Y of the XOR gate chip U1 through the third resistor R3 to input the sampling signal ADF, and whose second pin 2 is grounded, and the fourth resistor R4 is connected between the first pin 1 and the second pin 2 of the optocoupler chip U2, and its third pin 3 is grounded, and the fourth pin 4 is connected to the digital signal processor 30 through the fifth resistor R5 to output the DC signal AD_F, and the fifth pin 5 is connected to the second voltage source; the second capacitor C2, whose first end is connected to the fifth pin 5 of the optocoupler chip U2 and the second voltage source, and whose second end is grounded; the third capacitor C3, whose first end is connected between the fifth resistor R5 and the digital signal processor 30, and whose second end is grounded. The fifth resistor R5 and the third capacitor C3 constitute a filter circuit for converting the detection signal entering the optocoupler chip U2 to generate a DC signal AD_F.

[0073] Since the working voltage of the XOR gate chip U1 is different from the voltage values ​​carried by the square wave signal PWM and the power supply frequency detection signal ZERO, for example, the working voltage of the XOR gate chip U1 is 5V, and the voltage values ​​carried by the square wave signal PWM and the power supply frequency detection signal ZERO are 3.3V, in order to make the input voltage of the XOR gate chip U1 5V, the above circuit also includes: a voltage conversion module 40, whose input ends respectively input the power supply frequency detection signal ZERO and the square wave signal PWM, and whose output end is connected to the XOR logic module, which is used to convert the voltage values ​​carried by the power supply frequency detection signal ZERO and the square wave signal PWM, and output them to the XOR gate chip U1.

[0074] Figure 4 is a structural diagram of a voltage conversion module according to an embodiment of the present invention, such as Figure 4 As shown, the voltage conversion module 40 includes: a voltage conversion chip U3, whose first pin OE is connected to a third voltage source, whose second pin A0 inputs a power supply frequency detection signal, whose third pin A1 inputs a square wave signal PWM with the same frequency and phase as the power supply frequency detection signal ZERO, whose fourth pin A2 is connected to the first end of the first resistor R1, whose fifth pin A3 is connected to the first end of the second resistor R2, the second end of the first resistor R1 and the second end of the second resistor R2 are both grounded, whose sixth pin Y0 outputs the converted power supply frequency detection signal ZERO, and whose seventh pin Y1 outputs the converted square wave signal PWM.

[0075] In order to accurately determine whether the power supply frequency is abnormal, the digital signal processor 30 is specifically used to: determine whether the voltage value carried by the DC signal is zero; when the voltage value carried by the DC signal is zero, determine that the power supply frequency is normal; when the voltage value carried by the DC signal is not zero, determine that the power supply frequency is abnormal.

[0076] In summary, if Figure 1 to Figure 4As shown, this embodiment sets a hardware circuit for judging the authenticity of power supply frequency fluctuation. ZERO is a power supply frequency detection signal, and PWM is a square wave signal with the same frequency, the same phase, and the same duty cycle as the duty cycle of the power supply voltage when the frequency is normal, which is sent by the digital signal processor DSP according to the power supply frequency detection signal currently detected. The two signals are input into the voltage conversion chip (such as IC_74HCT241 chip) of the voltage conversion module for voltage conversion. Before the conversion, the voltage values ​​carried by the above two signals are both 3.3V. After the voltage conversion, the voltage values ​​carried by the output power supply frequency detection signal ZERO and the square wave signal PWM are 5V. The purpose of this process is to convert the voltage value of the signal to 5V and improve the signal driving ability. The power supply frequency detection signal ZERO and the square wave signal PWM are respectively input into the first XOR gate element and the second XOR gate element of the XOR gate chip (such as IC_HC86 chip), and are firstly XORed with the 0V voltage signal output by the ground line. This process can make the rising edge and the falling edge of the signal steeper, so that it becomes a standard square wave waveform. Then the processed power supply frequency detection signal ZERO and square wave signal PWM signal are input into the third XOR gate element of the XOR gate chip for XOR logic processing. Since the two signals have the same frequency and phase, if the duty cycle is also the same, a 0V voltage will be output. If the duty cycles of the two signals are different, a square wave signal with a certain duty cycle will be output. This square wave signal is input into the front stage of the optical coupling chip U3 (for example, IC_ACPL_P480 chip) of the difference detection circuit, and after optical coupling isolation, it is input into the filter circuit of the difference detection circuit for DC conversion, and the square wave signal with a certain duty cycle is converted into a DC signal AD_F. The DC voltage signal AD_F is input into the analog-to-digital conversion chip to be converted into a digital quantity, and then input into the digital signal processor 30. When the frequency abnormality is detected, the control program adds a level of fluctuation authenticity judgment. If the voltage value carried by the DC signal AD_F detected by the digital signal processor 30 is 0, it means that the system has a real power supply frequency abnormality at this time. At this time, the frequency abnormality is reported, and the induction heating equipment is controlled to shut down. If the voltage value of AD_F detected is not 0, it means that the system does not have a real power supply frequency abnormality at this time, and the induction heating equipment should remain powered on. By adding a circuit to realize the authenticity judgment function of the power supply frequency fluctuation and an additional control judgment method, it is determined whether the power supply frequency of the heating power supply equipment has actually fluctuated, or whether the power supply frequency detection function of the induction heating equipment has mistakenly detected a high frequency value due to interference, causing the system to perform power supply frequency abnormal protection. This solves the problem of frequent false protection and shutdown of the induction heating equipment due to interference, and improves the stability of the operation of the induction heating equipment.

[0077] Example 3

[0078] This embodiment provides an electric device, including the above-mentioned electric device power supply frequency abnormality detection circuit. In a specific implementation, the electric device is an induction heating device.

[0079] Example 4

[0080] This embodiment provides a method for detecting abnormal power supply frequency of an electric device, which is applied to the abnormal power supply frequency detection circuit in the above embodiment. Figure 5 : is a flow chart of a method for detecting abnormal power supply frequency according to an embodiment of the present invention. Figure 5 As shown, the method includes:

[0081] S101, obtaining a DC signal generated based on a power supply frequency detection signal and a square wave signal having the same frequency and phase as the power supply frequency detection signal.

[0082] Among them, the above-mentioned DC signal is generated after the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal are logically processed and then converted. The duty cycle of the square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal.

[0083] S102: determining whether the power supply frequency is abnormal according to the voltage value carried by the DC signal.

[0084] The power supply frequency abnormality detection method of this embodiment obtains a DC signal generated based on a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal, and then determines whether the power supply frequency is abnormal based on the voltage value carried by the DC signal. This can avoid false alarms of power supply frequency abnormality caused by interference spikes and improve the accuracy of power supply frequency abnormality protection.

[0085] Example 5

[0086] This embodiment provides another method for detecting abnormal power supply frequency of electrical equipment. In this embodiment, whether the power supply frequency is abnormal is determined based on the voltage value carried by the DC signal, specifically including: determining whether the voltage value carried by the DC signal is zero; if so, determining that the power supply frequency is normal; if not, determining that the power supply frequency is abnormal.

[0087] In the above scheme, when the frequency of the power supply frequency detection signal is abnormal, it is necessary to further determine whether the frequency abnormality of the power supply frequency detection signal is caused by an interference spike or an abnormal power supply frequency. If the frequency of the power supply frequency detection signal is normal, the power supply frequency must be normal, and there is no need to perform subsequent steps. Therefore, before obtaining a DC signal generated based on the power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal, the above method also includes: determining whether the frequency of the power supply frequency detection signal is abnormal; if not, directly determining that the power supply frequency is normal; if yes, triggering the acquisition of a DC signal generated based on the power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal.

[0088] The present invention is described in detail below with reference to a specific example. Figure 6 FIG. 1 is a flow chart of another method for detecting abnormal power supply frequency of an electrical device according to an embodiment of the present invention, wherein the electrical device is an induction heating device, such as Figure 6 As shown, the method includes:

[0089] S1, determine whether the frequency of the power supply frequency detection signal is abnormal; if not, execute step S2, if yes, execute step S3.

[0090] S2, confirm that the power supply frequency is normal and control the normal operation of the induction heating equipment.

[0091] S3, determine whether the voltage value of the DC signal generated based on the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal is 0; if yes, execute step S2, if not, execute step S4.

[0092] S4, determining that the power supply frequency is abnormal, and controlling the induction heating equipment to stop running.

[0093] If the frequency abnormality of the power supply frequency detection signal is caused by the abnormal power supply frequency, then the duty cycle of the power supply frequency detection signal will also change, and the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal will no longer be synchronized. After passing through the XOR gate chip, the generated sampling signal ADF is a square wave signal with a certain duty cycle. Therefore, the voltage value of the DC signal generated based on the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal is not 0; if the frequency abnormality of the power supply frequency detection signal is caused by interference spikes, then the duty cycle of the power supply frequency detection signal will not change, and the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal are completely synchronized. After passing through the XOR gate chip, the generated sampling signal ADF is a 0V voltage signal. Therefore, the voltage value of the DC signal generated based on the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal is 0.

[0094] Example 6

[0095] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned method for detecting abnormal power supply frequency of an electrical device is implemented.

[0096] 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.

[0097] 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.

[0098] 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 circuit for detecting abnormal power supply frequency of an electric device, characterized in that: The circuit comprises: An XOR logic module, used to input a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal, and perform XOR logic processing to generate a sampling signal; wherein the duty cycle of the square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal; A difference detection module, whose input end is connected to the XOR logic module, is used to convert the sampled signal into a DC signal and output it to a digital signal processor; The digital signal processor is used to determine whether the power supply frequency is abnormal according to the voltage value carried by the DC signal; The XOR logic module includes: an XOR gate chip, a first pin of which is connected to a first voltage source, one end of a third pin of which inputs the square wave signal, and the other end is connected to a second input end of a first XOR gate element inside the XOR gate chip, one end of a fourth pin of which is connected to an output end of the first XOR gate element, and the other end is connected to the difference detection module for outputting the sampling signal, and a fifth pin of which is grounded; the XOR gate chip also includes: a sixth pin, one end of which is connected to a ground wire for inputting a 0V voltage signal, and the other end is connected to a first input end of a second XOR gate element in the XOR gate chip; a seventh pin, one end of which is input with the power supply frequency detection signal, and the other end is connected to a second input end of the second XOR gate element; an eighth pin, one end of which is connected to the output end of the second XOR gate element, and the other end is connected to one end of a second pin of the XOR gate chip, for outputting the power supply frequency detection signal processed by the second XOR gate element to the second pin, and the other end of the second pin is connected to the first input end of the first XOR gate element.

2. The circuit according to claim 1, characterized in that The XOR logic module also includes: A first capacitor has a first end connected between the first pin of the XOR gate chip and the first voltage source, and a second end connected to the ground.

3. The circuit according to claim 1, characterized in that The XOR gate chip also includes: A ninth pin, one end of which is connected to the ground wire for inputting a 0V voltage signal, and the other end of which is connected to the first input end of the third XOR gate element in the XOR gate chip; A tenth pin, one end of which is input with the square wave signal, and the other end is connected to the second input end of the third XOR gate element; The eleventh pin has one end connected to the output end of the third XOR gate element and the other end connected to the third pin, and is used to output the square wave signal processed by the third XOR gate element to the third pin.

4. The circuit according to claim 1, characterized in that The difference detection module comprises: An optocoupler chip, wherein the first pin thereof is connected to the fourth pin of the XOR gate chip via a third resistor, the second pin thereof is grounded, the fourth resistor is connected between the first pin and the second pin of the optocoupler chip, the third pin thereof is grounded, the fourth pin is connected to the digital signal processor via a fifth resistor, and the fifth pin is connected to a second voltage source; A second capacitor, a first end of which is connected between the fifth pin of the optical coupling chip and the second voltage source, and a second end of which is grounded; A third capacitor has a first end connected between the fifth resistor and the digital signal processor, and a second end connected to the ground.

5. The circuit according to claim 1, characterized in that The circuit further comprises: A voltage conversion module, whose input end respectively inputs the power supply frequency detection signal and the square wave signal, and whose output end is connected to the XOR logic module, is used to convert the voltage values ​​carried by the power supply frequency detection signal and the square wave signal and output them to the XOR gate chip.

6. The circuit according to claim 5, characterized in that The voltage conversion module comprises: A voltage conversion chip, wherein the first pin thereof is connected to a third voltage source, the second pin thereof inputs a power supply frequency detection signal, the third pin thereof inputs a square wave signal having the same frequency and phase as the power supply frequency detection signal, the fourth pin thereof is connected to the first end of the first resistor, the fifth pin thereof is connected to the first end of the second resistor, the second end of the first resistor and the second end of the second resistor are both grounded, the sixth pin thereof outputs the converted power supply frequency detection signal, and the seventh pin thereof outputs the converted square wave signal.

7. The circuit according to claim 1, characterized in that The digital signal processor is specifically used for: Determining whether the voltage value carried by the DC signal is zero; When the voltage value carried by the DC signal is zero, determining that the power supply frequency is normal; When the voltage value carried by the DC signal is not zero, it is determined that the power supply frequency is abnormal.

8. An electrical device, characterized in that: The invention comprises the power supply frequency abnormality detection circuit of the electric equipment according to any one of claims 1 to 7.

9. The electrical equipment according to claim 8, characterized in that: The electrical equipment is an induction heating equipment.

10. A method for detecting abnormal power supply frequency of an electric device, applied to the circuit according to any one of claims 1 to 7, characterized in that: The method comprises: Acquire a DC signal generated based on a power supply frequency detection signal and a square wave signal with the same frequency and phase as the power supply frequency detection signal; wherein the DC signal is generated by performing XOR logic processing on the power supply frequency detection signal and the square wave signal with the same frequency and phase as the power supply frequency detection signal, and then converting the square wave signal, and the duty cycle of the square wave signal is equal to the duty cycle of the power supply voltage when the frequency is normal; Whether the power supply frequency is abnormal is determined according to the voltage value carried by the DC signal.

11. The method according to claim 10, characterized in that Judging whether the power supply frequency is abnormal according to the voltage value carried by the DC signal includes: Determining whether the voltage value carried by the DC signal is zero; If yes, it is determined that the power supply frequency is normal; If not, it is determined that the power supply frequency is abnormal.

12. The method according to claim 11, characterized in that Before acquiring a DC signal generated based on a power supply frequency detection signal and a square wave signal having the same frequency and phase as the power supply frequency detection signal, the method further includes: Determining whether the frequency of the power supply frequency detection signal is abnormal; If not, directly determine that the power supply frequency is normal; If yes, trigger acquisition of a DC signal generated based on the power supply frequency detection signal and a square wave signal having the same frequency and phase as the power supply frequency detection signal.

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 10 to 12 is implemented.

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