Voltage detection device, electrical equipment and voltage detection method thereof

Abstract

The invention discloses a voltage detection device, electrical equipment and a voltage detection method thereof, and the device comprises a control unit which is used for determining the interference frequency of a load in the working process of the load; the filtering unit is used for filtering a signal with the same interference frequency as the load from a power supply signal on the direct current side of the power supply of the load to obtain a power supply filtering signal; the sampling unit is used for sampling the power supply filtering signal to obtain a power supply sampling signal; and the detection unit is used for detecting based on the power supply sampling signal to obtain a voltage detection signal of the power supply of the load. According to the scheme, the adjustable filter is adopted to filter load interference, and the accuracy of power supply voltage detection of the load is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power management, and specifically relates to a voltage detection device, electrical equipment and a voltage detection method thereof, and more particularly to a voltage detection circuit for filtering out load interference, electrical equipment and a voltage detection method thereof. Background Art

[0002] Voltage detection is a critical component of power management systems, used to monitor whether the power supply voltage is within a safe range and ensure the proper operation of electrical equipment. Current voltage detection methods typically rely on voltage divider resistor networks and comparators, but these methods lack robustness and are susceptible to noise interference from the load side, at least in terms of detection accuracy.

[0003] The above content is only used to assist in understanding the technical solution of the present invention and does not constitute an admission that the above content is prior art. Summary of the Invention

[0004] The object of the present invention is to provide a voltage detection device, an electrical device and a voltage detection method thereof, so as to solve the problem that the voltage detection method in the related scheme usually relies on a voltage divider resistor network and a comparator, but has weak anti-interference ability and is easily interfered by noise on the load side, at least in terms of insufficient detection accuracy, so as to achieve the effect of improving the accuracy of load power supply voltage detection by filtering out load interference through the use of an adjustable filter.

[0005] The present invention provides a voltage detection device, which is arranged on the DC side of the power supply of a load and is used to detect the power supply voltage of the load; the voltage detection device includes: a sampling unit, a filtering unit, a detection unit and a control unit; wherein the control unit is used to determine the interference frequency of the load during the operation of the load; the filtering unit is used to filter out the signal with the same interference frequency as the load from the power supply signal on the DC side of the power supply of the load, so as to obtain a power supply filtered signal; the sampling unit is used to sample the power supply filtered signal to obtain a power supply sampling signal; and the detection unit is used to perform detection based on the power supply sampling signal to obtain a voltage detection signal of the load power supply.

[0006] In some embodiments, the sampling unit includes: a first voltage-dividing resistor and a second voltage-dividing resistor; wherein the first connection end of the first voltage-dividing resistor serves as the input end of the sampling unit; the output end of the filtering module is connected to the input end of the sampling unit; the second connection end of the first voltage-dividing resistor is connected to a preset power ground through the second voltage-dividing resistor; and the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the detection unit.

[0007] In some embodiments, the detection unit includes: a filter capacitor and a voltage detection module; wherein the filter capacitor is connected in parallel with the second voltage-dividing resistor; the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the voltage detection module; the input end of the voltage detection module serves as the input end of the detection unit; the output end of the voltage detection module serves as the output end of the detection unit and is used to output a voltage detection signal of the power supply of the load.

[0008] In some embodiments, the filtering unit includes: a filtering module and an adjustment module; wherein the filtering unit filters out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load to obtain a power filter signal, including: the adjustment module, which is used to output the filtering frequency control signal of the filtering module to the control end of the filtering module according to the interference frequency of the load under the control of the control unit; the filtering module is used to adjust the filtering frequency of the filtering module based on the filtering frequency control signal of the filtering module to obtain the current filtering frequency of the filtering module, so as to: operate at the current filtering frequency of the filtering module, filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal.

[0009] In some embodiments, the filtering module includes: a first regulating capacitor, a second regulating capacitor, and an regulating inductor; wherein, the DC side of the load's power supply is connected to the first connection end of the regulating inductor; the second connection end of the regulating inductor is connected to the input end of the sampling unit; the first connection end of the regulating inductor is connected to a preset power ground via the first regulating capacitor; the common end of the first connection end of the regulating inductor and the first regulating capacitor serves as the control end of the filtering module; the second connection end of the regulating inductor is connected to a preset power ground via the second regulating capacitor; the common end of the second connection end of the regulating inductor and the second regulating capacitor serves as the output end of the filtering module.

[0010] In some embodiments, the regulating module includes: a regulating power supply and a regulating resistor; wherein the input end of the interference frequency of the load is connected to the first connection end of the regulating power supply; the second connection end of the regulating power supply is connected to the control end of the filtering module, for outputting a first control signal as the filtering frequency control signal of the filtering module; the second connection end of the regulating power supply is connected to the control end of the filtering module after passing through the regulating resistor, for outputting a second control signal as the filtering frequency control signal of the filtering module.

[0011] In some embodiments, it also includes: the control unit is also used to determine the voltage regulation signal or current regulation signal related to the interference frequency of the load according to the interference frequency of the load; the regulation module, under the control of the control unit, outputs the filtering frequency control signal of the filtering module according to the interference frequency of the load, including: outputting the filtering frequency control signal of the filtering module according to the voltage regulation signal or current regulation signal related to the interference frequency of the load determined by the control unit; wherein, according to the voltage regulation signal related to the interference frequency of the load, the first control signal is output as the filtering frequency control signal of the filtering module; according to the current regulation signal related to the interference frequency of the load, the second control signal is output as the filtering frequency control signal of the filtering module.

[0012] In some embodiments, the control unit determines the voltage regulation signal or current regulation signal related to the interference frequency of the load according to the interference frequency of the load, including: determining whether the interference frequency of the load sampled at the current moment is less than the interference frequency of the load sampled at the previous moment according to the sampling period of the interference frequency of the load; if it is determined that the interference frequency of the load sampled at the current moment is less than the interference frequency of the load sampled at the previous moment, then, according to the correspondence between the set interference frequency and the set inductance adjustment amount, determining the set inductance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence as the set inductance value of the filter module corresponding to the interference frequency of the load. inductance adjustment amount; and converting the inductance adjustment amount of the filtering module corresponding to the interference frequency of the load into a current adjustment signal related to the interference frequency of the load; if it is determined that the interference frequency of the load sampled at the current moment is greater than the interference frequency of the load sampled at the previous moment, then according to the correspondence between the set interference frequency and the set capacitance adjustment amount, the set capacitance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence is determined as the capacitance adjustment amount of the filtering module corresponding to the interference frequency of the load; and converting the capacitance adjustment amount of the filtering module corresponding to the interference frequency of the load into a voltage adjustment signal related to the interference frequency of the load.

[0013] Matching the above device, the present invention further provides an electrical device, including: the voltage detection device described above.

[0014] In order to match the above-mentioned electrical equipment, the present invention provides a voltage detection method for electrical equipment on another aspect, comprising: determining the interference frequency of the load during the operation of the load; filtering out the signal with the same interference frequency as the load from the power supply signal on the DC side of the load's power supply through the filtering unit to obtain a power supply filter signal; sampling the power supply filter signal through the sampling unit to obtain a power supply sampling signal; and performing detection based on the power supply sampling signal through the detection unit to obtain a voltage detection signal of the load's power supply.

[0015] Therefore, the solution of the present invention is to detect the power supply voltage of the load, and an adjustable filter, an adjustment module, a voltage dividing resistor module and a voltage detection chip are set on the DC side of the load power supply; when the load is running, the operating frequency of the load is obtained, and the interference frequency f0 of the load is determined according to the operating frequency of the load; the input voltage value or input current value of the adjustment module is determined according to the interference frequency f0 of the load, so that the adjustment module outputs a corresponding control signal to the adjustable filter, so that the filtering frequency f0 of the adjustable filter is c The interference frequency f0 of the load is consistent. After the interference component consistent with the interference frequency f0 of the load is filtered out in the input signal on the DC side of the power supply through an adjustable filter, the detection signal of the power supply is determined by using a voltage divider resistor module and a voltage detection chip. Therefore, the accuracy of the power supply voltage detection of the load is improved by filtering out the load interference through the adjustable filter.

[0016] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic structural diagram of an embodiment of a voltage detection device of the present invention;

[0019] Figure 2 A schematic structural diagram of an embodiment of a voltage detection circuit for filtering out load interference;

[0020] Figure 3 A schematic structural diagram of an embodiment of an adjustment module;

[0021] Figure 4 A flow chart of an embodiment of a voltage detection method for filtering out load interference;

[0022] Figure 5 FIG. 1 is a flow chart of an embodiment of a method for detecting voltage of an electrical device according to the present invention. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Considering that the voltage detection method in the relevant scheme usually relies on a voltage-dividing resistor network and a comparator, but has weak anti-interference ability and is easily affected by noise interference on the load side, there are deficiencies at least in terms of detection accuracy. Specifically, the voltage detection method in the relevant scheme is to divide the input voltage to a lower value through a set of series resistors to obtain a divided power supply; the divided voltage is then input into the comparator for comparison with the reference voltage, and the comparator outputs a binary signal indicating whether the input voltage is higher than the reference voltage. This method is simple and easy to implement, but it has deficiencies. For example, loads such as compressors and fans will generate a large amount of noise such as electromagnetic interference and radio frequency interference. These noises are superimposed on the detection signal, causing the comparator output to be unstable, thereby affecting the accuracy of the detection. Especially when loads such as compressors and fans are working, the voltage detection method in the relevant scheme is extremely susceptible to noise interference, resulting in distorted detection results.

[0025] Furthermore, the resistance of the voltage divider resistor is not completely constant and can change with temperature, which can cause the voltage divider ratio to change, thus affecting detection accuracy. Therefore, the voltage detection methods used in related solutions typically rely on voltage divider resistor networks and comparators, which also have shortcomings in detection accuracy.

[0026] Therefore, the solution of the present invention proposes a voltage detection device, specifically a voltage detection circuit that filters out load interference. The interference frequency of the compressor is collected through software, and the value of the capacitor and / or inductor in the adjustable filter is changed according to the interference frequency of the compressor to control the filtering frequency, filter out load interference, and thus achieve accurate detection of the power supply voltage.

[0027] According to an embodiment of the present invention, a voltage detection device is provided. Figure 1 The following is a schematic diagram of the structure of an embodiment of the device of the present invention. The voltage detection device is disposed on the DC side of a load's power supply and is used to detect the load's power supply voltage; the load may be a compressor or fan. The voltage detection device includes a sampling unit, a filtering unit, a detection unit, and a control unit, wherein the filtering unit may be an adjustable filter and a regulation module.

[0028] The control unit is configured to determine an interference frequency of the load, such as the interference frequency f0, during operation of the load. The interference frequency of the load may be the load's operating frequency. Specifically, the interference frequency of the load is affected by many factors. However, when the load operates at a low frequency or generates low-frequency interference, the interference frequency of the load may be considered the load's operating frequency.

[0029] Specifically, the voltage detection device further includes an acquisition unit. The control unit is configured to determine the interference frequency of the load during operation of the load, and specifically includes: an acquisition unit disposed on the load side, such as a current sensor or frequency sensor of the load, and specifically configured to sample the operating frequency of the load when the load is operating; and the control unit is configured to determine the interference frequency of the load, such as the interference frequency f0 of the load, based on the operating frequency of the load during operation of the load.

[0030] The filtering unit is provided on the DC side of the load power supply, and is used to filter out the signal with the same interference frequency as the load from the power signal on the DC side of the load power supply, to obtain a power filter signal.

[0031] The sampling unit is provided at the output side of the filtering unit, such as a voltage-dividing resistor module, and is used to sample the power filter signal to obtain a power sampling signal.

[0032] The detection unit is provided at the output side of the filtering unit, and is used to perform detection based on the power sampling signal to obtain a voltage detection signal of the power supply of the load.

[0033] The present invention proposes a voltage detection solution that filters out load interference. To detect the load's power supply voltage, a regulation module and an adjustable filter are provided. The regulation module adjusts the filter frequency of the adjustable filter according to the load's interference frequency (such as the interference frequency of a compressor) to filter out load interference and achieve accurate detection of the load's power supply voltage. This improves detection accuracy and stability while also providing excellent anti-interference capabilities. It also addresses the problem of suboptimal detection results caused by interference in the voltage detection circuit due to current surges generated during startup of electrical equipment (such as compressors and fans) and electromagnetic radiation generated during operation.

[0034] In some embodiments, the sampling unit includes: a first voltage-dividing resistor and a second voltage-dividing resistor, where the first voltage-dividing resistor is, for example, resistor R1, and the second voltage-dividing resistor is, for example, resistor R2.

[0035] Among them, the first connection end of the first voltage-dividing resistor serves as the input end of the sampling unit; the output end of the filtering module is connected to the input end of the sampling unit; the second connection end of the first voltage-dividing resistor is connected to a preset power ground (such as power ground PGND) through the second voltage-dividing resistor; and the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the detection unit.

[0036] Figure 2 FIG. 1 is a structural diagram of an embodiment of a voltage detection circuit for filtering out load interference. Figure 2 As shown, the adjustable CLC band-stop filter includes: capacitor C2, capacitor C3 and inductor L1. The input end of the AC power supply AC is connected to the anode of the diode D1; the cathode of the diode D1 is connected to the power ground (PGND) after passing through the load (such as a variable frequency drive compressor). The cathode of the diode D1 is also connected to the power ground PGND after passing through the capacitor C1. The cathode of the diode D1 is also connected to the first connection end of the inductor L1; the first connection end of the inductor L1 is the control end CONTROL of the adjustable CLC band-stop filter, which is used to adjust the filtering frequency. The first connection end of the inductor L1 is connected to the power ground PGND after passing through the capacitor C2, and the second connection end of the inductor L1 is connected to the power ground PGND after passing through the capacitor C3.

[0037] In the solution of the present invention, a first voltage-dividing resistor and a second voltage-dividing resistor are used to perform voltage-dividing sampling on the power supply filter signal output by the filtering unit, so that the voltage-dividing voltage corresponding to the power supply voltage of the load can be accurately sampled, making it easier for the subsequent detection unit to accurately detect complex power supply voltages.

[0038] In some embodiments, the detection unit includes: a filter capacitor, such as capacitor C4, and a voltage detection module, such as voltage detection chip U1.

[0039] In which, the filter capacitor is connected in parallel with the second voltage-dividing resistor; the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the voltage detection module; the input end of the voltage detection module serves as the input end of the detection unit; the output end of the voltage detection module serves as the output end of the detection unit and is used to output the voltage detection signal of the power supply of the load.

[0040] like Figure 2As shown, the voltage detection circuit for filtering out load interference includes: a diode D1, a capacitor C1, an adjustable CLC band-stop filter, resistors R1 and R2, a capacitor C4, and a voltage detection chip U1. The second connection end of the inductor L1 is connected to the power ground PGND through resistors R1 and R2, and the capacitor C4 is connected in parallel with the resistor R2. The common end of the resistors R1 and R2 is connected to the VIN pin of the voltage detection chip U1; the GND1 pin of the voltage detection chip U1 is connected to the power ground PGND; the VDD1 pin of the voltage detection chip U1 is connected to the power supply +P5V; the VDD2 pin of the voltage detection chip U1 is connected to the power supply +5V; the VOUTP pin of the voltage detection chip U1 outputs the voltage sampling signal; and the GND2 pin of the voltage detection chip U1 is connected to ground (GND).

[0041] exist Figure 2 In the example shown, an adjustable filter, such as an adjustable CLC band-stop filter, is added, and the load frequency is acquired through software and transmitted to the regulation module for adjustment. Resistors R1 and R2 serve as voltage divider resistors, and capacitor C4 serves as a filter capacitor. Voltage detection chip U1 converts the input voltage at port VIN into sampling signals for ports VOUTP and VOUTN. In the solution of the present invention, the load can also be other AC loads, such as fans. Of course, DC loads also generate electromagnetic interference, so DC loads are also acceptable. However, the software acquires the operating frequency, not the current frequency.

[0042] In the solution of the present invention, a detection unit composed of a filter capacitor and a voltage detection module is used to filter the divided voltage output by the sampling unit before detection, which can further improve the accuracy of the power supply voltage detection of the load.

[0043] In some embodiments, the filtering unit includes: a filtering module and an adjusting module, and the filtering module is such as an adjustable filter.

[0044] The filtering unit filters out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load to obtain the power filter signal, including:

[0045] The regulation module is used to receive a voltage regulation signal or a current regulation signal related to the interference frequency of the load from the input end of the regulation module, and output the filtering frequency control signal of the filtering module to the control end of the filtering module according to the interference frequency of the load, specifically according to the voltage regulation signal or the current regulation signal related to the interference frequency of the load determined by the control unit.

[0046] The filtering module is configured to receive, from the control end of the filtering module, a filtering frequency control signal of the filtering module output by the regulating module, and adjust the filtering frequency of the filtering module based on the filtering frequency control signal of the filtering module to obtain the current filtering frequency of the filtering module, so as to: operate at the current filtering frequency of the filtering module, filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal. Specifically, the filtering module is configured to operate based on the filtering frequency control signal of the filtering module, so as to: filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal; the filtering frequency control signal of the filtering module is configured to adjust the filtering frequency of the filtering module, so as to obtain the current filtering frequency of the filtering module, so as to enable the filtering module to operate at the current filtering frequency of the filtering module, so as to: filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal.

[0047] In the solution of the present invention, an adjustment module and an adjustable filter are set up. The adjustment module converts the compressor interference frequency collected by the software, changes the value of the capacitor and / or inductor in the adjustable filter to control the filtering frequency, and filters out the load interference, thereby realizing accurate detection of the power supply voltage.

[0048] In some embodiments, the filtering module includes: a first regulating capacitor, a second regulating capacitor, and a regulating inductor, the first regulating capacitor being such as capacitor C2, the second regulating capacitor being such as capacitor C3, and the regulating inductor being such as inductor L1.

[0049] The DC side of the power supply of the load is connected to the first connection end of the regulating inductor; the second connection end of the regulating inductor is connected to the input end of the sampling unit.

[0050] The first connection end of the regulating inductor is connected to a preset power ground (such as a power ground PGND) through the first regulating capacitor; the common end of the first connection end of the regulating inductor and the first regulating capacitor serves as the control end of the filtering module, so as to adjust the filtering frequency of the filtering module from the control end of the filtering module.

[0051] The second connection end of the regulating inductor is connected to a preset power ground (such as power ground PGND) through the second regulating capacitor; the common end of the second connection end of the regulating inductor and the second regulating capacitor serves as the output end of the filtering module.

[0052] In the solution of the present invention, an adjustment module and a filtering module such as an adjustable filter are set. The adjustment module changes the value of the capacitor and / or inductor in the adjustable filter to control the filtering frequency and filter out load interference, thereby achieving accurate detection of the power supply voltage.

[0053] In some embodiments, the regulating module includes: a regulating power supply and a regulating resistor, the regulating power supply being, for example, an adjustable power supply E, and the regulating resistor being, for example, a resistor R3.

[0054] The input terminal of the interference frequency of the load is connected to the first connection terminal of the regulating power supply.

[0055] The second connection end of the regulating power supply is connected to the control end of the filtering module, and is used to output a first control signal as a filtering frequency control signal of the filtering module.

[0056] The second connection end of the regulating power supply is connected to the control end of the filtering module after passing through the regulating resistor, and is used to output a second control signal as a filtering frequency control signal of the filtering module.

[0057] Figure 3 FIG. 1 is a schematic diagram of the structure of an embodiment of the regulating module. Figure 3 As shown, the regulating module includes: an adjustable power supply E and a resistor R3. The first connection end of the adjustable power supply E is connected to the input end of the interference frequency f0 of the load, and the second connection end of the adjustable power supply E is divided into two paths: one path is connected to the first control terminal CONTROL1, and the other path is connected to the second control terminal CONTROL2 after passing through the resistor R3. The voltage detection circuit for filtering out load interference proposed in the solution of the present invention is mainly composed of a load, an adjustable filter, a regulating module and a voltage detection chip U1: the load is a compressor, the adjustable filter is composed of an inductor L1, a capacitor C2, and a capacitor C3, the regulating module is composed of an adjustable power supply E and a resistor R3, and the circuit where the voltage detection chip U1 is located includes resistor R1, resistor R2, capacitor C4, and voltage detection chip U1. The voltage detection chip U1 can use a chip with the model IC AMC1311.

[0058] In the solution of the present invention, by adjusting the adjustable power supply E and resistor R3 in the module, converting the compressor interference frequency collected by the software, changing the value of the capacitor and / or inductor in the adjustable filter to control the filtering frequency, and filtering out the load interference, accurate detection of the power supply voltage is achieved.

[0059] In some embodiments, the voltage detection device according to the solution of the present invention further includes: the control unit is further used to determine a voltage regulation signal or a current regulation signal related to the interference frequency of the load based on the interference frequency of the load.

[0060] The regulating module, under the control of the control unit, outputs a filtering frequency control signal of the filtering module according to the interference frequency of the load, including:

[0061] The regulation module is further configured to output a filter frequency control signal for the filter module based on a voltage regulation signal or a current regulation signal related to the interference frequency of the load determined by the control unit. The first control signal is output as the filter frequency control signal for the filter module based on the voltage regulation signal related to the interference frequency of the load, and the second control signal is output as the filter frequency control signal for the filter module based on the current regulation signal related to the interference frequency of the load. The voltage regulation signal or the current regulation signal related to the interference frequency of the load may be, for example, a voltage value V or a current value I converted from the interference frequency f0 of the load. The first control signal may be, for example, signal CONTROL1, and the second control signal may be, for example, signal CONTROL2. The filter frequency control signal for the filter module may be, for example, signal CONTROL.

[0062] Figure 4 FIG. 1 is a flow chart of an embodiment of a voltage detection method for filtering out load interference. Figure 4 As shown in FIG, the voltage detection method for filtering out load interference includes:

[0063] Step 1: When the load is running, obtain the working frequency of the load as the interference frequency f0 of the load, perform software sampling on the interference frequency f0 of the load, and then execute step 2.

[0064] like Figure 2 As shown, after the compressor is powered on, the power-on voltage input from the AC power supply AC is rectified by the rectifier diode D1 and filtered by the capacitor C1 to drive the compressor to operate. In the solution of the present invention, a branch is added to input the DC signal rectified by the rectifier diode D1 and filtered by the capacitor C1 into the voltage detection circuit. The software acquires the operating frequency (interference frequency) f0 by real-time sampling of the current frequency of the compressor during operation. Among them, the current frequency of the AC motor is usually equal to its operating frequency, that is, the interference frequency. The current frequency acquisition method can adopt the current frequency acquisition method in this field. The hardware part uses sensors and digital-to-analog converters to measure and convert analog signals into digital signals. The software collects and processes the acquired data through programs and algorithms to determine the current frequency.

[0065] Step 2: Convert the load interference frequency f0 into a voltage value V or a current value I according to the capacitance value C or the inductance value L corresponding to the load interference frequency f0, and then execute step 3.

[0066] Step 3: After the voltage value V or current value I passes through the adjustment module, the corresponding voltage value V or current value I is output to the adjustable CLC band-stop filter to adjust the filtering frequency of the adjustable CLC band-stop filter. The adjustable CLC band-stop filter after adjusting the filtering frequency is used to filter out the corresponding frequency noise in the power supply AC input signal, and then transmit it to the voltage detection chip U1 to obtain the real voltage value.

[0067] The voltage detection methods in related solutions include a filter circuit, which is typically composed of a capacitor with a constant capacitance value and a constant noise frequency. In other words, the capacitance value of the filter circuit in related solutions remains constant, and the corresponding filter frequency is fixed, which is not accurate or effective. The solution of the present invention, however, adds an adjustable filter circuit, which uses software to control the output of the adjustment module, effectively filtering out compressor interference and ensuring the reliability of voltage detection.

[0068] In some embodiments, the control unit determines, based on the interference frequency of the load, a voltage regulation signal or a current regulation signal related to the interference frequency of the load, including:

[0069] The control unit is further configured to determine, according to a sampling period of the load interference frequency, whether the load interference frequency sampled at the current moment is less than the load interference frequency sampled at the previous moment.

[0070] The control unit is further specifically configured to, if it is determined that the interference frequency of the load sampled at the current moment is less than the interference frequency of the load sampled at the previous moment, determine, based on the correspondence between the set interference frequency and the set inductance adjustment amount, the set inductance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence as the inductance adjustment amount of the filter module corresponding to the interference frequency of the load; and convert the inductance adjustment amount of the filter module corresponding to the interference frequency of the load into a current adjustment signal related to the interference frequency of the load.

[0071] The control unit is further configured to, if it is determined that the interference frequency of the load sampled at the current moment is greater than the interference frequency of the load sampled at the previous moment, determine, based on the correspondence between the set interference frequency and the set capacitance adjustment amount, the set capacitance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence as the capacitance adjustment amount of the filter module corresponding to the interference frequency of the load; and convert the capacitance adjustment amount of the filter module corresponding to the interference frequency of the load into a voltage adjustment signal related to the interference frequency of the load. The control unit is further configured to, if it is determined that the interference frequency of the load sampled at the current moment is equal to the interference frequency of the load sampled at the previous moment, not convert the adjustment signal and maintain the adjustment signal used at the previous moment, that is, if the voltage adjustment signal was used at the previous moment, the voltage adjustment signal is maintained; if the current adjustment signal was used at the previous moment, the current adjustment signal is maintained.

[0072] like Figure 4 As shown, the voltage detection method for filtering out load interference further includes: in step 2, calculating the corresponding capacitance value C or inductance value L according to the interference frequency f0 of the load:

[0073]

[0074] During the load operation, the interference frequency f0 of the load sampled at the current moment is compared with the interference frequency f0 of the load sampled at the previous moment according to the set sampling period. When the interference frequency f0 of the load increases, the capacitance value C needs to be reduced, while the inductance value L remains unchanged, so When the interference frequency f0 of the load decreases, the inductance value L needs to be increased, while the capacitance value C remains unchanged, so

[0075] In step 2, after calculating the corresponding capacitance value C or inductance value L according to the interference frequency f0 of the load, the capacitance value C or inductance value L corresponding to the interference frequency f0 of the load is converted into an external voltage value V or current value I.

[0076] The applied voltage value V or current value I varies depending on the adjustable capacitor and adjustable inductor, and the specific value is calculated by the software module. For example, for most adjustable variable capacitance capacitors, the relationship between the capacitance value C and the reverse bias voltage V is approximately:

[0077]

[0078] Where C0 is the capacitance at zero bias voltage, V0 is the reference voltage, and α is an exponent, typically between 1 and 2, determined by the material used. Once the desired C value is determined, the desired V value can be obtained.

[0079] like Figure 4As shown, the voltage detection method for filtering out load interference also includes: in step 3, transmitting the voltage value V or current value I determined in step 2 to the first connection terminal of the adjustable power supply E in the adjustment module, and transmitting it to the adjustable power supply E. The first connection terminal of the adjustable power supply E receives a power supply signal related to the interference frequency f0 of the load, that is, the voltage value V or current value I determined in step 2. The adjustment module contains an adjustable power supply E and a resistor R3. According to the needs, the control signal 1 channel or the control signal 2 channel is selected to output the corresponding voltage value or current value to the output of the adjustment module to the CONTROL terminal of the adjustable filter, such as the adjustable CLC band-stop filter, thereby changing the capacitance value of the capacitor and the inductance value of the inductor in the adjustable filter. The signal received by the CONTROL terminal of the adjustable CLC band-stop filter comes from the CONTROL1 terminal of the adjustment module or the CONTROL2 terminal of the adjustment module. By controlling the external voltage value V or current value I, the frequency f of the adjustable CLC band-stop filter is adjusted. c =f0, specifically filtering out the noise generated by load operation, so that the voltage detection chip U1 can detect the real voltage value.

[0080] The selection of the control signal CONTROL1 or CONTROL2 of the regulation module is determined by the interference frequency f0 of the compressor. To ensure the quality factor Q value of the adjustable CLC band-stop filter, the capacitance of the adjustable capacitor should be reduced when the interference frequency f0 of the compressor increases. The capacitance of the adjustable capacitor is controlled by the magnitude of the applied voltage, so CONTROL1 is selected at this time to directly control the capacitance value through the variable power supply. To ensure the quality factor Q value of the adjustable CLC band-stop filter, the inductance value of the adjustable inductor should be increased when the interference frequency f0 of the compressor decreases. The inductance value of the adjustable inductor is controlled by the magnitude of the current flowing through it, so CONTROL2 is selected at this time to control the inductance value through the variable current formed after the variable power supply flows through the resistor.

[0081] In order to filter out the clutter of frequency f0, the frequency f of the CLC band-stop filter needs to be adjusted. c =f0, and Quality Factor of Adjustable CLC Band-Rejection Filter The larger the Q value, the smaller the bandwidth of the adjustable CLC band-stop filter. In order to make the filtering more accurate, while ensuring f c At the same time, Q should be increased as much as possible. So there are two situations:

[0082] If the interference frequency f0 of the compressor detected by the software increases, the frequency f of the CLC band-stop filter can be adjusted. cTo ensure that the quality factor Q value of the adjustable CLC band-stop filter increases, the values of capacitors C2 and C3 should be reduced. The adjustable capacitors C2 and C3 change their own capacitance according to the external voltage value, so by changing the voltage value output by the adjustable power supply in the adjustment module and outputting it as a control signal, the filter frequency can be adjusted.

[0083] The interference frequency f0 of the compressor detected by the software is reduced, and the frequency f of the CLC band-stop filter can be adjusted. c To ensure that the quality factor Q value of the adjustable CLC band-stop filter increases, the value of the inductor L1 should be increased. The adjustable inductor L1 changes its own inductance value according to the current value flowing through it. Therefore, by changing the voltage value on the resistor R3 in the adjustment module, the corresponding control signal is output to adjust the frequency f of the adjustable CLC band-stop filter. c The variable current formed by the variable power supply flowing through resistor R3 is the corresponding control signal CONTROL2. The inductance of the adjustable inductor L1 is controlled by the current flowing through it (i.e., CONTROL2). As the inductance changes, the filter frequency changes accordingly. Therefore, changing the adjustable power supply E can change the filter frequency.

[0084] The technical solution of the present invention is to detect the power supply voltage of the load and set an adjustable filter, an adjustment module, a voltage divider resistor module and a voltage detection chip on the DC side of the load power supply; when the load is running, the operating frequency of the load is obtained, and the interference frequency f0 of the load is determined according to the operating frequency of the load; the input voltage value or input current value of the adjustment module is determined according to the interference frequency f0 of the load, so that the adjustment module outputs a corresponding control signal to the adjustable filter, so that the filtering frequency f0 of the adjustable filter is adjusted. c The interference frequency f0 of the load is consistent. After the interference component consistent with the interference frequency f0 of the load is filtered out in the input signal on the DC side of the power supply through an adjustable filter, the detection signal of the power supply is determined by using a voltage divider resistor module and a voltage detection chip. Therefore, the accuracy of the power supply voltage detection of the load is improved by filtering out the load interference through the adjustable filter.

[0085] According to an embodiment of the present invention, an electrical device corresponding to a voltage detection device is also provided. The electrical device may include the voltage detection device described above. The electrical device includes a fan and / or a compressor; the power supply of the load is the power supply of the fan and / or the power supply of the compressor. The voltage detection device is arranged on the DC side of the power supply of the load and is used to detect the power supply voltage of the load; wherein the load is, for example, a compressor, a fan, etc. The voltage detection device includes: a sampling unit, a filtering unit, a detection unit, and a control unit, wherein the filtering unit is, for example, an adjustable filter and an adjustment module.

[0086] The control unit is configured to determine the interference frequency of the load, such as the interference frequency f0 of the load, during operation of the load. Specifically, the voltage detection device further includes an acquisition unit. The control unit, configured to determine the interference frequency of the load during operation of the load, specifically includes an acquisition unit disposed on the load side, such as a current sensor or frequency sensor of the load, specifically configured to sample the operating frequency of the load while the load is operating. The control unit is configured to determine the interference frequency of the load, such as the interference frequency f0 of the load, based on the operating frequency of the load during operation of the load.

[0087] The filtering unit is provided on the DC side of the load power supply, and is used to filter out the signal with the same interference frequency as the load from the power signal on the DC side of the load power supply, to obtain a power filter signal.

[0088] The sampling unit is provided at the output side of the filtering unit, such as a voltage-dividing resistor module, and is used to sample the power filter signal to obtain a power sampling signal.

[0089] The detection unit is provided at the output side of the filtering unit, and is used to perform detection based on the power sampling signal to obtain a voltage detection signal of the power supply of the load.

[0090] In the solution of the present invention, a regulation module and an adjustable filter are provided to detect the power supply voltage of the load. The regulation module adjusts the filter frequency of the adjustable filter according to the interference frequency of the load (such as the interference frequency of the compressor) to filter out the load interference and achieve accurate detection of the load power supply voltage. This improves detection accuracy and stability while also providing good anti-interference capabilities. It also solves the problem of voltage detection circuits being disturbed by current surges generated during startup of electrical equipment (such as compressors and fans) and electromagnetic radiation generated during operation, resulting in suboptimal detection results.

[0091] In some embodiments, the sampling unit includes: a first voltage-dividing resistor and a second voltage-dividing resistor, where the first voltage-dividing resistor is, for example, resistor R1, and the second voltage-dividing resistor is, for example, resistor R2.

[0092] Among them, the first connection end of the first voltage-dividing resistor serves as the input end of the sampling unit; the output end of the filtering module is connected to the input end of the sampling unit; the second connection end of the first voltage-dividing resistor is connected to a preset power ground (such as power ground PGND) through the second voltage-dividing resistor; and the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the detection unit.

[0093] like Figure 2As shown, the adjustable CLC band-stop filter includes: capacitor C2, capacitor C3 and inductor L1. The input end of the AC power supply AC is connected to the anode of the diode D1; the cathode of the diode D1 is connected to the power ground (PGND) after passing through the load (such as a variable frequency drive compressor). The cathode of the diode D1 is also connected to the power ground PGND after passing through the capacitor C1. The cathode of the diode D1 is also connected to the first connection end of the inductor L1; the first connection end of the inductor L1 is the control end CONTROL of the adjustable CLC band-stop filter, which is used to adjust the filtering frequency. The first connection end of the inductor L1 is connected to the power ground PGND after passing through the capacitor C2, and the second connection end of the inductor L1 is connected to the power ground PGND after passing through the capacitor C3.

[0094] In the solution of the present invention, a first voltage-dividing resistor and a second voltage-dividing resistor are used to perform voltage-dividing sampling on the power supply filter signal output by the filtering unit, so that the voltage-dividing voltage corresponding to the power supply voltage of the load can be accurately sampled, making it easier for the subsequent detection unit to accurately detect complex power supply voltages.

[0095] In some embodiments, the detection unit includes: a filter capacitor, such as capacitor C4, and a voltage detection module, such as voltage detection chip U1.

[0096] In which, the filter capacitor is connected in parallel with the second voltage-dividing resistor; the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the voltage detection module; the input end of the voltage detection module serves as the input end of the detection unit; the output end of the voltage detection module serves as the output end of the detection unit and is used to output the voltage detection signal of the power supply of the load.

[0097] like Figure 2 As shown, the voltage detection circuit for filtering out load interference includes: a diode D1, a capacitor C1, an adjustable CLC band-stop filter, resistors R1 and R2, a capacitor C4, and a voltage detection chip U1. The second connection end of the inductor L1 is connected to the power ground PGND through resistors R1 and R2, and the capacitor C4 is connected in parallel with the resistor R2. The common end of the resistors R1 and R2 is connected to the VIN pin of the voltage detection chip U1; the GND1 pin of the voltage detection chip U1 is connected to the power ground PGND; the VDD1 pin of the voltage detection chip U1 is connected to the power supply +P5V; the VDD2 pin of the voltage detection chip U1 is connected to the power supply +5V; the VOUTP pin of the voltage detection chip U1 outputs the voltage sampling signal; and the GND2 pin of the voltage detection chip U1 is connected to ground (GND).

[0098] exist Figure 2In the example shown, an adjustable filter, such as an adjustable CLC band-stop filter, is added, and the load frequency is acquired through software and transmitted to the regulation module for adjustment. Resistors R1 and R2 serve as voltage divider resistors, and capacitor C4 serves as a filter capacitor. Voltage detection chip U1 converts the input voltage at port VIN into sampling signals for ports VOUTP and VOUTN. In the solution of the present invention, the load can also be other AC loads, such as fans. Of course, DC loads also generate electromagnetic interference, so DC loads are also acceptable. However, the software acquires the operating frequency, not the current frequency.

[0099] In the solution of the present invention, a detection unit composed of a filter capacitor and a voltage detection module is used to filter the divided voltage output by the sampling unit before detection, which can further improve the accuracy of the power supply voltage detection of the load.

[0100] In some embodiments, the filtering unit includes: a filtering module and an adjusting module, and the filtering module is such as an adjustable filter.

[0101] The filtering unit filters out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load to obtain the power filter signal, including:

[0102] The regulation module is used to receive a voltage regulation signal or a current regulation signal related to the interference frequency of the load from the input end of the regulation module, and output the filtering frequency control signal of the filtering module to the control end of the filtering module according to the interference frequency of the load, specifically according to the voltage regulation signal or the current regulation signal related to the interference frequency of the load determined by the control unit.

[0103] The filtering module is configured to receive, from the control end of the filtering module, a filtering frequency control signal of the filtering module output by the regulating module, and adjust the filtering frequency of the filtering module based on the filtering frequency control signal of the filtering module to obtain the current filtering frequency of the filtering module, so as to: operate at the current filtering frequency of the filtering module, filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal. Specifically, the filtering module is configured to operate based on the filtering frequency control signal of the filtering module, so as to: filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal; the filtering frequency control signal of the filtering module is configured to adjust the filtering frequency of the filtering module, so as to obtain the current filtering frequency of the filtering module, so as to enable the filtering module to operate at the current filtering frequency of the filtering module, so as to: filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, and obtain the power filter signal.

[0104] In the solution of the present invention, an adjustment module and an adjustable filter are set up. The adjustment module converts the compressor interference frequency collected by the software, changes the value of the capacitor and / or inductor in the adjustable filter to control the filtering frequency, and filters out the load interference, thereby realizing accurate detection of the power supply voltage.

[0105] In some embodiments, the filtering module includes: a first regulating capacitor, a second regulating capacitor, and a regulating inductor, the first regulating capacitor being such as capacitor C2, the second regulating capacitor being such as capacitor C3, and the regulating inductor being such as inductor L1.

[0106] The DC side of the power supply of the load is connected to the first connection end of the regulating inductor; the second connection end of the regulating inductor is connected to the input end of the sampling unit.

[0107] The first connection end of the regulating inductor is connected to a preset power ground (such as a power ground PGND) through the first regulating capacitor; the common end of the first connection end of the regulating inductor and the first regulating capacitor serves as the control end of the filtering module, so as to adjust the filtering frequency of the filtering module from the control end of the filtering module.

[0108] The second connection end of the regulating inductor is connected to a preset power ground (such as power ground PGND) through the second regulating capacitor; the common end of the second connection end of the regulating inductor and the second regulating capacitor serves as the output end of the filtering module.

[0109] In the solution of the present invention, an adjustment module and a filtering module such as an adjustable filter are set. The adjustment module changes the value of the capacitor and / or inductor in the adjustable filter to control the filtering frequency and filter out load interference, thereby achieving accurate detection of the power supply voltage.

[0110] In some embodiments, the regulating module includes: a regulating power supply and a regulating resistor, the regulating power supply being, for example, an adjustable power supply E, and the regulating resistor being, for example, a resistor R3.

[0111] The input terminal of the interference frequency of the load is connected to the first connection terminal of the regulating power supply.

[0112] The second connection end of the regulating power supply is connected to the control end of the filtering module, and is used to output a first control signal as a filtering frequency control signal of the filtering module.

[0113] The second connection end of the regulating power supply is connected to the control end of the filtering module after passing through the regulating resistor, and is used to output a second control signal as a filtering frequency control signal of the filtering module.

[0114] like Figure 3As shown, the regulating module includes: an adjustable power supply E and a resistor R3. The first connection end of the adjustable power supply E is connected to the input end of the interference frequency f0 of the load, and the second connection end of the adjustable power supply E is divided into two paths: one path is connected to the first control terminal CONTROL1, and the other path is connected to the second control terminal CONTROL2 after passing through the resistor R3. The voltage detection circuit for filtering out load interference proposed in the solution of the present invention is mainly composed of a load, an adjustable filter, a regulating module and a voltage detection chip U1: the load is a compressor, the adjustable filter is composed of an inductor L1, a capacitor C2, and a capacitor C3, the regulating module is composed of an adjustable power supply E and a resistor R3, and the circuit where the voltage detection chip U1 is located includes resistor R1, resistor R2, capacitor C4, and voltage detection chip U1. The voltage detection chip U1 can use a chip with the model IC AMC1311.

[0115] In the solution of the present invention, by adjusting the adjustable power supply E and resistor R3 in the module, converting the compressor interference frequency collected by the software, changing the value of the capacitor and / or inductor in the adjustable filter to control the filtering frequency, and filtering out the load interference, accurate detection of the power supply voltage is achieved.

[0116] In some embodiments, the voltage detection device according to the solution of the present invention further includes: the control unit is further used to determine a voltage regulation signal or a current regulation signal related to the interference frequency of the load based on the interference frequency of the load.

[0117] The regulating module, under the control of the control unit, outputs a filtering frequency control signal of the filtering module according to the interference frequency of the load, including:

[0118] The regulation module is further configured to output a filter frequency control signal for the filter module based on a voltage regulation signal or a current regulation signal related to the interference frequency of the load determined by the control unit. The first control signal is output as the filter frequency control signal for the filter module based on the voltage regulation signal related to the interference frequency of the load, and the second control signal is output as the filter frequency control signal for the filter module based on the current regulation signal related to the interference frequency of the load. The voltage regulation signal or the current regulation signal related to the interference frequency of the load may be, for example, a voltage value V or a current value I converted from the interference frequency f0 of the load. The first control signal may be, for example, signal CONTROL1, and the second control signal may be, for example, signal CONTROL2. The filter frequency control signal for the filter module may be, for example, signal CONTROL.

[0119] like Figure 4 As shown in FIG, the voltage detection method for filtering out load interference includes:

[0120] Step 1: When the load is running, obtain the working frequency of the load as the interference frequency f0 of the load, perform software sampling on the interference frequency f0 of the load, and then execute step 2.

[0121] like Figure 2 As shown, after the compressor is powered on, the power-on voltage input from the AC power supply AC is rectified by the rectifier diode D1 and filtered by the capacitor C1 to drive the compressor to operate. In the solution of the present invention, a branch is added to input the DC signal rectified by the rectifier diode D1 and filtered by the capacitor C1 into the voltage detection circuit. The software acquires the operating frequency (interference frequency) f0 by real-time sampling of the current frequency of the compressor during operation. Among them, the current frequency of the AC motor is usually equal to its operating frequency, that is, the interference frequency. The current frequency acquisition method can adopt the current frequency acquisition method in this field. The hardware part uses sensors and digital-to-analog converters to measure and convert analog signals into digital signals. The software collects and processes the acquired data through programs and algorithms to determine the current frequency.

[0122] Step 2: Convert the load interference frequency f0 into a voltage value V or a current value I according to the capacitance value C or the inductance value L corresponding to the load interference frequency f0, and then execute step 3.

[0123] Step 3: After the voltage value V or current value I passes through the adjustment module, the corresponding voltage value V or current value I is output to the adjustable CLC band-stop filter to adjust the filtering frequency of the adjustable CLC band-stop filter. The adjustable CLC band-stop filter after adjusting the filtering frequency is used to filter out the corresponding frequency noise in the power supply AC input signal, and then transmit it to the voltage detection chip U1 to obtain the real voltage value.

[0124] The solution of the present invention adds an adjustable filter circuit, and controls the output of the adjustment module through software, thereby effectively filtering out compressor interference and ensuring the reliability of voltage detection.

[0125] In some embodiments, the control unit determines, based on the interference frequency of the load, a voltage regulation signal or a current regulation signal related to the interference frequency of the load, including:

[0126] The control unit is further configured to determine, according to a sampling period of the load interference frequency, whether the load interference frequency sampled at the current moment is less than the load interference frequency sampled at the previous moment.

[0127] The control unit is further specifically configured to, if it is determined that the interference frequency of the load sampled at the current moment is less than the interference frequency of the load sampled at the previous moment, determine, based on the correspondence between the set interference frequency and the set inductance adjustment amount, the set inductance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence as the inductance adjustment amount of the filter module corresponding to the interference frequency of the load; and convert the inductance adjustment amount of the filter module corresponding to the interference frequency of the load into a current adjustment signal related to the interference frequency of the load.

[0128] The control unit is further configured to, if it is determined that the interference frequency of the load sampled at the current moment is greater than the interference frequency of the load sampled at the previous moment, determine, based on the correspondence between the set interference frequency and the set capacitance adjustment amount, the set capacitance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence as the capacitance adjustment amount of the filter module corresponding to the interference frequency of the load; and convert the capacitance adjustment amount of the filter module corresponding to the interference frequency of the load into a voltage adjustment signal related to the interference frequency of the load. The control unit is further configured to, if it is determined that the interference frequency of the load sampled at the current moment is equal to the interference frequency of the load sampled at the previous moment, not convert the adjustment signal and maintain the adjustment signal used at the previous moment, that is, if the voltage adjustment signal was used at the previous moment, the voltage adjustment signal is maintained; if the current adjustment signal was used at the previous moment, the current adjustment signal is maintained.

[0129] like Figure 4 As shown, the voltage detection method for filtering out load interference further includes: in step 2, calculating the corresponding capacitance value C or inductance value L according to the interference frequency f0 of the load:

[0130]

[0131] During the load operation, the interference frequency f0 of the load sampled at the current moment is compared with the interference frequency f0 of the load sampled at the previous moment according to the set sampling period. When the interference frequency f0 of the load increases, the capacitance value C needs to be reduced, while the inductance value L remains unchanged, so When the interference frequency f0 of the load decreases, the inductance value L needs to be increased, while the capacitance value C remains unchanged, so

[0132] In step 2, after calculating the corresponding capacitance value C or inductance value L according to the interference frequency f0 of the load, the capacitance value C or inductance value L corresponding to the interference frequency f0 of the load is converted into an external voltage value V or current value I.

[0133] The applied voltage value V or current value I varies depending on the adjustable capacitor and adjustable inductor, and the specific value is calculated by the software module. For example, for most adjustable variable capacitance capacitors, the relationship between the capacitance value C and the reverse bias voltage V is approximately:

[0134]

[0135] Where C0 is the capacitance at zero bias voltage, V0 is the reference voltage, and α is an exponent, typically between 1 and 2, determined by the material used. Once the desired C value is determined, the desired V value can be obtained.

[0136] like Figure 4 As shown, the voltage detection method for filtering out load interference also includes: in step 3, transmitting the voltage value V or current value I determined in step 2 to the first connection terminal of the adjustable power supply E in the adjustment module, and transmitting it to the adjustable power supply E. The first connection terminal of the adjustable power supply E receives a power supply signal related to the interference frequency f0 of the load, that is, the voltage value V or current value I determined in step 2. The adjustment module contains an adjustable power supply E and a resistor R3. According to the needs, the control signal 1 channel or the control signal 2 channel is selected to output the corresponding voltage value or current value to the output of the adjustment module to the CONTROL terminal of the adjustable filter, such as the adjustable CLC band-stop filter, thereby changing the capacitance value of the capacitor and the inductance value of the inductor in the adjustable filter. The signal received by the CONTROL terminal of the adjustable CLC band-stop filter comes from the CONTROL1 terminal of the adjustment module or the CONTROL2 terminal of the adjustment module. By controlling the external voltage value V or current value I, the frequency f of the adjustable CLC band-stop filter is adjusted. c =f0, specifically filtering out the noise generated by load operation, so that the voltage detection chip U1 can detect the real voltage value.

[0137] The selection of the control signal CONTROL1 or CONTROL2 of the regulation module is determined by the interference frequency f0 of the compressor. To ensure the quality factor Q value of the adjustable CLC band-stop filter, the capacitance of the adjustable capacitor should be reduced when the interference frequency f0 of the compressor increases. The capacitance of the adjustable capacitor is controlled by the magnitude of the applied voltage, so CONTROL1 is selected at this time to directly control the capacitance value through the variable power supply. To ensure the quality factor Q value of the adjustable CLC band-stop filter, the inductance value of the adjustable inductor should be increased when the interference frequency f0 of the compressor decreases. The inductance value of the adjustable inductor is controlled by the magnitude of the current flowing through it, so CONTROL2 is selected at this time to control the inductance value through the variable current formed after the variable power supply flows through the resistor.

[0138] In order to filter out the clutter of frequency f0, the frequency f of the CLC band-stop filter needs to be adjusted. c =f0, and Quality Factor of Adjustable CLC Band-Rejection Filter The larger the Q value, the smaller the bandwidth of the adjustable CLC band-stop filter. In order to make the filtering more accurate, while ensuring f c At the same time, Q should be increased as much as possible. So there are two situations:

[0139] If the interference frequency f0 of the compressor detected by the software increases, the frequency f of the CLC band-stop filter can be adjusted. c To ensure that the quality factor Q value of the adjustable CLC band-stop filter increases, the values of capacitors C2 and C3 should be reduced. The adjustable capacitors C2 and C3 change their own capacitance according to the external voltage value, so by changing the voltage value output by the adjustable power supply in the adjustment module and outputting it as a control signal, the filter frequency can be adjusted.

[0140] The interference frequency f0 of the compressor detected by the software is reduced, and the frequency f of the CLC band-stop filter can be adjusted. c To ensure that the quality factor Q value of the adjustable CLC band-stop filter increases, the value of the inductor L1 should be increased. The adjustable inductor L1 changes its own inductance value according to the current value flowing through it. Therefore, by changing the voltage value on the resistor R3 in the adjustment module, the corresponding control signal is output to adjust the frequency f of the adjustable CLC band-stop filter. c The variable current formed by the variable power supply flowing through resistor R3 is the corresponding control signal CONTROL2. The inductance of the adjustable inductor L1 is controlled by the current flowing through it (i.e., CONTROL2). As the inductance changes, the filter frequency changes accordingly. Therefore, changing the adjustable power supply E can change the filter frequency.

[0141] Since the processing and functions implemented by the electrical equipment of this embodiment basically correspond to the embodiments, principles and examples of the device, for any details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0142] According to an embodiment of the present invention, a voltage detection method for an electrical device corresponding to the electrical device is also provided. Figure 5 FIG2 is a flow chart of an embodiment of the method of the present invention. The voltage detection method of the electrical device may include steps S110 to S140.

[0143] At step S110, during the operation of the load, the interference frequency of the load, such as the interference frequency f0 of the load, is determined. Specifically, the voltage detection device further includes an acquisition unit. The control unit, which determines the interference frequency of the load during the operation of the load, specifically includes: an acquisition unit, disposed on the load side, such as a current sensor or frequency sensor of the load, specifically for sampling the operating frequency of the load when the load is operating; and the control unit, specifically for determining the interference frequency of the load, such as the interference frequency f0 of the load, based on the operating frequency of the load during the operation of the load.

[0144] In step S120 , the filtering unit filters out the signal having the same frequency as the interference of the load from the power signal on the DC side of the power supply of the load, thereby obtaining a power filter signal.

[0145] In step S130 , the power supply filter signal is sampled by the sampling unit to obtain a power supply sampling signal.

[0146] In step S140 , the detection unit performs detection based on the power sampling signal to obtain a voltage detection signal of the power supply of the load.

[0147] In the solution of the present invention, a regulation module and an adjustable filter are provided to detect the power supply voltage of the load. The regulation module adjusts the filter frequency of the adjustable filter according to the interference frequency of the load (such as the interference frequency of the compressor) to filter out the load interference and achieve accurate detection of the load power supply voltage. This improves detection accuracy and stability while also providing good anti-interference capabilities. It also solves the problem of voltage detection circuits being disturbed by current surges generated during startup of electrical equipment (such as compressors and fans) and electromagnetic radiation generated during operation, resulting in suboptimal detection results.

[0148] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned electrical equipment, for any details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0149] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0150] The foregoing description is merely an embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the claims.

Claims

1. A voltage detection device, characterized in that: It is set on the DC side of the power supply of the load and is used to detect the power supply voltage of the load; the voltage detection device includes: a sampling unit, a filtering unit, a detection unit and a control unit; wherein, The control unit is used to determine the interference frequency of the load during the operation of the load; The filtering unit is used to filter out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, so as to obtain a power filter signal; The sampling unit is used to sample the power filter signal to obtain a power sampling signal; The detection unit is used to perform detection based on the power sampling signal to obtain a voltage detection signal of the power supply of the load.

2. The voltage detection device according to claim 1, wherein: The sampling unit includes: a first voltage-dividing resistor and a second voltage-dividing resistor; wherein, The first connection end of the first voltage-dividing resistor serves as the input end of the sampling unit; the output end of the filtering module is connected to the input end of the sampling unit; the second connection end of the first voltage-dividing resistor is connected to a preset power ground after passing through the second voltage-dividing resistor; and the common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as the output end of the sampling unit and is connected to the input end of the detection unit.

3. The voltage detection device according to claim 1, wherein: The detection unit includes: a filter capacitor and a voltage detection module; wherein, The filter capacitor is connected in parallel with the second voltage-dividing resistor; a common end of the first voltage-dividing resistor and the second voltage-dividing resistor serves as an output end of the sampling unit and is connected to an input end of the voltage detection module; The input end of the voltage detection module serves as the input end of the detection unit; the output end of the voltage detection module serves as the output end of the detection unit, and is used to output a voltage detection signal of the power supply of the load.

4. The voltage detection device according to claim 1, wherein: The filtering unit includes: a filtering module and an adjusting module; wherein, The filtering unit filters out the signal with the same interference frequency as the load from the power supply signal on the DC side of the power supply of the load to obtain the power supply filtered signal, including: The regulating module is configured to output a filtering frequency control signal of the filtering module to a control terminal of the filtering module according to the interference frequency of the load under the control of the control unit; The filtering module is used to adjust the filtering frequency of the filtering module based on the filtering frequency control signal of the filtering module to obtain the current filtering frequency of the filtering module, so as to: operate at the current filtering frequency of the filtering module, filter out the signal with the same interference frequency as the load from the power supply signal on the DC side of the power supply of the load, and obtain the power supply filter signal.

5. The voltage detection device according to claim 4, characterized in that: The filtering module includes: a first regulating capacitor, a second regulating capacitor, and a regulating inductor; wherein, The DC side of the power supply of the load is connected to the first connection end of the regulating inductor; the second connection end of the regulating inductor is connected to the input end of the sampling unit; The first connection end of the regulating inductor is connected to a preset power ground via the first regulating capacitor; the common end of the first connection end of the regulating inductor and the first regulating capacitor serves as the control end of the filtering module; The second connection end of the regulating inductor is connected to a preset power ground via the second regulating capacitor; the common end of the second connection end of the regulating inductor and the second regulating capacitor serves as the output end of the filtering module.

6. The voltage detection device according to claim 4, characterized in that: The regulating module includes: regulating power supply and regulating resistance; wherein, An input terminal of the interference frequency of the load is connected to the first connection terminal of the regulating power supply; The second connection end of the regulating power supply is connected to the control end of the filtering module, and is used to output a first control signal as a filtering frequency control signal of the filtering module; The second connection end of the regulating power supply is connected to the control end of the filtering module after passing through the regulating resistor, and is used to output a second control signal as a filtering frequency control signal of the filtering module.

7. The voltage detection device according to any one of claims 4 to 6, characterized in that: Also includes: The control unit is further configured to determine, based on the interference frequency of the load, a voltage regulation signal or a current regulation signal related to the interference frequency of the load; The regulating module, under the control of the control unit, outputs a filtering frequency control signal of the filtering module according to the interference frequency of the load, including: According to the voltage regulation signal or current regulation signal related to the interference frequency of the load determined by the control unit, the filtering frequency control signal of the filtering module is output; wherein, according to the voltage regulation signal related to the interference frequency of the load, the first control signal is output as the filtering frequency control signal of the filtering module; according to the current regulation signal related to the interference frequency of the load, the second control signal is output as the filtering frequency control signal of the filtering module.

8. The voltage detection device according to claim 7, characterized in that: The control unit determines, according to the interference frequency of the load, a voltage regulation signal or a current regulation signal related to the interference frequency of the load, including: According to the sampling period of the load interference frequency, determine whether the load interference frequency sampled at the current moment is less than the load interference frequency sampled at the previous moment; If it is determined that the interference frequency of the load sampled at the current moment is less than the interference frequency of the load sampled at the previous moment, then, based on the correspondence between the set interference frequency and the set inductance adjustment amount, the set inductance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence is determined as the inductance adjustment amount of the filter module corresponding to the interference frequency of the load; and the inductance adjustment amount of the filter module corresponding to the interference frequency of the load is converted into a current adjustment signal related to the interference frequency of the load; If it is determined that the interference frequency of the load sampled at the current moment is greater than the interference frequency of the load sampled at the previous moment, then according to the correspondence between the set interference frequency and the set capacitance adjustment amount, the set capacitance value corresponding to the set interference frequency that is the same as the interference frequency of the load in the correspondence is determined as the capacitance adjustment amount of the filtering module corresponding to the interference frequency of the load; and the capacitance adjustment amount of the filtering module corresponding to the interference frequency of the load is converted into a voltage adjustment signal related to the interference frequency of the load.

9. An electrical device, characterized in that: include: The voltage detection device according to any one of claims 1 to 8.

10. A voltage detection method for electrical equipment according to claim 9, characterized in that: include: During the operation of the load, determine the interference frequency of the load; The filtering unit filters out the signal with the same interference frequency as the load from the power signal on the DC side of the power supply of the load, thereby obtaining a power filter signal; The power supply filter signal is sampled by the sampling unit to obtain a power supply sampling signal; The detection unit performs detection based on the power sampling signal to obtain a voltage detection signal of the power supply of the load.

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