Undervoltage detection method and device, electronic equipment and storage medium

Abstract

The invention provides an undervoltage detection method and device, electronic equipment and a storage medium, and relates to the technical field of voltage detection, and the method comprises the steps: determining an input voltage and an input current of an inverter circuit in a frequency converter; determining a load interference voltage based on the input current; determining a mains supply reference power supply voltage based on the input voltage and the load interference voltage; and judging whether the mains supply is in an undervoltage state or not based on the mains supply reference power supply voltage and a preset undervoltage threshold. Therefore, whether the mains supply is in the under-voltage state or not can be jointly judged based on the load interference voltage, the input voltage of the frequency converter and the preset under-voltage threshold value, and the load interference voltage is the voltage value of the part lowered by the load, so that the mains supply reference power supply voltage can reflect the voltage value of the frequency converter in the theoretical state; and the accuracy of judging the under-voltage state of the mains supply is improved.

Description

Technical Field

[0001] This disclosure relates to the field of voltage detection technology, and in particular to a method, apparatus, electronic device, and storage medium for detecting undervoltage. Background Technology

[0002] Mains power refers to electricity supplied by the city's public power grid. Mains power is transmitted through transmission lines to various points of use, such as homes, commercial buildings, and factories. Some equipment relies on mains power as its primary power source. Mains power first enters the inverter's rectifier circuit to be converted into direct current (DC), and then passes through the inverter's inverter circuit to be converted into alternating current (AC) capable of driving compressors.

[0003] For some household appliances, when the mains voltage is too low, controlling the inverter to drive the compressor may damage the inverter or the compressor. Therefore, it is necessary to determine whether the mains voltage is currently low in order to decide whether to shut down the inverter output.

[0004] The causes of mains voltage fluctuations are complex and influenced by a variety of factors. In related technologies, it is difficult to accurately determine whether the mains voltage is low simply by monitoring the input supply voltage of the inverter circuit. Summary of the Invention

[0005] This disclosure presents a method, apparatus, electronic device, and storage medium for detecting undervoltage, aiming to at least partially address one of the technical problems in the related art.

[0006] The first aspect of this disclosure provides a method for detecting undervoltage, comprising:

[0007] Determine the input voltage and input current of the inverter circuit in the frequency converter;

[0008] Based on the input current, determine the load interference voltage;

[0009] Based on the input voltage and the load interference voltage, determine the mains reference supply voltage;

[0010] Based on the mains reference supply voltage and the preset undervoltage threshold, it is determined whether the mains power is in an undervoltage state.

[0011] A second aspect of this disclosure provides an apparatus for detecting undervoltage, comprising:

[0012] The first determining module is used to determine the input voltage and input current of the inverter circuit in the frequency converter;

[0013] The second determining module is used to determine the load interference voltage based on the input current;

[0014] The third determining module is used to determine the mains reference supply voltage based on the input voltage and the load interference voltage;

[0015] The judgment module is used to determine whether the mains power is in an undervoltage state based on the mains power reference supply voltage and the preset undervoltage threshold.

[0016] A third aspect of this disclosure provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the undervoltage detection method of the embodiments of this disclosure.

[0017] A fourth aspect of this disclosure provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the undervoltage detection method disclosed in embodiments of this disclosure.

[0018] A fifth aspect of this disclosure provides a chip including a processor and an interface, the processor being configured to read instructions to execute the undervoltage detection method disclosed in embodiments of this disclosure.

[0019] In this embodiment, the input voltage and input current of the inverter circuit in the frequency converter are first determined. Then, based on the input current, the load interference voltage is determined. Next, based on the input voltage and the load interference voltage, the mains reference supply voltage is determined. Finally, based on the mains reference supply voltage and a preset undervoltage threshold, it is determined whether the mains is in an undervoltage state. Therefore, it is possible to jointly determine whether the mains is in an undervoltage state based on the load interference voltage, the frequency converter's input voltage, and the preset undervoltage threshold. The load interference voltage is the voltage value pulled down by the load, ensuring that the mains reference supply voltage reflects the frequency converter voltage value under theoretical conditions, thus improving the accuracy of the mains undervoltage determination.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure, wherein:

[0022] Figure 1 This is a flowchart illustrating the method for detecting undervoltage according to the first embodiment of this disclosure;

[0023] Figure 2 This is a schematic flowchart of a method for detecting undervoltage according to a second embodiment of the present disclosure;

[0024] Figure 3This is a structural block diagram of an undervoltage detection device according to an embodiment of the present disclosure;

[0025] Figure 4 This is a block diagram of an electronic device used to implement the undervoltage detection method of the embodiments of this disclosure. Detailed Implementation

[0026] Some embodiments of this disclosure will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. Various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but can be changed as will become apparent upon understanding this disclosure, except for operations that must be performed in a particular order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0027] The embodiments described in the following examples of this disclosure are not representative of all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0028] In related technologies, some solutions calculate the actual output power based on the inverter's output voltage and current, and then determine the undervoltage protection voltage threshold based on the actual output power. Different actual output powers correspond to different undervoltage protection voltage thresholds. Afterwards, it is necessary to determine whether the input voltage is lower than the undervoltage protection voltage threshold. This solution requires an undervoltage protection voltage threshold curve, which needs to be calibrated in advance, resulting in drawbacks such as poor adaptability and high microcontroller memory consumption.

[0029] To save on hardware costs, current products on the market typically only collect the supply voltage of the inverter circuit. When the mains power fluctuates, the supply voltage of the inverter circuit fluctuates with the mains voltage. Furthermore, the compressor starts under a heavy load, which lowers the supply voltage of the inverter circuit; once the compressor speed stabilizes, the supply voltage recovers somewhat. Therefore, judging the current undervoltage state of the mains power supply based on the supply voltage of the inverter circuit is extremely inaccurate.

[0030] In this disclosure, a method for detecting undervoltage is proposed to at least address one of the aforementioned problems.

[0031] It should be noted that the execution subject of the undervoltage detection method in this embodiment can be an undervoltage detection device, which can be implemented by software and / or hardware. The execution subject of the undervoltage detection method in this embodiment can be any type of electronic device, such as a refrigerator, washing machine, air conditioner, etc., and is not limited here.

[0032] In this embodiment of the disclosure, the method for detecting undervoltage will be described using a "device for detecting undervoltage" as the executing entity, hereinafter referred to as "device" and not limited thereto.

[0033] Figure 1 This is a flowchart illustrating a method for detecting undervoltage according to the first embodiment of this disclosure.

[0034] like Figure 1 As shown, the method includes:

[0035] S101: Determine the input voltage and input current of the inverter circuit in the frequency converter.

[0036] It should be noted that a frequency converter mainly consists of two parts: a rectifier circuit and an inverter circuit. The rectifier circuit converts AC mains power into DC power, and the inverter circuit converts DC power into AC power to drive the compressor.

[0037] More specifically, the main function of a rectifier circuit is to convert alternating current (AC) to direct current (DC). After the AC mains power enters the inverter, it first passes through the rectifier circuit. The rectifier circuit uses a series of power semiconductor devices (such as diodes and thyristors) to "smooth out the peaks and fill the valleys" of the AC waveform, transforming it into smooth DC. In this way, the originally fluctuating AC is converted into stable DC. The main function of an inverter circuit is to convert DC back to AC, and the frequency and amplitude of this AC can be adjusted. In household appliances such as air conditioners, key components like the compressor require AC with specific frequencies and amplitudes to drive them.

[0038] The input voltage can be the DC output voltage of the inverter's rectifier circuit, which is also the input supply voltage of the inverter circuit. The input current can be the output current of the inverter's rectifier circuit, which is also the input supply current of the inverter circuit.

[0039] One possible implementation is to measure both the output voltage and output current of the inverter circuit. The output voltage of the inverter circuit is also the three-phase voltage U of the compressor. A U B U C The output current of the inverter circuit is also the three-phase current I of the compressor. A I BI C The formula for calculating the output power P of an actual inverter circuit is:

[0040] P = U A *I A +U B *I B +U C *I C

[0041] Furthermore, the input voltage V0 of the inverter circuit can be collected, and the actual input current of the inverter circuit can be calculated based on the output power P of the inverter circuit. The formula is: I0 = P / V0

[0042] It should be noted that the above examples are merely illustrative and are not intended to limit this disclosure.

[0043] S102: Determine the load interference voltage based on the input current.

[0044] Load disturbance voltage refers to the supply voltage pulled down by the load, reflecting the impact of load changes on the voltage stability of the power supply system. Sudden changes in the load (such as starting, stopping, or sudden load changes) may cause fluctuations in the supply voltage.

[0045] For example, if the power supply voltage of the inverter circuit is V1, the large load when the compressor starts will lower the power supply voltage of the inverter circuit of the frequency converter, causing the power supply voltage to drop to V2. Therefore, the load interference voltage can be expressed as V1-V2, which is not limited here.

[0046] As one possible approach, the load interference voltage can be determined based on the ratio between the input current and a preset reference current, as well as a preset reference interference voltage.

[0047] The preset reference current can be a selected, representative current value used as a benchmark for calculating the load interference voltage. This value can be determined based on the equipment's rated current, historical data, or empirical values, and is not limited here.

[0048] The preset reference interference voltage can be the load interference voltage corresponding to the device under the reference current. The reference interference voltage needs to be determined according to the actual situation.

[0049] For ease of explanation, the preset reference current will be denoted as I below. ref The preset reference interference voltage is denoted as V. ref After determining the input current I0, the load interference voltage V1 can be calculated using the following formula:

[0050] V1 = V ref ×(Iref / I0)^α

[0051] Here, α is an adjustment factor used to adjust the sensitivity of the load to the influence of current changes on the load interference voltage. The value of α can be calibrated according to the actual situation and can be determined through experiments or simulations. If the load interference voltage is proportional to the current change, then α = 1; if the load interference voltage is more or less sensitive to the current change, the value of α will be adjusted accordingly.

[0052] As another possible implementation, the load interference voltage corresponding to the input current can be determined based on a preset mapping relationship.

[0053] The preset mapping relationship can be a mapping curve between load interference voltage and input current. In this embodiment, the corresponding relationship between load interference voltage and input current can be pre-recorded to form a mapping curve. This calibrated mapping curve can reflect the load interference voltage corresponding to different input currents.

[0054] It should be noted that the input current and corresponding load interference voltage can be measured and recorded in advance under different operating conditions (such as different load sizes, supply voltages, ambient temperatures, etc.), ensuring that the collected data has sufficient breadth and accuracy to cover various possible operating scenarios. Then, the collected data can be processed and analyzed, for example, removing outliers or erroneous data. Afterwards, a mapping curve can be plotted based on the data points of the input current and load interference voltage.

[0055] Understandably, if there are many data points and their distribution is complex, curve fitting techniques (such as polynomial fitting, exponential fitting, etc.) can be used to obtain a smooth and accurate mapping curve.

[0056] Optionally, after determining the input current, the load interference voltage corresponding to the input current can be directly determined based on this mapping curve. This allows for the rapid calculation of the corresponding load interference voltage based on the input current during real-time operation.

[0057] S103: Determine the mains reference supply voltage based on the input voltage and load interference voltage.

[0058] The mains reference supply voltage can be a predicted theoretical mains supply voltage. Mains voltage may fluctuate due to various reasons. The mains reference supply voltage represents the current mains voltage level during load operation, that is, the inverter's input voltage under load conditions.

[0059] Optionally, the sum of the input voltage and the load interference voltage can be used as the mains reference supply voltage.

[0060] For example, it can be calculated according to the following formula:

[0061]

[0062] Where, V2 represents the input voltage, V1 represents the load interference voltage, and V 市电 represents the reference power supply voltage of the mains electricity.

[0063] It should be noted that the above example is only for illustrative purposes and does not limit the present disclosure.

[0064] S104: Determine whether the mains electricity is in an undervoltage state based on the reference power supply voltage of the mains electricity and a preset undervoltage threshold.

[0065] Among them, the preset undervoltage threshold can be a threshold calibrated in advance for determining whether the mains electricity is in an undervoltage state. This preset undervoltage threshold can be a voltage value, and its specific size can be set according to the actual situation and will not be limited here.

[0066] As a possible implementation manner, if the reference power supply voltage of the mains electricity is less than the preset undervoltage threshold, it can be preliminarily determined that the mains electricity may be in an undervoltage state.

[0067] It should be noted that in order to avoid misjudgment caused by instantaneous voltage fluctuations, a duration threshold can be introduced as a further judgment condition. If the time when the reference power supply voltage of the mains electricity continuously is less than the preset undervoltage threshold reaches or exceeds the set duration threshold, it is determined that the mains electricity is indeed in an undervoltage state.

[0068] Optionally, it can be determined to be in an undervoltage state when the reference power supply voltage of the mains electricity is less than the preset undervoltage threshold and the duration of being less than the preset undervoltage threshold reaches the duration threshold.

[0069] Specifically, when the reference power supply voltage of the mains electricity is less than the preset undervoltage threshold, the duration threshold can be used to monitor whether the reference power supply voltage of the mains electricity continues to be low.

[0070] For example, if V 市电 < Vthreshold, start timing. When the duration reaches or exceeds the duration threshold T, the device can determine that the mains electricity is in an undervoltage state. Where, Vthreshold is the preset undervoltage threshold.

[0071] Optionally, when it is determined that the mains electricity is in an undervoltage state, the inverter circuit can be controlled to enter the undervoltage protection state and stop outputting.

[0072] As one embodiment, the control unit of the inverter circuit can perform corresponding undervoltage protection actions when it determines that the mains power is undervoltage. In this case, the control unit can shut down the output of the inverter circuit or limit its output to a very low level that will not damage the load or the circuit itself.

[0073] Optionally, after the inverter circuit enters the undervoltage protection state, the device can send status feedback to the terminal equipment of the operator or manager, informing them that the mains voltage is too low and the inverter circuit has stopped outputting. Simultaneously, the device can also trigger an alarm mechanism, such as emitting sound or light signals or sending alarm information via the network, to draw attention and prompt appropriate countermeasures.

[0074] Optionally, once the mains voltage returns to a normal level and remains so for a period of time (to ensure voltage stability), the device can automatically reset the undervoltage protection state of the inverter circuit. After resetting, the inverter circuit will resume normal operation and provide power to the compressor.

[0075] In this embodiment, the input voltage and input current of the inverter circuit in the frequency converter are first determined. Then, based on the input current, the load interference voltage is determined. Next, based on the input voltage and the load interference voltage, the mains reference supply voltage is determined. Finally, based on the mains reference supply voltage and a preset undervoltage threshold, it is determined whether the mains is in an undervoltage state. Therefore, it is possible to jointly determine whether the mains is in an undervoltage state based on the load interference voltage, the frequency converter's input voltage, and the preset undervoltage threshold. The load interference voltage is the voltage value pulled down by the load, ensuring that the mains reference supply voltage reflects the frequency converter voltage value under theoretical conditions, thus improving the accuracy of the mains undervoltage determination.

[0076] Figure 2 This is a schematic flowchart of a method for detecting undervoltage according to a second embodiment of this disclosure. Figure 2 As shown, the method includes:

[0077] S201: Obtain the output voltage, output current, and input voltage of the inverter circuit in the frequency converter.

[0078] The output voltage of the inverter current can be the three-phase voltage U of the compressor. A U B U C Alternatively, it could be the αβ axis voltage U of the compressor. α U β Alternatively, it could be the dq axis voltage U of the compressor. d U q No restrictions are imposed here.

[0079] The output current of the inverter can be the three-phase current I of the compressor.A I B I C Alternatively, it could be the compressor's αβ axis current I. α I β Alternatively, it could be the compressor's dq-axis current I. d I q No restrictions are imposed here.

[0080] Optionally, the input voltage of the inverter circuit in the frequency converter can be measured using a voltage measuring device, such as a voltage sensor, which is not limited here. Alternatively, the output voltage and input voltage of the inverter circuit in the frequency converter can be collected separately using a voltage acquisition circuit.

[0081] It should be noted that the output voltage, output current, and input voltage of the inverter circuit in the frequency converter can be parameters acquired in real time, and these parameters can be the actual operating parameters.

[0082] S202: Determine the output power of the inverter circuit based on its output voltage and output current.

[0083] The output power of the inverter circuit refers to the AC power actually supplied to the load during the conversion process, reflecting both the output capability of the inverter circuit and the load's power consumption capacity. In this embodiment, the output power refers to the AC power actually supplied to the compressor load by the inverter circuit during the conversion process. Since the power required by the compressor load may change in real time, it is necessary to calculate the actual output power of the inverter circuit.

[0084] As one implementation method, the output voltage and output current of the inverter circuit are respectively the three-phase phase voltages U of the compressor. A U B U C and three-phase phase current I A I B I C The output power P of the inverter circuit can then be calculated using the following formula:

[0085] P = U A *I A +U B *I B +U C *I C

[0086] In another implementation, the output voltage and output current of the inverter circuit are respectively the αβ axis voltage U of the compressor. α U β and αβ axis current I α I βThe output power P of the inverter circuit can then be calculated using the following formula:

[0087] P = 1.5 * (U α *I α +U β *I β )

[0088] As another implementation, the output voltage and output current of the inverter circuit are respectively the dq-axis voltage U of the compressor. d U q and dq axis current I d I q The output power P of the inverter circuit can then be calculated using the following formula:

[0089] P = 1.5 * (U d *I d +U q *I q )

[0090] It should be noted that the above example is only an illustrative example and is not intended to be limiting.

[0091] S203: Determine the input current of the inverter circuit based on the input voltage and output power.

[0092] Optionally, the input current of the actual inverter circuit can be calculated based on the output power P of the inverter circuit, using the following formula:

[0093] I1 = P / V1

[0094] It should be noted that the above examples are merely illustrative and are not intended to limit this disclosure.

[0095] S204: Determine the load interference voltage based on the current input current, the preset mains power supply frequency, and the capacitance value.

[0096] The AC power supply frequency refers to the number of times the AC power source changes direction per second, and its unit is Hertz (Hz). The AC power supply frequency may vary in different regions, and it is usually 50Hz or 60Hz.

[0097] As an example, in this embodiment of the disclosure, the capacitance value can be a bus electrolytic capacitor. In the inverter circuit, the bus electrolytic capacitor is a component used to realize energy storage and balance the supply and demand relationship of the power system. The bus electrolytic capacitor can convert electrical energy into chemical energy and store it. When the inverter circuit needs additional electrical energy, it can quickly release this stored electrical energy to maintain the stable operation of the system. When the DC voltage drops, the electrolytic capacitor discharges, converting the stored chemical energy into electrical energy and releasing it to maintain the stability of the DC bus voltage.

[0098] Optionally, the load interference voltage can be determined using the following formula:

[0099] V2 = I1 / (f*C)

[0100] Where V2 is the load interference voltage, f is the preset mains power supply frequency, and C is the capacitance value.

[0101] It should be noted that the above method for determining the load interference voltage is only an illustrative example and is not intended to limit this disclosure.

[0102] S205: Obtain multiple sets of input current and input voltage of the inverter circuit under different loads at the first supply voltage and the first supply frequency.

[0103] The first supply voltage can be a preset AC voltage. As an example, the first supply voltage can be set according to the mains supply voltage. For example, if the mains supply voltage is 220V AC, the first supply voltage can be set to 220V, or it can be 219V, 218V, etc., without limitation.

[0104] The first power supply frequency can be a preset power supply frequency, such as 50Hz, 52Hz, 55Hz, etc., and is not limited here.

[0105] Optionally, a current probe or multimeter can be used to measure the input current Iin of the inverter circuit of the frequency converter, and a voltage probe or multimeter can be used to measure the input voltage Vin of the inverter circuit of the frequency converter; no limitation is made here.

[0106] It should be noted that the output load of the inverter circuit can be adjusted to measure the input current and input voltage of the inverter circuit under different loads.

[0107] S206: Determine multiple initial correction coefficients based on the first supply voltage, the first supply frequency, and multiple sets of input current and input voltage.

[0108] The correction coefficient can be used to correct the impact of inverter efficiency and sampling error on the calculation results.

[0109] The initial correction coefficient is a parameter determined based on any set of input current and input voltage, first supply voltage, and first supply frequency.

[0110] The formula for calculating the initial correction coefficient can be:

[0111]

[0112] Where m is the initial correction coefficient, V in For the input voltage, Iin Input voltage V in Corresponding to the input current, V x f0 is the first supply voltage, f0 is the first supply frequency, and C is the capacitance value.

[0113] It should be noted that, assuming there are N sets of input currents and voltages, the input current and voltage of each set can be substituted into the above formula to obtain the corresponding initial correction coefficient for each set. Finally, N sets of initial correction coefficients m1, m2, m3, m4...m n .

[0114] S207: Use the average of multiple initial correction coefficients as the correction coefficient.

[0115] The correction factor is used to correct the load interference voltage, which helps to more accurately assess the load interference voltage.

[0116] For example, if multiple initial correction coefficients are m1, m2, m3, m4...m n Then (m1+m2+m3+m4...+m n The value of ) / n is used as the correction factor and is not limited here.

[0117] It should be noted that by calculating the average of multiple initial correction coefficients, the data can be smoothed, reducing interference from random noise or instantaneous fluctuations. This allows the correction coefficients to better reflect the overall or average characteristics of the system, rather than being affected by individual outliers. A single initial correction coefficient may be influenced by various factors, such as measurement errors, load variations, and environmental factors. By calculating the average, the influence of these factors can be neutralized, resulting in a correction coefficient that more closely approximates the actual situation, thus improving the accuracy and reliability of the correction coefficients.

[0118] S208: Based on the preset correction coefficient, the load interference voltage is corrected to obtain the corrected load interference voltage.

[0119] For example, if the load interference voltage is V2 and the correction factor is M, then M*V2 can be used as the corrected load interference voltage.

[0120] It should be noted that by applying the correction coefficients calculated in the above steps to the correction of the load interference voltage, a more accurate assessment result of the load interference voltage can be obtained, which is beneficial for subsequent reliable analysis and diagnosis of the undervoltage state.

[0121] S209: Determine the mains reference supply voltage based on the corrected load interference voltage and input voltage.

[0122] Optionally, the sum of the corrected load interference voltage and the input voltage can be used as the mains reference supply voltage.

[0123] For example, the following formula can be used:

[0124]

[0125] Among them, V 市电 V1 represents the mains reference supply voltage, V2 represents the input voltage, and M*V2 represents the corrected load interference voltage.

[0126] S210: Determine whether the mains power is in an undervoltage state based on the mains reference supply voltage and the preset undervoltage threshold.

[0127] It should be noted that the specific implementation of step S210 can be referred to the above embodiments, and will not be repeated here.

[0128] In this embodiment, the output voltage, output current, and input voltage of the inverter circuit in the frequency converter are first obtained. Then, the output power of the inverter circuit is determined based on the output voltage and output current. Next, the input current of the inverter circuit is determined based on the input voltage and output power. Then, the load interference voltage is determined based on the current input current, the preset mains power supply frequency, and the capacitor value. Then, multiple sets of input current and input voltage corresponding to different loads are obtained for the inverter circuit under the first power supply voltage and the first power supply frequency. Then, multiple initial correction coefficients are determined based on the first power supply voltage, the first power supply frequency, and the multiple sets of input current and input voltage. Then, the average of the multiple initial correction coefficients is used as the correction coefficient. Then, the load interference voltage is corrected based on the preset correction coefficient to obtain the corrected load interference voltage. Then, the mains reference power supply voltage is determined based on the corrected load interference voltage and the input voltage. Finally, the mains power is determined to be in an undervoltage state based on the mains reference power supply voltage and the preset undervoltage threshold. Therefore, by acquiring the input current and voltage data of the inverter circuit under different loads, calculating correction coefficients, and correcting the load interference voltage based on these coefficients, the corrected load interference voltage can be closer to the actual value, resulting in a more accurate mains reference supply voltage. By comparing this value with a preset undervoltage threshold, it is possible to quickly determine whether the mains power is undervoltage, allowing for timely measures to protect equipment from low-voltage damage and improve system safety and reliability. Thus, precise load interference voltage correction helps to more rationally adjust the inverter's operating parameters, optimize motor operating efficiency, and reduce unnecessary energy consumption. By proactively identifying and addressing power supply problems, costs associated with equipment damage or downtime for maintenance can be reduced, as can downtime caused by sudden failures.

[0129] Figure 3This is a schematic diagram of an undervoltage detection device according to an embodiment of the present disclosure. Figure 3 As shown, the undervoltage detection device 300 includes:

[0130] The first determining module 310 is used to determine the input voltage and input current of the inverter circuit in the frequency converter;

[0131] The second determining module 320 is used to determine the load interference voltage based on the input current;

[0132] The third determining module 330 is used to determine the mains reference supply voltage based on the input voltage and the load interference voltage;

[0133] The judgment module 340 is used to determine whether the mains power is in an undervoltage state based on the mains power reference supply voltage and the preset undervoltage threshold.

[0134] Optionally, the second determining module 320 is specifically used for:

[0135] The load interference voltage is determined based on the ratio between the input current and the preset reference current, and the preset reference interference voltage.

[0136] or,

[0137] The load interference voltage is determined based on the current input current, the preset mains power supply frequency, and the capacitance value.

[0138] Optionally, the third determining module 330 includes:

[0139] The correction unit is used to correct the load interference voltage based on a preset correction coefficient to obtain the corrected load interference voltage.

[0140] The first determining unit is used to determine the mains reference supply voltage based on the corrected load interference voltage and the input voltage.

[0141] Optionally, the correction unit is also used for:

[0142] The inverter circuit obtains multiple sets of input current and input voltage corresponding to different loads under the first supply voltage and the first supply frequency.

[0143] Based on the first power supply voltage, the first power supply frequency, and the multiple sets of input current and input voltage, a number of initial correction coefficients are determined;

[0144] The average of the plurality of initial correction coefficients is used as the correction coefficient.

[0145] Optional, the judgment module 340 is specifically used for:

[0146] If the mains reference supply voltage is less than the preset undervoltage threshold, and the duration of the voltage being less than the preset undervoltage threshold reaches a duration threshold, then the system is determined to be in an undervoltage state.

[0147] Optionally, the judgment module 340 is also used for:

[0148] If it is determined that the mains power is undervoltage, the inverter circuit is controlled to enter the undervoltage protection state and stop outputting.

[0149] Optionally, the first determining module 310 is specifically used for:

[0150] Obtain the output voltage, output current, and input voltage of the inverter circuit in the frequency converter;

[0151] The output power of the inverter circuit is determined based on its output voltage and output current.

[0152] The input current of the inverter circuit is determined based on the input voltage and the output power.

[0153] In this embodiment, the input voltage and input current of the inverter circuit in the frequency converter are first determined. Then, based on the input current, the load interference voltage is determined. Next, based on the input voltage and the load interference voltage, the mains reference supply voltage is determined. Finally, based on the mains reference supply voltage and a preset undervoltage threshold, it is determined whether the mains is in an undervoltage state. Therefore, it is possible to jointly determine whether the mains is in an undervoltage state based on the load interference voltage, the frequency converter's input voltage, and the preset undervoltage threshold. The load interference voltage is the voltage value pulled down by the load, ensuring that the mains reference supply voltage reflects the frequency converter voltage value under theoretical conditions, thus improving the accuracy of the mains undervoltage determination.

[0154] According to embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0155] Figure 4 A block diagram of an exemplary electronic device suitable for implementing embodiments of the present disclosure is shown. Figure 4 The electronic device 12 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments disclosed herein.

[0156] like Figure 4 As shown, the electronic device 12 is represented in the form of a general-purpose computing device. The components of the electronic device 12 may include, but are not limited to: one or more processors or processing units 16, system memory 28, and bus 18 connecting different system components (including system memory 28 and processing unit 16).

[0157] Bus 18 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. Examples of these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0158] Electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0159] Memory 28 may include computer system readable media in the form of volatile memory, such as Random Access Memory (RAM) 30 and / or cache memory 32. Electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 34 may be used to read and write non-removable, non-volatile magnetic media (… Figure 4 Not shown; usually referred to as a "hard drive".

[0160] although Figure 4 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disc drive for reading and writing to a removable non-volatile optical disc (e.g., a compact disc read-only memory (CD-ROM), a digital video disc read-only memory (DVD-ROM), or other optical media) may be provided. In these cases, each drive may be connected to bus 18 via one or more data media interfaces. Memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of this disclosure.

[0161] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 42 typically perform the functions and / or methods described in the embodiments of this disclosure.

[0162] Electronic device 12 can also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), and with one or more devices that enable a user to interact with electronic device 12, and / or with any device that enables electronic device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed via input / output (I / O) interface 22. Furthermore, electronic device 12 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 20. As shown, network adapter 20 communicates with other modules of electronic device 12 via bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with electronic device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0163] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing the undervoltage detection method mentioned in the foregoing embodiments.

[0164] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the applications disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0165] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

[0166] It should be noted that in the description of this disclosure, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0167] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.

[0168] It should be understood that various parts of this disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0169] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0170] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into a single processing module, or each unit can exist physically separately, or two or more units can be integrated into a single module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The aforementioned storage medium can be a read-only memory, a hard disk, or an optical disk, etc.

[0171] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0172] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A method of detecting an under-voltage, characterized by, The method comprises: determining an input voltage and an input current of an inverter circuit in a frequency converter; determining a load disturbance voltage based on the input current; determining a mains reference supply voltage based on the input voltage and the load disturbance voltage; judging whether the mains is in an under-voltage state based on the mains reference supply voltage and a preset under-voltage threshold.

2. The method of claim 1, wherein, The determining of the load disturbance voltage based on the input current comprises: determining the load disturbance voltage based on a ratio between the input current and a preset reference current and a preset reference disturbance voltage; or determining the load disturbance voltage based on the current input current, a preset mains supply frequency and a preset capacitance value. The determining of the mains reference supply voltage based on the input voltage and the load disturbance voltage comprises:

3. The method of claim 1, wherein, correcting the load disturbance voltage based on a preset correction coefficient to obtain a corrected load disturbance voltage; determining the mains reference supply voltage according to the corrected load disturbance voltage and the input voltage. Before the correcting of the load disturbance voltage based on the preset correction coefficient to obtain the corrected load disturbance voltage, the method further comprises:

4. The method of claim 3, wherein, obtaining a plurality of groups of input currents and input voltages of the inverter circuit corresponding to different loads under a first supply voltage and a first supply frequency of the frequency converter; determining a plurality of initial correction coefficients based on the first supply voltage, the first supply frequency and the plurality of groups of input currents and input voltages; taking an average of the plurality of initial correction coefficients as the correction coefficient. The judging of whether the mains is in the under-voltage state based on the mains reference supply voltage and the preset under-voltage threshold comprises:

5. The method of claim 1, wherein, determining that the mains is in the under-voltage state when the mains reference supply voltage is less than the preset under-voltage threshold and a duration of the mains reference supply voltage being less than the preset under-voltage threshold reaches a duration threshold. After the judging of whether the mains is in the under-voltage state based on the mains reference supply voltage and the preset under-voltage threshold, the method further comprises:

6. The method of claim 1, wherein, controlling the inverter circuit to enter an under-voltage protection state and stop outputting when it is determined that the mains is in the under-voltage state. The determining of the input voltage and the input current of the inverter circuit in the frequency converter comprises:

7. The method of claim 1, wherein, obtaining an output voltage, an output current and an input voltage of the inverter circuit in the frequency converter; determining an output power of the inverter circuit according to the output voltage and the output current of the inverter circuit; determining the input current of the inverter circuit according to the input voltage and the output power. The method comprises:

8. An apparatus for detecting an under-voltage, characterized by a first determining module configured to determine an input voltage and an input current of an inverter circuit in a frequency converter; a second determining module configured to determine a load disturbance voltage based on the input current; a third determining module configured to determine a mains reference supply voltage based on the input voltage and the load disturbance voltage; a judging module configured to judge whether the mains is in an under-voltage state based on the mains reference supply voltage and a preset under-voltage threshold. 9.An electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein, ​ The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-7.

10. A non-transitory computer readable storage medium having stored thereon computer instructions, wherein, The computer instructions are for causing the computer to perform the method of any one of claims 1-7.

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