Sampling system and calibration method and device thereof

Abstract

The invention relates to the technical field of electric energy meters, and discloses a sampling system and a calibration method and device thereof, applied to the sampling system, and the sampling system comprises a plurality of voltage sampling circuits. The method comprises the following steps: controlling the sampling system to work in a first effective value calculation mode or a second effective value calculation mode, and calculating to obtain a voltage effective value of each phase voltage sampling circuit; calculating a gain calibration coefficient and an effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage; and after the current voltage sampling value of each phase voltage sampling circuit is obtained, the voltage sampling value is corrected based on the gain calibration coefficient and the effective value conversion coefficient, and a voltage true value is obtained through calculation. According to the invention, the influence of potential floating among multiple sampling channels of the sampling system on an actual sampling result can be reduced, and the reliability of the sampling system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric energy meter, in particular to a sampling system and a calibration method and device thereof. BACKGROUND

[0002] The traditional electric meter voltage sampling circuit is generally isolated by a mutual inductor or uses N-phase as a system GND and a series voltage divider to realize the transmission of high voltage to low voltage, and finally input to an analog-to-digital converter (ADC) or a metering module for sampling. However, the potential between the GND and the reference level of the external ABCN is floating, which leads to unstable calibration process and unsatisfactory calibration results, and low system reliability.

[0003] In addition, there is also a method of using ABCN series high resistance circuit to raise the DC reference, and then realizing differential sampling to single-ended mode to ADC for sampling through operational amplifier impedance matching and voltage following. This kind of sampling method needs to use operational amplifier to realize large input impedance and small output impedance, and at the same time realize impedance matching. The purpose is to make the sampling resistance of the metering module or the ADC sampling part negligible relative to its input impedance, and realize high-precision sampling. However, this method needs to use more circuit hardware, which leads to low calibration accuracy and high circuit cost. SUMMARY

[0004] Therefore, the present application provides a sampling system and a calibration method and device thereof to solve the problem of low sampling accuracy caused by potential floating between each sampling channel of the sampling system in the prior art.

[0005] In a first aspect, the present application provides a calibration method applied to a sampling system, the sampling system comprising a plurality of voltage sampling circuits. After a rated calibration voltage is applied to the input end of the voltage sampling circuit, the method comprises: controlling the sampling system to work in a first effective value calculation mode or a second effective value calculation mode, and calculating the voltage effective value of each phase voltage sampling circuit; calculating the gain calibration coefficient and the effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage; after obtaining the current voltage sampling value of each phase voltage sampling circuit, correcting the voltage sampling value based on the gain calibration coefficient and the effective value conversion coefficient, and calculating the true voltage value; the first effective value calculation mode is to calculate the voltage effective value based on the sampling value of a single voltage sampling circuit; and the second effective value calculation mode is to calculate the voltage effective value based on the difference between the sampling values of two voltage sampling circuits.

[0006] The calibration method provided by the application adopts single-end calculation mode in the first effective value calculation to obtain gain calibration coefficients, which can eliminate the interference of neutral phase channel potential floating, accurately calculate the absolute error of each channel itself, and realize high-precision matching between channels of different phases; the second effective value calculation adopts differential calculation mode to obtain effective value conversion coefficients, which can effectively suppress common mode noise interference occurring between different phases and the neutral phase, and further improve the accuracy of sampling results.

[0007] In an optional embodiment, when the calculation of the gain calibration coefficients adopts the relative coefficient method, the rated calibration voltage is sequentially applied between the voltage sampling circuit of one phase and the voltage sampling circuit of the neutral phase, and zero voltage is applied to the voltage sampling circuits of the remaining phases; when the calculation of the gain calibration coefficients adopts the absolute coefficient method, the reference ground of the sampling system is led out, and the same rated calibration voltage is applied between the voltage sampling circuits of different phases and the reference ground; the sampling system is controlled to work in the first effective value calculation mode, and the process of calculating and obtaining the voltage effective value of the voltage sampling circuit of each phase includes: the root mean square of the current sampling voltage of the voltage sampling circuit of each phase is calculated respectively, and is stored as the voltage effective value.

[0008] In an optional embodiment, after the rated calibration voltage is sequentially applied between the voltage sampling circuit of one phase and the voltage sampling circuit of the neutral phase, the process of controlling the sampling system to work in the second effective value calculation mode includes: the root mean square of the difference between the current sampling voltage of the voltage sampling circuit of one phase and the voltage sampling circuit of the neutral phase is calculated respectively and stored as the voltage effective value.

[0009] In an optional embodiment, when the calculation of the gain calibration coefficients adopts the relative coefficient method, the input ends of the voltage sampling circuits of different phases are short-circuited to the reference voltage, the rated calibration voltage is sequentially applied between the voltage sampling circuit of one phase and the voltage sampling circuit of the neutral phase, and zero voltage is applied to the voltage sampling circuits of the remaining phases, or when the calculation of the gain calibration coefficients adopts the absolute coefficient method, the reference voltage point of the sampling system is led out, the input ends of the voltage sampling circuits of different phases are short-circuited to the reference voltage, and the same rated calibration voltage is applied between the voltage sampling circuits of different phases and the reference voltage point; the sampling system is controlled to work in the first effective value calculation mode, and the process of calculating and obtaining the voltage effective value of the voltage sampling circuit of each phase includes: the current sampling voltage of each voltage sampling circuit short-circuited to the reference voltage is stored as the direct current offset value; the current sampling voltage of each voltage sampling circuit is compensated by using the direct current offset value, and the root mean square of the compensated current sampling voltage is calculated and stored as the voltage effective value.

[0010] In an alternative embodiment, the sampling system further comprises a plurality of current sampling circuits, after the same rated current is sequentially applied to the input terminals of the current sampling circuits, the method further comprises: taking the current sampling current of one phase current sampling circuit as a reference current, and then calculating the current consistency coefficients of the phase current sampling circuits based on the reference current; after obtaining the current sampling values of the phase current sampling circuits, correcting the current sampling values based on the current consistency coefficients, and calculating the true current values.

[0011] In an alternative embodiment, after the rated calibration voltage and the rated current are respectively applied to the phase voltage sampling circuits and the current sampling circuits, the method further comprises: calculating the current sampling power values of the phases based on the current sampling voltages of the phase voltage sampling circuits and the current sampling currents of the phase current sampling circuits; correcting the theoretical power values after setting the power factor of the sampling system to 1; calculating the power gain correction coefficients of the phases based on the ratio of the corrected theoretical power values to the current sampling power values of the phases, so as to calibrate the gain of the sampling power values.

[0012] In an alternative embodiment, after the rated calibration voltage and the rated current are respectively applied to the phase voltage sampling circuits and the current sampling circuits, the method further comprises: calculating the current sampling power values of the phases based on the current sampling voltages of the phase voltage sampling circuits and the current sampling currents of the phase current sampling circuits; correcting the theoretical power values after setting the power factor of the sampling system to 0.5; calculating the power phase correction coefficients of the phases based on the ratio of the corrected theoretical power values to the current sampling power values of the phases, so as to calibrate the phase of the sampling power values.

[0013] In a second aspect, the present application provides a calibration device, comprising: a calculation mode switching module, configured to control the sampling system to work in a first effective value calculation mode or a second effective value calculation mode, and calculate the voltage effective values of the phase voltage sampling circuits; the first effective value calculation mode is based on the sampling values of a single voltage sampling circuit; the second effective value calculation mode is based on the difference between the sampling values of two voltage sampling circuits; a correction coefficient calculation module, configured to calculate the gain correction coefficients and the effective value conversion coefficients of the phase voltage sampling circuits based on the voltage effective values and the rated calibration voltage; and a correction module, configured to obtain the current voltage sampling values of the phase voltage sampling circuits, and then correct the voltage sampling values based on the gain correction coefficients and the effective value conversion coefficients, and calculate the true voltage values.

[0014] In a third aspect, the present application provides a sampling system, comprising: a plurality of voltage sampling circuits, a plurality of current sampling circuits, a metering module and a control circuit, wherein the input end of each voltage sampling circuit collects a phase voltage signal of a power system, and the output end of each voltage sampling circuit is connected with the input end of the metering module; the input end of each current sampling circuit collects a phase current signal of the power system, and the output end of each current sampling circuit is connected with the input end of the metering module; the output end of the metering module is connected with the control circuit, the metering module is used for processing the voltage signal and the current signal; the control circuit is used for implementing the calibration method of the first aspect or any one of the corresponding embodiments; and the metering module comprises one of a metering chip or an analog-to-digital converter.

[0015] In a fourth aspect, the present application provides a computer device, comprising: a memory and a processor, which are connected with each other in communication, the memory stores computer instructions, and the processor executes the calibration method of the first aspect or any one of the corresponding embodiments by executing the computer instructions.

[0016] In a fifth aspect, the present application provides a computer readable storage medium, which stores computer instructions, and the computer instructions are used for making a computer execute the calibration method of the first aspect or any one of the corresponding embodiments.

[0017] In a sixth aspect, the present application provides a computer program product, comprising computer instructions, and the computer instructions are used for making a computer execute the calibration method of the first aspect or any one of the corresponding embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0019] Figure 1 is a flowchart of the calibration method according to the embodiment of the present application; Figure 2 is a flowchart of the current calibration method according to the embodiment of the present application; Figure 3 is a flowchart of the power calibration method according to the embodiment of the present application; Figure 4 is a structural block diagram of the calibration device according to the embodiment of the present application; Figure 5 is a structural diagram of the sampling system according to the embodiment of the present application; Figure 6 is a specific circuit diagram of a voltage sampling circuit according to an embodiment of the present application; Figure 7 is a specific circuit diagram of a current sampling circuit according to an embodiment of the present application; Figure 8 is a structural diagram of another sampling system according to an embodiment of the present application; Figure 9 is a specific circuit diagram of another voltage sampling circuit according to an embodiment of the present application; Figure 10 is a specific circuit diagram of another current sampling circuit according to an embodiment of the present application; Figure 11 is a hardware structure schematic diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0021] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0022] For a multi-phase sampling system, the voltage sampling circuit of each sampling channel usually includes a plurality of series-connected or parallel-connected resistors. The resistors in each phase voltage sampling circuit cannot be completely consistent in accuracy, and therefore, the multi-phase voltage channel needs to be calibrated to eliminate the problem of inaccurate sampling results caused by potential floating between the sampling channels.

[0023] The present embodiment provides a calibration method applied to a sampling system. The sampling system includes a plurality of voltage sampling circuits. After a rated calibration voltage is applied to the input end of the voltage sampling circuit, as shown in FIG. 1, the method includes the following steps. Figure 1 Step S1: Control the sampling system to work in a first effective value calculation mode or a second effective value calculation mode, and calculate and obtain the voltage effective value of each phase voltage sampling circuit. The first effective value calculation mode is to calculate the voltage effective value based on the sampling value of a single voltage sampling circuit. The second effective value calculation mode is to calculate the voltage effective value based on the difference between the sampling values of two voltage sampling circuits.

[0024] ​Exemplarily, when the sampling system is used to collect the phase voltages of a three-phase power system, in the first effective value calculation mode, the A-phase voltage effective value is the root mean square of the A-phase voltage sampling value, the B-phase voltage effective value is the root mean square of the B-phase voltage sampling value, the C-phase voltage effective value is the root mean square of the C-phase voltage sampling value, and the N-phase voltage effective value is the root mean square of the N-phase voltage sampling value; in the second effective value calculation mode, the A-phase voltage effective value is the root mean square of the difference between the A-phase voltage instantaneous value and the N-phase voltage instantaneous value, the B-phase voltage effective value is the root mean square of the difference between the B-phase voltage instantaneous value and the N-phase voltage instantaneous value, and the C-phase voltage effective value is the root mean square of the difference between the C-phase voltage instantaneous value and the N-phase voltage instantaneous value.

[0025] Step S2: calculating the gain calibration coefficient and the effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage.

[0026] Specifically, the first effective value calculation mode includes two calculation methods of the relative coefficient calibration method and the absolute coefficient calibration method to calculate the gain calibration coefficient. When the relative coefficient calibration method is adopted, the rated calibration voltage applied to the input end of the voltage sampling circuit is: the rated calibration voltage is applied between one phase voltage sampling circuit and the neutral phase voltage sampling circuit in turn, and zero voltage is applied to the remaining phase voltage sampling circuit. Then, the gain calibration coefficient of each voltage sampling circuit is calculated by using the current effective value of each phase voltage.

[0027] Specifically, when the absolute coefficient calibration method is adopted, the rated calibration voltage applied to the input end of the voltage sampling circuit is: the same rated calibration voltage is applied between each phase voltage sampling circuit and the reference ground of the sampling system after the reference ground of the sampling system is led out. Then, the gain calibration coefficient of each voltage sampling circuit is calculated by using the current effective value of each phase voltage with the reference ground of the sampling system as the absolute reference.

[0028] Specifically, the second effective value calculation mode is used to calculate the effective value conversion coefficient, and the rated calibration voltage applied to the input end of the voltage sampling circuit is: the rated calibration voltage is applied between one phase voltage sampling circuit and the neutral phase voltage sampling circuit in turn. Then, the effective value conversion coefficient of each voltage sampling circuit is calculated according to the current effective value of each phase voltage.

[0029] Step S3: after obtaining the current voltage sampling value of each phase voltage sampling circuit, correcting the voltage sampling value based on the gain calibration coefficient and the effective value conversion coefficient, and calculating to obtain the voltage true value.

[0030] Specifically, after the relative error between each voltage sampling circuit is eliminated by using the gain calibration coefficient calculated in step S2, the current effective value of each phase voltage is calibrated by using the effective value conversion coefficient to obtain the voltage true value of each phase.

[0031] The calibration method provided by the embodiment adopts a single-end calculation mode for first effective value calculation, calculates gain calibration coefficients, can eliminate the interference of neutral phase channel potential floating, accurately calculates the absolute error of each channel itself, and realizes high-precision matching between channels of different phases; the second effective value calculation adopts a differential calculation mode, calculates effective value conversion coefficients, effectively suppresses common-mode noise interference occurring simultaneously between phases and the neutral phase, and further improves the accuracy of sampling results.

[0032] In some optional embodiments, when the sampling system comprises a voltage sampling circuit, a metering chip and a control circuit connected in sequence, the voltage sampling circuit is configured to collect phase voltages of a power line, the metering chip is configured to process voltage signals and current signals, and the control circuit is configured to perform calibration. The sampling system is controlled to work in a first effective value calculation mode, and the process of calculating the voltage effective value of each phase voltage sampling circuit includes: calculating the root mean square of the current sampling voltage of each phase voltage sampling circuit respectively, and storing the root mean square as the voltage effective value.

[0033] For example, the sampling system collects the voltages UA, UB and UC of a three-phase power line. When the gain calibration coefficient is calculated by using the relative coefficient method, the rated calibration voltage is sequentially applied between one phase voltage sampling circuit and the neutral phase voltage sampling circuit, and zero voltage is applied to the remaining phase voltage sampling circuit, and then the gain calibration coefficient of each phase voltage sampling circuit is calculated based on the voltage effective value and the rated calibration voltage. The specific steps are as follows: (1) Obtain the voltage effective value of each phase by using the first effective value calculation mode, and store the voltage effective value in the metering chip of the sampling system.

[0034] (2) Apply the rated voltage Ue to the A phase and the N phase, and apply 0V to the B phase and the C phase. Read the effective value register values of the metering chip of the UB and UC and UN channels as UA_ub, UA_uc and UA_un. Calculate the influence coefficient of the B phase relative to the neutral phase IndexUA_ub=UA_un / UA_ub and the influence coefficient of the C phase relative to the neutral phase IndexUA_uc=UA_un / UA_uc at this time.

[0035] (3) Apply the rated voltage Ue to the B phase and the N phase, and apply 0V to the A phase and the C phase. Read the effective value register values of the metering chip of the UA and UC and UN channels as UB_ua, UB_uc and UB_un. Calculate the influence coefficient of the A phase relative to the neutral phase IndexUB_ua=UB_un / UB_ua and the influence coefficient of the C phase relative to the neutral phase IndexUB_uc=UB_un / UB_uc at this time.

[0036] (4) C phase and N phase apply rated voltage Ue, A phase and B phase apply 0V, read the effective value register values of the metering chip of UA and UB and UN channel as UC_ua, UC_ub, UC_un, calculate the influence coefficient of A phase relative to neutral phase IndexUC_ua=UC_un / UC_ua at this time, the influence coefficient of B phase relative to neutral phase IndexUC_ub=UC_un / UC_ub at this time.

[0037] (5) A phase relative coefficient IndexAN=(IndexUB_ua+IndexUC_ua) / 2, B phase relative coefficient IndexBN=(IndexUA_ub+IndexUC_ub) / 2, C phase relative coefficient IndexCN=(IndexUA_uc+IndexUB_uc) / 2. Then write each phase relative coefficient as each phase gain calibration coefficient into the A phase voltage gain, B phase voltage gain, C phase voltage gain of the metering chip respectively, so that when the same relative ground voltage (relative to the GND of the metering chip) is input to the UA, UB, UC, UN terminals, the voltage effective values of A, B, C, N phases of the metering chip are consistent.

[0038] Exemplarily, the sampling system collects the voltages UA, UB, UC of the three-phase power line. When the gain calibration coefficient calculation adopts the absolute coefficient method, the reference ground of the sampling system is led out, then the same rated calibration voltage is applied between each phase voltage sampling circuit and the reference ground, and then the specific steps of calculating the gain calibration coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage are as follows: (1) Obtain each phase voltage effective value by using the first effective value calculation mode and store it in the metering chip of the sampling system.

[0039] (2) Lead out the reference ground GND of the system, add the same rated voltage Ue between A phase and GND, B phase and GND, C phase and GND, N phase and GND, read the data Ua_Reg_Abs in the A phase effective value register, the data Ub_Reg_Abs in the B phase effective value register, the data Uc_Reg_Abs in the C phase effective value register and the calculated theoretical effective value U_L, and then compare them to obtain A phase coefficient IndexA=U_L / Ua_Reg_Abs, B phase coefficient IndexB=U_L / Ub_Reg_Abs, C phase coefficient IndexC=U_L / Uc_Reg_Abs, N phase coefficient IndexN=U_L / UN_Reg_Abs, and then write them as each phase gain calibration coefficient into the A phase voltage gain, B phase voltage gain, C phase voltage gain and N phase voltage gain of the metering chip respectively.

[0040] In some alternative embodiments, when the sampling system comprises a voltage sampling circuit, a metering chip and a control circuit connected in sequence, the voltage sampling circuit is used to collect the voltage of each phase of the power line, the metering chip is used to process the voltage signal and the current signal, and the control circuit is used for calibration. The control sampling system works in the second effective value calculation mode, and the process of calculating the voltage effective value of each phase voltage sampling circuit includes: calculating the root mean square of the difference between the current sampling voltage of one phase voltage sampling circuit and the neutral phase voltage sampling circuit as the voltage effective value storage.

[0041] For example, the sampling system collects the voltages UA, UB and UC of a three-phase power line. The rated calibration voltage is applied between one phase voltage sampling circuit and neutral phase voltage sampling circuit in sequence, and then the specific steps of calculating the effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage are as follows: (1) Obtain the voltage effective value of each phase by using the second effective value calculation mode and store it in the metering chip of the sampling system.

[0042] (2) Apply the rated voltage Ue between A phase and N phase, B phase and N phase, and C phase and N phase in sequence, respectively read the data UA_RegNor in the A phase voltage effective value register, the data UB_RegNor in the B phase voltage effective value register and the data UC_RegNor in the C phase voltage effective value register, and then obtain the A phase effective value conversion coefficient kUa=Ue / UA_RegNor, the B phase effective value conversion coefficient kUb=Ue / UB_RegNor and the C phase effective value conversion coefficient kUc=Ue / UC_RegNor.

[0043] For example, after obtaining the effective value conversion coefficient of each phase in the above-mentioned manner, in the subsequent use process of the sampling circuit, the control circuit reads the value UA_Reg of the A phase voltage effective value register, then multiplies it by the A phase effective value conversion coefficient kUa to obtain the real A phase voltage Ua; reads the value UB_Reg of the B phase voltage effective value register, then multiplies it by the B phase effective value conversion coefficient kUb to obtain the real B phase voltage Ub; reads the value UC_Reg of the C phase voltage effective value register, then multiplies it by the C phase effective value conversion coefficient kUc to obtain the real C phase voltage Uc.

[0044] In some alternative embodiments, when the sampling system comprises a voltage sampling circuit, an analog-digital converter and a control circuit connected in sequence, the voltage sampling circuit is used to collect the voltage of each phase of the power line, the analog-digital converter is used to process the voltage signal and the current signal, and the control circuit is used for calibration. The control sampling system works in a first effective value calculation mode, and the process of calculating the voltage effective value of each phase voltage sampling circuit includes: storing the current sampling voltage of each phase voltage sampling circuit after shorting to the reference voltage as the DC offset value; using the DC offset value to compensate the current sampling voltage of each phase voltage sampling circuit, and calculating the root mean square of the compensated current sampling voltage as the voltage effective value.

[0045] Exemplarily, the sampling system collects the voltages UA, UB and UC of a three-phase power line. When the relative coefficient method is used to calculate the gain calibration coefficient, after the input end of each phase voltage sampling circuit is shorted to the reference voltage, the rated calibration voltage is sequentially applied between one phase voltage sampling circuit and the neutral phase voltage sampling circuit, and zero voltage is applied to the remaining phase voltage sampling circuit. The specific steps of calculating the gain calibration coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage are as follows: (1) Use the first effective value calculation mode to obtain the voltage effective value of each phase and store it in the analog-digital converter of the sampling system, and set the reference voltage values ua_Ref, ub_Ref, uc_Ref and un_Ref of each phase to 0.

[0046] (2) After the input end of the A-phase, B-phase, C-phase and N-phase voltage sampling circuit is shorted to the reference voltage, the sampling instantaneous values of the A-phase, B-phase, C-phase and N-phase are ua_Ref0, ub_Ref0, uc_Ref0 and uc_Ref0 respectively. The subsequent calculation of the voltage effective value is obtained by calculating the sampling instantaneous value minus the reference voltage value.

[0047] (3) Apply the rated voltage Ue to the A-phase and the N-phase, and apply 0V to the B-phase and the C-phase. Read the effective value register values of the measurement chip of the UB and UC channels as UA_ub, UA_uc and UA_un, and calculate the influence coefficient of the B-phase relative to the neutral phase IndexUA_ub=UA_un / UA_ub and the influence coefficient of the C-phase relative to the neutral phase IndexUA_uc=UA_un / UA_uc at this time.

[0048] (4) B phase and N phase apply rated voltage Ue, A phase and C phase apply 0V, read the effective value register values of the metering chip of UA and UC and UN channel as UB_ua, UB_uc, UB_un, calculate the influence coefficient of A phase relative to neutral phase IndexUB_ua=UB_un / UB_ua at this time, the influence coefficient of C phase relative to neutral phase IndexUB_uc=UB_un / UB_uc at this time.

[0049] (5) C phase and N phase apply rated voltage Ue, A phase and B phase apply 0V, read the effective value register values of the metering chip of UA and UB and UN channel as UC_ua, UC_ub, UC_un, calculate the influence coefficient of A phase relative to neutral phase IndexUC_ua=UC_un / UC_ua at this time, the influence coefficient of B phase relative to neutral phase IndexUC_ub=UC_un / UC_ub at this time.

[0050] (6) A phase relative coefficient IndexAN=(IndexUB_ua+IndexUC_ua) / 2, B phase relative coefficient IndexBN=(IndexUA_ub+IndexUC_ub) / 2, C phase relative coefficient IndexCN=(IndexUA_uc+IndexUB_uc) / 2. Then write the relative coefficient of each phase as the gain calibration coefficient of each phase into the A phase voltage gain, B phase voltage gain, C phase voltage gain of the metering chip respectively, so that when the same relative ground voltage (relative to the GND of the metering chip) is input to the UA, UB, UC, UN terminals, the voltage effective values of A, B, C, N phases of the metering chip are consistent.

[0051] Exemplarily, the sampling system collects the voltages UA, UB, UC of the three-phase power line. When the gain calibration coefficient calculation adopts the absolute coefficient method, the reference voltage point of the sampling system is led out, the input end of each phase voltage sampling circuit is short-circuited to the reference voltage, the same rated calibration voltage is applied between each phase voltage sampling circuit and the reference voltage point, and then the specific steps of calculating the gain calibration coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage are as follows: (1) Obtain the voltage effective value of each phase by using the first effective value calculation mode, store it in the metering chip of the sampling system, and set the reference voltage values ua_Ref, ub_Ref, uc_Ref, un_Ref of each phase to 0.

[0052] (2) The input end of the voltage sampling circuit of phase A, phase B, phase C and phase N is short-circuited to the reference voltage REFV, and the instantaneous values of the sampling values of phase A, phase B, phase C and phase N are ua_Ref0, ub_Ref0, uc_Ref0 and un_Ref0 respectively. The subsequent calculation of the effective value of the voltage is obtained by subtracting the reference voltage value from the sampling instantaneous value.

[0053] (3) The same rated voltage Ue is applied between phase A and REFV, between phase B and REFV, between phase C and REFV, and between phase N and REFV, and the effective value of the voltage of phase A Ua_Reg_Abs, the effective value of the voltage of phase B Ub_Reg_Abs, the effective value of the voltage of phase C Uc_Reg_Abs and the calculated theoretical effective value U_L are obtained. After comparison, the influence coefficient of phase A IndexA=U_L / Ua_Reg_Abs, the influence coefficient of phase B IndexB=U_L / Ub_Reg_Abs, the influence coefficient of phase C IndexC=U_L / Uc_Reg_Abs, and the influence coefficient of phase N IndexN=U_L / UN_Reg_Abs are obtained. After multiplying the influence coefficient of each phase by the originally stored effective value, the calibrated voltage effective value is calculated.

[0054] In some optional embodiments, the sampling system further comprises a plurality of current sampling circuits for collecting the currents of each phase of the power line. After the same rated current is applied to the input end of the current sampling circuit in turn, as shown in Figure 2 The calibration method further comprises: Step S4: After taking the current sampling current of one of the phase current sampling circuits as the reference current, the current consistency coefficient of each phase current sampling circuit is calculated based on the reference current.

[0055] Step S5: After obtaining the current sampling values of each phase current sampling circuit, the current sampling values are corrected based on the current consistency coefficient, and the true current value is calculated.

[0056] Exemplarily, when the sampling system comprises a voltage sampling circuit, a current sampling circuit, a metering chip and a control circuit, the calibration method specifically comprises the following steps: (1) Current channel consistency calibration: input the same rated current Ie to the input end of the three-phase current sampling circuit, read the A-phase current sampling value IA_RegNorl, B-phase current sampling value IB_RegNorl and C-phase current sampling value IC_RegNorl, set the A-phase current sampling value IA_RegNorl as the reference current, set the A-phase current consistency coefficient IndexIA as 1, then the B-phase current consistency coefficient IndexIB = IA_RegNorl / IB_RegNorl, the C-phase current consistency coefficient IndexIC = IC_RegNorl / IC_RegNorl, and write into the metering chip.

[0057] (2) Current coefficient calibration: read the current effective values of the current A-phase, B-phase and C-phase, recorded as IA_RegNor2, IB_RegNor2 and IC_RegNor2, calculate the A-phase current effective value conversion coefficient kIa = Ie / IA_RegNorl, the B-phase current effective value conversion coefficient kIb = Ie / IB_RegNor2, and the C-phase current effective value conversion coefficient kIc = Ie / IC_RegNor2.

[0058] (3) Multiply the instantaneous sampling value of each phase current by the effective value conversion coefficient of the phase to obtain the real value of each phase current.

[0059] Exemplarily, when the sampling system includes a voltage sampling circuit, a current sampling circuit, an analog-to-digital converter and a control circuit, the calibration method specifically includes the following steps: (1) Set the reference current values ia_Ref0, ib_Ref0 and ic_Ref0 of each phase to 0, which are stored as the DC offset reference values of the A-phase, B-phase and C-phase respectively.

[0060] (2) Effective value calculation: the A-phase current effective value is the root mean square of the difference between the A-phase current sampling value and the A-phase reference current, the B-phase current effective value is the root mean square of the difference between the B-phase current sampling value and the B-phase reference current, and the C-phase current effective value is the root mean square of the difference between the C-phase current sampling value and the C-phase reference current.

[0061] (3) After inputting the same rated current Ie to the input end of the three-phase current sampling circuit, calculate the A-phase current effective value IA_RegNorl, the B-phase current effective value IB_RegNorl and the C-phase current effective value IC_RegNorl. Set the A-phase current consistency coefficient IndexIA as 1, then the B-phase current consistency coefficient IndexIB = IA_RegNorl / IB_RegNor, and the C-phase current consistency coefficient IndexIC = IC_RegNorl / IC_RegNor. Multiply the instantaneous value sampling value of each phase by IndexIA, IndexIB and IndexIC as the current root mean square effective value calculation.

[0062] (4) Current coefficient calibration: read the current effective values of the A-phase, B-phase and C-phase, denoted as IA_RegNor2, IB_RegNor2 and IC_RegNor2, and calculate the A-phase current effective value conversion coefficient kIa=Ie / IA_RegNor1, the B-phase current effective value conversion coefficient kIb=Ie / IB_RegNor2 and the C-phase current effective value conversion coefficient kIc=Ie / IC_RegNor2.

[0063] (5) Multiply the instantaneous sampling value of each phase current by the effective value conversion coefficient of the phase to obtain the real value of each phase current.

[0064] In some optional embodiments, after applying the rated calibration voltage and the rated current to the voltage sampling circuit and the current sampling circuit of each phase respectively, the calibration method further includes: Figure 3 as shown in the figure, the calibration method further includes: Step S6: calculating the current sampling power value of each phase according to the current sampling voltage of each phase voltage sampling circuit and the current sampling current of each phase current sampling circuit.

[0065] Step S7: correcting the theoretical power value after setting the power factor of the sampling system to 1.

[0066] Step S8: calculating the power gain correction coefficient of each phase based on the ratio of the corrected theoretical power value to the current sampling power value of each phase, so as to calibrate the gain of the sampling power value.

[0067] Exemplarily, when the sampling system includes a voltage sampling circuit, a current sampling circuit, a metering chip and a control circuit, the specific steps of power gain calibration are as follows: (1) input the rated voltage Ue to the input end of each phase voltage sampling circuit, input the rated current Ie to the input end of each phase voltage sampling circuit, calculate the rated power Pe, and set the power factor of the control circuit to 1.

[0068] (2) read the power gain effective value PA_RegNor of the A-phase, the power gain effective value PB_RegNor of the B-phase and the power gain effective value PC_RegNor of the C-phase, calculate the A-phase power gain coefficient IndexPA=Pe / PA_RegNor, the B-phase power gain coefficient IndexPB=Pe / PB_RegNor and the C-phase power gain coefficient IndexPC=Pe / PC_RegNor.

[0069] Exemplarily, when the sampling system includes a voltage sampling circuit, a current sampling circuit, an analog-to-digital converter and a control circuit, the specific steps of power gain calibration are as follows: (1) The input end of each phase voltage sampling circuit inputs rated voltage Ue, the input end of each phase voltage sampling circuit inputs rated current Ie, the rated power Pe is calculated, and the power factor of the control circuit is set to 1.

[0070] (2) The power gain effective value PA_RegNor of phase A, the power gain effective value PB_RegNor of phase B, and the power gain effective value PC_RegNor of phase C are read, at this time, the effective values of phases A, B, and C are not multiplied by IndexPA and IndexPB and IndexPC.

[0071] (3) The power gain coefficient IndexPA of phase A is calculated as IndexPA=Pe / PA_RegNor, the power gain coefficient IndexPB of phase B is calculated as IndexPB=Pe / PB_RegNor, and the power gain coefficient IndexPC of phase C is calculated as IndexPC=Pe / PC_RegNor.

[0072] Step S9: The current sampling power value of each phase is calculated and obtained according to the current sampling voltage of each phase voltage sampling circuit and the current sampling current of each phase current sampling circuit.

[0073] Step S10: The theoretical power value is corrected after the power factor of the sampling system is set to 0.5.

[0074] Step S11: Based on the ratio of the corrected theoretical power value to the current sampling power value of each phase, the power phase correction coefficient of each phase is calculated, so as to calibrate the phase of the sampling power value.

[0075] Exemplarily, when the sampling system includes a voltage sampling circuit, a current sampling circuit, a metering chip, and a control circuit, (1) The input end of each phase voltage sampling circuit inputs rated voltage Ue, the input end of each phase voltage sampling circuit inputs rated current Ie, the rated power Pe is calculated, and the power factor of the control circuit is set to 0.5.

[0076] (2) The power gain effective value PA_RegNor2 of phase A, the power gain effective value PB_RegNor2 of phase B, and the power gain effective value PC_RegNor2 of phase C are read, the power phase coefficient IndexPA2 of phase A is calculated as IndexPA2=Pe*0.5 / PA_RegNor2, the power phase coefficient IndexPB2 of phase B is calculated as IndexPB2=Pe*0.5 / PB_RegNor2, and the power phase coefficient IndexPC2 of phase C is calculated as IndexPC2=Pe*0.5 / PC_RegNor2.

[0077] (3) IndexPA2, IndexPB2, and IndexPC2 are written into the metering chip.

[0078] Exemplarily, when the sampling system comprises a voltage sampling circuit, a current sampling circuit, an analog-digital converter and a control circuit, the specific steps of power phase calibration are as follows: (1) The input end of each phase voltage sampling circuit inputs rated voltage Ue, the input end of each phase voltage sampling circuit inputs rated current Ie, the rated power Pe is calculated, and the power factor of the control circuit is set to 0.5.

[0079] (2) Read the power gain effective value PA_RegNor2 of phase A, the power gain effective value PB_RegNor2 of phase B, and the power gain effective value PC_RegNor2 of phase C, at this time, the effective values of phases A, B and C are multiplied by IndexPA and IndexPB and IndexPC.

[0080] (3) Calculate the power phase coefficient IndexPA2 of phase A = Pe*0.5 / PA_RegNor2, the power phase coefficient IndexPB2 of phase B = Pe*0.5 / PB_RegNor2, and the power phase coefficient IndexPC2 of phase C = Pe*0.5 / PC_RegNor2.

[0081] (4) Convert IndexPA2, IndexPB2 and IndexPC2 into phase shift parameters, participate in power effective value calculation, and the final power effective value is the effective value after phase shift and gain calibration.

[0082] It should be noted that after voltage calibration, the three-phase four-wire or three-phase three-wire of the power system needs to be configured, and the voltage instantaneous value is processed respectively. The phase voltage instantaneous value of three-phase four-wire is equal to the difference between the phase voltage instantaneous value and the zero line voltage instantaneous value, and the three-phase three-wire instantaneous value is equal to the difference between the two phase voltage instantaneous values. After the instantaneous value is processed, it participates in the subsequent calculation of voltage effective value and power effective value. Whether the sampling system includes a metering module or an analog-digital converter, when the three-phase four-wire needs to be switched to three-phase three-wire, the calculation of AB line effective value is participated by the difference between the instantaneous values of phase A and phase B, and the calculation of BC line effective value is participated by the difference between the instantaneous values of phase B and phase C. The calculation of AC line effective value is participated by the difference between the instantaneous values of phase A and phase C, and through this way, the effective value calculation of line voltage is realized, that is, the switching between three-phase three-wire and three-phase four-wire can be realized without changing the input voltage terminal.

[0083] Optionally, when the power system is single-phase, based on the above calibration method, only one way of voltage (2 voltage sampling circuits) and one way of current (1 current sampling circuit) need to be sampled, so as to realize the calibration of single-phase sampling system.

[0084] A calibration device is also provided in the embodiment, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be described again. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation of hardware, or a combination of software and hardware, is also possible and contemplated.

[0085] The embodiment provides a calibration device, as shown in the accompanying drawings, comprising: Figure 4 The computing mode switching module 401 is configured to control the sampling system to operate in a first effective value computing mode or a second effective value computing mode, and to compute and obtain voltage effective values of the voltage sampling circuits of each phase; the first effective value computing mode is based on the sampling value of a single voltage sampling circuit; and the second effective value computing mode is based on the difference between the sampling values of two voltage sampling circuits.

[0086] The correction coefficient computing module 402 is configured to compute the gain correction coefficient and the effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage.

[0087] The correction module 403 is configured to, after obtaining the current voltage sampling value of each phase voltage sampling circuit, correct the voltage sampling value based on the gain correction coefficient and the effective value conversion coefficient, and to compute and obtain the voltage true value.

[0088] Further function descriptions of the above-mentioned modules and units are the same as those of the corresponding embodiments, and will not be described again.

[0089] The calibration device in the embodiment is presented in the form of functional units, where the units refer to ASIC (Application Specific Integrated Circuit, special-purpose integrated circuit) circuits, processors and memories that execute one or more software or fixed programs, and / or other devices that can provide the above-mentioned functions.

[0090] The embodiment provides a sampling system, comprising a plurality of voltage sampling circuits, a plurality of current sampling circuits, a metering module and a control circuit, the input end of each voltage sampling circuit collects a voltage signal of each phase of a power system, and the output end of each voltage sampling circuit is connected with the input end of the metering module; the input end of each current sampling circuit collects a current signal of each phase of the power system, and the output end of each current sampling circuit is connected with the input end of the metering module; the output end of the metering module is connected with the control circuit, and the metering module is configured to process the voltage signal and the current signal; and the control circuit is configured to implement the calibration method of the first aspect or any of the corresponding embodiments. The metering module comprises one of a metering chip or an analog-to-digital converter.

[0091] ​Exemplarily, as shown in Figure 5 The sampling system includes, when the metering module includes a metering chip, the metering chip (#41~#42), a plurality of voltage sampling circuits (#11~#14), a plurality of current sampling circuits (#31~#32), three-phase transformers (#21~#22), and a control circuit 5.

[0092] Exemplarily, Figure 5 In the metering chip, the input end of each voltage sampling circuit is respectively connected with the A, B, C, and N phase voltage lines of the power grid, and the voltage sampling circuit is used for voltage division of the voltage signals on the A, B, C, and N phases of the power grid to obtain small signals, which are input to the four voltage sampling channels of the metering chip. Each three-phase transformer is sleeved on the power grid voltage line, and is used for converting the large current signal on the primary side into a small current signal. The current sampling circuit is used for converting the small current signal into a small voltage signal that can be sampled by the metering chip, and inputting the small voltage signal to the current sampling channel of the metering chip. The metering chip is used for processing the electrical signals on the voltage sampling channel and the current sampling channel, and directly converting into the effective values of voltage and current and indirectly converting into digital signal parameters such as power and energy. The control circuit is responsible for data interaction of the metering chip, including reading the digital signals of the electric quantity and the energy and the gain and calibration of the voltage channel and the current channel, and the consistency calibration of the voltage channel. The control circuit 5 realizes the calibration function by using the calibration method in the above embodiment when the system contains the metering chip.

[0093] Figure 5 The metering chip further includes an isolation module 6, an indicator 7, a communication module 8, a key 9, a storage module 10, a voltage stabilizing module 11, and an isolation power supply 12.

[0094] Specifically, Figure 5 In the metering chip, the indicator 7 has four indicator lights: 2-way pulse signals of the metering chip, 1-way Wifi networking signal indication, and 1-way power supply indication. The Wifi indicator light: 1Hz flicker indicates initialization and network searching, 2Hz flicker indicates networking, and constant light indicates successful networking and normal data.

[0095] Specifically, Figure 5 In the metering chip, the communication module 8 adopts a Wi-Fi communication module, which is used for data interaction with a background system and transmits the electric quantity and energy related to the background system. The communication module 8 is isolated from other modules through the isolation module 6 through an RS485 circuit, so as to avoid the influence of module interference signals on RS485 communication.

[0096] Specifically, Figure 5In the embodiment, the key 9 is used for networking and resetting the device or restarting the device. Networking: long press the key 6 for 5 seconds to re-network, enter the network configuration mode, and the Wi-Fi indicator light blinks at 1 Hz. Resetting the device: short press the key 6 for 5 seconds to enter the resetting device preparation phase, and the Wi-Fi indicator light blinks at 5 Hz for 40 seconds. In this time interval, long press the key for 12 seconds to enter the resetting device recovery factory settings. Restarting the device: short press the key 3 times within 1 second to restart the device.

[0097] Specifically, Figure 5 In the embodiment, the storage module 10 is used for storing configuration parameters, calibration data and electric energy data of the metering chip. The AC-DC power supply is used for providing one power output for the entire system through the full-wave rectification from the voltage signal terminals Ua, Ub, Uc and Un and through the flyback switching power supply. The voltage stabilizing module 11 is used for converting the voltage output by the AC-DC power supply into the voltage required by the system. The isolation power supply 12 is used for isolating the voltage output by the AC-DC power supply to output one voltage to the isolation module chip and the RS485 power supply.

[0098] Specifically, Figure 6 In the embodiment, the specific circuit structure of the voltage sampling circuit is that the metering chip has four groups of voltage sampling channels, and each voltage sampling circuit channel is composed of a differential sampling circuit formed by a plurality of series-connected resistors. Figure 7 The specific circuit structure of the current sampling circuit is used for differential sampling.

[0099] Specifically, as shown in Figure 8 When the metering module includes an analog-to-digital converter, the sampling system includes a plurality of voltage sampling circuits (#11~#14), a current sampling circuit #31, a three-phase mutual inductor #21, a control circuit 5 and an analog-to-digital converter 13. The voltage and current sampled signals are collected by the analog-to-digital converter 5. The analog-to-digital converter 13 can sample positive and negative signals or only sample positive signals. If only positive signals are sampled, the direct current component in the sampling instantaneous value needs to be removed. The control circuit 5 realizes the calibration function by using the calibration method in the above embodiment when the system includes the analog-to-digital converter. Figure 8 The functions of the remaining parts are not repeated here.

[0100] Specifically, Figure 9 In the embodiment, the specific circuit structure of the voltage sampling circuit is that the metering chip has four groups of voltage sampling channels, and each voltage sampling circuit channel is composed of a differential sampling circuit formed by a plurality of series-connected resistors. Figure 10 The specific circuit structure of the current sampling circuit is used for differential sampling.

[0101] The embodiment of the present application also provides a computer device having the above Figure 4The cloud desktop clipboard data processing apparatus shown.

[0102] See Figure 11 , Figure 11 is a structural schematic diagram of a computer device provided by an optional embodiment of the present application. As shown in Figure 11 , the computer device includes one or more processors 100, a memory 200, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are communicatively connected to each other by using different buses, and can be installed on a common motherboard or in other manners as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or graphics information of a GUI stored in the memory for displaying on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, multiple processors and / or multiple buses can be used with multiple memories and multiple memory, if needed. Also, multiple computer devices can be connected, each providing part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 11 The processor 100 is taken as an example in the figure.

[0103] The processor 100 can be a central processor, a network processor, or a combination thereof. The processor 100 can further include hardware modules. The hardware modules can be application specific integrated circuits, programmable logic devices, or a combination thereof. The programmable logic devices can be complex programmable logic devices, field programmable logic gate arrays, general array logic, or any combination thereof.

[0104] The memory 200 stores instructions executable by the at least one processor 100, so that the at least one processor 100 executes the method shown in the above embodiments.

[0105] The memory 200 can include a program storage area and a data storage area. The program storage area can store an operating system and application programs required by at least one function; the data storage area can store data created according to the use of the computer device, etc. In addition, the memory 200 can include a high-speed random access memory, and can also include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state memory device. In some optional embodiments, the memory 200 can optionally include a memory remotely arranged with respect to the processor 100, and these remote memories can be connected to the computer device by a network. Examples of the network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0106] The memory 200 can include a volatile memory, such as a random access memory, and / or can include a non-volatile memory, such as a flash memory, hard disk, or solid state drive. The memory 200 can also include a combination of the above-mentioned types of memory.

[0107] The computer device also includes a communication interface 300 for the computer device to communicate with other devices or communication networks.

[0108] The embodiments of the present application also provide a computer readable storage medium, and the method according to the embodiments of the present application can be implemented in hardware, firmware, or recorded in a storage medium, or be implemented as computer code stored in a remote storage medium or non-transitory machine readable storage medium and stored in a local storage medium to be downloaded through a network, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor, or programmable or special purpose hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid state disk, etc. Further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that the computer, processor, microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the method shown in the above embodiments.

[0109] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, the method and / or technical solutions according to the present application can be invoked or provided. Those skilled in the art should understand that the form of computer program instructions in a computer readable medium includes but is not limited to source files, executable files, installation package files, etc. Correspondingly, the way of computer program instructions executed by a computer includes but is not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0110] Although the embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A calibration method, characterized by, The method is applied to a sampling system comprising a plurality of voltage sampling circuits, and after a rated calibration voltage is applied to the input ends of the voltage sampling circuits, the method comprises: controlling the sampling system to operate in a first effective value calculation mode or a second effective value calculation mode, and calculating the voltage effective value of each phase voltage sampling circuit; calculating the gain calibration coefficient and the effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage; after obtaining the current voltage sampling value of each phase voltage sampling circuit, correcting the voltage sampling value based on the gain calibration coefficient and the effective value conversion coefficient, and calculating the voltage true value; the first effective value calculation mode is to calculate the voltage effective value based on the sampling value of a single voltage sampling circuit; the second effective value calculation mode is to calculate the voltage effective value based on the difference between the sampling values of two voltage sampling circuits.

2. The calibration method of claim 1, wherein, When the calculation of the gain calibration coefficient adopts a relative coefficient method, the rated calibration voltage is sequentially applied between one phase voltage sampling circuit and a neutral phase voltage sampling circuit, and zero voltage is applied to the remaining phase voltage sampling circuits; when the calculation of the gain calibration coefficient adopts an absolute coefficient method, the reference ground of the sampling system is led out, and the same rated calibration voltage is applied between each phase voltage sampling circuit and the reference ground; the process of controlling the sampling system to operate in the first effective value calculation mode and calculating the voltage effective value of each phase voltage sampling circuit comprises: after calculating the root mean square of the current sampling voltage of each phase voltage sampling circuit respectively, the root mean square is stored as the voltage effective value.

3. The method of calibration of claim 1, wherein, After the rated calibration voltage is sequentially applied between one phase voltage sampling circuit and a neutral phase voltage sampling circuit, the process of controlling the sampling system to operate in the second effective value calculation mode comprises: the root mean square of the difference between the current sampling voltages of one phase voltage sampling circuit and a neutral phase voltage sampling circuit is calculated respectively and stored as the voltage effective value.

4. The calibration method of claim 1, wherein, When the calculation of the gain calibration coefficient adopts a relative coefficient method, the input ends of each phase voltage sampling circuit are short-circuited to the reference voltage, the rated calibration voltage is sequentially applied between one phase voltage sampling circuit and a neutral phase voltage sampling circuit, and zero voltage is applied to the remaining phase voltage sampling circuits, or when the calculation of the gain calibration coefficient adopts an absolute coefficient method, the reference voltage point of the sampling system is led out, the input ends of each phase voltage sampling circuit are short-circuited to the reference voltage, and the same rated calibration voltage is applied between each phase voltage sampling circuit and the reference voltage point; the process of controlling the sampling system to operate in the first effective value calculation mode and calculating the voltage effective value of each phase voltage sampling circuit comprises: the current sampling voltage of each phase voltage sampling circuit after being short-circuited to the reference voltage is stored as a direct current offset value; the current sampling voltage of each phase voltage sampling circuit is compensated respectively by using the direct current offset value, and the root mean square of the compensated current sampling voltage is calculated and stored as the voltage effective value.

5. The method of calibration of claim 1, wherein, The sampling system further comprises a plurality of current sampling circuits, and after the same rated current is sequentially applied to the input ends of the current sampling circuits, the method further comprises: After taking the current sampling current of one phase current sampling circuit as a reference current, the current consistency coefficient of each phase current sampling circuit is calculated respectively based on the reference current; After obtaining the current sampling value of each phase current sampling circuit, the current sampling value is corrected based on the current consistency coefficient, and the real current value is calculated and obtained.

6. The method of calibration of claim 5, wherein, After applying the rated calibration voltage and the rated current to each phase voltage sampling circuit and current sampling circuit respectively, the method further comprises: According to the current sampling voltage of each phase voltage sampling circuit and the current sampling current of each phase current sampling circuit, the current sampling power value of each phase is calculated; After setting the power factor of the sampling system to 1, the theoretical power value is modified; Based on the ratio of the modified theoretical power value to the current sampling power value of each phase, the power gain correction coefficient of each phase is calculated, so as to calibrate the gain of the sampling power value.

7. The method of calibration of claim 5, wherein, After applying the rated calibration voltage and the rated current to each phase voltage sampling circuit and current sampling circuit respectively, the method further comprises: According to the current sampling voltage of each phase voltage sampling circuit and the current sampling current of each phase current sampling circuit, the current sampling power value of each phase is calculated; After setting the power factor of the sampling system to 0.5, the theoretical power value is modified; Based on the ratio of the modified theoretical power value to the current sampling power value of each phase, the power phase correction coefficient of each phase is calculated, so as to calibrate the phase of the sampling power value.

8. A calibration device, characterized by It comprises: The calculation mode switching module is used to control the sampling system to work in the first effective value calculation mode or the second effective value calculation mode, and calculate and obtain the voltage effective value of each phase voltage sampling circuit; The first effective value calculation mode is based on the sampling value of a single voltage sampling circuit; the second effective value calculation mode is based on the difference between the sampling values of two voltage sampling circuits; The correction coefficient calculation module is used to calculate the gain calibration coefficient and the effective value conversion coefficient of each phase voltage sampling circuit based on the voltage effective value and the rated calibration voltage; The correction module is used to obtain the current voltage sampling value of each phase voltage sampling circuit, correct the voltage sampling value based on the gain calibration coefficient and the effective value conversion coefficient, and calculate and obtain the real voltage value.

9. A sampling system, characterized by, It comprises: A plurality of voltage sampling circuits, a plurality of current sampling circuits, a metering module and a control circuit, wherein, The input end of each voltage sampling circuit collects the voltage signal of each phase of the power system respectively, and the output end of each voltage sampling circuit is connected with the input end of the metering module; The input end of each current sampling circuit collects the current signal of each phase of the power system respectively, and the output end of each current sampling circuit is connected with the input end of the metering module; The output end of the metering module is connected with the control circuit, and the metering module is used to process the voltage signal and the current signal; The control circuit is used to realize the calibration method of any one of claims 1 to 7; The metering module comprises one of a metering chip or an analog-to-digital converter.

10. A computer device, comprising: It comprises: A memory and a processor, which are connected in communication with each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the calibration method of any one of claims 1 to 7.

11. A computer readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for causing a computer to perform the calibration method of any one of claims 1 to 7.

12. A computer program product, characterised in that, The computer readable storage medium stores computer instructions for causing a computer to perform the calibration method of any one of claims 1 to 7. The computer readable storage medium stores computer instructions for causing a computer to perform the calibration method of any one of claims 1 to 7.

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