Three-phase electric parameter measuring system and method based on double metering chips

Abstract

The invention discloses a three-phase electric parameter measurement system and method based on double metering chips, and belongs to the technical field of electric power measurement. The technical problems to be solved are that the existing three-metering chip scheme for three-phase electric parameter measurement is high in hardware cost, calculation precision and real-time performance are difficult to consider at the same time, and the requirement for the calculation capability of a processor is high. According to the technical scheme, two high-precision metering chips are adopted to respectively collect instantaneous values of B-phase voltage and C-phase voltage and current, and a synchronous control module, a voltage calculation module and a current calculation module are arranged in a main controller; the synchronous control module realizes double-phase data synchronization through a lightweight state machine and a synchronous flag bit, the voltage calculation module adopts a virtual ground algorithm to analyze and solve coordinates of a reference ground potential F point so as to calculate A-phase voltage, the current calculation module obtains A-phase current through inversion based on a vector algorithm, and finally complete measurement of three-phase electric parameters is realized.

Description

Technical Field

[0001] This invention belongs to the field of power measurement technology, specifically relating to a three-phase electrical parameter measurement system and method based on dual metering chips. Background Technology

[0002] In existing three-phase electricity metering technology, the mainstream approach uses a three-metering chip scheme, which employs three independent metering chips to measure the voltage and current parameters of the three phases, respectively. However, the main drawback of the existing three-metering chip scheme is:

[0003] (1) High hardware costs: The three-chip solution directly leads to a multiple increase in the cost of core hardware materials. At the same time, the multi-chip solution requires more peripheral circuits (such as crystal oscillators, power management, isolation communication, etc.), which further increases the overall system cost and physical space occupation.

[0004] (2) It is difficult to balance computational accuracy and real-time performance: When dealing with complex algorithms such as 'virtual ground' calculation, the existing three-metering scheme often faces the inherent contradiction between computational accuracy and system real-time performance.

[0005] (3) High requirements for processor computing power: It is necessary to ensure the real-time acquisition of three metering chips at the same time. The complex computing tasks place extremely high demands on the processor's clock frequency and memory resources.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] To address the aforementioned technical problems in the existing technology, this invention provides a three-phase electrical parameter measurement system and method based on dual metering chips, which solves the technical problems of high hardware cost, difficulty in balancing calculation accuracy and real-time performance, and high requirements for processor computing power in existing three-phase electrical parameter measurement schemes with three metering chips.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: A three-phase electrical parameter measurement system based on dual metering chips includes: a main controller and a high-precision metering chip, wherein the high-precision metering chip includes a first chip and a second chip; the main controller integrates a synchronization control module, a voltage calculation module, and a current calculation module. The first chip is used to collect the instantaneous voltage and current values ​​of phase B in the three-phase power supply, and the second chip is used to collect the instantaneous voltage and current values ​​of phase C in the three-phase power supply. Both the first chip and the second chip establish communication and power supply connections with the main controller. The synchronization control module tracks the readiness status of the B-phase and C-phase data acquisition through a lightweight state machine and a synchronization flag bit. It polls the synchronization flag bit and triggers the voltage calculation module and current calculation module to start only when the B-phase and C-phase data acquisition is ready. The voltage calculation module employs a virtual ground algorithm, constructing two intersecting circle models based on AFC and BFC three-point systems, utilizing the ideal equilibrium state of the three-phase system. The coordinates of the reference ground potential F point are obtained by analyzing the characteristics, and the phase voltage and line voltage of phase A are calculated. The current calculation module uses a vector algorithm. After determining the relative relationship between the voltage and current of phase B and phase C by the voltage-current angle and determining the corresponding current vector, it inversely calculates the phase current and line current of phase A.

[0009] Furthermore, the workflow of the synchronization control module includes: The system completes instantaneous data acquisition of phases B and C at fixed intervals, and immediately sets the corresponding synchronization flag after acquisition. The lightweight state machine contains multiple working states, and switches states according to the state of the synchronization flag and the data acquisition status, triggering the metering process of phase A electrical parameters. If no data acquisition for a certain phase is detected within a set time, a preset abnormal handling strategy is executed.

[0010] Furthermore, the polling period for the synchronization flag bit by the synchronization control module is consistent with the fixed period; The synchronization flag is a variable of type uint8_t. A value of 1 indicates that the corresponding phase data acquisition is ready, and a value of 0 indicates that the corresponding phase data acquisition is not ready. When both phase synchronization flags are 1, it is determined that both phase B and phase C data acquisition are ready.

[0011] Furthermore, the working states of the lightweight state machine include IDLE state, GETDATA state and RESET state. IDLE state is the standby state between two data acquisitions. GETDATA state is the working state in which the timer with the fixed period reaches its countdown and the main controller sends a data request to the two high-precision metering chips. RESET state is the abnormal recovery state entered after three consecutive GETDATA state data acquisition failures. The preset exception handling strategy is to reset the communication serial port between the main controller and the chip, and then re-initiate the data acquisition request after the reset.

[0012] Furthermore, the execution steps of the virtual ground algorithm include: Establish a two-dimensional coordinate system, define the endpoint coordinates and voltage data format of phase B and phase C voltages; based on Based on its properties, the center of the circle is derived. Located on the perpendicular bisector of AB and Determine the center of the circle coordinates and radius Similarly, the center of the circle can be derived. coordinates and radius ; Joint center , The coordinates of point F are analytically solved using the corresponding equations of the two circles and geometric constraints. Based on the coordinates of point F and the instantaneous voltage values ​​of phases B and C, calculate the phase voltage and line voltage of phase A; if there are cases where the two circles have no intersection, two intersections, or the three-phase system is unbalanced, execute the preset adjustment strategy. Furthermore, the two-dimensional coordinate system takes the initial reference point of the three-phase virtual reference ground as its origin, the positive direction of the B-phase voltage vector as the X-axis, and the direction perpendicular to the X-axis upwards as the Y-axis; the voltage data format is a floating-point instantaneous value, with the unit being V; the equations of the two circles are:

[0013]

[0014] in, for coordinate, for Coordinates; Solve for the coordinates of point F by eliminating the quadratic terms of the two circle equations using the elimination method.

[0015] Furthermore, the preset adjustment strategy of the virtual ground algorithm is as follows: If the two circles have no intersection or two intersection points, then the center of the circle... , After correcting the coordinates with geometric mean, the coordinates of point F are recalculated; if the three-phase system is unbalanced, the average of the effective coordinates of point F obtained from the most recent preset collection is used as the compensation value, and the effective coordinates of point F are obtained by combining the current calculation results.

[0016] Furthermore, the execution steps of the vector algorithm include: Through the active power formula Reactive power formula The pressure angles of phases B and C were calculated. ; Using the voltage vectors of phase B and phase C in the two-dimensional coordinate system as a reference, and based on the pressure-current angle... The sign and magnitude of the value are used to determine the leading or lagging phase relationship between the current vector and the voltage vector, and thus determine the current vectors of phase B and phase C. Based on the principle that the sum of the three-phase current vectors is zero, the A-phase current vector is obtained through formula inversion calculation. The specific formula is as follows:

[0017] The A-phase current vector is mapped to the two-dimensional coordinate system, and the actual magnitude of the A-phase current is obtained through analytical calculation of the vector coordinates.

[0018] Furthermore, the actual magnitude of the phase A current is calculated using the following formula:

[0019] in, Let be the coordinates of the current vector in a two-dimensional coordinate system.

[0020] Furthermore, the communication interface type between the first chip, the second chip, and the main controller is UART, and the communication protocol adopts the general protocol for metering chips; the power supply connection between the first chip, the second chip, and the main controller is DC power supply. Compared with the prior art, the three-phase electrical parameter measurement system and method based on dual metering chips provided by the present invention, through the dual metering chip architecture and dedicated algorithm, collects two-phase electrical parameters with only two metering chips, and calculates the electrical parameters of the other phase by combining the algorithm, so as to achieve high-precision, low-cost and high real-time measurement of three-phase electrical parameters. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the calculation process for measuring three-phase voltage using the virtual ground algorithm provided in an embodiment of the present invention; Figure 2 A schematic diagram of the three-phase voltage geometric modeling and solution of the virtual ground algorithm provided in this embodiment of the invention; Figure 3 This is a schematic diagram of the calculation process for measuring three-phase current using a vector algorithm provided in an embodiment of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0023] It should be noted that, unless otherwise specifically stated, the relative arrangement and numerical expressions of the components and steps described in these embodiments should not be construed as limiting the scope of the invention.

[0024] The following description of exemplary embodiments is merely illustrative and is not intended to limit the invention or its application or use in any way. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail herein, but where applicable, such techniques, methods, and apparatus should be considered part of this specification.

[0025] Example 1 See Figure 1 , Figure 1 The present invention proposes a three-phase electrical parameter measurement system based on dual metering chips, comprising: a main controller and high-precision metering chips, wherein the high-precision metering chips include a first chip and a second chip; both metering chips establish communication and power supply connections with the main controller, the communication interface type is UART, the communication protocol adopts the general protocol of metering chips, and the power supply method is DC power supply; The first chip is dedicated to collecting the instantaneous voltage and current values ​​of phase B in a three-phase power supply, and the second chip is dedicated to collecting the instantaneous voltage and current values ​​of phase C in a three-phase power supply. The main controller integrates three functional modules: a synchronization control module, a voltage calculation module, and a current calculation module. These three modules work collaboratively. The synchronization control module synchronizes the timing and verifies the validity of data acquired from the two chips. Based on the synchronized electrical parameter data for phases B and C, the voltage and current calculation modules use dedicated algorithms to calculate the phase voltage, line voltage, phase current, and line current of phase A, ultimately achieving complete measurement of the three-phase electrical parameters. Specifically, this includes: M1, Synchronization Control Module: This is the core module that enables synchronized data acquisition from both metering chips and ensures consistency in the timing of electrical parameter calculations. It tracks the "ready" status of the B-phase and C-phase data acquisition through a lightweight state machine and synchronization flags, continuously polling the synchronization flags. Only when both B-phase and C-phase data are ready is the voltage calculation module and current calculation module triggered to start working. The specific execution flow is as follows: Data Acquisition and Flag Setting: The system completes the acquisition of instantaneous voltage and current data of phase B and phase C at a fixed period of 160ms. After the data acquisition of each phase is completed, the main controller immediately sets the corresponding synchronization flag bit. The synchronization flag bit is a variable of type uint8_t. The polling period of the main controller for the synchronization flag bit is consistent with the data acquisition period, which is 160ms. The assignment rule for the synchronization flag bit is as follows: a value of 1 indicates that the data is ready, a value of 0 indicates that the data is not ready, and when both phase flag bits are 1, it is determined that the data is fully ready.

[0026] Data Readiness Verification: While polling the synchronization flag, the main controller performs auxiliary validity verification on the data acquired from phases B and C. During the acquisition of two-phase data in a single operation, data is considered ready only if normal data is acquired from both phases. The criteria for normal data are: standard three-phase electrical measurement range, voltage acquisition value 0-450V, current acquisition value 0-60A, and a data acquisition error threshold of ±2%. Data exceeding the range / threshold is considered invalid. Lightweight state machine state switching: The lightweight state machine includes three working states: IDLE, GETDATA, and RESET. The state machine automatically switches states based on the synchronization flag status and data acquisition status, thereby triggering the A-phase data metering process. The triggering conditions for each state are as follows: IDLE state is the initial standby state between two data acquisitions; GETDATA state is the working state when the 160ms timer expires and the main controller sends a data request to the two metering chips; RESET state is the abnormal recovery state entered after multiple consecutive GETDATA state data acquisition failures. Specifically, "multiple consecutive failures" refers to three consecutive GETDATA state data acquisition / verification failures, triggering the RESET abnormal state.

[0027] Anomaly Detection and Handling: During the data acquisition cycle, the main controller continuously monitors the readiness status of phase B and phase C data. If no data for a certain phase is detected within a set time, it is determined to be a data acquisition anomaly, and a preset anomaly handling strategy is executed. In this embodiment, the anomaly handling strategy is to reset the serial port when a communication anomaly occurs. After the serial port is reset, the main controller re-initiates the data acquisition request. The set time is defined as 200ms; if no response is received after waiting for another 10ms, it is determined to be an anomaly.

[0028] M2, Voltage Calculation Module: Employs a virtual ground algorithm to calculate the phase voltage and line voltage of phase A. This algorithm transforms the three-phase voltage vector relationship into a geometric problem, utilizing the ideal equilibrium state of the three-phase system. Based on the inherent characteristics of the method, an intersecting circle model is constructed to analytically solve for the coordinates of the reference ground potential point F. Then, combined with the voltage data of phases B and C, the voltage of phase A is calculated. This completely avoids the convergence and initial value sensitivity problems of numerical iteration methods, balancing computational accuracy and real-time performance. (See also...) Figure 1 The specific execution steps are as follows: Two-dimensional coordinate system and parameter definition: Establish a two-dimensional coordinate system and define the endpoint coordinates and voltage data format of phase B and phase C voltages; the core rules for establishing the coordinate system are: the origin is the initial reference point of the three-phase virtual reference ground, the X-axis is the positive direction of the phase B voltage vector, the Y-axis is perpendicular to the X-axis and upwards, and the voltage data format is a floating-point instantaneous value with the unit being V.

[0029] Determining the center and radius of intersecting circles: See [link / reference] Figure 2 ,based on Based on its properties, the center of the circle is derived. Located on the perpendicular bisector of AB and °, take The coordinates are half of coordinates A; use this to determine the center of the circle. coordinates and radius ( (where the radius is 1), and similarly, the center of the circle is derived. coordinates and radius ( (with radius) The coordinates are half of the C coordinates.

[0030] Solving for the coordinates of point F, which is the reference ground potential: Combine the equations of the center of the circle. , The corresponding equations of the two circles, combined with geometric constraints such as the convergence of the three lines of an isosceles triangle and the Pythagorean theorem, are analytically solved to obtain the coordinates of the reference ground potential point F; the core expression of the equations of the two circles is:

[0031]

[0032] in, for coordinate, for Coordinates; The steps for solving the simultaneous equations are as follows: eliminate the quadratic term using the elimination method to obtain the linear equation, substitute the linear equation into any circular equation, and combine the 120° inherent characteristics of the three-phase system to find the unique valid intersection point, which is the coordinate of point F.

[0033] Phase A voltage calculation: Based on the coordinates of point F obtained from the solution, combined with the instantaneous voltage data of phases B and C collected by the first and second chips, the phase voltage and line voltage of phase A are calculated; the core conversion ratio between the geometric coordinates of point F and the actual voltage value is 1 coordinate unit corresponds to 0.01V actual voltage value, that is, the magnitude of the coordinate value is the actual instantaneous value of the corresponding phase voltage, and the line voltage is the vector difference magnitude of the coordinate values ​​of the corresponding two phases.

[0034] Abnormal situation handling: If, during the calculation of the coordinates of point F and the voltage of phase A, two intersection points of the two circles or system imbalance occurs, the main controller will execute a preset adjustment strategy; the core operation of the preset adjustment strategy is as follows: Two circles with no intersection / two intersections: Yes , The coordinates are corrected using the geometric mean, and the solution for point F is recalculated. System imbalance: The average of the three most recent valid F-point coordinates is used as the compensation value, and the valid F-point coordinates are obtained by combining them with the current calculation results.

[0035] M3, Current Calculation Module: Employs a vector algorithm to calculate the phase current and line current of phase A. This algorithm is based on the fundamental principle that the sum of the three-phase current vectors is zero in a non-leakage system. It obtains the phase A current vector through the inversion of the current vectors of phases B and C, and then maps the vector to a two-dimensional coordinate system to calculate the actual current magnitude. The calculation path is fixed, the time consumption is short, and it is suitable for low-computing-power main controllers. (See reference...) Figure 3 The specific execution steps are as follows: M31, pressure-current angle and current vector determination: through the active power formula Reactive power formula The pressure angles of phases B and C were calculated. (This refers to the pressure-flow angle); taking the voltage vectors of phase B and phase C in the two-dimensional coordinate system as a reference, based on the pressure-flow angle... The sign and magnitude of the current vector are used to determine the leading / lagging phase relationship between the current vector and the voltage vector (the voltage-current angle is when the current leads the voltage and when it is when the current lags the voltage). Based on this phase relationship, the direction and magnitude of the current vectors of phase B and phase C are determined in a two-dimensional coordinate system, thus completing the calibration of the current vector.

[0036] M32, Phase A Current Vector Inversion: Based on the principle that the sum of the three-phase current vectors is 0, the current vector of phase A is calculated through formula inversion. The specific formula is as follows:

[0037] M33, Calculation of the actual current magnitude of phase A: Map the inverted phase A current vector to a two-dimensional coordinate system, and calculate the actual magnitude of the phase A current through vector coordinate analysis. Simultaneously, combine the vector characteristics to obtain the phase current and line current of phase A. The formula for converting current vector coordinates into actual current values ​​is as follows:

[0038] in, The coordinates of the current vector in a two-dimensional coordinate system are given. The calculated result is the actual instantaneous value of the current, in A. In this three-phase measurement system, the line current and phase current values ​​are consistent.

[0039] Example 2 This embodiment is an alternative implementation of the three-phase electrical parameter measurement system based on Embodiment 1. The core hardware architecture and algorithm principles remain consistent with Embodiment 1, with adjustments made only to adapt the functional allocation of the dual metering chips. The alternative solution can be implemented individually or in combination, as detailed below: In this embodiment, the acquisition functions of the two high-precision metering chips can be reversed. Specifically, the first chip is used to acquire the instantaneous voltage and current values ​​of phase C in the three-phase power supply, and the second chip is used to acquire the instantaneous voltage and current values ​​of phase B in the three-phase power supply.

[0040] The communication connection and power supply connection between the chip and the main controller, as well as the data transmission rules, are completely consistent with those in Example 1. The synchronous control module, voltage calculation module, and current calculation module of the main controller do not make any adjustments to the data processing flow and calculation logic. Only the phase identifier of the data is changed for adaptability, so that the complete measurement of three-phase electrical parameters can be realized, adapting to different hardware layouts and wiring requirements.

[0041] Example 3 This embodiment is an alternative implementation of the three-phase electrical parameter measurement system based on Embodiment 1. The core hardware architecture and algorithm principles remain consistent with Embodiment 1, with adjustments made only to the implementation of the virtual ground algorithm. The alternative solution can be implemented individually or in combination, as detailed below: This implementation method is suitable for application scenarios where measurement accuracy requirements are not extremely high. By simplifying the calculation process of the virtual ground algorithm, the computational load on the main controller is reduced, further saving computing resources. Specifically, it includes two simplified forms, one of which can be selected according to the actual scenario: Solving for point F at a fixed theoretical position: When the three-phase system tends to be in equilibrium, the reference ground potential point F in the virtual ground algorithm is directly assumed to be located at a fixed theoretical position in the two-dimensional coordinate system (consistent with the coordinate system reference in Example 1, with the fixed theoretical coordinate as the origin (0,0)). There is no need to solve for the coordinates of point F in real time by constructing an intersecting circle model and solving simultaneous equations. Instead, the phase voltage and line voltage of phase A are calculated directly using this fixed coordinate combined with the instantaneous voltage values ​​of phases B and C, according to the voltage conversion rules in Example 1.

[0042] A lookup table replaces real-time geometric analytical calculation: Based on the voltage values ​​of phase B and phase C within the conventional three-phase power measurement range, the corresponding coordinates of point F and the voltage value of phase A are calculated in advance using the virtual ground algorithm of Example 1. The above data is then used to construct a lookup table according to the correspondence and pre-stored in the main controller. During actual measurement, after the main controller acquires the voltage acquisition data of phase B and phase C, it directly matches the corresponding coordinates of point F and the voltage value of phase A in the lookup table, without the need to perform real-time geometric modeling and analytical calculation.

[0043] Both simplified forms omit the core real-time geometric solution step in the virtual ground algorithm, significantly reducing the algorithm's computation time and lowering the computing power requirements of the main controller while meeting the scene measurement accuracy requirements.

[0044] Example 4 This embodiment is an alternative implementation of the three-phase electrical parameter measurement system based on Embodiment 1. The core hardware architecture and algorithm principles remain consistent with Embodiment 1, with adjustments made only to the dual-chip data synchronization control mechanism. The alternative can be implemented individually or in combination, as detailed below: This implementation replaces the synchronous flag polling method in Example 1 with an interrupt-driven method, which is suitable for application scenarios with higher requirements for real-time data acquisition and can further reduce system data processing latency. The specific implementation process is as follows: Both high-precision metering chips are equipped with hardware interrupt triggering modules. When either chip completes the instantaneous data acquisition of voltage and current of phase B / C, it immediately sends a hardware interrupt signal to the main controller through the hardware interrupt triggering module. After receiving the hardware interrupt signal, the main controller immediately enters the interrupt service routine. In the routine, it checks the data acquisition readiness status of phase B and phase C. The data validity verification standard is completely consistent with that of Example 1. If the interrupt service routine determines that both phase B and phase C data are ready, the main controller immediately triggers the voltage calculation module and current calculation module to start working; if the data of either phase is not ready, the main controller waits for a hardware interrupt signal from another chip until the data of both phases meet the ready conditions.

[0045] In summary, the present invention has the following advantages: (1) The hardware cost of the core metering module is significantly reduced, the system integration is improved, the PCB layout is simplified, which is conducive to the miniaturization of the measuring equipment; (2) The core algorithm is a deterministic analytical calculation that does not require iteration, which achieves high-precision measurement of three-phase electrical parameters while meeting the real-time requirements of the system; (3) The overall computational load is significantly reduced, and it can run stably on low-cost, low-frequency microcontrollers, thus broadening the application scope of the technology in cost-sensitive scenarios; (4) It is not sensitive to harmonic interference, effectively avoids angle calculation errors caused by nonlinear load waveform distortion, and improves the robustness and measurement accuracy of the system under complex working conditions.

[0046] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A three-phase electrical parameter measurement system based on dual metering chips, characterized in that, include: The system includes a main controller and a high-precision metering chip, wherein the high-precision metering chip comprises a first chip and a second chip; the main controller integrates a synchronization control module, a voltage calculation module, and a current calculation module. The first chip is used to collect the instantaneous voltage and current values ​​of phase B in the three-phase power supply, and the second chip is used to collect the instantaneous voltage and current values ​​of phase C in the three-phase power supply. Both the first chip and the second chip establish communication and power supply connections with the main controller. The synchronization control module tracks the readiness status of the B-phase and C-phase data acquisition through a lightweight state machine and a synchronization flag bit. It polls the synchronization flag bit and triggers the voltage calculation module and current calculation module to start only when the B-phase and C-phase data acquisition is ready. The voltage calculation module employs a virtual ground algorithm, constructing two intersecting circle models based on AFC and BFC three-point systems, utilizing the ideal equilibrium state of the three-phase system. The coordinates of the reference ground potential F point are obtained by analyzing the characteristics, and the phase voltage and line voltage of phase A are calculated. The current calculation module uses a vector algorithm. After determining the relative relationship between the voltage and current of phase B and phase C by the voltage-current angle and determining the corresponding current vector, it inversely calculates the phase current and line current of phase A.

2. The three-phase electrical parameter measurement system based on dual metering chips according to claim 1, characterized in that, The workflow of the synchronization control module includes: The system completes instantaneous data acquisition of phases B and C at fixed intervals, and immediately sets the corresponding synchronization flag after acquisition. The lightweight state machine contains multiple working states, and switches states according to the state of the synchronization flag and the data acquisition status, triggering the metering process of phase A electrical parameters. If no data acquisition for a certain phase is detected within a set time, a preset abnormal handling strategy is executed.

3. The three-phase electrical parameter measurement system based on dual metering chips according to claim 2, characterized in that, The polling period for the synchronization flag bit by the synchronization control module is the same as the fixed period. The synchronization flag is a variable of type uint8_t. A value of 1 indicates that the corresponding phase data acquisition is ready, and a value of 0 indicates that the corresponding phase data acquisition is not ready. When both phase synchronization flags are 1, it is determined that both phase B and phase C data acquisition are ready.

4. The three-phase electrical parameter measurement system based on dual metering chips according to claim 3, characterized in that, The lightweight state machine has three working states: IDLE, GETDATA, and RESET. The IDLE state is the standby state between two data acquisitions. The GETDATA state is the working state where the fixed-period timer reaches its countdown and the main controller sends a data request to the two high-precision metering chips. The RESET state is the abnormal recovery state entered after three consecutive GETDATA state data acquisition failures. The preset exception handling strategy is to reset the communication serial port between the main controller and the chip, and then re-initiate the data acquisition request after the reset.

5. The three-phase electrical parameter measurement system based on dual metering chips according to claim 1, characterized in that, The execution steps of the virtual ground algorithm include: Establish a two-dimensional coordinate system, define the endpoint coordinates and voltage data format of phase B and phase C voltages; based on Based on its properties, the center of the circle is derived. Located on the perpendicular bisector of AB and Determine the center of the circle coordinates and radius Similarly, the center of the circle can be derived. coordinates and radius ; Joint center , The coordinates of point F are analytically solved using the corresponding equations of the two circles and geometric constraints. Based on the coordinates of point F and the instantaneous voltage values ​​of phases B and C, calculate the phase voltage and line voltage of phase A; if there is no intersection between the two circles, two intersections, or an imbalance in the three-phase system, execute the preset adjustment strategy.

6. The three-phase electrical parameter measurement system based on dual metering chips according to claim 5, characterized in that, The two-dimensional coordinate system uses the initial reference point of the three-phase virtual reference ground as the origin, the positive direction of the B-phase voltage vector as the X-axis, and the direction perpendicular to the X-axis upwards as the Y-axis; the voltage data format is floating-point instantaneous value, with the unit being V; the equations of the two circles are: in, for coordinate, for Coordinates; Solve for the coordinates of point F by eliminating the quadratic terms of the two circle equations using the elimination method.

7. The three-phase electrical parameter measurement system based on dual metering chips according to claim 5, characterized in that, The preset adjustment strategy of the virtual ground algorithm is as follows: If the two circles have no intersection or two intersection points, then the center of the circle... , After correcting the coordinates with geometric mean, the coordinates of point F are recalculated; if the three-phase system is unbalanced, the average of the effective coordinates of point F obtained from the most recent preset collection is used as the compensation value, and the effective coordinates of point F are obtained by combining the current calculation results.

8. The three-phase electrical parameter measurement system based on dual metering chips according to claim 1, characterized in that, The execution steps of the vector algorithm include: Through the active power formula Reactive power formula The pressure angles of phases B and C were calculated. ; Using the voltage vectors of phase B and phase C in the two-dimensional coordinate system as a reference, and based on the pressure-current angle... The sign and magnitude of the value are used to determine the leading or lagging phase relationship between the current vector and the voltage vector, and thus determine the current vectors of phase B and phase C. Based on the principle that the sum of the three-phase current vectors is zero, the A-phase current vector is obtained through formula inversion calculation. The specific formula is as follows: The A-phase current vector is mapped to the two-dimensional coordinate system, and the actual magnitude of the A-phase current is obtained through analytical calculation of the vector coordinates.

9. The three-phase electrical parameter measurement system based on dual metering chips according to claim 8, characterized in that, The actual magnitude of the phase A current can be calculated using the following formula: in, Let be the coordinates of the current vector in a two-dimensional coordinate system.

10. The three-phase electrical parameter measurement system based on dual metering chips according to claim 1, characterized in that, The communication interface between the first chip, the second chip and the main controller is UART, and the communication protocol adopts the metering chip general protocol; the power supply connection between the first chip, the second chip and the main controller is DC power supply.

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