A high-precision remote control branch measurement system and method for power parameter measurement

Abstract

The present invention discloses a high-precision remote control branch measurement system and method for power parameter measurement, and relates to the field of power measurement technology. The method comprises: measuring power parameters and electric energy data in real time and storing them, calculating the operating status of each branch of the system based on the measured power parameters and electric energy data through a state estimation algorithm; executing remote control commands based on the real-time state estimation results through an encryption method based on the SM1 algorithm combined with identity authentication, adjusting the switches and loads of each branch based on a fuzzy logic control algorithm, and recording related control events; managing the timestamp of the system through a clock module during the measurement process, and performing ordinary time calibration and broadcast time calibration through a communication interface. The present invention significantly improves the accuracy of power parameter measurement and system security through high-frequency sampling, temperature-compensated clock, data encryption and power-off protection technology, and realizes real-time monitoring and precise control of multiple branches.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power measurement, and in particular to a high-precision remote-controlled branch measurement system and method for electric power parameter measurement. Background Art

[0002] At present, power parameter measurement and control plays a key role in modern power systems. With the development of smart grids, more accurate measurements and real-time remote monitoring capabilities are required. However, traditional measurement equipment mostly uses low-frequency sampling, which is difficult to accurately respond to rapid changes in power parameters, resulting in large measurement errors, especially in the measurement of positive and reverse active energy, which directly affects the accuracy of power dispatch and billing; existing remote control systems have high latency, and data transmission lacks effective encryption protection, making them vulnerable to network attacks and threatening system security.

[0003] In addition, the current data storage system lacks power-off protection, resulting in data loss during sudden power outages, affecting the stability of power grid operation and fault tracing. The time synchronization module lacks temperature compensation, and is prone to time drift when the ambient temperature changes greatly, affecting measurement accuracy and system reliability. The existing system has low integration, and most measurement and control modules operate independently, which increases system complexity, reduces response speed, and is difficult to meet intelligent needs. Summary of the invention

[0004] In response to the above problems, the present invention proposes a high-precision remote control branch measurement system, which significantly improves the accuracy of power parameter measurement and system safety through high-frequency sampling, temperature compensated clock, data encryption and power-off protection technology, and realizes real-time monitoring and precise control of multiple branches, which is suitable for the intelligent management of modern power systems.

[0005] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0006] A high-precision remote control branch measurement system for power parameter measurement, the system comprising:

[0007] A branch measurement module is used to measure power parameters and electric energy data in real time, including forward and reverse active electric energy, total and split-phase power, split-phase voltage, split-phase current, frequency and power factor; the forward and reverse active electric energy includes independent measurement of combined-phase and split-phase electric energy;

[0008] A main control module, used to calculate the operating state of each branch of the system based on the data measured by the branch measurement module through a state estimation algorithm;

[0009] The remote control module is used to execute remote control commands based on the real-time state estimation results, through the encryption method based on the SM1 algorithm, combined with identity authentication, adjust the switches and loads of each branch based on the fuzzy logic control algorithm, and record related control events;

[0010] Data storage and recording module, used to store the data collected in historical time with at least 2 decimal places or the number of electric energy pulses and generate reports regularly, ensuring that the system can save data for at least 3 years in the event of power failure, and record key events in system operation;

[0011] Data communication module, used to support DL / T 698.45 and DL / T 645-2007 protocols, uses RS-485 interface for communication within 3 seconds after power-on, and the communication baud rate is 9600bps; supports active event reporting, and is equipped with a backup power supply to realize active reporting of power outages;

[0012] The clock module has a built-in temperature compensation circuit, with a daily timing error of no more than 1 second / day. It has the functions of calendar, timing and leap year automatic conversion, and can perform ordinary time calibration and broadcast time calibration through the communication interface;

[0013] The security protection module is used for encryption and security authentication through the ESAM module, and adopts the SM1 algorithm to ensure the security of remote control and data communication.

[0014] As a preferred solution of the present invention, the branch measurement module performs high-frequency sampling on each branch voltage and current signal, following the Nyquist sampling theorem, with the sampling frequency being greater than twice the highest frequency of the signal, and converting them into phasors through discrete Fourier transform.

[0015] As a preferred solution of the present invention, the state estimation algorithm is specifically a weighted least squares method, and the formula is:

[0016] J ( x ) = ∑ i = 1 m w i [ z i − h i ( x ) ] 2 ;

[0017] In the formula, is the objective function, is the measured value, is the nonlinear function of the system model, is the weighting coefficient, is the state vector to be estimated; Represents the number of each data sample, ranging from 1 to m.

[0018] As a preferred solution of the present invention, the remote control module is provided with a relay circuit inside for controlling the external load switch, and is capable of detecting whether the access state of the control circuit is valid, and is capable of identifying the switch input position change, and actively reporting if a state quantity position change event occurs;

[0019] The relevant control events include:

[0020] When a tripping event occurs due to remote control, the remote control tripping event is recorded and actively reported;

[0021] When the remote control allows the closing operation, the closing permission event is recorded and reported actively.

[0022] As a preferred solution of the present invention, the key events in the operation of the system include:

[0023] The total number of overvoltages in each phase, as well as the occurrence and end times of the last 10 overvoltages and the corresponding electrical energy data;

[0024] The total number of overcurrents in each phase, as well as the occurrence and end times of the last 10 overcurrents and the corresponding electric energy data;

[0025] The total number of total and phase power reverse events, as well as the time of the last 10 power reverse events and the corresponding electric energy data;

[0026] The total number of power outages and the time when the last 10 power outages occurred and ended;

[0027] The total number of programming times and the most recent 10 programming records. Each programming record includes the earliest programming time of a data item during the programming period and the data identifiers of the last 10 programming items during the programming period;

[0028] The total number of ordinary time adjustments, and the times before and after the most recent 10 ordinary time adjustments;

[0029] The total number of broadcast time adjustment and the time before and after the last 10 broadcast time adjustment;

[0030] Total number and total time of overloads in each phase, and duration of the last 10 overloads;

[0031] Permanently record the total number of resets, the time of occurrence of the last 10 reset events, and the electric energy data at the time of reset;

[0032] Total number of occurrences and / or total cumulative time of each event;

[0033] The total number of remote signal change events and the time when the last 10 remote signal changes occurred;

[0034] The total number of control loop abnormal events and the time when the most recent 10 control loop abnormal events occurred.

[0035] As a preferred solution of the present invention, the temperature compensation circuit includes:

[0036] The temperature sensor, humidity sensor and air pressure sensor are used to monitor the ambient temperature, humidity and air pressure respectively, and send the information to the real-time clock module;

[0037] A real-time clock module includes a crystal oscillator as a time reference for maintaining accurate time, and receives environmental parameters to adjust the clock frequency according to temperature changes;

[0038] MCU chip, used to execute temperature compensation algorithm;

[0039] NVM memory for storing calibration parameters and compensated temperature values.

[0040] As a preferred solution of the present invention, the temperature compensation algorithm is specifically:

[0041] Based on the nonlinear regression model, multi-dimensional environmental parameters are used for optimization, including ambient temperature, humidity and pressure. The compensation formula is as follows:

[0042] ;

[0043] In the formula, is the temperature value after compensation; is the measured real-time temperature value; is the reference temperature value; , , are the compensation coefficients obtained through experimental fitting; is the current humidity value, is the current air pressure value.

[0044] As a preferred solution of the present invention, the clock module uses an environmentally friendly lithium battery as a dedicated backup power supply for the clock. The capacity of the lithium battery is not less than 1200mAh, and the clock can maintain normal operation for at least 5 years after power failure. Ordinary time calibration is performed point-to-point through a ciphertext + MAC method, and broadcast time calibration is performed through a plaintext method. The time calibration deviation does not exceed 10 minutes, and broadcast time calibration is limited to once a day.

[0045] A high-precision remote control branch measurement method for power parameter measurement, the method comprising:

[0046] Real-time measurement and storage of power parameters and electric energy data, including forward and reverse active electric energy, total and split-phase power, split-phase voltage, split-phase current, frequency and power factor; the forward and reverse active electric energy includes independent measurement of combined-phase and split-phase electric energy;

[0047] The operating status of each branch of the system is calculated based on the measured power parameters and electric energy data through the state estimation algorithm;

[0048] According to the real-time state estimation results, the remote control command is executed through the encryption method based on the SM1 algorithm combined with identity authentication, the switches and loads of each branch are adjusted based on the fuzzy logic control algorithm, and the relevant control events are recorded;

[0049] During the measurement process, the system's timestamp is managed through the clock module, and ordinary time calibration and broadcast time calibration are performed through the communication interface.

[0050] As a preferred solution of the present invention, the clock module has a built-in temperature compensation circuit, and the temperature compensation algorithm is executed by the MCU chip. The temperature compensation algorithm is specifically:

[0051] Based on the nonlinear regression model, multi-dimensional environmental parameters are used for optimization, including ambient temperature, humidity and pressure. The compensation formula is as follows:

[0052] ;

[0053] In the formula, is the temperature value after compensation; is the measured real-time temperature value; is the reference temperature value; , , are the compensation coefficients obtained through experimental fitting; is the current humidity value, is the current air pressure value.

[0054] The beneficial effects of the present invention are as follows: through the high-frequency sampling of the branch measurement module, the power parameters of each branch can be accurately measured, which greatly improves the measurement accuracy; the state estimation can use redundant measurement data to accurately calculate the real-time operation status of the distribution network through mathematical algorithms, which not only reduces the measurement error, but also improves the reliability and integrity of the data; through the remote control module, accurate control and remote operation of multiple branches can be achieved, which improves the intelligence level of the system; the power-off protection and encrypted transmission of data ensure the reliability and security of the system in harsh environments, and solve the problems of power-off data loss and weak data security in the prior art. The temperature compensation circuit of the clock module further improves the accuracy of time recording, so that the system can maintain stable performance under long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0056] Figure 1 It is a schematic diagram of the modular structure of the system of the present invention;

[0057] Figure 2 A structural diagram of a hardware clock circuit in an embodiment of the present invention;

[0058] Figure 3 The present invention is a flow chart of the method. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0060] like Figure 1 As shown, it is an embodiment of the present invention, which provides a high-precision remote control branch measurement system for power parameter measurement, including a branch measurement module, a main control module, a remote control module, a data storage and recording module, a data communication module, a clock module and a safety protection module;

[0061] The shunt measurement module provides the main control module with real-time measured power parameters and electric energy data; the main control module receives the data from the shunt measurement module, and calculates the operating status of each branch of the system based on these data, and passes the calculation results to the remote control module; the remote control module receives the state estimation results of the main control module, executes the remote control command according to the results, and records the relevant control events, and passes the control events and data to the data storage and recording module or the data communication module; data storage and recording module: receives the data and event records of the shunt measurement module and the remote control module, stores these data and generates reports regularly; the data communication module communicates with the shunt measurement module, the remote control module, the data storage and recording module, etc., and supports data exchange and event reporting; the clock module provides timestamp services for other modules in the system, and performs ordinary time synchronization and broadcast time synchronization with other modules through the communication interface; the security protection module interacts with the remote control module and the data communication module to ensure the security of communication and control, and protects the system from unauthorized access through encryption and security authentication.

[0062] (1) Shunt measurement module

[0063] Used to measure power parameters and energy data in real time, including forward and reverse active energy (the combined and split-phase energy is measured independently, and the total energy is not calculated by arithmetic addition of the split-phase energy), total and split-phase power, split-phase voltage, split-phase current, frequency and power factor;

[0064] Power measurement range: P Q (Starting power) ~1.15U nom ×1.2I max ; Voltage measurement range: 0.6U nom ~1.2U nom (Unom is the nominal voltage); current measurement range: I min ~1.2I max ; Frequency measurement range: 47.5Hz~52.5Hz; Power factor measurement range: -1.0~1.0; Measurement error (reference error) does not exceed ±1%;

[0065] The shunt measurement module performs high-frequency sampling on the voltage and current signals of each shunt, following the Nyquist sampling theorem, with the sampling frequency being greater than twice the highest frequency of the signal, and converting them into phasors through discrete Fourier transform.

[0066] (2) Main control module

[0067] Used to calculate the operating state of each branch of the system based on the data measured by the branch measurement module through a state estimation algorithm;

[0068] The state estimation algorithm is specifically the weighted least squares method, and the formula is:

[0069] J ( x ) = ∑ i = 1 m w i [ z i − h i ( x ) ] 2 ;

[0070] In the formula, is the objective function, is the measured value, is the nonlinear function of the system model, is the weighting coefficient, is the state vector to be estimated; Represents the number of each data sample, ranging from 1 to m.

[0071] (3) Remote control module

[0072] It is used to execute remote control commands (such as tripping and closing) based on the real-time state estimation results through encryption based on the SM1 algorithm and identity authentication, adjust the switches and loads of each branch based on the fuzzy logic control algorithm, and record related control events;

[0073] The remote control module is equipped with a relay circuit inside to control the external load switch, realize direct control of external equipment, detect whether the access status of the control circuit is valid, and identify the switch input position change. If a state quantity change event occurs, it will be actively reported;

[0074] Relevant control events include:

[0075] When a tripping event occurs due to remote control, the remote control tripping event is recorded and actively reported;

[0076] When the remote control allows the closing operation, the closing permission event is recorded and reported actively.

[0077] (4) Data storage and recording module

[0078] It is used to store the data collected in the historical time with at least 2 decimal places or the number of electric energy pulses and generate reports regularly, ensuring that the system can save data for at least 3 years in the event of power failure and record key events in the operation of the system;

[0079] Key events in system operation include:

[0080] The total number of overvoltages in each phase, as well as the occurrence and end times of the last 10 overvoltages and the corresponding electrical energy data;

[0081] The total number of overcurrents in each phase, as well as the occurrence and end times of the last 10 overcurrents and the corresponding electric energy data;

[0082] The total number of total and phase power reverse events, as well as the time of the last 10 power reverse events and the corresponding electric energy data;

[0083] The total number of power outages and the time when the last 10 power outages occurred and ended;

[0084] The total number of programming times and the most recent 10 programming records. Each programming record includes the earliest programming time of a data item during the programming period and the data identifiers of the last 10 programming items during the programming period;

[0085] The total number of ordinary time adjustments, and the times before and after the most recent 10 ordinary time adjustments;

[0086] The total number of broadcast time adjustment and the time before and after the last 10 broadcast time adjustment;

[0087] Total number and total time of overloads in each phase, and duration of the last 10 overloads;

[0088] Permanently record the total number of resets, the time of occurrence of the last 10 reset events, and the electric energy data at the time of reset;

[0089] Total number of occurrences and / or total cumulative time of each event;

[0090] The total number of remote signal change events and the time when the last 10 remote signal changes occurred;

[0091] The total number of control loop abnormal events and the time when the most recent 10 control loop abnormal events occurred.

[0092] (5) Data communication module

[0093] It is used to support DL / T 698.45 and DL / T 645-2007 protocols. It uses the RS-485 interface to communicate within 3 seconds after power-on, and the communication baud rate is 9600bps. It supports active event reporting and is equipped with a backup power supply to realize active reporting of power outages.

[0094] Supports communication modules such as HPLC, micro-power wireless, dual-mode communication unit, etc. The communication rate supports 1200bps, 2400bps, 4800bps, and 9600bps; the factory default configuration is HPLC communication module.

[0095] (6) Clock module

[0096] It has a built-in temperature compensation circuit, and the daily timing error does not exceed 1 second / day. It has the functions of calendar, timing and leap year automatic conversion, and can perform ordinary time calibration and broadcast time calibration through the communication interface;

[0097] The function of the temperature compensation circuit is to adjust the frequency of the crystal oscillator in real time according to the output of the temperature sensor. The frequency can be fine-tuned by adjusting the load capacitance of the crystal or adding a variable capacitor (such as a varactor diode) to the crystal oscillator circuit;

[0098] like Figure 2 As shown, the temperature compensation circuit includes:

[0099] The temperature sensor, humidity sensor and air pressure sensor are used to monitor the ambient temperature, humidity and air pressure respectively, and send the information to the real-time clock module;

[0100] Real-time clock module (RTC), including a crystal oscillator as a time reference (the crystal oscillator is the core of the hardware clock, which provides a stable frequency signal for the circuit. The frequency of the quartz crystal is affected by temperature changes, so a temperature compensation circuit is required to reduce this effect), used to maintain accurate time, and receive environmental parameters to adjust the clock frequency according to temperature changes;

[0101] MCU chip, used to execute temperature compensation algorithm, specifically:

[0102] Based on the nonlinear regression model, multi-dimensional environmental parameters are used for optimization, including ambient temperature, humidity and pressure. The compensation formula is as follows:

[0103] ;

[0104] In the formula, is the temperature value after compensation; is the measured real-time temperature value; is the reference temperature value; , , are the compensation coefficients obtained through experimental fitting; is the current humidity value, is the current air pressure value;

[0105] NVM memory is used to store calibration parameters (ambient temperature, humidity, pressure, supplementary coefficients, etc.) and compensated temperature values.

[0106] The clock module uses an environmentally friendly lithium battery as a dedicated backup power source for the clock. The capacity of the lithium battery is not less than 1200mAh, and it can maintain the normal operation of the clock for at least 5 years after power failure. Ordinary time synchronization uses the ciphertext + MAC method for point-to-point time synchronization, and broadcast time synchronization uses the plaintext method. The time synchronization deviation does not exceed 10 minutes, and broadcast time synchronization is limited to once a day.

[0107] Ciphertext + MAC is a method of data transmission and verification, where MAC stands for Message Authentication Code. This method combines data encryption and message authentication to provide data confidentiality, integrity, and authentication.

[0108] Ciphertext: Ciphertext is the result obtained by encrypting the original data. The encryption process uses a specific encryption algorithm and key to convert the original data (plaintext) into an unreadable ciphertext form to ensure the confidentiality of the data.

[0109] MAC (Message Authentication Code): MAC is a cryptographic code used to verify the integrity and authentication of a message. It is calculated using a specific MAC algorithm using a given key and message. The MAC value is transmitted as an additional part of the message. The receiver can recalculate the MAC value using the same key and MAC algorithm and compare it with the received MAC value to verify the integrity of the message and confirm the legitimacy of the source of the message.

[0110] The working principle of the ciphertext + MAC method is as follows:

[0111] The sender first encrypts the original data using the encryption algorithm and key to generate ciphertext;

[0112] Next, the sender uses the MAC algorithm and the same key (or another dedicated MAC key) to calculate the ciphertext and generate a MAC value;

[0113] The sender sends the ciphertext and MAC value to the receiver;

[0114] After receiving the data, the receiver first recalculates the MAC value using the same key and MAC algorithm;

[0115] The receiver compares the recalculated MAC value with the received MAC value. If the two are consistent, it means that the ciphertext has not been tampered with during transmission and the sender's identity has been verified;

[0116] Finally, the receiver uses the same key and encryption algorithm to decrypt the ciphertext and restore the original data.

[0117] Security considerations: The ciphertext + MAC method provides double security. On the one hand, encryption ensures the confidentiality of data and prevents unauthorized access and leakage. On the other hand, MAC verifies the integrity of the data and the legitimacy of the source, preventing the data from being tampered with or forged during transmission.

[0118] The following is the compensation coefficient , , The experimental fitting process is:

[0119] 1. Purpose

[0120] Through multiple sets of experiments, the temperature changes under different temperature, humidity and air pressure conditions were measured, and the compensation coefficients in the temperature compensation algorithm were fitted using the experimental data. , , , thereby improving the accuracy of temperature measurement and making up for the shortcomings of the linear compensation algorithm in the prior art.

[0121] 2. Experimental Equipment

[0122] Temperature sensor: accuracy ±0.1℃;

[0123] Humidity sensor: accuracy ±1% RH;

[0124] Air pressure sensor: accuracy ±0.1 hPa;

[0125] Temperature control box: the control temperature range is -40℃ to 85℃, the accuracy is ±0.5℃;

[0126] Climate chamber: used to control humidity and air pressure conditions;

[0127] Data acquisition system.

[0128] 3. Experimental variables

[0129] Control variable: reference temperature value : 25℃; the test time for each test should be kept consistent (e.g. 1 hour).

[0130] Independent variables:

[0131] Actual temperature value : Set different temperature values, ranging from -40℃ to 85℃;

[0132] Current humidity value : Set to 10%, 30%, 50%, 70%, 90%;

[0133] Current air pressure : Set to 950 hPa, 1000 hPa, 1050 hPa;

[0134] Dependent variable: Compensated temperature value .

[0135] 4. Experimental Procedure

[0136] Initial setting: Set the temperature control box at different actual temperature values (-40℃, -20℃, 0℃, 20℃, 40℃, 60℃, 85℃), at each temperature point, use a temperature control box to keep the temperature constant;

[0137] Adjust humidity and air pressure: Under each temperature setting, set different humidity (10%, 30%, 50%, 70%, 90%) and air pressure conditions (950 hPa, 1000 hPa, 1050 hPa), and record the corresponding humidity, air pressure and temperature change values;

[0138] Data collection: Record the real-time temperature value measured by the temperature sensor under different humidity and air pressure conditions and compare it to the standard reference temperature Compare and record the temperature difference;

[0139] Repeat the experiment: In order to obtain reliable results, perform three repeated experiments at each temperature point, record three sets of data, and finally take the average value.

[0140] 5. Experimental data samples

[0141] Table 1 shows the measured data under different humidity and air pressure conditions at some temperature points:

[0142] Table 1 Measurement data

[0143]

[0144] 6. Fitting the Model

[0145] Through the experimental data, the compensation coefficient is obtained by fitting using the nonlinear regression method. , , ;

[0146] Fitting steps:

[0147] Use the least squares method to fit the effects of temperature, humidity, and air pressure on the measured temperature difference;

[0148] Perform regression analysis using tools such as MATLAB or Python to obtain the compensation coefficient , , ;

[0149] Fit each set of experimental data, calculate the error and adjust the fitting model.

[0150] 7. Experimental results and conclusions

[0151] The final compensation coefficient obtained by fitting , , as follows:

[0152] (Temperature compensation coefficient, reflecting the changing trend of temperature error with temperature difference);

[0153] (Humidity compensation coefficient, reflecting the impact of humidity on temperature)

[0154] (Air pressure compensation coefficient, reflecting the effect of air pressure on temperature)

[0155] Experimental conclusion:

[0156] The influence of temperature, humidity and air pressure on the measured temperature is verified by experimental data. Compared with the existing linear temperature compensation algorithm, this scheme introduces humidity and air pressure compensation, which significantly improves the accuracy of temperature compensation.

[0157] Experiments show that the nonlinear regression model can more accurately reflect the relationship between temperature, humidity and air pressure, and the temperature error after compensation is controlled within ±0.1℃, which is significantly better than the existing technology.

[0158] (7) Security protection module

[0159] Used for encryption and security authentication through the ESAM module, using the SM1 algorithm to ensure the security of remote control and data communication.

[0160] In addition to the above seven modules, the system also has the following functions:

[0161] 1. Clear:

[0162] Clear the data such as electric energy, frozen quantity, event records, etc. stored in the branch measurement module;

[0163] The zeroing operation should be recorded permanently as an event, and safety measures should be taken to prevent unauthorized operations;

[0164] The bottom value of the shunt measurement module can only be cleared and cannot be set.

[0165] 2. Freeze:

[0166] Minute freeze (load record): The storage space of the load record is at least guaranteed to record the total active energy of forward and reverse directions, phase voltage, phase current, active power, and power factor by default. When the interval is 15 minutes, the data volume of no less than 300 days can be recorded; the load record interval can be set within the range of (1 to 60) minutes, and the default interval is 15 minutes;

[0167] Daily freeze: Stores the amount of electricity at 0:00 every day. It should be able to store 62 days of data. If the daily freeze time is missed during a power outage, the daily frozen data will be supplemented when the power is restored. A maximum of the latest 7 days of frozen data can be supplemented.

[0168] The frozen content and identifier shall comply with the requirements of DL / T 698.45, and the default value is 2 decimal places for electric energy.

[0169] 3. Software Upgrade

[0170] It has the function of local program upgrade via RS-485 interface.

[0171] like Figure 3 As shown in FIG. 1 , another embodiment of the present invention provides a high-precision remote control branch quantity measurement method for power parameter measurement, comprising the following steps:

[0172] S1: Real-time measurement and storage of power parameters and electric energy data, including forward and reverse active electric energy, total and split-phase power, split-phase voltage, split-phase current, frequency and power factor; the forward and reverse active electric energy includes independent measurement of combined-phase and split-phase electric energy;

[0173] S2: Calculate the operating status of each branch of the system based on the measured power parameters and electric energy data through the state estimation algorithm;

[0174] S3: Based on the real-time state estimation results, the remote control command is executed through the encryption method based on the SM1 algorithm combined with identity authentication, the switches and loads of each branch are adjusted based on the fuzzy logic control algorithm, and related control events are recorded;

[0175] S4: During the measurement process, the clock module manages the system’s timestamp, and the communication interface performs ordinary time calibration and broadcast time calibration;

[0176] The clock module has a built-in temperature compensation circuit, and the temperature compensation algorithm is executed by the MCU chip. The specific temperature compensation algorithm is:

[0177] Based on the nonlinear regression model, multi-dimensional environmental parameters are used for optimization, including ambient temperature, humidity and pressure. The compensation formula is as follows:

[0178] ;

[0179] In the formula, is the temperature value after compensation; is the measured real-time temperature value; is the reference temperature value; , , are the compensation coefficients obtained through experimental fitting; is the current humidity value, is the current air pressure value.

[0180] In summary, the present invention can accurately measure the power parameters of each branch through high-frequency sampling of the branch measurement module, greatly improving the measurement accuracy; the state estimation can use redundant measurement data to accurately calculate the real-time operating status of the distribution network through mathematical algorithms, which not only reduces measurement errors, but also improves the reliability and integrity of the data; through the remote control module, it can achieve precise control and remote operation of multiple branches, improving the intelligence level of the system; the power-off protection and encrypted transmission of data ensure the reliability and security of the system in harsh environments, and solve the problems of power-off data loss and weak data security in the prior art. The temperature compensation circuit of the clock module further improves the accuracy of time recording, allowing the system to maintain stable performance under long-term operation.

[0181] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A high-precision remote control branch measurement system for power parameter measurement, characterized in that: The system comprises: A branch measurement module is used to measure power parameters and electric energy data in real time, including forward and reverse active electric energy, total and split-phase power, split-phase voltage, split-phase current, frequency and power factor; the forward and reverse active electric energy includes independent measurement of combined-phase and split-phase electric energy; A main control module, used to calculate the operating state of each branch of the system based on the data measured by the branch measurement module through a state estimation algorithm; The remote control module is used to execute remote control commands based on the real-time state estimation results, through the encryption method based on the SM1 algorithm, combined with identity authentication, adjust the switches and loads of each branch based on the fuzzy logic control algorithm, and record related control events; Data storage and recording module, used to store the data collected in historical time with at least 2 decimal places or the number of electric energy pulses and generate reports regularly, ensuring that the system can save data for at least 3 years in the event of power failure, and record key events in system operation; Data communication module, used to support DL / T 698.45 and DL / T 645-2007 protocols, uses RS-485 interface for communication within 3 seconds after power-on, and the communication baud rate is 9600bps; supports active event reporting, and is equipped with a backup power supply to realize active reporting of power outages; The clock module has a built-in temperature compensation circuit, with a daily timing error of no more than 1 second / day. It has the functions of calendar, timing and leap year automatic conversion, and can perform ordinary time calibration and broadcast time calibration through the communication interface; Security protection module, used for encryption and security authentication through ESAM module, using SM1 algorithm to ensure the security of remote control and data communication; The temperature compensation circuit comprises: The temperature sensor, humidity sensor and air pressure sensor are used to monitor the ambient temperature, humidity and air pressure respectively, and send the information to the real-time clock module; A real-time clock module includes a crystal oscillator as a time reference for maintaining accurate time, and receives environmental parameters to adjust the clock frequency according to temperature changes; The MCU chip is used to execute a temperature compensation algorithm, wherein the temperature compensation algorithm is specifically: Based on the nonlinear regression model, multi-dimensional environmental parameters are used for optimization, including ambient temperature, humidity and pressure. The compensation formula is as follows: ； In the formula, is the temperature value after compensation; is the measured real-time temperature value; is the reference temperature value; , , are the compensation coefficients obtained through experimental fitting; is the current humidity value, is the current air pressure value; NVM memory for storing calibration parameters and compensated temperature values.

2. A high-precision remote control branch measurement system for power parameter measurement according to claim 1, characterized in that: The branch measurement module performs high-frequency sampling on the voltage and current signals of each branch, following the Nyquist sampling theorem, with the sampling frequency being greater than twice the highest frequency of the signal, and converting them into phasors through discrete Fourier transform.

3. A high-precision remote control branch measurement system for power parameter measurement according to claim 1, characterized in that: The state estimation algorithm is specifically a weighted least squares method, and the formula is: ； In the formula, is the objective function, is the measured value, is the nonlinear function of the system model, is the weighting coefficient, is the state vector to be estimated; Represents the number of each data sample, ranging from 1 to m.

4. A high-precision remote control branch measurement system for power parameter measurement according to claim 1, characterized in that: The remote control module is provided with a relay circuit inside to control the external load switch, and can detect whether the access state of the control circuit is valid, and can identify the switch input position change, and actively report if a state quantity position change event occurs; The relevant control events include: When a tripping event occurs due to remote control, the remote control tripping event is recorded and actively reported; When the remote control allows the closing operation, the closing permission event is recorded and reported actively.

5. A high-precision remote control branch measurement system for power parameter measurement according to claim 1, characterized in that: The key events in the operation of the system include: The total number of overvoltages in each phase, as well as the occurrence and end times of the last 10 overvoltages and the corresponding electrical energy data; The total number of overcurrents in each phase, as well as the occurrence and end times of the last 10 overcurrents and the corresponding electric energy data; The total number of total and phase power reverse events, as well as the time of the last 10 power reverse events and the corresponding electric energy data; The total number of power outages and the time when the last 10 power outages occurred and ended; The total number of programming times and the most recent 10 programming records. Each programming record includes the earliest programming time of a data item during the programming period and the data identifiers of the last 10 programming items during the programming period; The total number of ordinary time adjustments, and the times before and after the most recent 10 ordinary time adjustments; The total number of broadcast time adjustment and the time before and after the last 10 broadcast time adjustment; Total number and total time of overloads in each phase, and duration of the last 10 overloads; Permanently record the total number of resets, the time of occurrence of the last 10 reset events, and the electric energy data at the time of reset; Total number of occurrences and / or total cumulative time of each event; The total number of remote signal change events and the time when the last 10 remote signal changes occurred; The total number of control loop abnormal events and the time when the most recent 10 control loop abnormal events occurred.

6. A high-precision remote control branch measurement system for power parameter measurement according to claim 1, characterized in that: The clock module uses an environmentally friendly lithium battery as a dedicated backup power supply for the clock. The capacity of the lithium battery is not less than 1200mAh, and it can maintain the normal operation of the clock for at least 5 years after power failure. Ordinary time calibration is performed point-to-point through the ciphertext + MAC method, and broadcast time calibration is performed through plaintext. The time calibration deviation does not exceed 10 minutes, and broadcast time calibration is limited to once a day.

7. A measurement method for a high-precision remote-controlled branch measurement system for power parameter measurement according to any one of claims 1 to 6, characterized in that: The method comprises: Real-time measurement and storage of power parameters and electric energy data, including forward and reverse active electric energy, total and split-phase power, split-phase voltage, split-phase current, frequency and power factor; the forward and reverse active electric energy includes independent measurement of combined-phase and split-phase electric energy; The operating status of each branch of the system is calculated based on the measured power parameters and electric energy data through the state estimation algorithm; According to the real-time state estimation results, the remote control command is executed through the encryption method based on the SM1 algorithm combined with identity authentication, the switches and loads of each branch are adjusted based on the fuzzy logic control algorithm, and the relevant control events are recorded; During the measurement process, the system's timestamp is managed through the clock module, and ordinary time calibration and broadcast time calibration are performed through the communication interface.

8. The measuring method according to claim 7, characterized in that: The clock module has a built-in temperature compensation circuit, and the temperature compensation algorithm is executed by the MCU chip. The temperature compensation algorithm is specifically: ； In the formula, is the temperature value after compensation; is the measured real-time temperature value; is the reference temperature value; , , are the compensation coefficients obtained through experimental fitting; is the current humidity value, is the current air pressure value.

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