Voltage sag event monitoring device and monitoring method thereof

Abstract

The application discloses a voltage sag event monitoring device and a monitoring method thereof, and relates to the technical field of power quality monitoring, in particular to a voltage sag event monitoring device and a monitoring method thereof. The device comprises a signal acquisition module, a main control module and a storage module, the main control module comprises a sag real-time monitoring unit, a sandglass monitoring unit, a sag event response execution unit and a sag event management unit; the signal acquisition module generates a sag interruption signal when an original voltage signal meets a sag triggering condition, the sag real-time monitoring unit generates sag occurrence information and a flip signal in response to the interruption signal in each interruption period, the sandglass monitoring unit judges whether the sag is recovered according to the flip signal and generates sag recovery information, the sag event response execution unit generates sag event information when a reporting condition is met, and the sag event information is stored and managed by the sag event management unit and then stored persistently by the storage module. The application realizes accurate determination of the start and end boundaries of a voltage sag event without increasing hardware cost, and is suitable for power quality monitoring of a three-phase multifunctional electric energy meter.

Description

Technical Field

[0001] This invention relates to the field of power quality monitoring technology, and in particular to a voltage sag event monitoring device and its monitoring method. Background Technology

[0002] Voltage sags are important disturbances in the field of power quality, and their detection and recording are of great significance for power grid operation and maintenance and equipment protection.

[0003] Currently, there are two main technical approaches for recording voltage sag events: One approach involves using a dedicated chip combined with a large-capacity storage unit and a high-performance MCU to achieve complete recording and in-depth analysis of the sag waveform. For example, patent application CN113946959A discloses a method for extracting voltage sag data segments. However, this approach has high hardware costs and system complexity, making it difficult to meet the needs of large-scale deployment. The second approach uses a conventional three-phase metering chip, which triggers an interrupt by configuring a voltage threshold and the continuous half-cycle waveform number, and the MCU records the data. For example, patent application CN104360145A provides a voltage sag monitoring device based on a data acquisition card, comprising a pre-amplifier circuit, a data acquisition card, and a computer connected in sequence. This approach is simple in structure and low in cost, but it can only identify that "an event is occurring," making it difficult to accurately determine the start and end boundaries of the event. Furthermore, it has significant shortcomings in long-term repeated sag recording and suppressing false alarms under abnormal operating conditions.

[0004] In summary, existing voltage sag monitoring methods are insufficient to accurately determine the boundaries of sag events on a low-cost hardware platform, and cannot meet the dual requirements of cost-effectiveness and monitoring reliability of three-phase multi-function instruments. Summary of the Invention

[0005] The main objective of this invention is to propose a voltage sag event monitoring device and its monitoring method, which aims to solve the technical problem that existing solutions are unable to simultaneously achieve accurate boundary determination of sag events on a low-cost hardware platform.

[0006] To achieve the above objectives, the present invention provides a voltage sag event monitoring device and a monitoring method thereof.

[0007] In a first aspect, the present invention provides a voltage sag event monitoring device. The device includes a signal acquisition module, a main control module, and a storage module. The main control module includes a real-time sag monitoring unit, an hourglass monitoring unit, a sag event response execution unit, and a sag event management unit. A first end of the real-time sag monitoring unit is connected to the signal acquisition module, a second end is connected to the first end of the sag event response execution unit, and a third end is connected to the first end of the hourglass monitoring unit. A second end of the hourglass monitoring unit is connected to the second end of the sag event response execution unit. A third end of the sag event response execution unit is connected to the sag event management unit.

[0008] The signal acquisition module is used to monitor the original voltage signal in real time and generate a sag interruption signal when the amplitude of the original voltage signal meets the sag triggering condition.

[0009] The temporary descent real-time monitoring unit is used to respond to the temporary descent interruption signal in each interruption cycle, generate temporary descent occurrence information and a flip signal, and send the flip signal to the hourglass monitoring unit;

[0010] The hourglass monitoring unit is used to determine whether the temporary descent has been restored based on whether the flip signal is continuously received, and to generate temporary descent restoration information when it is determined that the temporary descent has been restored.

[0011] The temporary landing event response execution unit is used to generate temporary landing event information based on the temporary landing occurrence information, the temporary landing recovery information, and the temporary landing event reporting conditions;

[0012] The temporary landing event management unit is used to store and manage the temporary landing event information;

[0013] The storage module is used to persistently store the temporary landing event information.

[0014] Furthermore, the signal acquisition module is used to monitor in real time whether the half-wave peak value of the original voltage signal is lower than a preset sag threshold, and to start sending the sag interrupt signal when the half-wave peak value is lower than the preset sag threshold for the first time, and to stop sending the sag interrupt signal when the half-wave peak value is greater than the preset sag threshold.

[0015] Furthermore, the real-time sag monitoring unit is also used to acquire the voltage amplitude of the original voltage signal in each interruption cycle, and terminate the processing flow of the current interruption cycle when the voltage amplitude is less than a preset voltage threshold, without generating the sag occurrence information and the flip signal; the preset voltage threshold is less than the preset sag threshold.

[0016] Furthermore, the operating cycle of the hourglass monitoring unit is shorter than the interruption cycle of the temporary descent real-time monitoring unit; the hourglass monitoring unit is also used to enter a moving state after receiving the flip signal, enter a stationary state when not receiving the flip signal, and determine temporary descent recovery after the stationary state lasts for a first preset time threshold, and generate the temporary descent recovery information.

[0017] Furthermore, the reporting conditions for the temporary landing event include: the duration of the temporary landing in the temporary landing occurrence information is greater than a second preset time threshold and the temporary landing event response execution unit receives the temporary landing recovery information.

[0018] Furthermore, the sag occurrence information includes at least residual voltage information, and the sag real-time monitoring unit is also used to update the residual voltage information to the residual voltage of the current interruption period when the residual voltage of the current interruption period is less than the residual voltage of the previous interruption period.

[0019] Furthermore, the sag event response execution unit is also used to convert the residual voltage in the sag occurrence information from a half-wave peak value to an effective value, convert the sag occurrence information into a standard format, and filter the sag occurrence information converted into a standard format.

[0020] Furthermore, the temporary landing event management unit is also used to manage metadata and the temporary landing event information; the temporary landing event information is stored in the storage module in a circular buffer structure with the beginning and end connected, and the metadata includes at least the total number of events in the circular buffer, the latest event index, and the oldest event index.

[0021] Furthermore, the sag occurrence information includes the sag occurrence time, number of interruptions, sag occurrence flag, residual voltage information, and the phase in which the sag occurred.

[0022] Secondly, the present invention also provides a monitoring method based on the voltage sag event monitoring device described in the first aspect. The method includes:

[0023] Step S1: Monitor the original voltage signal in real time, and generate a sag interruption signal when the amplitude of the original voltage signal meets the sag triggering condition;

[0024] Step S2: In response to the temporary descent interruption signal during each interruption cycle, generate temporary descent occurrence information and a flip signal;

[0025] Step S3: Determine whether the temporary landing has been restored based on whether the flip signal is continuously received, and generate temporary landing restoration information when it is determined that the temporary landing has been restored;

[0026] Step S4: Generate temporary landing event information based on the temporary landing occurrence information, the temporary landing recovery information, and the temporary landing event reporting conditions;

[0027] Step S5: Store and manage the temporary landing event information;

[0028] Step S6: Persistently store the temporary landing event information.

[0029] The aforementioned voltage sag event monitoring device and method, wherein the main control module, through the sag real-time monitoring unit, responds to the sag interrupt signal generated by the signal acquisition module in each interrupt cycle, generating sag occurrence information and a flip signal. The hourglass monitoring unit independently determines sag recovery based on whether the flip signal is continuously received, generating sag recovery information. Finally, the sag event response execution unit integrates the sag occurrence information and sag recovery information, generating sag event information when reporting conditions are met. This information is then persistently stored in the storage module after being managed by the sag event management unit. Through this technical solution, the present invention utilizes a low-cost metering chip as the event trigger front-end output interrupt signal. The main control module, through the coordinated cooperation of its internal units, transmits the underlying instantaneous voltage sag event information. The interruption signal is converted into a transient power sag event record with complete timestamps and characteristic parameters, achieving accurate determination of the start and end boundaries of transient power sag events without increasing hardware costs. Simultaneously, the hourglass monitoring unit separates the transient power sag recovery time judgment logic from the interrupt cycle of the transient power sag real-time monitoring unit, allowing the hourglass monitoring unit to independently complete timing and judgment, avoiding time-consuming operations in the main control module's interrupt service routine and effectively reducing the consumption of main control module processing resources. The transient power sag event response execution unit completes the reporting condition judgment in a low-frequency cycle independent of the interrupt service routine, avoiding interference with the interrupt handling process. The transient power sag event management unit persistently stores event information in the storage module through a storage management mechanism, ensuring the continuity and integrity of event records. Thus, the reliability and accuracy requirements of three-phase multi-functional instruments for power quality monitoring are met on a low-cost hardware platform. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the voltage sag event monitoring device according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram comparing the traditional threshold determination method with the interrupt signal conversion method of this invention.

[0033] Figure 3 This is a flowchart of the real-time monitoring unit for temporary drops in an embodiment of the present invention;

[0034] Figure 4 This is a flowchart of the hourglass monitoring unit according to an embodiment of the present invention;

[0035] Figure 5 The detailed working process of the hourglass monitoring unit in this embodiment of the invention;

[0036] Figure 6 This is a flowchart of the temporary landing event response execution unit according to an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram showing the before and after conversion of temporary landing information into a standard format according to an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of the storage structure for temporary landing event information according to an embodiment of the present invention;

[0039] Figure 9 This is a schematic flowchart of the monitoring method of the voltage sag event monitoring device according to an embodiment of the present invention.

[0040] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] like Figure 1 As shown, this embodiment provides a voltage sag event monitoring device, including a signal acquisition module, a main control module, and a storage module. The main control module is connected to the signal acquisition module via a signal line, and the main control module is connected to the storage module via a signal line. The signal acquisition module includes a low-cost metering chip, which is responsible for acquiring the raw signal and standardizing the signal. The main control module is responsible for event management and sag feature extraction, and the storage module is responsible for long-term recording of sag events.

[0044] The signal acquisition module in this embodiment is used to monitor the original voltage signal in real time and generate a sag interruption signal (M3) when the amplitude of the original voltage signal meets the sag triggering condition. Figure 2 As shown, Figure 2The upper part shows the traditional threshold judgment method, which relies on high-precision acquisition and recording of the entire waveform. This method has high requirements for chip cost and requires a strict 10ms sampling period for half-wave peak calculation. It is difficult to implement in multi-functional tables with high functional integration. For example, the logic of daily freezing, monthly freezing, and monthly settlement will occupy tens to hundreds of milliseconds of program cycle. Figure 2 The lower part illustrates the method used by the signal acquisition module in this embodiment. Unlike traditional solutions, this embodiment utilizes the inherent half-wave peak value judgment and interrupt output capabilities of a low-cost metering chip to convert the sag voltage waveform into a sag interrupt signal. The main control module only needs to focus on this sag interrupt signal and analyze it using a preset algorithm to determine the occurrence and recovery of a sag, without relying on full waveform recording. This reduces hardware costs while ensuring the reliability and real-time performance of monitoring. Specifically, the signal acquisition module monitors in real-time whether the half-wave peak value of the original voltage signal in the line is lower than a preset sag threshold, using a half-wave period (e.g., 10ms). When the half-wave peak value first falls below the preset sag threshold, a sag is determined to have occurred, and a sag interrupt signal is initiated. When the half-wave peak value exceeds the preset sag threshold, a sag recovery is determined, and the transmission of the sag interrupt signal stops. The sag interrupt signal is in the form of a rectangular wave. During the duration of the sag, the rectangular wave operates on a half-wave period, with each period containing one rising edge and one falling edge.

[0045] During the occurrence and recording of a temporary landing event, the main control module receives a temporary landing interruption signal that has been standardized by the signal acquisition module. It then analyzes this interruption signal using its internal temporary landing monitoring algorithm (A1) to identify, extract features from, and record the temporary landing event. Subsequently, the main control module sends the temporary landing event content detected by the monitoring algorithm to the storage module for long-term storage. The storage module is preferably an EEPROM.

[0046] In this embodiment, the main control module includes a temporary landing real-time monitoring unit, an hourglass monitoring unit, a temporary landing event response execution unit, and a temporary landing event management unit. The first end of the temporary landing real-time monitoring unit is connected to the signal acquisition module, the second end is connected to the first end of the temporary landing event response execution unit, and the third end is connected to the first end of the hourglass monitoring unit. The second end of the hourglass monitoring unit is connected to the second end of the temporary landing event response execution unit. The third end of the temporary landing event response execution unit is connected to the temporary landing event management unit.

[0047] After the sag interruption signal is captured by the main control module, the sag real-time monitoring unit starts working. It continuously refreshes the sag occurrence information (M1) within each interrupt cycle and sends a flip signal to the hourglass monitoring unit according to the interrupt cycle, thus activating the hourglass monitoring unit. The sag real-time monitoring unit continuously analyzes the sag interruption signal and outputs sag occurrence information for subsequent processing by the sag event response execution unit. In this embodiment, the sag occurrence information includes the sag occurrence time, interruption count, sag occurrence flag, residual voltage information, and the phase of the sag.

[0048] In a preferred embodiment, the real-time sag monitoring unit acquires the voltage amplitude of the original voltage signal in each interruption cycle. When the voltage amplitude is less than a preset voltage threshold, the processing flow of the current interruption cycle is terminated, and no sag occurrence information or flip signal is generated, wherein the preset voltage threshold is less than a preset sag threshold. The sag occurrence information includes at least residual voltage information. When the residual voltage in the current interruption cycle is less than the residual voltage recorded in the previous interruption cycle, the real-time sag monitoring unit updates the residual voltage information to the residual voltage value of the current interruption cycle to retain the lowest voltage during the sag. Thus, the residual voltage information refers to the lowest residual voltage finally determined by the real-time sag monitoring unit after continuous comparison and updating in each interruption cycle during the sag period.

[0049] Figure 3 The flowchart of the real-time sag monitoring unit is shown. Taking the monitoring of a sag in a single phase as an example, the real-time sag monitoring unit is executed once every interrupt cycle (10ms) during the occurrence and duration of the sag. First, the real-time sag monitoring unit judges the voltage amplitude of the phase. If it is less than 10% of the voltage specification of the three-phase multi-function meter, the current cycle ends directly and is not considered as a sag; otherwise, the process continues. If the current execution cycle is the interrupt cycle triggered by the sag occurrence time T1, the system time is used as the sag occurrence time in the sag occurrence information, a flip signal is sent to the hourglass monitoring unit, the sag occurrence flag is set, the interrupt count is incremented by 1, the current half-wave peak value is recorded as the residual voltage information, and the phase of the sag occurrence is updated. If the current execution cycle is within the sag duration after the sag occurrence time, the current residual voltage is compared with the residual voltage recorded in the previous cycle in each interrupt cycle, the lower value is retained as the residual voltage information for this cycle, a flip signal is sent to the hourglass monitoring unit, and the interrupt count is incremented by 1.

[0050] When the half-wave peak value exceeds the preset sag threshold again, the sag is restored, the sag occurrence information stops refreshing, and the flip signal sent to the hourglass monitoring unit stops. After not receiving the flip signal, the hourglass monitoring unit enters a static state, and after remaining in the static state for a first preset time threshold, it determines that the sag has been restored and generates sag restoration information.

[0051] The hourglass monitoring unit is used to determine whether the temporary descent has been restored based on whether a flip signal is continuously received, and generates temporary descent restoration information (M2) when the temporary descent is determined to be restored. Specifically, the hourglass monitoring unit enters a moving state after receiving a flip signal, enters a stationary state when no flip signal is received, and determines that the temporary descent has been restored after the stationary state has been maintained for a first preset time threshold, and generates temporary descent restoration information. Figure 4 The flowchart of the hourglass monitoring unit is shown. Its overall working logic is as follows: the hourglass monitoring unit checks whether a flip signal is received in each running cycle. When a flip signal is received, the hourglass performs a flip operation and drives the sand to flow. Subsequently, the output state of the temporary descent recovery information is refreshed according to whether the sand continues to flow. In addition, in order to facilitate sensitive capture of the flip signal sent by the temporary descent real-time monitoring unit, the running cycle of the hourglass monitoring unit is shorter than the interrupt cycle of the temporary descent real-time monitoring unit (for example, when the interrupt cycle is 10ms, the running cycle of the hourglass monitoring unit is 5ms or less).

[0052] Figure 5 The detailed workflow of the hourglass monitoring unit is further demonstrated. The unit maintains a symmetrical hourglass model. The two regions A and B of the hourglass are represented by variables H1 and H2 in the program, respectively. The values ​​of H1 and H2 represent the number of sand grains in regions A and B, respectively. The total number of sand grains is represented by a constant K (K equals the maximum capacity of a single region). The hourglass is initialized to a static state STA1, at which point all the sand is concentrated in one region.

[0053] The hourglass monitoring unit checks for a flip signal during each operating cycle. Upon receiving a flip signal, the hourglass flips and switches to the motion state STA1; otherwise, it remains in its current state. In motion state STA1, the sand flows according to gravity. For every unit of sand that flows, the source region decreases by 1 and the target region increases by 1, until the source region is depleted (value 0) or the target region is saturated (value K). When both H1 and H2 are greater than 0, the hourglass is in motion state STA1, indicating that the sand is flowing; when either H1 or H2 equals 0 (or the other equals K), the hourglass switches to the stationary state STA2, indicating that the sand has stopped flowing. Regardless of the hourglass's state, the sand continues to flow according to gravity by default.

[0054] When the hourglass switches from the moving state STA1 to the stationary state STA2, the hourglass monitoring unit starts a recovery confirmation timer. If no flip signal is received again within a first preset time threshold (e.g., 10ms) and the hourglass remains in the stationary state STA2, it is determined that the temporary descent has been successfully recovered. A temporary descent recovery message is generated and sent to the temporary descent event response execution unit (U1) to inform it that the temporary descent has been recovered. If a flip signal is received again within 10ms, the hourglass switches back to the moving state STA1, indicating that the temporary descent is still ongoing. The recovery confirmation timer is reset to zero and monitoring resumes. Through this mechanism, the hourglass monitoring unit uses the flow of sand as the criterion for determining whether a temporary descent has been recovered—continuous sand flow indicates that a temporary descent is occurring, and the sand flow stops and continues for a preset time, indicating that the temporary descent has been recovered. This mechanism separates the timing judgment logic for temporary landing recovery from the interruption cycle of the temporary landing real-time monitoring unit, and allows the hourglass monitoring unit to independently complete the tracking and judgment. This avoids performing time-consuming operations in the main control module's interrupt service routine, effectively reducing the consumption of the main control module's processing resources. At the same time, because the hourglass monitoring unit has a short operating cycle and a sensitive response, it can accurately capture the temporary landing recovery time without increasing the burden on the temporary landing real-time monitoring unit, ensuring the accuracy and reliability of the temporary landing duration statistics.

[0055] The sag event response execution unit generates sag event information based on sag occurrence information, sag recovery information, and sag event reporting conditions. Furthermore, this unit also converts the residual voltage in the sag occurrence information from a half-wave peak value to an effective value, converts the sag occurrence information into a standard format, and filters the converted sag occurrence information. The sag event response execution unit communicates with the sag real-time monitoring unit and the hourglass monitoring unit via function calls, combining the sag occurrence information sent by the real-time monitoring unit and the sag recovery information sent by the hourglass monitoring unit to determine the sag event reporting conditions. Simultaneously, the sag event response execution unit communicates with the sag event management unit via function calls; when the sag event reporting conditions are met, it calls the sag event management unit to report the filtered sag event information, which is ultimately stored in the storage module.

[0056] Figure 6The flowchart of the temporary landing event response execution unit is shown. The temporary landing event response execution unit runs within a preset cycle (e.g., 100ms), continuously analyzing temporary landing occurrence and recovery information. The unit first determines whether the temporary landing duration in the temporary landing occurrence information is greater than a second preset time threshold (e.g., 10ms, meaning the temporary landing real-time monitoring unit has executed at least one interrupt cycle), and then determines whether the temporary landing recovery information has been received. When both conditions are met simultaneously, the temporary landing event reporting condition is established, and the temporary landing event response execution unit begins the subsequent data processing and reporting process; otherwise, the current cycle ends directly, indicating that there is currently no valid temporary landing event information to process.

[0057] When the reporting conditions for a voltage dip event are met, the voltage dip event response execution unit first formats the voltage dip occurrence information, specifically including two steps: converting the residual voltage from a half-wave peak value to an effective value, and converting all information in the voltage dip occurrence information into a standard format. For example... Figure 7 As shown, the sag event information includes the sag occurrence time (year, month, day, hour, minute, second, millisecond), the number of interruptions (used to calculate the duration), the sag occurrence flag (true / false), the residual voltage (half-wave peak value), and the phase of the sag occurrence (0, 1, 2 correspond to phases A, B, and C, respectively). After conversion by the sag event response execution unit, the above information is organized into a standard format. The sag occurrence time is presented in a standardized time format, the duration is calculated by multiplying the number of interruptions by the interrupt cycle (e.g., 10 interruptions correspond to 100ms), the residual voltage is converted to a valid value, and the phase is identified by A, B, and C, making the sag event information more intuitive and easier for subsequent processing and analysis.

[0058] Subsequently, the sag event response execution unit filters the information converted to the standard format. Specifically, this includes filtering out false events with zero duration, filtering out events with residual voltage changes within the hysteresis voltage threshold to prevent frequent event reporting from affecting the storage module's lifespan, and filtering out invalid events with abnormal residual voltage. In one specific implementation, a residual voltage less than 10V is considered an invalid event with abnormal residual voltage. After filtering, the sag event response execution unit calls the sag event management unit to report the filtered sag event information (M4) and store it for an extended period.

[0059] Through the above mechanism, the temporary landing event response execution unit completes the reporting condition determination, data format conversion and validity filtering in a low-frequency period (100ms) independent of the interrupt service routine. This avoids interference with the interrupt processing flow of the temporary landing real-time monitoring unit and ensures that the temporary landing event information reported to the storage module is consistent, readable and valid.

[0060] The temporary landing event management unit is used to store and manage temporary landing event information. It manages the addition, deletion, modification, and viewing of temporary landing events. During the event reporting phase, it is invoked by the temporary landing event response execution unit to perform the addition operation for temporary landing events. The temporary landing event management unit does not run in a fixed program cycle; rather, it is a passively invoked program that only executes when called by other programs.

[0061] In a preferred embodiment, the temporary landing event management unit is also used to manage metadata and temporary landing event information. Specifically, the information in the temporary landing event management unit includes two parts: metadata and temporary landing event information. The metadata records the total number of events, the latest event index, and the oldest event index, while the temporary landing event information is stored in the storage module. The information in the temporary landing event management unit is stored briefly in the ROM of the main control module for data exchange during program calls, and also stored long-term in the storage module (e.g., EEPROM) to ensure long-term retention even after power failure. When the device is powered on, the temporary landing event management unit extracts the event information from the storage module and synchronizes it to the ROM; if there is no valid data in the storage module, the metadata and event information are cleared.

[0062] Temporary event information is stored in the storage module in a circular buffer structure with the first and last events connected. The metadata includes at least the total number of events in the circular buffer, the latest event index, and the oldest event index.

[0063] like Figure 8 As shown, temporary descent event information is stored in the storage module using a circular buffer structure with each event linked to the next. The total number of events, the latest event index, and the oldest event index in this circular structure are recorded by metadata. When adding a new event, the circular buffer is first checked for fullness. If the buffer is not full, it means the total number of currently recorded temporary descent events is less than the maximum number that the device can store, so the total number of events in the metadata is incremented by one. If the event being written is the first event, both the latest and oldest event indices point to this event. Subsequent events are sequentially placed after the previous event, and the latest event index is updated to the position of the most recently added event, with the metadata updated synchronously. If adding an event causes the buffer to become full, it means the total number of events is about to exceed the maximum number that the device can store, so the new event overwrites the event position pointed to by the oldest event index, the oldest event index is incremented by one and points to the next consecutive position, and so on. Through this circular buffer management mechanism, the temporary descent event management unit achieves efficient and orderly storage of temporary descent events within a limited storage space, ensuring full utilization of storage resources and that the latest events are always recorded.

[0064] The storage module is used to persistently store temporary landing event information processed by the temporary landing event management unit. In a preferred embodiment, the storage module uses EEPROM to achieve long-term preservation of temporary landing event information in the event of power failure. The storage module is connected to the main control module via signal lines, receives temporary landing event information reported by the main control module through the temporary landing event management unit, and persistently writes it according to the storage structure of a circular buffer. Unlike the ROM in the main control module, which is used for short-term storage of data exchange during program execution, the temporary landing event information in the storage module is not affected by power failure. After the device is powered on again, the temporary landing event management unit automatically synchronizes the historical event information in the storage module to the ROM, ensuring the continuity and integrity of the event records. By setting up an independent non-volatile storage module, the main control module can immediately release processing resources after the temporary landing event is reported, without occupying the internal storage space of the main control module for a long time. This ensures reliable storage of temporary landing event information while improving the operating efficiency of the main control module.

[0065] This embodiment of the voltage sag event monitoring device reconstructs the functional boundaries between the metering chip and the main control module, abandoning the traditional approach of relying on full waveform recording. It positions the low-cost metering chip as a fast-response event triggering front-end, utilizing its internally preset threshold judgment and interrupt output capabilities to monitor the voltage status in real time and output a sag interrupt signal when conditions are met. Simultaneously, the main control module acts as the event management and feature extraction center. Upon receiving the interrupt signal, it executes refined software logic through its internally constructed sag real-time monitoring unit, hourglass monitoring unit, sag event response execution unit, and sag event management unit. This includes recording the event start time, tracking and locking the residual voltage extreme value during the sag in real time, accurately determining the event end boundary using the recovery confirmation mechanism of the hourglass monitoring unit, and filtering invalid operating conditions. Through a collaborative mechanism of hardware triggering and software shaping, this embodiment successfully transforms the underlying instantaneous interrupt signal into a sag event record with complete timestamps and characteristic parameters without increasing hardware costs, achieving high-reliability power quality monitoring on a low-cost hardware platform.

[0066] Example 2

[0067] like Figure 9 As shown in the figure, this embodiment provides a monitoring method for a voltage sag event monitoring device. This method can be performed by... Figure 1 The voltage sag event monitoring device shown in the diagram performs the following steps:

[0068] Step S1: Monitor the original voltage signal in real time, and generate a sag interrupt signal when the amplitude of the original voltage signal meets the sag trigger condition.

[0069] Specifically, the signal acquisition module monitors in real time whether the half-wave peak value of the original voltage signal in the line is lower than a preset sag threshold, using a half-wave period (e.g., 10ms). Figure 2 As shown, unlike traditional solutions that rely on high-precision full-waveform acquisition and recording, this embodiment utilizes the half-wave peak value judgment and interrupt output capabilities of the low-cost metering chip to convert the sag voltage waveform into a sag interrupt signal. The interrupt signal is preferably a rectangular wave. When the half-wave peak value is first less than a preset sag threshold, a sag is determined to have occurred, and the signal acquisition module begins sending a sag interrupt signal. When the half-wave peak value is greater than the preset sag threshold, a sag is determined to have recovered, and the signal acquisition module stops sending the sag interrupt signal.

[0070] Step S2: In each interrupt cycle, in response to the sag interrupt signal, sag occurrence information and toggle signal are generated.

[0071] Specifically, the real-time monitoring unit for temporary drops is executed once every interrupt cycle (10ms). For example... Figure 3 As shown, the real-time sag monitoring unit first judges the voltage amplitude of the phase. If it is less than 10% of the voltage specification of the three-phase multi-function meter, the processing flow of the current interruption cycle is terminated, and it is not considered as a sag; otherwise, the process continues. If the current execution cycle is the interruption cycle triggered by the sag occurrence time T1, the system time is used as the sag occurrence time in the sag occurrence information, a reversal signal is sent to the hourglass monitoring unit, the sag occurrence flag is set, the interruption count is incremented by 1, the current half-wave peak value is recorded as the residual voltage information, and the phase of the sag occurrence is updated. If the current execution cycle is within the sag duration period after the sag occurrence time, the current residual voltage is compared with the residual voltage recorded in the previous cycle in each interruption cycle, the lower value is retained as the residual voltage information of this cycle, a reversal signal is sent to the hourglass monitoring unit, and the interruption count is incremented by 1.

[0072] Step S3: Determine whether the temporary landing has been restored based on whether a flip signal is continuously received, and generate temporary landing restoration information when it is determined that the temporary landing has been restored.

[0073] Specifically, the hourglass monitoring unit operates within a program cycle shorter than the interrupt cycle (e.g., 5ms) to sensitively capture the flip signal. Figure 4 and Figure 5As shown, the hourglass monitoring unit maintains a symmetrical hourglass model internally. The two regions A and B of the hourglass are represented by variables H1 and H2 in the program. When a flip signal is received, the hourglass performs a flip operation and switches to the moving state STA1, where the sand flows in the direction of gravity. When no flip signal is received, the hourglass maintains its current state, and the sand continues to flow until it stops, at which point the hourglass switches to the stationary state STA2. When the hourglass switches from the moving state STA1 to the stationary state STA2, the hourglass monitoring unit starts a recovery confirmation timer. If no flip signal is received again within a first preset time threshold (e.g., 10ms) and the hourglass remains in the stationary state STA2, it is determined that the temporary descent has been successfully recovered. A temporary descent recovery message is generated and sent to the temporary descent event response execution unit. If a flip signal is received again within 10ms, the hourglass switches back to the moving state STA1, indicating that the temporary descent is still ongoing. The recovery confirmation timer is reset to zero and monitoring resumes.

[0074] Step S4: Generate temporary landing event information based on temporary landing occurrence information, temporary landing recovery information, and temporary landing event reporting conditions.

[0075] Specifically, the temporary landing event response execution unit runs within a preset period (e.g., 100ms) of program flow, continuously analyzing temporary landing occurrence and recovery information. For example... Figure 6 As shown, the sag event response execution unit first determines whether the sag duration in the sag occurrence information is greater than a second preset time threshold (e.g., 10ms, meaning the sag real-time monitoring unit has executed at least one interrupt cycle), and then determines whether the sag recovery information has been received. When both conditions are met simultaneously, the sag event reporting condition is established, and the sag event response execution unit begins the data processing procedure. Specifically, this includes converting the residual voltage from a half-wave peak value to an effective value, and converting all information in the sag occurrence information into a standard format. For example... Figure 7 As shown, the converted sag occurrence time is presented in a standardized time format, and the duration is calculated by multiplying the number of interrupts by the interrupt cycle. The residual voltage is converted to an effective value, and the phases are identified by A, B, and C, respectively. Subsequently, the sag event response execution unit filters the converted information, specifically filtering out spurious events with a duration of zero, events with residual voltage changes within the hysteresis voltage threshold, and invalid events with abnormal residual voltage. After filtering, filtered sag event information is generated.

[0076] Step S5: Store and manage the temporary landing event information.

[0077] Specifically, the temporary landing event management unit is invoked by the temporary landing event response execution unit to perform the addition operation of the temporary landing event. The temporary landing event management unit does not run in a fixed program cycle, but is a passively invoked program that only executes when called by other programs. For example... Figure 8As shown, temporary event information is stored in the storage module using a circular buffer structure with the first and last events connected. The metadata records the total number of events, the latest event index, and the oldest event index. When adding a new event, the system first checks if the circular buffer is full. If the buffer is not full, the total number of events in the metadata is incremented, and the new event is sequentially placed after the previous event. If the event being written is the first event, both the latest and oldest event indices point to that event. If adding an event causes the buffer to become full, the new event overwrites the event position pointed to by the oldest event index, the oldest event index is incremented, and it points to the next consecutive position, and so on in a loop.

[0078] Step S6: Persistently store the temporary landing event information.

[0079] Specifically, the temporary landing event information processed by the temporary landing event management unit is sent to the storage module for long-term storage. The storage module is preferably an EEPROM to ensure long-term preservation of the temporary landing event information even during power outages. Unlike the ROM in the main control module, which is used for short-term data exchange during program execution, the temporary landing event information in the storage module is unaffected by power outages. After the device is powered on again, the temporary landing event management unit automatically synchronizes the historical event information from the storage module to the ROM, ensuring the continuity and integrity of the event records.

[0080] The voltage sag event monitoring method in this embodiment utilizes a collaborative mechanism combining hardware triggering and software shaping. It transforms the instantaneous interrupt signal output by the low-cost metering chip into a sag event record with complete timestamps and characteristic parameters, processed step-by-step by a sag real-time monitoring unit, an hourglass monitoring unit, a sag event response execution unit, and a sag event management unit built within the main control module. This process meets power quality monitoring requirements. The method separates the sag recovery time judgment logic from the interrupt cycle of the sag real-time monitoring unit, allowing the hourglass monitoring unit to independently complete the timing and judgment. This avoids time-consuming operations within the main control module's interrupt service routine, effectively reducing the resource consumption of the main control module. The sag event response execution unit completes reporting condition judgment, data format conversion, and valid event filtering in a low-frequency cycle independent of the interrupt service routine, avoiding interference with the interrupt handling process and ensuring the consistency, readability, and validity of the reported event information. The sag event management unit achieves efficient and orderly event storage within limited storage space through a circular buffer management mechanism. The entire methodology achieves highly reliable power quality monitoring on a low-cost hardware platform without increasing hardware costs.

[0081] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A voltage sag event monitoring device, characterized in that, The device includes a signal acquisition module, a main control module, and a storage module. The main control module includes a temporary landing real-time monitoring unit, an hourglass monitoring unit, a temporary landing event response execution unit, and a temporary landing event management unit. The first end of the temporary landing real-time monitoring unit is connected to the signal acquisition module, the second end is connected to the first end of the temporary landing event response execution unit, and the third end is connected to the first end of the hourglass monitoring unit. The second end of the hourglass monitoring unit is connected to the second end of the temporary landing event response execution unit. The third end of the temporary landing event response execution unit is connected to the temporary landing event management unit. The signal acquisition module is used to monitor the original voltage signal in real time and generate a sag interruption signal when the amplitude of the original voltage signal meets the sag triggering condition. The temporary descent real-time monitoring unit is used to respond to the temporary descent interruption signal in each interruption cycle, generate temporary descent occurrence information and a flip signal, and send the flip signal to the hourglass monitoring unit; The hourglass monitoring unit is used to determine whether the temporary descent has been restored based on whether the flip signal is continuously received, and to generate temporary descent restoration information when it is determined that the temporary descent has been restored. The temporary landing event response execution unit is used to generate temporary landing event information based on the temporary landing occurrence information, the temporary landing recovery information, and the temporary landing event reporting conditions; The temporary landing event management unit is used to store and manage the temporary landing event information; The storage module is used to persistently store the temporary landing event information.

2. The voltage sag event monitoring device according to claim 1, characterized in that, The signal acquisition module is used to monitor in real time whether the half-wave peak value of the original voltage signal is lower than a preset sag threshold, and to start sending the sag interrupt signal when the half-wave peak value is lower than the preset sag threshold for the first time, and to stop sending the sag interrupt signal when the half-wave peak value is greater than the preset sag threshold.

3. The voltage sag event monitoring device according to claim 1, characterized in that, The real-time monitoring unit for voltage dips is also used to acquire the voltage amplitude of the original voltage signal in each interruption cycle, and terminate the processing flow of the current interruption cycle when the voltage amplitude is less than a preset voltage threshold, without generating the voltage dip occurrence information and the flip signal. The preset voltage threshold is less than the preset sag threshold.

4. The voltage sag event monitoring device according to claim 1, characterized in that, The operating cycle of the hourglass monitoring unit is shorter than the interruption cycle of the temporary descent real-time monitoring unit; the hourglass monitoring unit is also used to enter a moving state after receiving the flip signal, enter a stationary state when not receiving the flip signal, and determine temporary descent recovery after the stationary state lasts for a first preset time threshold, and generate the temporary descent recovery information.

5. The voltage sag event monitoring device according to claim 1, characterized in that, The reporting conditions for the temporary landing event include: the duration of the temporary landing in the temporary landing occurrence information is greater than a second preset time threshold and the temporary landing event response execution unit receives the temporary landing recovery information.

6. The voltage sag event monitoring device according to claim 1, characterized in that, The sag occurrence information includes at least residual voltage information. The sag real-time monitoring unit is also used to update the residual voltage information to the residual voltage of the current interruption period when the residual voltage of the current interruption period is less than the residual voltage of the previous interruption period.

7. The voltage sag event monitoring device according to claim 1, characterized in that, The sag event response execution unit is also used to convert the residual voltage in the sag occurrence information from a half-wave peak value to an effective value, convert the sag occurrence information into a standard format, and filter the sag occurrence information converted into a standard format.

8. The voltage sag event monitoring device according to claim 1, characterized in that, The temporary landing event management unit is also used to manage metadata and the temporary landing event information; the temporary landing event information is stored in the storage module in a circular buffer structure with the beginning and end connected, and the metadata includes at least the total number of events in the circular buffer, the latest event index, and the oldest event index.

9. The voltage sag event monitoring device according to claim 1, characterized in that, The transient information includes the transient occurrence time, number of interruptions, transient occurrence flag, residual voltage information, and the phase in which the transient occurred.

10. A monitoring method based on the voltage sag event monitoring device according to any one of claims 1-9, characterized in that, The method includes: Step S1: Monitor the original voltage signal in real time, and generate a sag interruption signal when the amplitude of the original voltage signal meets the sag triggering condition; Step S2: In response to the temporary descent interruption signal during each interruption cycle, generate temporary descent occurrence information and a flip signal; Step S3: Determine whether the temporary landing has been restored based on whether the flip signal is continuously received, and generate temporary landing restoration information when it is determined that the temporary landing has been restored; Step S4: Generate temporary landing event information based on the temporary landing occurrence information, the temporary landing recovery information, and the temporary landing event reporting conditions; Step S5: Store and manage the temporary landing event information; Step S6: Persistently store the temporary landing event information.

Images