Adaptive control method, system and distribution box for distribution box

Abstract

The application relates to the technical field of distribution box control, and discloses an adaptive control method and system for a distribution box and the distribution box. The method comprises the following steps: collecting voltage values at the incoming line side of the distribution box and current values of each branch line at a preset sampling period; calculating a voltage deviation rate according to the voltage values, and determining that voltage drop occurs if the voltage deviation rate is greater than zero; performing correlation analysis on the current change rate and the voltage deviation rate, and marking a dynamic high-power load corresponding to a second branch line with a correlation greater than a preset threshold as a disturbance source; calculating a total power adjustment amount if not all sensitive loads are in a standby state; calculating the contribution proportion of each disturbance source to voltage drop and determining the power adjustment amount and a new power limit value of each disturbance source according to the contribution proportion, and sending a power limit instruction to each disturbance source to limit the operating power within the new power limit value. The application can maximize the energy supply efficiency of power loads while protecting sensitive loads.

Description

Technical Field

[0001] This application relates to the field of distribution box control technology, and in particular to an adaptive control method, system and distribution box for distribution boxes. Background Technology

[0002] In industrial production and power distribution scenarios, distribution boxes often need to supply power to both sensitive loads (such as precision CNC machine tools and medical equipment) and dynamic high-power loads (such as DC charging piles for electric vehicles and large motors). Sensitive loads are extremely sensitive to voltage fluctuations; momentary undervoltage or overvoltage may lead to product scrapping, control logic errors, or equipment aging. Meanwhile, dynamic high-power loads operate with high power and frequent start-stop cycles, and their power surges can easily cause momentary voltage drops on the incoming side of the distribution box.

[0003] Traditional distribution box protection methods typically rely on circuit breakers or simple over / under voltage protection devices, which have high operating thresholds and often only trigger tripping after a voltage drop has severely impacted sensitive loads, failing to achieve dynamic adjustment before or during events. Some existing solutions uniformly limit the total power of all high-power loads, but this approach cannot distinguish the true source of disturbance, leading to unnecessary power reduction of loads unrelated to voltage drops, reducing overall power efficiency. Furthermore, fixed power limits cannot adapt to the severity and real-time trends of voltage drops, easily resulting in under- or over-adjustment and causing repeated voltage oscillations. In addition, existing technologies lack awareness of the actual operating status of sensitive loads, applying power limits even when sensitive loads are in standby or off-peak states, causing unnecessary resource waste and a degraded user experience. Therefore, there is an urgent need for an intelligent distribution box control method that can detect voltage drops in real time, accurately locate disturbance sources, adaptively calculate power adjustment amounts, and differentiate between sensitive loads and dynamic high-power loads.

[0004] Therefore, the present invention provides an adaptive control method, system, and distribution box for a distribution box. Summary of the Invention

[0005] This application provides an adaptive control method, system, and distribution box for use in distribution boxes, which enables rapid recovery and intelligent power optimization when the voltage of the distribution box drops.

[0006] In a first aspect, this application provides an adaptive control method for a distribution box, the method comprising: Step S1: Collect the voltage value of the incoming line side of the distribution box at a preset sampling period, and also collect the current value of each branch line at the same sampling period. The branch lines include the first branch line and the second branch line. Step S2: Calculate the voltage deviation rate based on the collected voltage value. If the voltage deviation rate is greater than zero, it is determined that a voltage drop has occurred. When a voltage drop occurs, calculate the current change rate of each second branch line. Step S3: Perform correlation analysis on the current change rate and voltage deviation rate, obtain the second branch line whose correlation with the voltage deviation rate is greater than the preset correlation threshold, and mark the dynamic high-power load connected to the corresponding second branch line as the disturbance source. Step S4: Determine whether all sensitive loads connected to the first branch line are in standby mode. If not, calculate the total power adjustment amount. The total power adjustment amount represents the total power value of the dynamic high-power loads that need to be reduced. Step S5: Calculate the contribution ratio of each disturbance source to the voltage drop, calculate the power adjustment amount of each disturbance source according to the contribution ratio, calculate the new power limit of each disturbance source, send a power limit command to each disturbance source, and after receiving the power limit command, the disturbance source limits its operating power to within the new power limit.

[0007] Compared with the prior art, the beneficial effects of the present invention are at least as follows: The technical solution provided in this application, by collecting the incoming line voltage and branch line current, and combining the correlation analysis of voltage deviation rate and current change rate, can accurately identify the specific disturbance source causing voltage drop, avoiding indiscriminate limitation on all high-power loads, thereby maximizing the available power and power supply efficiency of dynamic high-power loads; the total power adjustment is calculated by weighting the current value, historical accumulated value, and change trend value based on the voltage deviation rate, which ensures a rapid response to voltage drop, eliminates steady-state error, suppresses system oscillation, and allows the voltage to smoothly recover to the rated value; after a voltage drop, a power limiting command is sent in a gradual manner to avoid power loss. The system mitigates current surges and reverse voltage fluctuations caused by sudden rate changes; it gradually increases the power limits of each load after voltage recovery while continuously monitoring voltage status to prevent secondary voltage drops; it determines whether a sensitive load is in standby mode by detecting its actual power, and only initiates power adjustment when the sensitive load is working, avoiding meaningless power reduction operations, extending the lifespan of communication components and processors, and improving the economic efficiency of system operation; by recording relevant data for each voltage drop event and automatically adjusting the control coefficients, the system can adapt to long-term changes in grid impedance and load characteristics, continuously optimize recovery time, and achieve self-learning, adaptive, high-performance voltage stability control. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1This is a schematic diagram of one embodiment of the adaptive control method for a distribution box in this application. Figure 2 This is a schematic diagram of an embodiment of an adaptive control system for a distribution box in this application. Detailed Implementation

[0010] This application provides an adaptive control method, system, and distribution box for a distribution box. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0011] For ease of understanding, the specific process of the embodiments of this application is described below. Please refer to [link / reference]. Figure 1 One embodiment of the adaptive control method for a distribution box in this application includes: Step S1: The acquisition module of the control unit acquires the voltage value of the incoming side of the distribution box at a preset sampling period, and also acquires the current value of each branch line at the same sampling period. The branch lines include the first branch line and the second branch line. Specifically, distribution boxes used in mixed-load power distribution scenarios typically supply power to two types of loads simultaneously: sensitive loads, such as high-precision CNC machine tools, which are highly sensitive to voltage stability and frequency fluctuations and whose products may be scrapped due to momentary undervoltage or overvoltage; and dynamic high-power loads, such as multiple DC charging piles for electric vehicles, which operate with high power, frequent start-stop cycles, and dynamically changing charging power demands. When multiple high-power loads are consuming power, a momentary voltage drop may occur on the incoming line side of the distribution box. At this time, the voltage value may not reach the level that triggers a traditional circuit breaker to trip, but for sensitive loads, this power command may cause accuracy deviations, control logic errors, or internal capacitor aging. Existing solutions usually involve uniformly limiting the total power of high-power loads or investigating the cause of the fault afterward, but by then, scrap may have already been produced, resulting in losses. To enable the distribution box to sense power changes in real time and dynamically and accurately adjust the power distribution of dynamic high-power loads, maximizing the energy supply efficiency of dynamic high-power loads without triggering the sensitive thresholds of sensitive loads.

[0012] The control unit's acquisition module collects the voltage and frequency values ​​of the incoming line side of the distribution box at a preset sampling period. It also collects the current value of each branch line at a uniform sampling period. The branch lines include the first branch line and the second branch line. The first branch line refers to the branch line connected to the sensitive load, which refers to the electrical equipment that is sensitive to voltage fluctuations. The second branch line refers to the branch line connected to the dynamic high-power load, which refers to the electrical equipment whose working power is variable and has a large power value.

[0013] Step S2: The calculation module of the control unit calculates the voltage deviation rate based on the collected voltage value. If the voltage deviation rate is greater than zero, it is determined that a voltage drop has occurred. When a voltage drop occurs, the current change rate of each second branch line is calculated. Specifically, to quantify the degree of voltage deviation from the rated value—because only by knowing how much the voltage has deviated can the necessary adjustment actions be determined—the control unit's calculation module calculates the voltage deviation rate based on the collected voltage values. The voltage deviation rate is calculated as follows: subtract the real-time voltage value from the rated voltage to obtain the voltage difference; then divide the voltage difference by the rated voltage to obtain the voltage deviation rate. The rated voltage refers to the rated voltage of the power system connected to the distribution box's incoming line, which is the standard voltage value provided by the power supplier to the user. When the voltage deviation rate is greater than zero, it indicates that the rated voltage is greater than the real-time voltage value, and a voltage drop has occurred. Voltage drops are usually caused by a sudden increase in the power of one or more high-power loads. This increase in power manifests as an increase in current in the circuit. The rate of change of current is the speed at which the current changes. If the rate of change of current for a certain load is large, it indicates that the power of that load is rising rapidly, which is likely the cause of the voltage drop. To identify the dynamic high-power load causing the voltage drop, the rate of change of current for each second branch line is calculated. The rate of change of current reflects the speed and direction of power change of the dynamic high-power load connected to the second branch line. The current change rate is calculated by subtracting the current value from the current value at the previous sampling time from the current value at the current sampling time, and then dividing the current difference by the sampling period to obtain the current change rate.

[0014] Step S3: Perform correlation analysis on the current change rate and voltage deviation rate, obtain the second branch line whose correlation with the voltage deviation rate is greater than the preset correlation threshold, and mark the dynamic high-power load connected to the corresponding second branch line as the disturbance source. Specifically, a large current change rate is not necessarily the real cause of voltage drop. It could also be due to external power grid fluctuations or a chain reaction caused by power changes in other loads. Directly identifying the load with the largest current change rate as the disturbance source might be incorrect. Therefore, correlation analysis is used to compare the correlation between the current change rate and the voltage deviation rate. If the waveform of the current change rate is highly consistent with the waveform of the voltage deviation rate, it indicates a causal relationship between the two. To determine the degree of statistical correlation between the current change rate and the voltage drop process, correlation analysis is performed on the current change rate and the voltage deviation rate. Correlation analysis can eliminate random factors and identify the load that truly affects the voltage. By performing correlation analysis on the current change rate and the voltage deviation rate, the second branch line with a correlation greater than the preset correlation threshold is obtained. In order to screen out the loads that cause voltage drops from all dynamic high-power loads and determine the adjustment targets for subsequent power adjustments, the dynamic high-power loads connected to the corresponding second branch line are marked as disturbance sources. Assuming there are a total of five dynamic high-power loads with correlation coefficients of 0.95, 0.92, 0.45, 0.30, and 0.10, and the preset correlation threshold is 0.9, then the two dynamic high-power loads with correlation coefficients of 0.95 and 0.92 are marked as disturbance sources.

[0015] If the source of the disturbance is not known, adjusting loads unrelated to the voltage drop during subsequent power adjustments will unnecessarily reduce the power of these loads, while the actual source of the disturbance will continue to worsen the voltage, thus failing to achieve the goal of effectively restoring the voltage.

[0016] Step S4: Determine whether all sensitive loads connected to the first branch line are in standby mode. If not, calculate the total power adjustment amount. The total power adjustment amount represents the total power value of the dynamic high-power loads that need to be reduced. Specifically, the original goal of this technical solution is to maintain the operating efficiency of dynamic high-power loads as much as possible while protecting sensitive loads. Whether power limitation is required for dynamic high-power loads when voltage drops occur depends on whether there are sensitive loads operating at that time. Sensitive loads refer to electrical equipment that is very sensitive to voltage fluctuations, such as precision machine tools. During operation, even a brief and small voltage drop may cause deviations in machining accuracy. Therefore, when sensitive loads are operating, power adjustment measures must be taken to quickly return the voltage to the rated value. Conversely, when all sensitive loads are in standby mode, this means they are not performing critical actions. In this case, the impact of a voltage drop is reduced efficiency of the dynamic high-power load itself, but without significant loss or failure. In other words, the severity of the voltage drop is greatly reduced. However, performing power adjustment in this situation may have negative consequences. Firstly, power adjustment means lowering the power limit of the dynamic high-power load; if the dynamic high-power load is a charging station, this will extend charging time. Secondly, power adjustment itself consumes computational resources and may cause frequent fluctuations in the charging station's power. Finally, if the voltage drop is caused by temporary fluctuations in the upstream power grid, limiting the local dynamic high-power load will not solve the problem. Therefore, it is necessary to first determine whether all sensitive loads connected to the first branch line are in standby mode. If not, a reasonable power adjustment amount needs to be calculated. This adjustment amount should be sufficient to restore the voltage from the drop state to its rated value. Therefore, the total power adjustment amount is calculated based on the current value of the voltage deviation rate, the historical cumulative value of the voltage deviation rate, and the trend value of the voltage deviation rate. The specific calculation process will be explained in detail later. The total power adjustment amount represents the total power value of the dynamic high-power load that needs to be reduced.

[0017] Step S5: Calculate the contribution ratio of each disturbance source to the voltage drop, calculate the power adjustment amount of each disturbance source according to the contribution ratio, calculate the new power limit of each disturbance source, send a power limit command to each disturbance source, and after receiving the power limit command, the disturbance source limits its operating power to within the new power limit.

[0018] Specifically, distributing all power adjustment amounts equally among all disturbance sources may lead to unreasonable consequences. To rationally allocate the total power reduction required to each dynamic high-power load identified as a disturbance source, the contribution ratio of each disturbance source to the voltage drop is calculated. This contribution ratio can be obtained by dividing the Pearson correlation coefficient of each disturbance source by the sum of the Pearson correlation coefficients of all disturbance sources. Then, the power adjustment amount for each disturbance source is calculated based on its contribution ratio. Assuming the total power adjustment amount is 10 kW, the correlation coefficient of disturbance source A is 0.95, the correlation coefficient of disturbance source B is 0.85, and the correlation coefficient of disturbance source C is 0.20, with a total correlation coefficient of 2.0, resulting in contribution ratios of A=0.475, B=0.425, and C=0.10, respectively. The allocated power adjustment amounts are: A=4.75 kW, B=4.25 kW, and C=1.0 kW. The new power limit is the current power limit of the disturbance source minus the power adjustment allocated to that disturbance source. Assuming disturbance source A currently has a power limit of 150 kW and an allocated power adjustment of 4.75 kW, then the new power limit for disturbance source A = 150 - 4.75 = 145.25 kW. This calculation of the new power limit gives each disturbance source a clearly defined new power ceiling.

[0019] The control unit of the distribution box is connected to the dynamic high-power load (such as a charging pile) via a communication network. Since the control unit cannot directly control the power output of the load, it can only request the internal control system of the load to perform power limiting by sending commands. The power limiting command is sent to each disturbance source. The power limiting command contains a new power limit value. After receiving the power limiting command, the disturbance source limits its operating power to within the new power limit value. For example, if the current actual charging power of charging pile A is 148 kW, after receiving the new power limit value of 145.25 kW, its internal controller changes the power upper limit to 145.25 kW. Since the current power of 148 kW exceeds the upper limit, the controller gradually reduces the output current and stabilizes the power at 145 kW within a few hundred milliseconds.

[0020] By sending power limiting commands to multiple disturbance sources, the power of these sources is stabilized at the new power limit, thereby restoring the voltage on the incoming side of the distribution box to its rated value.

[0021] In one specific embodiment, the voltage deviation rate is calculated based on the collected voltage values, specifically including the following steps: The voltage difference is obtained by subtracting the real-time voltage value from the rated voltage, and the voltage deviation rate is obtained by dividing the voltage difference by the rated voltage. The current change rate is calculated as follows: subtract the current value at the previous sampling time from the current value at the current sampling time to obtain the current difference, and divide the current difference by the sampling period to obtain the current change rate.

[0022] In one specific embodiment, obtaining the second branch line whose correlation with the voltage deviation rate is greater than a preset correlation threshold specifically includes the following steps: Calculate the Pearson correlation coefficient between the current change rate and voltage deviation rate of each second branch line. The dynamic high-power loads corresponding to the second branch lines whose absolute values ​​of the Pearson correlation coefficients are greater than the preset correlation threshold are identified as disturbance sources. If no Pearson correlation coefficient is greater than the correlation threshold, all dynamic high-power loads connected to the second branch lines are identified as disturbance sources.

[0023] Specifically, to quantify the correlation between current changes and voltage dips for each dynamic high-power load, the Pearson correlation coefficient between the current change rate and voltage deviation rate of each second branch is calculated. For example, the voltage deviation rate sequence for the past 10 sampling periods is 0.01, 0.02, 0.03, 0.02, 0.01, and the current change rate sequence for dynamic high-power load A is 100, 200, 300, 200, 100. Calculations show that the Pearson correlation coefficient between the two sequences is close to 1. To filter out dynamic high-power loads highly correlated with voltage dips, the Pearson correlation coefficient between the current change rate and voltage deviation rate of each second branch is calculated. If the absolute value of the Pearson correlation coefficient for a certain second branch is greater than a preset correlation threshold... If the dynamic high-power loads corresponding to the second branch line are marked as disturbance sources, then the calculated correlation coefficients may not be greater than the correlation threshold. In this case, the disturbance source cannot be identified through correlation analysis. There may be a variety of reasons for this situation. For example, the voltage drop may not be caused by the local dynamic high-power loads, but by fluctuations in the upstream power grid, or multiple loads may increase their power by a small amount at the same time. The correlation between each load and the voltage change is not high individually, but their combined effect causes the voltage drop. In any case, if no power reduction measures are taken, the voltage may remain low, damaging sensitive loads. Therefore, in this case, all dynamic high-power loads connected to the second branch line are identified as disturbance sources. Subsequently, their power can be reduced on average to restore the voltage as quickly as possible in the safest way.

[0024] In one specific embodiment, the total power adjustment is calculated based on the voltage deviation rate, which specifically includes the following steps: The first component is obtained by multiplying the first coefficient by the voltage deviation rate. The second component is obtained by multiplying the second coefficient by the historical accumulation value of the voltage deviation rate. The third component is obtained by multiplying the third coefficient by the change trend value of the voltage deviation rate. The total power adjustment is obtained by adding the first, second, and third components. The first, second, and third coefficients are preset values ​​with physical units, and their physical units are power units.

[0025] Specifically, to calculate how much power needs to be reduced to restore the voltage to its rated value after a voltage drop, while avoiding voltage overshoot or prolonged periods below the rated value, two problems arise if the adjustment is calculated solely based on the current voltage deviation rate. First, when the voltage deviation rate is small, the calculated adjustment is also small, potentially insufficient to fully restore the voltage to its rated value, leading to a prolonged period of voltage stabilization below the rated value. Second, when the voltage changes rapidly, responses based solely on the current value always lag behind the change, easily causing repeated voltage oscillations. If the adjustment is calculated only based on the historical cumulative value of the voltage deviation rate, the power adjustment will continuously increase until the voltage returns to its rated value, but this can easily lead to over-adjustment. If the power adjustment is calculated based on the trend value, it can act in advance while the voltage deviation rate is still deteriorating, providing a fast response and suppressing oscillations, but it cannot eliminate steady-state errors. Therefore, the above three methods are combined to calculate the total power adjustment, ensuring both fast response and avoiding steady-state errors and system oscillations. First, the first coefficient is multiplied by the current voltage deviation rate to obtain the first component, which is responsible for quickly responding to the current voltage deviation.

[0026] The second component is obtained by multiplying the second coefficient by the historical accumulation value of the voltage deviation rate. The second component is responsible for eliminating long-term small deviations. The historical accumulation value of the voltage deviation rate refers to the sum of the voltage deviation rates measured at all sampling times from the beginning of the current voltage drop to the current moment. The magnitude of the second coefficient determines the contribution of the historical accumulation value to the total power adjustment. It can be preset according to the characteristics of the actual system. The second coefficient can control the speed of eliminating steady-state error. If the second coefficient is too large, a small historical accumulation will cause a large power adjustment, resulting in excessive power adjustment, changing the voltage from low to high. If the second coefficient is too small, the speed of eliminating steady-state error will be very slow, causing the voltage to remain below the rated value for a long time. The second coefficient can also prevent integral saturation. Integral saturation refers to the phenomenon that the system response time is too slow due to an excessively large historical accumulation. Presetting an appropriate second coefficient can alleviate this steady-state problem.

[0027] The third component is obtained by multiplying the third coefficient by the trend value of the voltage deviation rate. The third component is the load consistent oscillation and prediction trend. The trend value of the voltage deviation rate refers to the difference between the voltage deviation rate at the current sampling time and the voltage deviation rate at the previous time. This difference reflects whether the voltage deviation rate is increasing or decreasing, and how fast it is increasing. The product of the third coefficient and the trend value serves as a prediction term, enabling the control unit to react according to the current trend. A suitable third coefficient can make the system quickly stabilize without overshoot.

[0028] Assume a distribution box has a rated voltage of 220 volts, a current real-time voltage of 209 volts, and a voltage deviation rate of 0.05. The sampling period is 100 milliseconds, and the voltage drop has lasted for 1 second (i.e., 10 sampling periods). During this 1 second, the voltage deviation rate has remained stable at around 0.05, without further deterioration or recovery. The trend value of the voltage deviation rate is close to zero, and the historical cumulative value of the voltage deviation rate is 0.05 × 10 = 0.5. Assume the three coefficients are preset as follows: first coefficient = 100 kW, second coefficient = 10 kW, third coefficient = 20 kW. The first component = 100 kW × 0.05 = 5 kW, the second component = 10 kW × 0.5 = 5 kW, and the third component = 20 kW × 0 = 0 kW. The total power adjustment is 5 + 5 + 0 = 10 kW. Therefore, the control unit will ultimately reduce the total power of the dynamically high-power load by 10 kW.

[0029] The total power adjustment is calculated by combining three components, which enables the voltage to be restored to the rated value in a short time and with a small fluctuation after a voltage drop.

[0030] In one specific embodiment, after the voltage drop ends, the following steps are also performed: Record relevant data for this voltage drop, including the start time, end time, voltage deviation rate sequence, power change sequence of each disturbance source, and recovery time. Based on multiple relevant data from historical records, automatically adjust the first, second, and third coefficients.

[0031] Specifically, to gradually shorten the voltage recovery time when subsequent voltage dips occur, after each voltage dip—meaning after calculating the total power adjustment and adjusting the power of each disturbance source to restore the voltage to the rated value—relevant data about the voltage and the voltage dip are recorded. This data includes the start time and end time of the voltage dip (the time it takes for the voltage to recover to the rated value), the voltage deviation rate sequence (the voltage deviation rate sequence between the start and end times), and the power change sequence of each disturbance source (the power change of each dynamic high-power load marked as a disturbance source during the voltage dip, including the power limit change and the actual power change of each disturbance source). The recovery time is equal to the end time minus the start time, reflecting the duration of the control response. The shorter the recovery time, the better the control effect.

[0032] The initial values ​​of the first, second, and third coefficients are estimated based on experience or theoretical values, but they will change over time. Grid impedance and load characteristics may change, and stabilization may affect the equipment's response speed. Fixed coefficients cannot achieve optimal results in all situations. To find better coefficient values ​​so that the recovery time is shorter when a similar voltage drop occurs again, the first, second, and third coefficients are automatically adjusted based on multiple relevant historical data. A common adjustment method is iterative optimization. For example, data from the most recent N voltage drops is saved. After each voltage drop, the recovery time is compared with the average recovery time of the previous few drops. If the current recovery time is shorter, the adjustment direction of the coefficients is correct, and the coefficients are fine-tuned in the same direction the next time. If the current recovery time is longer, the adjustment direction is wrong, and the coefficients are adjusted in the opposite direction the next time. The adjustment step size is a fixed small value. A sequential adjustment strategy is usually adopted: first, fix the second and third coefficients, adjust the first coefficient alone until the change in the first coefficient no longer significantly shortens the recovery time, then adjust the second coefficient, and finally adjust the third coefficient. This avoids mutual interference caused by adjusting multiple coefficients simultaneously.

[0033] Assuming the initial first coefficient was 100, it was increased by 5 to 105 in the last adjustment. The recovery time for this voltage drop was 1.5 seconds. The average recovery time for the past 5 events was 1.6 seconds, indicating a shorter recovery time. This suggests that increasing the first coefficient was beneficial. Therefore, in the next adjustment, the first coefficient is increased by another 5 to 110. If, after the next adjustment, the recovery time becomes 1.7 seconds, longer than the average of 1.5 seconds, it means the increase was too large. The first coefficient is then reduced by 10, returning to 100. After multiple iterations, the recovery time stabilizes at around 1.2 seconds, showing no further significant improvement. The next adjustment then begins with the second coefficient, repeating the process. Through multiple rounds of automatic adjustment, the three coefficients gradually converge to a set of values ​​suitable for the current state, resulting in shorter recovery times for subsequent voltage drops and a faster, more stable response.

[0034] In one specific embodiment, sending a power limiting command to each disturbance source includes the following steps: The power limiting command is sent to each disturbance source in a gradual manner. The gradual manner means that the power limiting command is decomposed into multiple sub-commands. Each sub-command requires the power limit of the disturbance source to be changed gradually. The power change between two adjacent sub-commands is less than or equal to the preset gradual step size. The sub-commands are sent sequentially at fixed time intervals.

[0035] Specifically, to avoid adverse consequences caused by a sudden and drastic reduction in power, a power limit command is sent to each disturbance source in a gradual manner. If the control unit directly sends a final new power limit, the load's internal control loop may attempt to reduce the power to the target value as quickly as possible. This rapid and large power change will generate a momentary current surge on the incoming side of the distribution box. The surge may cause reverse voltage fluctuations, such as the voltage rising too much first and then falling again, or even causing other loads to malfunction. To avoid the above situation, the power limit command is decomposed into multiple sub-commands. For example, if the current power limit is 150 kW and the final target limit is 130 kW, the total change is 20 kW, and the preset gradual step size is 5 kW, the control unit decomposes the command into 4 sub-commands: the first step is to reduce to 145 kW, the second step is to reduce to 140 kW, the third step is to reduce to 135 kW, and the fourth step is to reduce to 130 kW. The first sub-command requires the load to change the power limit from 150 kW to 145 kW. After receiving the sub-command, the load sets the upper limit to 145 kW. If the current actual power is 148 kW, the load will smoothly decrease to around 145 kW. To control the rhythm of sub-command transmission and ensure sufficient time intervals between adjacent adjustments, allowing the dynamic high-power load to complete one adjustment and stabilize before proceeding to the next, the control unit is equipped with a timer. After sending the first sub-command, the control unit waits for a set time interval. After the time expires, it sends the second sub-command, waits again, and so on, until all sub-commands have been sent. These steps make the power change process of the dynamic high-power load smoother, avoiding current surges, reverse voltage fluctuations, and stress damage to internal equipment caused by sudden power drops. Simultaneously, the gradual change method provides a smooth transition for voltage regulation in the upstream power grid and distribution box, reducing the risk of voltage overshoot or subsequent drops, thus improving overall stability and the safety of the load equipment.

[0036] In one specific embodiment, while limiting the operating power within the new power limit, the following steps are also performed: The voltage deviation rate is continuously monitored. When the voltage deviation rate changes from greater than zero to equal to zero, it is determined that the voltage has recovered. Then, the power limit of each dynamic high-power load connected to each second branch line is gradually increased. The gradual increase is done by increasing a fixed increment each time and waiting for a fixed observation period after each increase. If the voltage deviation rate remains at zero or negative within the observation period, the power limit is increased again. If the voltage deviation rate becomes positive again, the power limit is stopped, and the calculation of the total power adjustment amount and subsequent steps are repeated.

[0037] Specifically, in order to gradually restore the power limit of the previously reduced dynamic high-power load after the voltage recovers to the rated value, so that the dynamic high-power load can return to normal operation, the voltage status is continuously monitored during the recovery process. If the voltage is found to drop again, the recovery is immediately stopped and the power adjustment mode is re-entered.

[0038] To track voltage changes in real time and provide a basis for determining whether the voltage has recovered to its rated value and whether it has deteriorated again during the recovery process, the voltage deviation rate is continuously monitored. When the voltage deviation rate changes from greater than zero to equal zero, it is determined that the voltage has recovered to the rated value. At this point, the power recovery process is initiated. That is, the power limits of each dynamic high-power load connected to each second branch line are gradually increased. The gradual increase is done by adding a fixed increment each time, and waiting for a fixed observation period after each increase. During the observation period, if the voltage deviation rate remains zero or negative, the power limit is increased again. If the voltage deviation rate becomes positive again, it indicates that a voltage drop has occurred again. At this point, the increase of the power limit is stopped, and the calculation of the total power adjustment and subsequent steps are repeated. Through this process, after the voltage returns to normal, the power limits of the dynamic high-power loads can smoothly rise back to their rated values, thereby restoring power supply capacity.

[0039] In one specific embodiment, determining whether a sensitive load connected to the first branch line is in a standby state includes the following steps: Calculate the real-time power of each sensitive load connected to the first branch line based on the current value of each first branch line. Compare the real-time power with the preset rated power. If the real-time power is less than or equal to 10% of the rated power for three consecutive sampling periods, it is determined that the sensitive load is in a non-working state. If it is determined that a voltage drop has occurred and all sensitive loads are in standby state, the calculation of the total power adjustment amount and subsequent steps are not executed, and the power of the dynamic high-power load remains unchanged.

[0040] Specifically, to avoid unnecessary interference with dynamic high-power loads, when a voltage drop occurs, first determine if all sensitive loads are in an inactive state. If all sensitive loads are in an inactive state, it means that no sensitive equipment will be damaged by the voltage drop, therefore, power adjustment measures are unnecessary, and the dynamic high-power load can continue to operate at its current power. Since the current value itself cannot directly determine whether a load is inactive, as different loads have different rated currents—for example, the inactive current of a large machine tool might be 0.5 amps, while the inactive current of a small device might be 0.05 amps—this is important. The real-time power of each sensitive load connected to the first branch line is calculated based on the current value of each first branch line. The real-time power is obtained by multiplying the current by the voltage and then by the power factor. The non-working state (including shutdown, standby, sleep, etc.) means that the load is not performing its main task and may only be maintaining the necessary auxiliary circuits or in standby or sleep state. Therefore, the power consumption is much lower than the rated power. By setting a low threshold, such as 10% of the rated power, the working state and the non-working state can be distinguished. Therefore, the real-time power is compared with the preset rated power. When the real-time power is less than or equal to 10% of the rated power for three consecutive sampling periods, it is determined that the sensitive load is in a non-working state. When it is determined that a voltage drop has occurred and all sensitive loads are in standby state, the calculation of the total power adjustment amount and subsequent steps are not performed, and the power of the dynamic high-power load remains unchanged. This method ensures that power limiting of dynamic high-power loads is only applied when sensitive loads are actually in operation (i.e., real-time power is high and may be affected by voltage drops). When all sensitive loads are in non-operational states (e.g., shutdown at night, standby, or ultra-low power mode), voltage drops are considered low-risk events and no intervention is taken. This reduces the number of times dynamic high-power loads are unnecessarily power-reduced, improves the utilization efficiency of dynamic high-power load devices, and eliminates the need for frequent load calculations and command transmissions, thus extending the lifespan of communication components and processors.

[0041] The adaptive control method for a distribution box in the embodiments of this application has been described above. The adaptive control system for a distribution box in the embodiments of this application is described below. Please refer to [link / reference]. Figure 2 One embodiment of the adaptive control system for a distribution box in this application includes: The acquisition module acquires the voltage value of the incoming line side of the distribution box at a preset sampling period, and also acquires the current value of each branch line at the same sampling period. The branch lines include the first branch line and the second branch line. The detection module calculates the voltage deviation rate based on the collected voltage value. If the voltage deviation rate is greater than zero, it determines that a voltage drop has occurred. When a voltage drop occurs, it calculates the current change rate of each second branch line. The judgment module performs correlation analysis on the current change rate and voltage deviation rate, identifies the second branch line whose correlation with the voltage deviation rate is greater than a preset correlation threshold, and marks the dynamic high-power load connected to the corresponding second branch line as a disturbance source. The decision module determines whether all sensitive loads connected to the first branch line are in standby mode. If not, it calculates the total power adjustment amount, which represents the total power value of the dynamic high-power loads that need to be reduced. The adjustment module calculates the contribution ratio of each disturbance source to the voltage drop, calculates the power adjustment amount of each disturbance source according to the contribution ratio, calculates the new power limit for each disturbance source, and sends a power limit command to each disturbance source. After receiving the power limit command, the disturbance source limits its operating power to within the new power limit.

[0042] This application also provides a distribution box, the control unit of which includes a memory and a processor. The memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the processor performs the steps of the adaptive control method for the distribution box described in the above embodiments.

[0043] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An adaptive control method for a distribution box, the method being executed by a control unit of the distribution box, characterized in that, The method includes: Step S1: Collect the voltage value of the incoming line side of the distribution box at a preset sampling period, and also collect the current value of each branch line at the same sampling period. The branch lines include the first branch line and the second branch line. Step S2: Calculate the voltage deviation rate based on the collected voltage value. If the voltage deviation rate is greater than zero, it is determined that a voltage drop has occurred. When a voltage drop occurs, calculate the current change rate of each second branch line. Step S3: Perform correlation analysis on the current change rate and voltage deviation rate, obtain the second branch line whose correlation with the voltage deviation rate is greater than the preset correlation threshold, and mark the dynamic high-power load connected to the corresponding second branch line as the disturbance source. Step S4: Determine whether all sensitive loads connected to the first branch line are in standby mode. If not, calculate the total power adjustment amount. The total power adjustment amount represents the total power value of the dynamic high-power loads that need to be reduced. Step S5: Calculate the contribution ratio of each disturbance source to the voltage drop, calculate the power adjustment amount of each disturbance source according to the contribution ratio, calculate the new power limit of each disturbance source, send a power limit command to each disturbance source, and after receiving the power limit command, the disturbance source limits its operating power to within the new power limit.

2. The method according to claim 1, characterized in that, The voltage deviation rate is calculated based on the collected voltage values, including: The voltage difference is obtained by subtracting the real-time voltage value from the rated voltage, and the voltage deviation rate is obtained by dividing the voltage difference by the rated voltage. The current change rate is calculated as follows: subtract the current value at the previous sampling time from the current value at the current sampling time to obtain the current difference, and divide the current difference by the sampling period to obtain the current change rate.

3. The method according to claim 1, characterized in that, The second branch line with a correlation greater than a preset correlation threshold is obtained, including: Calculate the Pearson correlation coefficient between the current change rate and voltage deviation rate of each second branch line. The dynamic high-power loads corresponding to the second branch lines whose absolute values ​​of the Pearson correlation coefficients are greater than the preset correlation threshold are identified as disturbance sources. If no Pearson correlation coefficient is greater than the correlation threshold, all dynamic high-power loads connected to the second branch lines are identified as disturbance sources.

4. The method according to claim 1, characterized in that, The total power adjustment is calculated based on the voltage deviation rate, including: The first component is obtained by multiplying the first coefficient by the voltage deviation rate. The second component is obtained by multiplying the second coefficient by the historical accumulation value of the voltage deviation rate. The third component is obtained by multiplying the third coefficient by the change trend value of the voltage deviation rate. The total power adjustment is obtained by adding the first, second, and third components. The first, second, and third coefficients are preset values ​​with physical units, and their physical units are power units.

5. The method according to claim 1, characterized in that, After the voltage drop ends, the following is also executed: Record relevant data for this voltage drop, including the start time, end time, voltage deviation rate sequence, power change sequence of each disturbance source, and recovery time. Based on multiple relevant data from historical records, automatically adjust the first, second, and third coefficients.

6. The method according to claim 1, characterized in that, Send power limiting instructions to each disturbance source, including: The power limiting command is sent to each disturbance source in a gradual manner. The gradual manner means that the power limiting command is decomposed into multiple sub-commands. Each sub-command requires the power limit of the disturbance source to be changed gradually. The power change between two adjacent sub-commands is less than or equal to the preset gradual step size. The sub-commands are sent sequentially at fixed time intervals.

7. The method according to claim 1, characterized in that, While limiting the operating power to the new power limit, the following also applies: The voltage deviation rate is continuously monitored. When the voltage deviation rate changes from greater than zero to equal to zero, it is determined that the voltage has recovered. Then, the power limit of each dynamic high-power load connected to each second branch line is gradually increased. The gradual increase is done by increasing a fixed increment each time and waiting for a fixed observation period after each increase. If the voltage deviation rate remains at zero or negative within the observation period, the power limit is increased again. If the voltage deviation rate becomes positive again, the power limit is stopped, and the calculation of the total power adjustment amount and subsequent steps are repeated.

8. The method according to claim 1, characterized in that, Determine whether the sensitive load connected to the first branch line is in standby mode, including: Calculate the real-time power of each sensitive load connected to the first branch line based on the current value of each first branch line. Compare the real-time power with the preset rated power. If the real-time power is less than or equal to 10% of the rated power for three consecutive sampling periods, it is determined that the sensitive load is in a non-working state. If it is determined that a voltage drop has occurred and all sensitive loads are in standby state, the calculation of the total power adjustment amount and subsequent steps are not executed, and the power of the dynamic high-power load remains unchanged.

9. An adaptive control system for a distribution box, used to implement the adaptive control method for a distribution box as described in any one of claims 1-8, characterized in that, The system includes: The acquisition module acquires the voltage value of the incoming line side of the distribution box at a preset sampling period, and also acquires the current value of each branch line at the same sampling period. The branch lines include the first branch line and the second branch line. The detection module calculates the voltage deviation rate based on the collected voltage value. If the voltage deviation rate is greater than zero, it determines that a voltage drop has occurred. When a voltage drop occurs, it calculates the current change rate of each second branch line. The judgment module performs correlation analysis on the current change rate and voltage deviation rate, identifies the second branch line whose correlation with the voltage deviation rate is greater than a preset correlation threshold, and marks the dynamic high-power load connected to the corresponding second branch line as a disturbance source. The decision module determines whether all sensitive loads connected to the first branch line are in standby mode. If not, it calculates the total power adjustment amount, which represents the total power value of the dynamic high-power loads that need to be reduced. The adjustment module calculates the contribution ratio of each disturbance source to the voltage drop, calculates the power adjustment amount of each disturbance source according to the contribution ratio, calculates the new power limit for each disturbance source, and sends a power limit command to each disturbance source. After receiving the power limit command, the disturbance source limits its operating power to within the new power limit.

10. A distribution box, characterized in that, The control unit of the distribution box includes: A memory and at least one processor, wherein the memory stores instructions; The at least one processor invokes the instructions in the memory to cause the control unit of the distribution box to execute the adaptive control method for the distribution box as described in any one of claims 1-8.

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