Power distribution network voltage treatment device

Abstract

The invention relates to the technical field of voltage treatment, in particular to a power distribution network voltage treatment device which comprises a data acquisition module, a data calculation module, an abnormality judgment module and a negative feedback module. By monitoring and analyzing key parameters of a power system in real time, the voltage stability and the power supply reliability of a power distribution network are remarkably improved, by means of an automatic anomaly judgment and load adjustment mechanism of the device, human intervention is reduced, operation errors are reduced, and by rapidly responding to the voltage deviation and stability problems, the power distribution network safety is improved. In addition, a closed-loop control strategy enables the system to dynamically adjust a load change rate threshold value according to real-time feedback, the self-adaptive capability of the system is enhanced, it is ensured that the voltage can be kept stable under various load and operation conditions, and in long term, the system has high reliability. The intelligent voltage treatment is helpful for reducing power loss and prolonging the service life of power equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage governance, and in particular, to a distribution network voltage governance device. Background Art

[0002] The modern power system has an increasing demand for efficient, stable and intelligent management. With the development of the economy and the acceleration of the industrialization process, the load of the power system has become more and more complex and unpredictable. Coupled with the access of new loads such as distributed energy and electric vehicle charging stations, the distribution network faces more severe voltage stability challenges. In addition, the competition in the power market and the improvement of users' requirements for power supply quality have also promoted the research and application of distribution network voltage governance technology. The distribution network voltage governance device can quickly respond to voltage deviations and load changes in the power grid through real-time monitoring and automatic adjustment, maintain voltage stability, improve power supply reliability, and ensure the safe, economic and efficient operation of the power system.

[0003] The patent document with the publication number CN106786657A discloses a power quality comprehensive governance device for a distribution network. The power quality comprehensive governance device includes: a main circuit and a control circuit. The main circuit includes: a transformer TR, a filter component LC, a filter reactor La, a first three-level inverter CON1, and a second three-level inverter CON2. The primary winding of the transformer TR is connected in series between the power supply U1 and the load FZ1. The first three-level inverter CON1 is connected in series to the power grid after passing through the filter component LC and the secondary winding of the transformer TR. The second three-level inverter CON2 is connected in parallel with the load FZ1 after passing through the filter reactor La. The control signal input ends of the first three-level inverter CON1 and the second three-level inverter CON2 are respectively electrically connected to the control signal output end of the control circuit. This device only collects the voltage and current information between the primary side of the transformer and the load, and may not be able to comprehensively monitor the state of the power grid, including three-phase imbalance, harmonic content, etc. Moreover, the lack of real-time data on the load side may lead to an inability to accurately evaluate the impact of load changes on the power grid. Summary of the Invention

[0004] Therefore, the present invention provides a distribution network voltage governance device to overcome the problem of poor voltage governance effect caused by inaccurate analysis of power grid state information due to single data collection in the prior art.

[0005] To achieve the above object, the present invention provides a distribution network voltage governance device, including:

[0006] A data acquisition module for acquiring the real-time voltage, real-time current, real-time active power of each node in the distribution network, and the node voltage recovery duration;

[0007] A data calculation module, connected to the data acquisition module, for calculating voltage deviation, voltage stability index, and current load change rate according to real-time voltage, real-time current, real-time active power, rated voltage, and a preset time increment;

[0008] An abnormality determination module, connected to the data calculation module, for determining the type of abnormality according to the voltage deviation, the voltage stability index, the current load change rate, a preset voltage deviation threshold, a preset voltage stability index threshold, and a preset standard current load change rate threshold. When the abnormality determination module determines that there is a load abnormality, it determines the degree of load abnormality according to the current load change rate, a first current load change rate threshold, and a second current load change rate threshold, and makes corresponding adjustments according to the degree of load abnormality;

[0009] A negative feedback module, respectively connected to the data acquisition module and the abnormality determination module, for making a determination according to the node voltage recovery duration, a preset target node voltage recovery duration, and a preset time increment. When the negative feedback module determines that it is necessary to adjust the first current load change rate threshold, it adjusts the first current load change rate threshold according to the node voltage recovery duration, the target node voltage recovery duration, and a preset load change rate safety range. When the negative feedback module determines that it is necessary to adjust the second current load change rate threshold, it adjusts the second current load change rate threshold according to the node voltage recovery duration, the target node voltage recovery duration, a preset time increment, and a preset load change rate safety range.

[0010] Further, when the abnormality determination module determines that there is a load abnormality, it compares the current load change rate with the first current load change rate threshold and the second current load change rate threshold respectively,

[0011] If the current load change rate is less than the first current load change rate threshold, the abnormality determination module determines it as a mild change abnormality and reduces the non-critical part of the load;

[0012] If the current load change rate is greater than or equal to the first current load change rate threshold and less than the second current load change rate threshold, the abnormality determination module determines it as a moderate change abnormality and issues a demand response signal;

[0013] If the current load change rate is greater than the second current load change rate threshold, the abnormality determination module determines it as a drastic change abnormality, disconnects the power supply and issues an alarm.

[0014] Further, the negative feedback module makes a determination according to the node voltage recovery duration, a recovery duration threshold, and a preset time increment collected by the data acquisition module,

[0015] If the node voltage recovery duration is greater than or equal to the recovery duration threshold and less than the sum of the recovery duration threshold and a preset time increment, the negative feedback module determines that it is necessary to adjust the first current load change rate threshold;

[0016] If the node voltage recovery duration is greater than or equal to the sum of the recovery duration threshold and the preset time increment, the negative feedback module determines that it is necessary to adjust the second current load change rate threshold.

[0017] Further, when the negative feedback module determines that it is necessary to adjust the first current load change rate threshold, it calculates the adjusted first current load change rate threshold according to the node voltage recovery duration and the preset load change rate safety range.

[0018] Q1’ = Q1 × (1 + k × (T - T’) / T’), Q1” = max(min(Q1’, Qmax), Qmin),

[0019] where Q1’ is the first current load change rate threshold after the first calculation, Q1 is the first current load change rate threshold before adjustment, k is the conversion coefficient, T’ is the recovery duration threshold, T is the node voltage recovery duration, Q1” is the adjusted first current load change rate threshold, Qmax is the maximum value of the load change rate safety range, and Qmin is the minimum value of the load change rate safety range.

[0020] Further, when the negative feedback module determines that it is necessary to adjust the second current load change rate threshold, it calculates the adjusted second current load change rate threshold according to the node voltage recovery duration, the preset load change rate safety range, and the preset time increment.

[0021] Q2’ = Q2 × (1 + k × (T - (T’ + ΔT)) / T’), Q2” = max(min(Q2’, Qmax), Qmin),

[0022] where Q2’ is the second current load change rate threshold after the first calculation, Q2 is the second current load change rate threshold before adjustment, k is the conversion coefficient, ΔT is the preset time increment, Q2” is the adjusted second current load change rate threshold, Qmax is the maximum value of the load change rate safety range, and Qmin is the minimum value of the load change rate safety range.

[0023] Further, the data calculation module calculates the voltage deviation according to the real-time voltage and the rated voltage.

[0024] v = (V - V0) / V0,

[0025] where v is the voltage deviation, V is the real-time voltage, and V0 is the rated voltage.

[0026] Further, the data calculation module calculates a voltage stability index based on the real-time voltage and the real-time active power,

[0027]

[0028] where s is the voltage stability index, P is the real-time active power, is the partial derivative.

[0029] Further, the data calculation module calculates a load current change rate according to a preset time increment and the change amount of the real-time current within the time increment,

[0030] C = ΔI / ΔT,

[0031] where C is the load current change rate, ΔI is the change amount of the real-time current within the time increment, and ΔT is the preset time increment.

[0032] Further, the abnormality determination module compares the voltage deviation with a preset voltage deviation threshold,

[0033] If the voltage deviation is greater than or equal to the voltage deviation threshold, the abnormality determination module determines that a voltage deviation abnormality occurs, and compares the voltage stability index with the voltage stability index threshold,

[0034] If the voltage stability index is greater than or equal to the voltage stability index threshold, the abnormality determination module determines that a voltage stability abnormality occurs.

[0035] Further, when the abnormality determination module determines that a voltage stability abnormality occurs, it compares the current load change rate with a standard current load change rate threshold,

[0036] If the current load change rate is greater than the standard current load change rate threshold, the abnormality determination module determines that a load abnormality occurs.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows,

[0038] By real-time monitoring and analysis of key parameters of the power system, the voltage stability and power supply reliability of the distribution network are significantly improved. The device's automated abnormality judgment and load adjustment mechanism not only reduces human intervention and operational errors, but also effectively prevents the risk of voltage collapse and power supply interruption by quickly responding to voltage deviations and stability issues. In addition, the closed-loop control strategy enables the system to dynamically adjust the load change rate threshold based on real-time feedback, enhances the system's adaptive ability, and ensures that voltage stability can be maintained under various loads and operating conditions. In the long run, this intelligent voltage management not only helps reduce power loss, avoid equipment overload, and extend the service life of power equipment, but also reduces maintenance costs and improves the economic benefits of the power system. At the same time, by ensuring the continuity and stability of power supply, the user's power experience is enhanced. In addition, the device can also improve production efficiency by reducing power outages.

[0039] Furthermore, by responding to different load changes in a graded manner, more sophisticated and effective voltage management can be provided. Reducing non-critical loads during mild abnormal changes can maintain grid stability without affecting critical services. Demand response signals issued during moderate abnormal changes can encourage users to reduce electricity consumption or increase power generation, helping to avoid more serious grid problems. Emergency measures during drastic abnormal changes, such as disconnecting power and alarming, can prevent grid overload and potential equipment damage, ensuring the long-term reliability of the grid and the safety of users' electricity use. Through this multi-level protection and response strategy, the distribution network voltage management device can improve the resilience and adaptability of the entire power system.

[0040] Furthermore, the dynamic adjustment mechanism of the negative feedback module has significant benefits for the voltage management of the distribution network. First, it allows the device to automatically adjust the load change rate threshold according to the real-time voltage recovery situation, making the voltage management more accurate and efficient. Secondly, by adjusting the threshold in a timely manner, unnecessary over-adjustment and under-adjustment can be avoided, reducing the impact on users' electricity consumption, while improving the stability of the power grid. In addition, this adaptive adjustment can also help prevent voltage collapse, enhance the power grid's ability to respond to emergencies, and ensure the continuity and reliability of power supply. Ultimately, the intelligent adjustment of the negative feedback module can improve the operating efficiency of the entire power system and the user's electricity experience.

[0041] Furthermore, by dynamically adjusting the first current load change rate threshold, it is possible to finely respond to the real-time operation status of the power grid and improve the flexibility and adaptability of voltage management. This method ensures that even when the voltage recovery time exceeds expectations, the system can maintain voltage stability by adjusting the load change rate threshold, avoid voltage collapse, and enhance the robustness of the power grid. At the same time, by limiting the threshold within a safe range, it is ensured that the power grid equipment will not be damaged due to excessive load changes, thereby extending the equipment life and reducing maintenance costs.

[0042] Furthermore, the adjustment strategy of the negative feedback module provides an adaptive load management mechanism for the distribution network, which can dynamically adjust the load change rate threshold according to the actual voltage recovery situation. This dynamic adjustment helps optimize the response speed of the power grid, enabling it to more effectively address the issue of voltage recovery delay. By keeping the threshold within a safe range, this mechanism not only ensures the stability of the power grid but also avoids equipment damage or power supply interruption caused by excessive load changes.

[0043] Furthermore, calculating the voltage deviation can provide the deviation between the real-time voltage and the rated voltage, helping to detect voltage anomalies in a timely manner. Quantifying the voltage deviation facilitates comparison and analysis, providing a numerical basis for voltage stability analysis and accurate voltage deviation data for the anomaly determination module to assist it in making an accurate judgment of the anomaly type. By calculating the voltage deviation, preventive measures can be taken in advance to avoid power supply instability or equipment damage caused by voltage problems.

[0044] Furthermore, the voltage stability index is obtained by calculating the partial derivative of the real-time voltage with respect to the real-time active power. This process involves a quantitative analysis of the relationship between voltage changes and active power changes, thereby evaluating the voltage stability under active power changes. The beneficial effect of this method lies in its ability to accurately capture the response characteristics of the voltage to load changes, providing key information for the voltage governance device of the distribution network, enabling the system to monitor and predict voltage stability in real time, and taking adjustment measures in a timely manner to effectively prevent voltage collapse.

[0045] Furthermore, the accurate calculation of the load current change rate is crucial for timely detecting and responding to load fluctuations in the power grid. It can help the system prevent voltage instability and power supply interruption, thereby improving the stability of the power grid and the reliability of power supply.

[0046] Furthermore, through continuous monitoring and determination, the voltage governance device of the distribution network can quickly respond to voltage anomalies, prevent voltage collapse, and ensure the stability of the power grid and the continuity of power supply. In addition, accurately determining the anomaly type helps implement more precise adjustment strategies, improve the voltage governance efficiency, and enhance the reliability of the entire power system and the power consumption experience of users.

[0047] Furthermore, the load anomaly determination mechanism allows the system to further confirm whether there is a load problem after detecting voltage stability anomalies, enabling a more comprehensive assessment of the health status of the power grid. After determining a load anomaly, the system can take corresponding measures, such as adjusting the power generation, reallocating the load, or adopting demand-side management strategies, to relieve the power grid pressure, prevent voltage collapse, and ensure the stability and reliability of power supply. Description of the Drawings

[0048] Figure 1The following is a schematic structural diagram of the distribution network voltage governance device according to this embodiment;

[0049] Figure 2 The following is a determination logic diagram for determining the abnormal degree of current load according to this embodiment;

[0050] Figure 3 The following is a determination logic diagram for determining the adjustment of the current load threshold according to this embodiment;

[0051] Figure 4 The following is a determination logic diagram for determining abnormal voltage deviation according to this embodiment. Detailed implementation manners

[0052] In order to make the objectives and advantages of the present invention clearer and more understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0054] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0055] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] Please refer to Figure 1 as shown, which is a schematic structural diagram of the distribution network voltage governance device according to this embodiment;

[0057] This embodiment provides a distribution network voltage governance device, including:

[0058] A data acquisition module for acquiring the real-time voltage, real-time current, real-time active power of each node of the distribution network, and the node voltage recovery duration;

[0059] A data calculation module, connected to the data acquisition module, is used to calculate voltage deviation, voltage stability index, and current load change rate based on real-time voltage, real-time current, and real-time active power;

[0060] An abnormality determination module, connected to the data calculation module, is used to determine the type of abnormality according to voltage deviation, voltage stability index, current load change rate, preset voltage deviation threshold, preset voltage stability index threshold, and preset standard current load change rate threshold. When the abnormality determination module determines that there is a load abnormality, it determines the load abnormality degree according to the current load change rate, the first current load change rate threshold, and the second current load change rate threshold, and makes corresponding adjustments according to the load abnormality degree;

[0061] A negative feedback module, connected to the data acquisition module and the abnormality determination module respectively, is used to make a determination according to the node voltage recovery duration, preset target node voltage recovery duration, and preset time increment. When the negative feedback module determines that it is necessary to adjust the first current load change rate threshold, it adjusts the first current load change rate threshold according to the node voltage recovery duration, target node voltage recovery duration, and preset load change rate safety range. When the negative feedback module determines that it is necessary to adjust the second current load change rate threshold, it adjusts the second current load change rate threshold according to the node voltage recovery duration, target node voltage recovery duration, preset time increment, and preset load change rate safety range.

[0062] First, the data acquisition module collects the voltage, current, and power data of each node in the distribution network in real time, and then the data calculation module calculates the voltage deviation, voltage stability index, and current load change rate based on these data. The abnormality determination module uses these calculation results to compare with the preset thresholds to identify and determine the type and severity of voltage abnormalities, and makes load adjustments if necessary. Finally, the negative feedback module automatically adjusts the load change rate threshold according to the comparison between the voltage recovery time and the target time to optimize the voltage governance effect.

[0063] By real-time monitoring and analyzing the key parameters of the power system, the voltage stability and power supply reliability of the distribution network have been significantly improved. The device's automated anomaly determination and load adjustment mechanism not only reduce human intervention and operational errors but also effectively prevent the risks of voltage collapse and power supply interruption by quickly responding to voltage deviation and stability issues. In addition, the closed-loop control strategy enables the system to dynamically adjust the load change rate threshold according to real-time feedback, enhancing the system's adaptability and ensuring voltage stability under various load and operating conditions. In the long run, this intelligent voltage governance not only helps reduce power losses, avoid equipment overload, and extend the service life of power equipment but also reduces maintenance costs and improves the economic efficiency of the power system. At the same time, by ensuring the continuity and stability of power supply, it enhances the user's electricity consumption experience. In addition, the device can also improve production efficiency by reducing power outage events.

[0064] The voltage deviation threshold refers to the difference between the actual voltage and the rated voltage. It is the standard for judging whether the voltage is within the acceptable range and depends on the standards of the power system, the sensitivity of equipment to voltage fluctuations, and historical data, etc. Usually, it is within the range of ±5% to ±10% of the rated voltage. In this embodiment, it is set to ±5V. A stricter threshold helps maintain voltage stability and reduces the impact of voltage anomalies on equipment.

[0065] The voltage stability index threshold is an index calculated based on real-time voltage and active power and is used to evaluate voltage stability. It depends on the system's design standards, historical stability data, and load characteristics, etc. Generally, it is set between 1.0 and 1.5 and is applicable to occasions with higher requirements for voltage stability. In this embodiment, the voltage stability index threshold is set to 1.2, aiming to balance the system's stability and tolerance to voltage fluctuations. This threshold is neither too strict to avoid frequent adjustments due to small fluctuations nor too loose to ensure timely measures are taken when the voltage stability significantly deteriorates.

[0066] The standard current load change rate threshold is the rate of change of the current load within a specific time and depends on the system's load characteristics, historical load change data, user demand, etc. Generally, it is set between 0.01 and 0.05 and is applicable to systems that are sensitive to load changes or require fine control. In this embodiment, it is set to 0.03, which can fine-tune minor load changes without affecting the normal electricity consumption of users.

[0067] The first current load change rate threshold is the judgment standard for mild change anomalies and depends on the system's tolerance to mild load changes. Generally, it is set between 0.05 and 0.15 and is applicable to general load changes, which can balance the system's stability and response speed. In this embodiment, it is set to 0.06, allowing the device to respond to smaller load changes but not being overly sensitive.

[0068] The second current load change rate threshold is the criterion for judging moderate to severe change anomalies and depends on: the system's response strategy to large load changes, which is generally set above 0.15. In this embodiment, it is set to 0.15, providing a boundary for moderate to large load changes. When the load change exceeds the first threshold but does not reach the second threshold, the system will issue a demand response signal, which usually means that more proactive measures are needed to cope with the load change, such as adjusting the power generation plan or increasing the reserve capacity.

[0069] The target node voltage recovery duration is the time when the system hopes to restore the voltage to normal, depending on the system's recovery ability and the equipment's tolerance to voltage interruption. Generally, the shorter the better, but the system capabilities and costs need to be balanced. In this embodiment, it is set to 0.3 seconds. Rapidly restoring the voltage can reduce the impact of voltage interruption on users.

[0070] The safe range of load change rate is the maximum and minimum values that the load change rate can accept without affecting the system stability, depending on the system's stability and the safe operating range of the equipment. Generally, it is set according to the system design and historical operation data. In this embodiment, the minimum value is set to 0.01 and the maximum value is set to 0.2, which can ensure that the load change does not exceed the boundary of the system's safe operation and avoid equipment damage or system instability.

[0071] The time increment is a parameter in the distribution network voltage governance device used to evaluate and adjust the load change rate threshold. It represents the additional time the system waits to observe the voltage recovery situation after the voltage recovery time exceeds a certain preset threshold and then makes a threshold adjustment. Generally, it is set between several seconds and dozens of seconds and is applicable to systems with fast response. In this embodiment, it is set to 0.2 seconds. Selecting an appropriate time increment can provide a buffer period for the system to more accurately evaluate the voltage recovery situation and make more appropriate load change rate threshold adjustments accordingly. A shorter time increment is suitable for occasions with high requirements for fast response, while a longer time increment is suitable for occasions that require more cautious evaluation of the voltage recovery situation. By reasonably setting the time increment, the accuracy of voltage governance can be improved, unnecessary adjustments can be reduced, and thus the operating efficiency and stability of the entire power grid can be enhanced.

[0072] Please continue to refer to Figure 2 as shown, which is the decision logic diagram for determining the abnormal degree of current load in this embodiment;

[0073] Specifically, when the abnormal determination module determines that there is a load abnormality, it compares the current load change rate with the first current load change rate threshold and the second current load change rate threshold respectively.

[0074] If the current load change rate is less than the first current load change rate threshold, the anomaly determination module determines it as a mild change anomaly and reduces the non-critical part of the load;

[0075] If the current load change rate is greater than or equal to the first current load change rate threshold and less than the second current load change rate threshold, the anomaly determination module determines it as a moderate change anomaly and issues a demand response signal;

[0076] If the current load change rate is greater than the second current load change rate threshold, the anomaly determination module determines it as a drastic change anomaly, disconnects the power supply and issues an alarm.

[0077] By comparing the real-time monitored current load change rate with two preset current load change rate thresholds, different degrees of load anomalies are identified. If the current load change rate is below the first threshold, the module classifies the anomaly as a mild change and takes measures to reduce non-critical loads to balance the system. When the change rate exceeds the first threshold but is below the second threshold, it is determined as a moderate change anomaly. At this time, the module will issue a demand response signal to stimulate load-side management or adjust the power generation side output. If the change rate exceeds the second threshold, it is considered a drastic change anomaly, and the module will take more drastic measures, including disconnecting the power supply and triggering an alarm, to protect the system from damage.

[0078] By grading the response to different load change situations, more refined and effective voltage governance is provided. Reducing non-critical loads during mild change anomalies can maintain grid stability without affecting critical services. The demand response signal issued during moderate change anomalies can encourage users to reduce electricity consumption or increase power generation, helping to avoid more serious grid problems. Emergency measures such as disconnecting the power supply and alarm during drastic change anomalies can prevent grid overload and potential equipment damage, ensuring the long-term reliability of the grid and the safety of users' electricity consumption. Through this multi-level protection and response strategy, the distribution network voltage governance device can improve the resilience and adaptability of the entire power system.

[0079] Please continue to refer to Figure 3 as shown, which is the decision logic diagram for determining the adjustment of the current load threshold in this embodiment;

[0080] Specifically, the negative feedback module makes a determination based on the node voltage recovery duration, recovery duration threshold, and preset time increment collected by the data acquisition module.

[0081] If the node voltage recovery duration is greater than or equal to the recovery duration threshold and less than the sum of the recovery duration threshold and the preset time increment, the negative feedback module determines that the first current load change rate threshold needs to be adjusted;

[0082] If the node voltage recovery duration is greater than or equal to the sum of the recovery duration threshold and a preset time increment, the negative feedback module determines that it is necessary to adjust the second current load change rate threshold.

[0083] The negative feedback module analyzes and judges based on the node voltage recovery duration obtained by the data acquisition module, in combination with the preset recovery duration threshold and time increment. When the actual node voltage recovery duration reaches or exceeds the preset recovery duration threshold but is lower than the sum of the threshold and the time increment, the negative feedback module determines that it is necessary to adjust the first current load change rate threshold. If the recovery time exceeds this sum, indicating that the voltage recovery is too slow, the negative feedback module further judges that it is necessary to adjust the second current load change rate threshold. Such adjustments are based on the actual voltage recovery situation to optimize the system's response and adaptability.

[0084] The dynamic adjustment mechanism of the negative feedback module has significant benefits for the voltage governance of the distribution network. First, it allows the device to automatically adjust the load change rate threshold according to the real-time voltage recovery situation, making the voltage governance more accurate and efficient. Second, by adjusting the threshold in a timely manner, unnecessary overshoot and undershoot can be avoided, reducing the impact on user electricity consumption and improving the stability of the power grid. In addition, this adaptive adjustment helps to prevent voltage collapse, enhance the power grid's response ability to emergencies, and ensure the continuity and reliability of power supply. Finally, the intelligent adjustment of the negative feedback module can improve the operating efficiency of the entire power system and the user's electricity consumption experience.

[0085] Specifically, when the negative feedback module determines that it is necessary to adjust the first current load change rate threshold, it calculates the adjusted first current load change rate threshold according to the node voltage recovery duration and the preset load change rate safety range.

[0086] Q1’ = Q1 × (1 + k × (T - T’) / T’), Q1” = max(min(Q1, Qmax), Qmin),

[0087] where Q1’ is the first current load change rate threshold after the first calculation, Q1 is the first current load change rate threshold before adjustment, k is the conversion coefficient, T’ is the recovery duration threshold, T is the node voltage recovery duration, Q1” is the adjusted first current load change rate threshold, Qmax is the maximum value of the load change rate safety range, and Qmin is the minimum value of the load change rate safety range.

[0088] When the negative feedback module detects that the first current load change rate threshold needs to be adjusted, it calculates a new load change rate threshold Q1' based on the node voltage recovery duration T and the preset recovery duration threshold T'. This calculation utilizes the conversion coefficient k and the proportional difference between the current recovery time and the threshold. Subsequently, the negative feedback module compares this threshold with the preset safety range from Qmin to Qmax to ensure that the adjusted first current load change rate threshold Q1” is neither lower than the minimum value nor higher than the maximum value of the safety range, thereby ensuring that the power grid can make necessary adjustments on the premise of safety.

[0089] By dynamically adjusting the first current load change rate threshold, it is possible to finely respond to the real-time operating conditions of the power grid, improving the flexibility and adaptability of voltage governance. This method ensures that even when the voltage recovery time exceeds expectations, the system can maintain voltage stability by adjusting the load change rate threshold, avoiding voltage collapse, and enhancing the robustness of the power grid. At the same time, by restricting the threshold within the safety range, it is ensured that power grid equipment will not be damaged due to too rapid load changes, thereby extending the equipment life and reducing maintenance costs.

[0090] The first current load change rate threshold is the target value of the load change rate calculated based on the current system state and some preset safety parameters. This value reflects the load change rate that the system hopes to achieve under the given node voltage recovery duration and recovery duration threshold, so as to restore the voltage to the normal level as quickly as possible without exceeding the safety range.

[0091] The conversion coefficient k is used in the distribution network voltage governance device to adjust the calculation of the load change rate threshold. It is a key parameter that affects the adjustment amplitude and response speed of the load change rate threshold. The requirements for voltage stability will affect the selection of k to ensure that the system will not overreact to small deviations. The specific value of the conversion coefficient k will be determined according to the specific needs of the distribution network and the above factors. Generally, a smaller k is between 0.1 and 1, suitable for systems that require gradual adjustment; a larger k is above 1, suitable for systems that require rapid adjustment. In this embodiment, k is set to 2, which means that the system is more sensitive to the deviation of the voltage recovery time, so that the load change rate threshold can be adjusted faster to cope with the voltage deviation, and the device can quickly respond to the voltage deviation and accelerate the voltage recovery process.

[0092] Specifically, when the negative feedback module determines that the second current load change rate threshold needs to be adjusted, it calculates the adjusted second current load change rate threshold according to the node voltage recovery duration and the preset load change rate safety range.

[0093] Q2’ = Q2 × (1 + k × (T - (T’ + ΔT)) / T’), Q2” = max(min(Q2’, Qmax), Qmin)

[0094] Wherein, Q2’ is the second current load change rate threshold after one calculation, Q2 is the second current load change rate threshold before adjustment, k is the conversion coefficient, ΔT is the preset time increment, Q2” is the adjusted second current load change rate threshold, Qmax is the maximum value of the load change rate safety range, and Qmin is the minimum value of the load change rate safety range.

[0095] When the negative feedback module identifies that the second current load change rate threshold needs to be adjusted, it calculates the second current load change rate threshold Q2' in a state using the current node voltage recovery duration T, the preset recovery duration threshold T', the preset time increment ΔT, and the conversion coefficient k. This calculation process involves weighting the difference between the actual recovery time and the expected recovery time and its increment, and then adding it to the existing first current load change rate threshold Q2. Subsequently, to ensure the safe operation of the power grid, the negative feedback module compares the calculated threshold with the preset load change rate safety range Qmin to Qmax, and takes the maximum value within this range as the adjusted second current load change rate threshold Q2”.

[0096] The adjustment strategy of the negative feedback module provides an adaptive load management mechanism for the distribution network, which can dynamically adjust the load change rate threshold according to the actual voltage recovery situation. This dynamic adjustment helps to optimize the response speed of the power grid, enabling it to more effectively cope with the problem of voltage recovery delay. By keeping the threshold within the safe range, this mechanism not only ensures the stability of the power grid but also avoids equipment damage or power supply interruption caused by too rapid load changes.

[0097] The second current load change rate threshold is the target value of the load change rate obtained in the power system voltage governance device according to specific conditions and calculation formulas. This value reflects the second load change rate that the system hopes to achieve under specific system recovery duration conditions, in order to achieve voltage recovery or maintain system stability without exceeding the safe range.

[0098] Specifically, the data calculation module calculates the voltage deviation based on the real-time voltage and the rated voltage,

[0099] v = (V - V0) / V0,

[0100] where v is the voltage deviation, V is the real-time voltage, and V0 is the rated voltage.

[0101] The data calculation module calculates the voltage deviation v based on the real-time monitored voltage V and the rated voltage V0 set by the system. The voltage deviation is obtained through the formula, that is, the difference between the real-time voltage and the rated voltage divided by the rated voltage.

[0102] Calculating the voltage deviation can provide the deviation between the real-time voltage and the rated voltage, helping to detect voltage anomalies in a timely manner. Quantifying the voltage deviation facilitates comparison and analysis, providing a numerical basis for voltage stability analysis and accurate voltage deviation data for the anomaly determination module to assist in making accurate judgments on the type of anomaly. By calculating the voltage deviation, preventive measures can be taken in advance to avoid power supply instability or equipment damage caused by voltage problems.

[0103] Specifically, the data calculation module calculates the voltage stability index based on the real-time voltage and real-time active power.

[0104]

[0105] Where s is the voltage stability index, and P is the real-time active power. is the partial derivative.

[0106] This module evaluates the sensitivity of the voltage to changes in active power through the partial derivative of the real-time voltage V with respect to the real-time active power P. This calculation involves quantifying the ratio between the voltage change rate and the active power change rate to obtain the voltage stability index, which reflects the ability of the voltage to remain stable when the active power changes and is a key quantitative parameter for voltage stability analysis.

[0107] The voltage stability index is obtained by calculating the partial derivative of the real-time voltage with respect to the real-time active power. This process involves quantitative analysis of the relationship between voltage changes and active power changes to evaluate the voltage stability under active power changes. The beneficial effect of this method is that it can accurately capture the response characteristics of the voltage to load changes, providing key information for the voltage governance device of the distribution network, enabling the system to monitor and predict voltage stability in real time, and taking adjustment measures in a timely manner to effectively prevent voltage collapse.

[0108] Specifically, the data calculation module calculates the load current change rate based on the preset time increment and the change amount of the real-time current within the time increment.

[0109] C = ΔI / ΔT,

[0110] Where C is the load current change rate, ΔI is the change amount of the real-time current within the time increment, and ΔT is the preset time increment.

[0111] The data calculation module monitors the change of the real-time current in the distribution network and divides the change amount within the preset time increment by the time increment to obtain the load current change rate.

[0112] The accurate calculation of the load current change rate is crucial for promptly detecting and responding to load fluctuations in the power grid. It can help the system prevent voltage instability and power supply interruptions, thereby improving the stability of the power grid and the reliability of power supply.

[0113] Please continue to refer to Figure 4 As shown, it is the determination logic diagram for determining abnormal voltage deviation in this embodiment;

[0114] Specifically, the abnormal determination module compares the voltage deviation with a preset voltage deviation threshold.

[0115] If the voltage deviation is greater than or equal to the voltage deviation threshold, the abnormal determination module determines that there is an abnormal voltage deviation, and compares the voltage stability index with the voltage stability index threshold.

[0116] If the voltage stability index is greater than or equal to the voltage stability index threshold, the abnormal determination module determines that there is an abnormal voltage stability.

[0117] The abnormal determination module first compares the real-time monitored voltage deviation with the preset voltage deviation threshold. When the voltage deviation reaches or exceeds this threshold, the module identifies an abnormal voltage deviation. Subsequently, the module further compares the voltage stability index with the preset voltage stability index threshold. If the stability index also reaches or exceeds the threshold, it is determined that there is an abnormal voltage stability in the system.

[0118] Through continuous monitoring and determination, the distribution network voltage governance device can quickly respond to voltage abnormal conditions, prevent voltage collapse, and ensure the stability of the power grid and the continuity of power supply. In addition, accurately determining the type of abnormality helps to implement more precise adjustment strategies, improve the voltage governance efficiency, and enhance the reliability of the entire power system and the user's power consumption experience.

[0119] Specifically, when the abnormal determination module determines that there is an abnormal voltage stability, it compares the current load change rate with the load change rate threshold.

[0120] If the current load change rate is greater than the load change rate threshold, the abnormal determination module determines that there is a load abnormality.

[0121] In the distribution network voltage governance device, once the abnormal determination module detects an abnormal voltage stability, it will immediately evaluate the current load change rate. The module compares the current load change rate calculated in real time with the preset load change rate threshold. If the current current load change rate exceeds the set threshold, then the module will determine that there is a load abnormality in the system.

[0122] The determination mechanism for abnormal load allows the system to further confirm whether there is a load problem after detecting abnormal voltage stability, so as to more comprehensively evaluate the health status of the power grid. After determining abnormal load, the system can take corresponding measures, such as adjusting power generation, reallocating load or adopting demand-side management strategies, to relieve the power grid pressure, prevent voltage collapse, and ensure the stability and reliability of power supply.

[0123] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0124] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A distribution network voltage management device, characterized in that: include: Data acquisition module, used to collect the real-time voltage, real-time current, real-time active power and node voltage recovery time of each node in the distribution network; A data calculation module, connected to the data acquisition module, for calculating a voltage deviation, a voltage stability index and a current load change rate according to the real-time voltage, the real-time current, the real-time active power, the rated voltage and a preset time increment; an abnormality determination module, connected to the data calculation module, for determining the type of abnormality according to the voltage deviation, the voltage stability index, the current load change rate, a preset voltage deviation threshold, a preset voltage stability index threshold, and a preset standard current load change rate threshold; when determining that a load abnormality occurs, the abnormality determination module determines the degree of load abnormality according to the current load change rate, the first current load change rate threshold, and the second current load change rate threshold, and makes corresponding adjustments according to the degree of load abnormality; A negative feedback module is respectively connected to the data acquisition module and the abnormality determination module, and is used to make a determination based on the node voltage recovery time, the preset target node voltage recovery time and the preset time increment. When the negative feedback module determines that the first current load change rate threshold needs to be adjusted, the first current load change rate threshold is adjusted based on the node voltage recovery time, the target node voltage recovery time and the preset load change rate safety range. When the negative feedback module determines that the second current load change rate threshold needs to be adjusted, the second current load change rate threshold is adjusted based on the node voltage recovery time, the target node voltage recovery time, the preset time increment and the preset load change rate safety range.

2. The distribution network voltage management device according to claim 1, characterized in that: When determining that a load abnormality occurs, the abnormality determination module compares the current load change rate with the first current load change rate threshold and the second current load change rate threshold respectively. If the current load change rate is less than the first current load change rate threshold, the abnormality determination module determines it as a slight change abnormality and reduces the load of the non-critical part; If the current load change rate is greater than or equal to the first current load change rate threshold and less than the second current load change rate threshold, the abnormality determination module determines it as a moderate change abnormality and sends a demand response signal; If the current load change rate is greater than the second current load change rate threshold, the abnormality determination module determines that it is a drastic change abnormality, disconnects the power supply and issues an alarm.

3. The distribution network voltage management device according to claim 2, characterized in that: The negative feedback module makes a determination based on the node voltage recovery time, the recovery time threshold and the preset time increment collected by the data collection module. If the node voltage recovery time is greater than or equal to the recovery time threshold, and less than the sum of the recovery time threshold and the preset time increment, the negative feedback module determines that the first current load change rate threshold needs to be adjusted; If the node voltage recovery time is greater than or equal to the sum of the recovery time threshold and the preset time increment, the negative feedback module determines that the second current load change rate threshold needs to be adjusted.

4. The distribution network voltage management device according to claim 3, characterized in that: When the negative feedback module determines that the first current load change rate threshold needs to be adjusted, the negative feedback module calculates the adjusted first current load change rate threshold according to the node voltage recovery time and the preset load change rate safety range. Q1'=Q1×(1+k×(T-T') / T'), Q1”=max(min(Q1’, Qmax),Qmin), Among them, Q1' is the first current load change rate threshold after one calculation, Q1 is the first current load change rate threshold before adjustment, k is the conversion coefficient, T' is the recovery time threshold, T is the node voltage recovery time, Q1" is the first current load change rate threshold after adjustment, Qmax is the maximum value of the load change rate safety range, and Qmin is the minimum value of the load change rate safety range.

5. The distribution network voltage management device according to claim 4, characterized in that: When the negative feedback module determines that the second current load change rate threshold needs to be adjusted, the negative feedback module calculates the adjusted second current load change rate threshold according to the node voltage recovery time, the preset load change rate safety range and the preset time increment. Q2'=Q2×(1+k×(T-(T'+ΔT)) / T'), Q2”=max(min(Q2’, Qmax),Qmin), Among them, Q2' is the second current load change rate threshold after one calculation, Q2 is the second current load change rate threshold before adjustment, k is the conversion coefficient, ΔT is the preset time increment, Q2" is the second current load change rate threshold after adjustment, Qmax is the maximum value of the load change rate safety range, and Qmin is the minimum value of the load change rate safety range.

6. The distribution network voltage management device according to claim 5, characterized in that: The data calculation module calculates the voltage deviation according to the real-time voltage and the rated voltage. v=(V-V0) / V0, Where v is the voltage deviation, V is the real-time voltage, and V0 is the rated voltage.

7. The distribution network voltage management device according to claim 6, characterized in that: The data calculation module calculates the voltage stability index according to the real-time voltage and real-time active power. Among them, s is the voltage stability index, P is the real-time active power, is the partial derivative.

8. The distribution network voltage management device according to claim 7, characterized in that: The data calculation module calculates the load current change rate according to the preset time increment and the change amount of the real-time current within the time increment. C=ΔI / ΔT, Where C is the load current change rate, ΔI is the change in real-time current within the time increment, and ΔT is the preset time increment.

9. The distribution network voltage management device according to claim 8, characterized in that: The abnormality determination module compares the voltage deviation with a preset voltage deviation threshold. If the voltage deviation is greater than or equal to the voltage deviation threshold, the abnormality determination module determines that a voltage deviation abnormality occurs, and compares the voltage stability index with the voltage stability index threshold. If the voltage stability index is greater than or equal to the voltage stability index threshold, the abnormality determination module determines that a voltage stability abnormality occurs.

10. The distribution network voltage management device according to claim 9, characterized in that: When determining that voltage stability is abnormal, the abnormality determination module compares the current load change rate with the standard current load change rate threshold. If the current load change rate is greater than the standard current load change rate threshold, the abnormality determination module determines that a load abnormality occurs.

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