Substation DC power supply operation management method and system based on supercapacitor energy storage

Abstract

The present invention discloses a method and system for managing the operation of a DC power supply of a transformer substation based on supercapacitor energy storage. The method comprises: connecting a DC protection device based on supercapacitor energy storage in parallel to a DC bus; when AC power is supplied normally, the DC protection device supplies power to the load and replenishes the discharged electric energy to the supercapacitor; when AC power cannot be supplied normally, a DC protection module provides power supply demand for the DC bus; when the voltage of the supercapacitor cannot meet the requirement of the DC bus, the voltage of the supercapacitor is increased by a boost unit to meet the requirement of the DC bus. The present invention utilizes the DC protection device based on supercapacitor energy storage to realize the uninterrupted provision of reliable DC power to the DC bus, thereby improving the safety and reliability of the operation of the DC system.

Description

Technical Field

[0001] The present invention relates to the technical field of substation DC power supply management, and in particular to a substation DC power supply operation management method and system based on supercapacitor energy storage. Background Art

[0002] The DC power supply system is an important part of the substation. It is the power supply for secondary systems such as relay protection control devices, automation devices, high-voltage circuit breaker opening and closing mechanisms, communications, metering, and emergency lighting. Under normal circumstances, the DC power supply system is provided by the station AC power through a rectifier. When there is a sudden AC power failure, the station DC power supply system is powered by a battery pack, and the battery pack becomes the only DC power supply. Therefore, the battery pack is considered to be one of the most core components in the DC system of the substation and an important guarantee for the safe and stable operation of the substation system. However, at present, both the dual-electric dual-charge DC power supply system and the single-electric single-charge DC power supply system are powered by a single series battery pack. The failure of any battery will cause the entire battery pack to be unable to supply power to the outside. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a substation DC power supply operation management method and system based on supercapacitor energy storage, which eliminates the failure mode of the DC busbar losing voltage as a whole due to the inability to remove the short-circuit fault circuit of the current battery, reduces the risk of hidden dangers caused by DC power supply system failure, and improves the safe and stable operation of the DC system. The technical solution is as follows:

[0004] In a first aspect, a method for operating and managing a DC power supply of a substation based on supercapacitor energy storage is provided, comprising:

[0005] Connecting a DC protection device based on supercapacitor energy storage in parallel to the DC bus;

[0006] When the AC power is supplied normally, the DC protection device supplies power to the load while replenishing the discharged energy to the supercapacitor;

[0007] When the AC power cannot be supplied normally, the DC guarantee module provides power supply for the DC bus; when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased through the boost unit to meet the requirements of the DC bus.

[0008] In some embodiments, the DC protection device based on supercapacitor energy storage includes: a charging unit, a capacitor module, and a boost unit;

[0009] The charging unit is used to charge the supercapacitor module;

[0010] The capacitor module is connected in parallel to the DC bus, and the capacitor module is connected in parallel first and then in series;

[0011] The boost unit is used to boost the voltage output by the capacitor module to meet the DC bus requirement.

[0012] In some embodiments, the operation management method includes:

[0013] Obtaining the voltage, current and temperature data of the supercapacitor corresponding to the sampling time point during the charging process; the charging process adopts constant current charging to a preset voltage, and then constant voltage charging based on the preset voltage until the current is less than a preset value, and determining that the charging process is completed;

[0014] Based on the voltage, current and temperature data during the charging process, voltage time series data, current time series data and temperature time series data are formed, and based on the voltage time series data, current time series data and temperature time series data, a super capacitor characteristic parameter time series matrix is ​​formed;

[0015] Compare the characteristic parameter time series matrices of all supercapacitors, and select the characteristic parameter time series matrices representing abnormalities and their corresponding supercapacitors;

[0016] For the supercapacitor corresponding to the characteristic parameter timing matrix representing the abnormality, the corresponding supercapacitor usage performance consumption progress is analyzed.

[0017] In some embodiments, comparing the characteristic parameter timing matrices of all supercapacitors includes:

[0018] Based on the voltage time series data of all supercapacitors, A first supercapacitors with a shorter service time are obtained as first reference capacitors, and the voltage time series data of the first reference capacitors are obtained;

[0019] Sorting A first supercapacitors and their voltage time series data based on the voltage rising rate in the constant current charging stage in the voltage time series data of the first reference capacitor, removing isolated time series data, and calculating the weight of the remaining time series data based on the inverse of the voltage rising rate;

[0020] Calculating similarity based on the voltage time series data of all super capacitors and the voltage time series data of the first reference capacitor, wherein the similarity is calculated based on weighted calculation based on the corresponding weights of the A first super capacitors;

[0021] The performance of all supercapacitors is ranked based on the similarity. The one with greater similarity indicates that the supercapacitor has better performance.

[0022] Obtain B supercapacitors whose supercapacitor performance is poor as shown by voltage time series data to form a supercapacitor set B1;

[0023] Based on the same idea, B supercapacitors with poor supercapacitor performance are obtained from the current time series data to form a supercapacitor set B2, and B supercapacitors with poor supercapacitor performance are obtained from the temperature time series data to form a supercapacitor set B3.

[0024] Based on the supercapacitors in the supercapacitor sets B1, B2, and B3, at least one supercapacitor is obtained as a first warning supercapacitor.

[0025] In some embodiments, comparing the characteristic parameter timing matrices of all supercapacitors includes:

[0026] Obtain the voltage, current, and temperature time series data of each supercapacitor during the historical charging process;

[0027] Extract the change trend characteristics of the voltage time series data of a single supercapacitor during multiple charging processes; based on the change trend characteristics of the voltage time series data, extract C supercapacitors with large performance changes represented by the voltage time series data to form a supercapacitor set C1;

[0028] Based on the same idea, C supercapacitors with large performance changes represented by current time series data are extracted to form supercapacitor set C2; multiple supercapacitors with large performance changes represented by temperature time series data are extracted to form supercapacitor set C3;

[0029] At least one second warning supercapacitor is obtained based on the supercapacitors in the supercapacitor sets C1, C2, and C3.

[0030] In some embodiments, extracting the variation trend characteristics of the voltage time series data during multiple charging processes of a single supercapacitor includes:

[0031] The change curve of the voltage time series data during the first charging process is used as the basic curve;

[0032] The difference between the voltage time series data of each remaining charging process and the voltage time series data of the first charging process is calculated respectively and accumulated to obtain a first accumulated sum;

[0033] respectively calculating the difference of the voltage time series data in two adjacent charging processes and accumulating them to obtain a second cumulative sum;

[0034] The first accumulated sum and the second accumulated sum are used as the variation trend characteristics of the voltage time series data in multiple charging processes of a single super capacitor.

[0035] In some embodiments, based on the variation trend characteristics of the voltage time series data, extracting C supercapacitors with large performance variations represented by the voltage time series data to form a supercapacitor set C1 includes:

[0036] Based on the change trend characteristics of the voltage time series data, the performance change value of the supercapacitor is calculated, and the performance change value is sorted based on the size of the performance change value and the supercapacitors corresponding to the performance change values ​​whose performance change values ​​are greater than the first preset threshold are obtained to form a supercapacitor sequence C1 sorted by the size of the performance change value; wherein, based on the change trend characteristics of the voltage time series data, the performance change value of the supercapacitor is calculated, including: calculating the performance change value of the supercapacitor based on the product of the first cumulative sum and the second cumulative sum;

[0037] or

[0038] Based on the change trend characteristics of the voltage time series data, i.e., the vector composed of the first cumulative sum and the second cumulative sum, clustering is performed to obtain multiple change trend characteristic clusters;

[0039] For multiple clusters, a supercapacitor set C1 is formed based on supercapacitors corresponding to the cluster with the largest first cumulative sum average or the largest second cumulative sum average in the clusters.

[0040] In some embodiments, analyzing the usage performance consumption progress of the supercapacitor corresponding to the supercapacitor corresponding to the characteristic parameter time series matrix representing the abnormality includes:

[0041] For the early warning supercapacitor, a constant current discharge process is performed regularly to collect the voltage, current and time data of the constant current discharge process;

[0042] Based on the constant current discharge process data, the supercapacitor equivalent circuit parameters are calculated to obtain the supercapacitor equivalent series resistance and capacitance;

[0043] Based on the equivalent circuit parameters obtained from multiple constant current discharge processes of the supercapacitor, a time variation curve of the equivalent series internal resistance and capacitance of the supercapacitor is obtained;

[0044] Based on the time variation curve of the equivalent circuit parameters, the performance of the supercapacitor is monitored. When the capacitance of the equivalent circuit parameters decreases and / or the equivalent series resistance increases, it is determined that the performance of the supercapacitor has decreased.

[0045] The performance degradation of the supercapacitor is determined based on the capacitance reduction and / or equivalent series resistance increase of the equivalent circuit parameters and the factory initial equivalent circuit parameters of the supercapacitor.

[0046] In some embodiments, the substation DC power supply operation management method based on supercapacitor energy storage further includes:

[0047] Based on the time variation curve of equivalent circuit parameters, analyze the time point of abnormal variation;

[0048] The cause of the abnormal change is determined based on the voltage, current and temperature monitoring data of the supercapacitor at the time of the abnormal change.

[0049] In a second aspect, a substation DC power supply operation management system based on supercapacitor energy storage is provided, the system comprising:

[0050] A DC protection device, the DC protection device is a DC protection device based on supercapacitor energy storage, and the DC protection device is connected in parallel to a DC bus; the DC protection device provides two working modes: one working mode is: when AC power is supplied normally, the DC protection device supplies power to the load while replenishing the discharged electric energy to the supercapacitor; the other working mode is: when AC power cannot be supplied normally, a DC protection module is used to provide power supply requirements for the DC bus; and when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased by a boost unit to meet the requirements of the DC bus.

[0051] The present invention provides a method and system for managing the operation of a DC power supply in a substation based on supercapacitor energy storage, which has the following beneficial effects: a DC protection device based on supercapacitor energy storage is connected in parallel to a DC bus; when AC power is supplied normally, the DC protection device supplies power to the load while replenishing the discharged electric energy to the supercapacitor; when AC power cannot be supplied normally, the DC protection module provides power supply demand for the DC bus; when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased by a boost unit to meet the requirements of the DC bus. The present invention forms a supercapacitor DC protection technical solution through a DC protection device based on supercapacitor energy storage, which eliminates the current failure mode of the DC bus as a whole losing pressure due to the inability to remove the short-circuit fault circuit of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flow chart of a method for managing the operation of a DC power supply in a substation based on supercapacitor energy storage in an embodiment of the present application;

[0053] Figure 2 is a flow chart of a supercapacitor module operation management method in an embodiment of the present application;

[0054] Figure 3 is a flow chart of a method for selecting a first warning supercapacitor based on a characteristic parameter timing matrix of a supercapacitor in an embodiment of the present application;

[0055] Figure 4 is a flow chart of a method for selecting a second warning supercapacitor based on a characteristic parameter timing matrix of a supercapacitor in an embodiment of the present application;

[0056] Figure 5 It is a flow chart of the method for analyzing the performance of supercapacitors in the embodiment of the present application. DETAILED DESCRIPTION

[0057] 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.

[0058] See also Figure 1 The present application embodiment provides a method for managing the operation of a DC power supply in a substation based on supercapacitor energy storage, the method comprising the following steps:

[0059] Step 1, connecting a DC protection device based on supercapacitor energy storage in parallel to the DC bus;

[0060] Step 2: When the AC power is supplied normally, the DC protection device supplies power to the load and replenishes the discharged energy to the supercapacitor;

[0061] Step 3: When the AC power cannot be supplied normally, the DC guarantee module provides power supply demand for the DC bus; when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased by the boost unit to meet the requirements of the DC bus.

[0062] In the embodiment of the present application, the AC power cannot be supplied normally, including AC power failure, AC power cannot provide the voltage required by the DC bus, that is, it is lower than the voltage required by the DC bus, and the voltage fluctuation is large. The embodiment of the present application forms a supercapacitor DC protection technical solution, realizes the protection mode of short-circuit fault removal of the DC system of the substation system, eliminates the current battery due to the short-circuit fault circuit can not be removed, resulting in the overall voltage loss of the DC bus, and enhances the safe and reliable operation of the DC system.

[0063] In one embodiment, the DC protection device based on supercapacitor energy storage includes: a charging unit, a capacitor module, and a boost unit;

[0064] The charging unit is used to charge the supercapacitor module;

[0065] The capacitor module is connected in parallel to the DC bus, and the capacitor module is connected in parallel first and then in series;

[0066] The boost unit is used to boost the voltage output by the capacitor module to meet the DC bus requirement.

[0067] Specifically, the DC protection device based on supercapacitor energy storage includes: a charging unit, a capacitor module, and a boost unit connected to the busbar in sequence;

[0068] The charging unit is used to take AC or DC as input, convert it into DC power required by the DC system of the substation, and input it into the DC bus;

[0069] The capacitor module is located at the output end of the charging unit and is connected in parallel to the DC bus. The capacitor module is connected in parallel first and then in series.

[0070] One end of the boost unit is connected to the capacitor module, and the other end is connected to the DC system load. The boost unit is connected in series to the DC bus. The boost unit includes a boost circuit and a diode circuit connected in parallel at both ends of the boost circuit.

[0071] The DC protection device in the embodiment of the present application has a simple circuit and realizes the integrated functions of providing uninterrupted power to the load, supplying power to the DC bus, and charging the supercapacitor.

[0072] (A) When AC power is supplied normally, the AC power is input into the charging unit for DC power conversion; after the conversion, the capacitor module is charged on the one hand, and the DC system load is powered on the other hand; when the capacitor module is fully charged, the charging of the capacitor module is stopped, and only the DC system load is powered;

[0073] (B) When the AC power cannot be supplied normally, the fully charged capacitor module supplies power to the DC bus. When the DC power passes through the boost unit:

[0074] (B1) When the voltage does not meet the requirements of the DC system load (DC bus), the diode circuit in the boost unit is blocked and the boost circuit is turned on, and the voltage of the DC bus is increased through the boost circuit;

[0075] (B2) When the voltage meets the requirements of the DC system load (DC bus), the diode circuit in the boost unit is turned on while the boost circuit is not turned on, and the voltage provided by the capacitor module is directly used to power the DC system load.

[0076] The supercapacitor has a different principle of storing electricity from the battery, and the discharge termination voltage of the supercapacitor can be close to zero volts. In order to fully utilize the storage capacity in the capacitor bank, the embodiment of the present application designs a boost power supply unit that supports boosting low voltage to normal working voltage. The boost unit has technical requirements of low working voltage, high reliability, and stable output voltage. Even if the discharge voltage of the capacitor module is relatively low in the later stage of discharge, the boost unit can continue to supply power to the DC system load.

[0077] In one embodiment, the boost unit includes: an inductor L1, a switch tube Q1 and a diode D1, wherein one end of the inductor L1 is connected to the capacitor C1, the other end of the inductor L1 is respectively connected to the anode of the diode D1 and the MOS tube Q1, the cathode of the diode D1 is respectively connected to the capacitor C2 and the load resistor RL, and the two ends of the capacitor C1 are connected to the input voltage; the voltage across the capacitor C2 provides the working voltage for the load resistor RL, and provides energy to the load. The boost process of the boost unit includes:

[0078] (1) Turn on the switch tube Q1. Under the action of the input voltage, the inductor L1 stores energy, and the capacitor C2 provides energy to the load resistor RL to keep the load resistor RL working. At this time, the terminal voltage across the capacitor C2 is within the voltage range required by the bus.

[0079] (2) When the terminal voltage across capacitor C2 does not reach the voltage required by the bus, the switch tube is turned off, and the energy stored in inductor L1 is applied to capacitor C2. The terminal voltage across capacitor C2 increases until it reaches the voltage range required by the bus.

[0080] (3) Repeat the above (1) and (2) to control the terminal voltage across capacitor C2 to always reach the voltage range required by the bus.

[0081] In a preferred embodiment, the capacitor module is connected to a balancing circuit for balancing the voltages of the individual capacitors.

[0082] See also Figure 2 In one embodiment, the substation DC power supply operation management method based on supercapacitor energy storage includes:

[0083] Step A1, obtaining the voltage, current and temperature data of the supercapacitor corresponding to the sampling time point during the charging process; the charging process adopts constant current charging to a preset voltage, and then constant voltage charging based on the preset voltage until the current is less than a preset value, and determining that the charging process is completed;

[0084] Step A2, forming voltage time series data, current time series data, and temperature time series data based on the voltage, current, and temperature data during the charging process, and forming a supercapacitor characteristic parameter time series matrix based on the voltage time series data, current time series data, and temperature time series data;

[0085] Step A3, comparing the characteristic parameter time series matrices of all supercapacitors, and screening out the characteristic parameter time series matrices representing abnormalities and their corresponding supercapacitors;

[0086] Step A4, for the supercapacitor corresponding to the characteristic parameter timing matrix characterizing the abnormality, the corresponding supercapacitor usage performance consumption progress is analyzed. Specifically, the usage performance consumption progress of the supercapacitor corresponding to the characteristic parameter timing matrix characterizing the abnormality can be determined based on the usage time of the supercapacitor and the voltage change rate of the constant current charging stage, the duration of the constant voltage charging stage, the voltage loss value of the static stage after charging, and the temperature change rate in the characteristic parameter timing matrix characterizing the abnormality.

[0087] See also Figure 3 In one embodiment, the above step A3, comparing the characteristic parameter timing matrices of all supercapacitors, comprises the following steps:

[0088] A301, based on the voltage time series data of all supercapacitors, obtaining A first supercapacitors with a shorter service time as first reference capacitors, and obtaining voltage time series data of the first reference capacitors;

[0089] A302, sorting A first supercapacitors and their voltage time series data based on the voltage rising rate in the constant current charging stage in the voltage time series data of the first reference capacitor, removing isolated time series data, and calculating the weight of the remaining time series data based on the inverse of the voltage rising rate;

[0090] A303, calculating similarity based on the voltage time series data of all super capacitors and the voltage time series data of the first reference capacitor, wherein the similarity is calculated based on weighted calculation corresponding to the A first super capacitors;

[0091] A304, sorts the performance of all supercapacitors based on similarity, and the one with greater similarity indicates better performance;

[0092] A305, obtaining B supercapacitors whose supercapacitor performance is poor as indicated by voltage time series data, to form a supercapacitor set B1;

[0093] A306, based on the same idea, i.e., the method provided by the above steps A301-A305, the current time series data of all supercapacitors are used to obtain B supercapacitors with poor supercapacitor performance from the current time series data to form a supercapacitor set B2, and the temperature time series data of all supercapacitors are used to obtain B supercapacitors with poor supercapacitor performance from the temperature time series data to form a supercapacitor set B3;

[0094] A307: Obtain at least one supercapacitor as a first warning supercapacitor based on the supercapacitors in the supercapacitor sets B1, B2, and B3.

[0095] It is understood that in a supercapacitor module, multiple supercapacitors of the same specification and model are generally connected in series and parallel to ensure the terminal voltage balance of a single supercapacitor and the current balance of multiple branches to the greatest extent. In the embodiment of the present application, multiple supercapacitors are connected in parallel first and then in series.

[0096] In the embodiment of the present application, considering the situation that a single supercapacitor in the supercapacitor module needs to be replaced and repaired separately, different capacitors in the supermodule have been put into use for different times, resulting in different performance consumption of different capacitors in the supermodule. A supercapacitor with the shortest time in use is used as a reference capacitor for analysis.

[0097] In the above similarity calculation process, considering that among the A first supercapacitors, the performance consumption of different supercapacitors cannot be simply assumed to change linearly with the length of time put into use, the A first supercapacitors have different contributions to characterizing the maximum performance of the supercapacitor, and the weights of the A first supercapacitors are calculated respectively.

[0098] A first supercapacitors and their voltage timing data are sorted to remove isolated timing data. The isolated timing data can be removed based on the distance between the voltage rise rate of the first supercapacitor in the constant current charging stage and the voltage rise rate of other first supercapacitors in the constant current charging stage.

[0099] The at least one supercapacitor is obtained as the first warning supercapacitor based on the supercapacitors in the supercapacitor sets B1, B2, and B3, and the overlapping supercapacitors in the supercapacitor sets B1, B2, and B3 are used as the first warning supercapacitor.

[0100] See also Figure 4 In another embodiment, the above step A3, comparing the characteristic parameter timing matrices of all supercapacitors, includes the following steps:

[0101] Step A311, obtaining the voltage, current, and temperature time series data of each supercapacitor during the historical charging process;

[0102] Step A312, extracting the change trend characteristics of the voltage time series data of a single supercapacitor in multiple charging processes (characterizing the change law of the charging voltage curve of a single capacitor in the process of gradual performance degradation, and also characterizing the distinguishing characteristics of the voltage curves of supercapacitors in different performance periods);

[0103] Step A313, based on the variation trend characteristics of the voltage time series data, C supercapacitors with large performance variations represented by the voltage time series data are extracted to form a supercapacitor set C1;

[0104] Step A314, based on the same idea, i.e., based on the method of the above steps A311 to A313, C supercapacitors with large performance changes represented by current time series data are extracted to form a supercapacitor set C2, and multiple supercapacitors with large performance changes represented by temperature time series data are extracted to form a supercapacitor set C3;

[0105] Step A315: obtaining at least one second warning supercapacitor based on the supercapacitors in the supercapacitor sets C1, C2, and C3.

[0106] In the embodiments of the present application, various situations are considered, such as the supercapacitors in the same supercapacitor module are put into use at the same time or all the supercapacitors in the same supercapacitor module are replaced at the same time during subsequent maintenance, resulting in the total time of all the supercapacitors in the supercapacitor module being put into use being roughly the same. In this case, in the embodiments of the present application, all historical voltage, current, and temperature changes of the same supercapacitor are analyzed to implement a "self-comparison" process. It can be understood that in the embodiments of the present application, it is believed that the performance of the supercapacitor is better in the initial stage of use, and as the time of use increases, the performance shows a gradual downward trend. However, if the performance degradation trend is abnormal, it is characterized that the supercapacitor needs to focus on its performance consumption.

[0107] The obtaining of at least one second warning supercapacitor based on supercapacitors in the supercapacitor sets C1, C2, and C3 includes: using overlapping supercapacitors in the supercapacitor sets C1, C2, and C3 as second warning supercapacitors.

[0108] In one embodiment, the above step A312, extracting the variation trend characteristics of the voltage time series data in multiple charging processes of a single supercapacitor, includes:

[0109] A3121, the change curve of the voltage time series data during the first charging process is used as the basic curve;

[0110] A3122, respectively calculating the difference between the voltage time series data of each remaining charging process and the voltage time series data of the first charging process and accumulating them to obtain a first accumulated sum;

[0111] A3123, respectively calculating the difference of the voltage time series data in two adjacent charging processes and accumulating them to obtain a second accumulated sum;

[0112] A3124, based on the first accumulated sum and the second accumulated sum as the change trend characteristics of the voltage time series data in multiple charging processes of a single supercapacitor.

[0113] In the embodiment of the present application, considering that from a macroscopic perspective, the capacitance performance represented by the voltage timing data of a single supercapacitor during multiple charging processes gradually decreases, and from a microscopic perspective, the capacitance performance decrease represented by the voltage timing data in a shorter time or between fewer charging times does not change linearly or significantly. Therefore, in the embodiment of the present application, a plurality of difference degrees are superimposed to represent the change trend characteristics of the voltage timing data of a single supercapacitor during multiple charging processes. Based on the change trend characteristics, the performance change differences of different supercapacitors can be effectively distinguished based on the collected data of fewer charging times.

[0114] In one embodiment, in step A313, based on the variation trend characteristics of the voltage time series data, C supercapacitors with large performance variations represented by the voltage time series data are extracted to form a supercapacitor set C1, including:

[0115] Step A3131, based on the change trend characteristics of the voltage time series data, calculating the performance change value of the supercapacitor, sorting based on the size of the performance change value and obtaining the supercapacitors corresponding to the performance change values ​​whose performance change values ​​are greater than the first preset threshold to form a supercapacitor sequence C1 sorted by the size of the performance change value; wherein, based on the change trend characteristics of the voltage time series data, calculating the performance change value of the supercapacitor includes: calculating the performance change value of the supercapacitor based on the product of the first cumulative sum and the second cumulative sum;

[0116] In another embodiment, in step A313, based on the variation trend characteristics of the voltage time series data, C supercapacitors with large performance variations represented by the voltage time series data are extracted to form a supercapacitor set C1, including:

[0117] Step A3132, clustering is performed based on the change trend characteristics of the voltage time series data, that is, the vector composed of the first cumulative sum and the second cumulative sum, to obtain multiple change trend characteristic clusters;

[0118] Step A3133: for multiple clusters, a supercapacitor set C1 is formed based on supercapacitors corresponding to the cluster with the largest first cumulative sum average or the largest second cumulative sum average in the clusters.

[0119] See also Figure 5 In one embodiment, in the above step A4, analyzing the usage performance consumption progress of the supercapacitor corresponding to the characteristic parameter timing matrix representing the abnormality includes:

[0120] Step A41, regularly performing a constant current discharge process for the warning supercapacitor, and collecting voltage, current, and time data of the constant current discharge process;

[0121] Step A42, based on the constant current discharge process data, calculating the supercapacitor equivalent circuit parameters to obtain the supercapacitor equivalent series resistance and capacitance;

[0122] Step A43, obtaining a time variation curve of the equivalent series internal resistance and capacitance of the supercapacitor based on equivalent circuit parameters obtained during multiple constant current discharge processes of the supercapacitor;

[0123] Step A44, monitoring the performance of the supercapacitor based on the time variation curve of the equivalent circuit parameter, and determining that the performance of the supercapacitor is degraded when the capacitance of the equivalent circuit parameter decreases and / or the equivalent series resistance increases;

[0124] Step A45, determining the degradation of the performance of the supercapacitor based on the capacitance reduction and / or equivalent series resistance increase of the equivalent circuit parameters and the factory initial equivalent circuit parameters of the supercapacitor.

[0125] In the embodiment of the present application, the performance consumption of the warning supercapacitor is analyzed based on the equivalent circuit parameters obtained during the constant current discharge process. Specifically, the factory initial equivalent circuit parameters can be used as reference values, and the capacitance reduction or equivalent series resistance increase can be used to characterize the degradation of the performance of the supercapacitor. When the capacity decreases by 20% compared with the initial capacity, it indicates that the supercapacitor has failed. When it reaches twice the initial equivalent series resistance of the supercapacitor, it indicates that the supercapacitor has failed. Among them, obtaining the equivalent series resistance and capacitance of the supercapacitor based on the constant current discharge process is an existing technology. The resistance value and capacitance value in the supercapacitor equivalent circuit model can be obtained according to the predetermined supercapacitor equivalent circuit model and the electrical parameters of the constant current discharge process. For example, the equivalent circuit model of the supercapacitor is first determined. If an equivalent parallel resistor is connected in parallel to the supercapacitor and an equivalent series resistor is connected in series at the same time, the equivalent parallel resistance can be ignored during the supercapacitor charging and discharging process. According to the relevant calculation formula of the capacitor The capacitance value can be calculated based on the constant current and voltage changes over a period of time during the constant current discharge process, and then the equivalent series resistance can be calculated.

[0126] In one embodiment, after the above step A45, the method further includes:

[0127] A46, based on the time variation curve of the equivalent circuit parameters, analyze the time point of abnormal variation; determine the cause of the abnormal variation based on the voltage, current and temperature monitoring data of the supercapacitor at the time point of abnormal variation.

[0128] The embodiment of the present application provides a further step for analyzing the cause of the supercapacitor failure. During long-term use, the equivalent circuit parameters of the supercapacitor gradually change. If a sudden change occurs, the cause is further located and investigated.

[0129] The substation DC power supply operation and management system based on supercapacitor energy storage provided in the embodiment of the present application includes:

[0130] A DC protection device, the DC protection device is a DC protection device based on supercapacitor energy storage, and the DC protection device is connected in parallel to a DC bus; the DC protection device provides two working modes: one working mode is: when AC power is supplied normally, the DC protection device supplies power to the load while replenishing the discharged electric energy to the supercapacitor; the other working mode is: when AC power cannot be supplied normally, a DC protection module is used to provide power supply requirements for the DC bus; and when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased by a boost unit to meet the requirements of the DC bus.

[0131] For the specific limitations of the substation DC power supply operation and management system based on supercapacitor energy storage, please refer to the limitations of the substation DC power supply operation and management method based on supercapacitor energy storage above, which will not be repeated here.

[0132] The present invention is not limited to the above-mentioned specific implementation modes. Various changes made by ordinary technicians in this field based on the above-mentioned concepts without creative work are all within the protection scope of the present invention.

Claims

1. A method for operating and managing a DC power supply in a substation based on supercapacitor energy storage, characterized in that: include: Connecting a DC protection device based on supercapacitor energy storage in parallel to the DC bus; When the AC power is supplied normally, the DC protection device supplies power to the load while replenishing the discharged energy to the supercapacitor; When the AC power cannot be supplied normally, the DC protection module provides power supply demand for the DC bus; when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased through the boost unit to meet the requirements of the DC bus; The operation management method includes: obtaining voltage, current, and temperature data of a supercapacitor corresponding to a sampling time point during a charging process; the charging process adopts constant current charging to a preset voltage first, and then constant voltage charging based on the preset voltage until the current is less than a preset value, and determining that the charging process is finished; forming voltage timing data, current timing data, and temperature timing data based on the voltage, current, and temperature data during the charging process, and forming a supercapacitor characteristic parameter timing matrix based on the voltage timing data, current timing data, and temperature timing data; comparing the characteristic parameter timing matrices of all supercapacitors, screening out the characteristic parameter timing matrices representing abnormalities and their corresponding supercapacitors; analyzing the usage performance consumption progress of the corresponding supercapacitor corresponding to the characteristic parameter timing matrix representing the abnormalities; The method for comparing the characteristic parameter timing matrix of all supercapacitors includes: based on the voltage timing data of all supercapacitors, obtaining A first supercapacitors with a shorter service time as first reference capacitors, and obtaining the voltage timing data of the first reference capacitors; sorting the A first supercapacitors and their voltage timing data based on the voltage rise rate in the constant current charging stage in the voltage timing data of the first reference capacitors, removing isolated timing data, and calculating the weight of the remaining timing data based on the inverse of the voltage rise rate; calculating the similarity based on the voltage timing data of all supercapacitors and the voltage timing data of the first reference capacitor, wherein the similarity is calculated based on A weighted calculation is performed on the corresponding weights of the A first supercapacitors; the usage performance of all supercapacitors is sorted based on the similarity, and the supercapacitor with greater similarity has better performance; B supercapacitors with poor supercapacitor performance characterized by voltage timing data are obtained to form a supercapacitor set B1; based on the same idea, B supercapacitors with poor supercapacitor performance from current timing data are obtained to form a supercapacitor set B2, and B supercapacitors with poor supercapacitor performance characterized by temperature timing data are obtained to form a supercapacitor set B3; based on the supercapacitors in the above supercapacitor sets B1, B2, and B3, at least one supercapacitor is obtained as the first warning supercapacitor.

2. The substation DC power supply operation management method based on supercapacitor energy storage according to claim 1 is characterized in that: The DC protection device based on supercapacitor energy storage includes: a charging unit, a capacitor module, and a boost unit; The charging unit is used to charge the supercapacitor module; The capacitor module is connected in parallel to the DC bus, and the capacitor module is connected in parallel first and then in series; The boost unit is used to boost the voltage output by the capacitor module to meet the DC bus requirement.

3. The substation DC power supply operation management method based on supercapacitor energy storage according to claim 1 is characterized in that: The method of comparing the characteristic parameter timing matrix of all supercapacitors includes: Obtain the voltage, current, and temperature time series data of each supercapacitor during the historical charging process; Extract the change trend characteristics of the voltage time series data of a single supercapacitor during multiple charging processes; based on the change trend characteristics of the voltage time series data, extract C supercapacitors with large performance changes represented by the voltage time series data to form a supercapacitor set C1; Based on the same idea, C supercapacitors with large performance changes represented by current time series data are extracted to form supercapacitor set C2; multiple supercapacitors with large performance changes represented by temperature time series data are extracted to form supercapacitor set C3; At least one second warning supercapacitor is obtained based on the supercapacitors in the supercapacitor sets C1, C2, and C3.

4. The substation DC power supply operation management method based on supercapacitor energy storage according to claim 3 is characterized in that: Extract the changing trend characteristics of the voltage time series data of a single supercapacitor during multiple charging processes, including: The change curve of the voltage time series data during the first charging process is used as the basic curve; The difference between the voltage time series data of each remaining charging process and the voltage time series data of the first charging process is calculated respectively and accumulated to obtain a first accumulated sum; respectively calculating the difference of the voltage time series data in two adjacent charging processes and accumulating them to obtain a second cumulative sum; The first accumulated sum and the second accumulated sum are used as the variation trend characteristics of the voltage time series data in multiple charging processes of a single super capacitor.

5. The method for managing the operation of a DC power supply in a substation based on supercapacitor energy storage according to claim 4, characterized in that: The method of extracting C supercapacitors with large performance changes represented by the voltage time series data based on the change trend characteristics of the voltage time series data to form a supercapacitor set C1 includes: Based on the change trend characteristics of the voltage time series data, the performance change value of the supercapacitor is calculated, and the performance change value is sorted based on the size of the performance change value and the supercapacitors corresponding to the performance change values ​​whose performance change values ​​are greater than the first preset threshold are obtained to form a supercapacitor set C1 sorted by the size of the performance change value; wherein, based on the change trend characteristics of the voltage time series data, the performance change value of the supercapacitor is calculated, including: calculating the performance change value of the supercapacitor based on the product of the first cumulative sum and the second cumulative sum; or Based on the change trend characteristics of the voltage time series data, i.e., the vector composed of the first cumulative sum and the second cumulative sum, clustering is performed to obtain multiple change trend characteristic clusters; For multiple clusters, a supercapacitor set C1 is formed based on supercapacitors corresponding to the cluster with the largest first cumulative sum average or the largest second cumulative sum average in the clusters.

6. The method for managing the operation of a DC power supply in a substation based on supercapacitor energy storage according to claim 1, characterized in that: The supercapacitor usage performance consumption progress corresponding to the supercapacitor analysis corresponding to the characteristic parameter timing matrix representing the abnormality includes: For the early warning supercapacitor, a constant current discharge process is performed regularly to collect the voltage, current and time data of the constant current discharge process; Based on the constant current discharge process data, the supercapacitor equivalent circuit parameters are calculated to obtain the supercapacitor equivalent series resistance and capacitance; Based on the equivalent circuit parameters obtained from multiple constant current discharge processes of the supercapacitor, a time variation curve of the equivalent series internal resistance and capacitance of the supercapacitor is obtained; Based on the time variation curve of the equivalent circuit parameters, the performance of the supercapacitor is monitored. When the capacitance of the equivalent circuit parameters decreases and / or the equivalent series resistance increases, it is determined that the performance of the supercapacitor has decreased. The performance degradation of the supercapacitor is determined based on the capacitance reduction and / or equivalent series resistance increase of the equivalent circuit parameters and the factory initial equivalent circuit parameters of the supercapacitor.

7. The method for managing the operation of a DC power supply in a substation based on supercapacitor energy storage according to claim 6, characterized in that: Also includes: Based on the time variation curve of equivalent circuit parameters, analyze the time point of abnormal variation; The cause of the abnormal change is determined based on the voltage, current and temperature monitoring data of the supercapacitor at the time of the abnormal change.

8. The substation DC power supply operation and management system based on supercapacitor energy storage is characterized by: include: A DC protection device, the DC protection device is a DC protection device based on supercapacitor energy storage, and the DC protection device is connected in parallel to the DC bus; the DC protection device provides two working modes: one working mode is: when the AC power is normally supplied, the DC protection device supplies power to the load while replenishing the discharged electric energy to the supercapacitor; the other working mode is: when the AC power cannot be supplied normally, the DC protection module is used to provide power supply requirements for the DC bus; and when the voltage of the supercapacitor cannot meet the requirements of the DC bus, the voltage of the supercapacitor is increased by the boost unit to meet the requirements of the DC bus; The operation management method implemented by the operation management system includes: obtaining the voltage, current and temperature data of the supercapacitor corresponding to the sampling time point during the charging process; the charging process adopts constant current charging to a preset voltage first, and then constant voltage charging based on the preset voltage until the current is less than a preset value, and determining that the charging process is over; based on the voltage, current and temperature data during the charging process, voltage timing data, current timing data and temperature timing data are formed, and a supercapacitor characteristic parameter timing matrix is ​​formed based on the voltage timing data, current timing data and temperature timing data; comparing the characteristic parameter timing matrices of all supercapacitors, screening out the characteristic parameter timing matrices representing abnormalities and their corresponding supercapacitors; for the supercapacitor corresponding to the characteristic parameter timing matrix representing the abnormality, analyzing the usage performance consumption progress of the corresponding supercapacitor; The method for comparing the characteristic parameter timing matrix of all supercapacitors includes: based on the voltage timing data of all supercapacitors, obtaining A first supercapacitors with a shorter service time as first reference capacitors, and obtaining the voltage timing data of the first reference capacitors; sorting the A first supercapacitors and their voltage timing data based on the voltage rise rate in the constant current charging stage in the voltage timing data of the first reference capacitors, removing isolated timing data, and calculating the weight of the remaining timing data based on the inverse of the voltage rise rate; calculating the similarity based on the voltage timing data of all supercapacitors and the voltage timing data of the first reference capacitor, wherein the similarity is calculated based on A weighted calculation is performed on the corresponding weights of the A first supercapacitors; the usage performance of all supercapacitors is sorted based on the similarity, and the supercapacitor with greater similarity has better performance; B supercapacitors with poor supercapacitor performance characterized by voltage timing data are obtained to form a supercapacitor set B1; based on the same idea, B supercapacitors with poor supercapacitor performance from current timing data are obtained to form a supercapacitor set B2, and B supercapacitors with poor supercapacitor performance characterized by temperature timing data are obtained to form a supercapacitor set B3; based on the supercapacitors in the above supercapacitor sets B1, B2, and B3, at least one supercapacitor is obtained as the first warning supercapacitor.

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