Reactive power fine compensation method and intelligent capacitor device

Abstract

The invention provides a reactive power fine compensation method and an intelligent capacitor device. The intelligent capacitor device is used for providing reactive compensation for a target power system; the intelligent capacitor device comprises a multi-channel capacitor bank and a processor, the capacitor bank comprises a plurality of capacitors, the capacitors correspond to fling-cut switches, and the method configures device fling-cut parameters and capacitor fling-cut modes of the intelligent capacitor device; during automatic switching, acquiring a system power parameter of the target power system in the current round and a device power parameter of the intelligent capacitor device; based on a switching power threshold in the system power parameter, the device power parameter and the device switching parameter, determining a power compensation adjustment result, determining a capacitor switching result, and determining a target capacitor in a target capacitor bank to be switched from the capacitor bank; the target capacitor is switched when the preset switching time interval in the switching parameters of the device is reached, and the fine switching compensation effect is improved by adopting less compensation and multi-switching.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a reactive power refined compensation method and an intelligent capacitor device. Background Art

[0002] In the user distribution network, there are a large number of inductive loads such as motors, transformers, reactors, fluorescent lamps, etc., and these loads require a large amount of capacitive reactive power to compensate. Existing reactive compensation devices are mainly divided into two categories: passive and active compensation. Passive compensation devices are mainly FC fixed compensation and static VAR compensator (SVC). Among them, capacitors are the main compensation power devices. However, conventional reactive compensation systems generally use a single capacitor (5-30kvar) of the same capacity. The large differential capacity may be too large or over-compensated or under-compensated, and the compensation accuracy is low. In addition, the reactive power in the user distribution network changes due to changes in working conditions and loads. The existing reactive compensation system only compensates for the user distribution network, rather than for specific reactive power requirements, which further leads to low compensation accuracy. Summary of the invention

[0003] In view of this, the purpose of this application is to provide a reactive power fine-grained compensation method and an intelligent capacitor device, which, through a polling switching strategy and the principle of less capacitor compensation and more switching, performs fine-grained compensation for the reactive power of the target power system.

[0004] A method for fine-grained reactive power compensation provided in an embodiment of the present application is applied to an intelligent capacitor device, which is used to provide reactive power compensation for a target power system; the intelligent capacitor device comprises: a multi-channel capacitor bank and a processor, each capacitor bank comprises a plurality of capacitors and a switching switch corresponding to each capacitor, and a control input end of the switching switch is connected to a control output end of the processor;

[0005] The method comprises:

[0006] Based on the properties and / or business requirements of the target power system, configuring the device switching parameters of the intelligent capacitor device and the capacitor switching mode in the device switching parameters; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching;

[0007] When the capacitor switching mode is automatic switching, the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device are obtained; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power;

[0008] The processor determines a power compensation adjustment result based on a system power parameter, a device power parameter and the switching power threshold of the target power system in the current round, and determines a capacitor switching result of the intelligent capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and capacitor state maintenance corresponding to maintaining power compensation;

[0009] The processor determines a target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor group;

[0010] When the time interval between the last switching round reaches the preset switching time interval, the processor switches the target capacitor through the switching switch of the target capacitor, and enters the next switching round after the switching is completed.

[0011] In some embodiments, in the reactive power refined compensation method, the types of the multi-channel capacitor group include a separate compensation capacitor group and a common compensation capacitor group; the multiple capacitors in the separate compensation capacitor group correspond to multiple phases of the target power system based on phase-to-ground separate compensation; the multiple capacitors in the common compensation capacitor group correspond to three phases of the target power system based on phase-to-phase common compensation;

[0012] The processor determines a target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor group, including:

[0013] The processor determines whether the three phases of the target power system meet the preset balance condition based on the system power parameters of the target power system in the current round, and determines the three-phase balance judgment result;

[0014] Based on the three-phase balance judgment result, determine the target category of the target capacitor group to be switched; wherein, when the three-phase balance judgment result is that the three-phase is balanced, the category of the corresponding capacitor group is a common compensation capacitor group; when the three-phase balance judgment result is that the three-phase is unbalanced, the category of the corresponding capacitor group is a separate compensation capacitor group;

[0015] Based on the switching state of the capacitor group and the capacitor switching result of the next round, the target capacitor group to be switched is determined from the capacitor groups of the target category according to the polling order of the preset capacitor group, and the target capacitor to be switched in the target capacitor group is determined.

[0016] In some embodiments, in the reactive power refined compensation method, based on the switching state of the capacitor bank and the capacitor switching result of the next round, according to the polling order of the preset capacitor bank, the target capacitor bank to be switched is determined from the capacitor banks of the target category, including:

[0017] Determining a capacitor bank in a compensation state based on the switching state of the capacitor bank;

[0018] Based on the capacitor switching result of the current round, the capacitor bank to be put into operation in the current round is determined in sequence from the capacitor banks of the target category after the capacitor bank put into operation for compensation in the current round according to the polling order of the preset capacitor banks;

[0019] The capacitor bank in the compensation state is removed, and the capacitor bank to be put into use in the current round is put into use.

[0020] In some embodiments, in the reactive power refined compensation method, determining the target category of the target capacitor bank to be switched based on the three-phase balance judgment result includes:

[0021] When the three-phase balance judgment result is three-phase balance and the capacitor switching result of the next round is capacitor switching; based on the switching state of the capacitor group, it is judged whether the common compensation capacitor groups are all in the compensation state;

[0022] If so, it is determined that the target category of the target capacitor bank to be switched is a split compensation capacitor bank.

[0023] In some embodiments, in the reactive power refined compensation method, determining the target capacitor to be switched in the target capacitor group includes:

[0024] For the split compensation capacitor group, the target capacitor to be switched in the target capacitor group is determined based on the phase to be compensated; when the three-phase balance judgment result is three-phase balance, the phase to be compensated is three-phase;

[0025] For the common compensation capacitor bank, it is determined that the three-phase capacitors in the target capacitor bank are all target capacitors.

[0026] In some embodiments, in the reactive power refined compensation method, the switching parameters include two sets of switching power thresholds, corresponding to the reactive power in the positive direction and the negative direction of the target power system respectively; the processor determines the power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, and determines the intelligent capacitor device before the capacitor switching result of the current round based on the power compensation adjustment result, and the method further includes:

[0027] Based on the photovoltaic power generation current signal collected by the intelligent capacitor device, determine the direction of the reactive power of the target power system; wherein, if the photovoltaic power generation current signal is collected, determine that the reactive power is negative, and if the photovoltaic power generation current signal is not collected, determine that the reactive power is positive;

[0028] Based on the determination of the direction of reactive power of the target power system, determining a switching power threshold with a matching direction from two sets of switching power thresholds;

[0029] Accordingly, the processor determines a power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, including:

[0030] The processor determines a power compensation adjustment result based on the system power parameters of the target power system in the current round, the device power parameters and the switching power threshold matched with the direction.

[0031] In some embodiments, in the reactive power refined compensation method, the processor determines a power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, and determines the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result, including:

[0032] When the system reactive capacity is less than 0, the system power factor is updated to an opposite number to obtain an updated system power factor;

[0033] When the system active capacity is less than the preset active capacity threshold, or the system active capacity is greater than or equal to the preset active capacity threshold and the system power factor is less than the preset power factor threshold, it is determined that the power compensation adjustment result is to reduce the power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is capacitor removal;

[0034] When the system active capacity is greater than or equal to the preset active capacity threshold, and the system power factor is greater than or equal to the preset power factor threshold and less than the switching power threshold, comparing the device reactive capacity of the smart capacitor device with the system reactive capacity;

[0035] If the reactive capacity of the device is greater than or equal to the reactive capacity of the system, the power compensation adjustment result is determined to be maintaining power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is determined to be maintaining the capacitor state;

[0036] If the reactive capacity of the device is less than the reactive capacity of the system, it is determined whether the three-phase currents of the system current are all greater than the preset current threshold value;

[0037] If not, determining that the power compensation adjustment result is to maintain power compensation, and determining that the capacitor switching result of the intelligent capacitor device in the current round is to maintain the capacitor state;

[0038] If so, it is determined that the power compensation adjustment result is to increase the power compensation, and it is determined that the capacitor switching result of the intelligent capacitor device in the current round is capacitor switching.

[0039] In some embodiments, the reactive power refined compensation method further includes:

[0040] When the capacitor switching mode is manual switching, each capacitor in the multi-channel capacitor group is displayed in the graphical user interface of the terminal device;

[0041] In response to a switching operation for a specific capacitor, generating a switching instruction for the specific capacitor, and sending the switching instruction to a processor of the smart capacitor device;

[0042] The processor of the intelligent capacitor device controls the specific capacitor to perform a switching operation based on the switching instruction.

[0043] In some embodiments, in the reactive power refined compensation method, the configuration device switching parameters include:

[0044] Displaying a reactive power configuration control in a graphical user interface of a terminal device; the reactive power configuration control includes a 4-quadrant indicator symbol;

[0045] Based on the reactive power configuration control, two sets of switching power thresholds corresponding to reactive power in positive and negative directions of the target power system are configured with reference to the four-quadrant indicator symbol;

[0046] Among them, the two sets of switching power thresholds corresponding to the reactive power in the positive direction of the target power system are applicable to the 1st and 4th quadrant compensation modes; the two sets of switching power thresholds corresponding to the reactive power in the negative direction of the target power system are applicable to the 2nd and 3rd quadrant compensation modes.

[0047] In some embodiments, a smart capacitor device is further provided, the smart capacitor device is used to provide reactive power compensation for a target power system; the smart capacitor device comprises: a multi-channel capacitor bank and a processor, each capacitor bank comprises a plurality of capacitors and a switching switch corresponding to each capacitor, and a control input end of the switching switch is connected to a control output end of the processor;

[0048] The smart capacitor device is used to configure the device switching parameters of the smart capacitor device and the capacitor switching mode in the device switching parameters based on the properties and / or business requirements of the target power system; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching;

[0049] The intelligent capacitor device is used to obtain the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device when the capacitor switching mode is automatic switching; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power;

[0050] The processor in the smart capacitor device is used to determine the power compensation adjustment result based on the system power parameter of the target power system in the current round, the device power parameter and the switching power threshold, and determine the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and maintaining capacitor state corresponding to maintaining power compensation;

[0051] The processor in the intelligent capacitor device is used to determine the target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determine the target capacitor to be switched in the target capacitor group;

[0052] The processor in the intelligent capacitor device is used to switch the target capacitor through the switching switch of the target capacitor when the time interval between the previous switching round reaches the preset switching time interval, and enter the next switching round after the switching is completed.

[0053] In an embodiment of the present application, a method for fine-grained reactive power compensation and an intelligent capacitor device are provided; the intelligent capacitor device is used to provide reactive power compensation for a target power system; the intelligent capacitor device includes: a multi-channel capacitor group and a processor, each capacitor group includes a plurality of capacitors and a switching switch corresponding to each capacitor, and the control input end of the switching switch is connected to the control output end of the processor; based on the attributes and / or business requirements of the target power system, the device switching parameters of the intelligent capacitor device and the capacitor switching mode in the device switching parameters are configured; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching; when the capacitor switching mode is automatic switching, the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device are obtained; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power; the processor is based on the system power parameters, device power parameters and The switching power threshold determines the power compensation adjustment result, and determines the capacitor switching result of the intelligent capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to the increase of power compensation, capacitor removal corresponding to the decrease of power compensation, and capacitor state corresponding to the maintenance of power compensation; the processor determines the target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the current round, and determines the target capacitor to be switched in the target capacitor group; when the time interval between the switching of the previous round reaches the preset switching time interval, the processor switches the target capacitor through the switching switch of the target capacitor, and enters the next round of switching after the switching is completed; in this way, the polling switching is set according to a specific mode, and in each round of polling switching, the demand for reactive compensation is comprehensively judged according to parameters such as voltage, current, power factor, reactive power, and active power, and automatic compensation is performed to avoid switching oscillation and reduce compensation dead zone, and the principle of less compensation and more switching is adopted to make the switching compensation fine effect good, realize refined multi-level compensation, and improve compensation accuracy.

[0054] Furthermore, based on the design of the separate compensation capacitor group and the common compensation capacitor group, reactive power compensation and three-phase unbalanced current regulation are taken into consideration, thereby further improving the refinement of reactive power compensation.

[0055] Furthermore, when the common compensation capacitor group is insufficient, the separate compensation capacitor groups are put into use at the same time to provide reactive power compensation for the three-phase circuits of the target power system at the same time, giving full play to the role of the capacitors and making the compensation strategy more flexible.

[0056] Furthermore, the capacitor group is replaced in each polling, and the capacitors that are already in use are replaced with capacitors that are not in use, thereby extending the life of the capacitors, preventing a group of capacitors from failing due to long-term operation and affecting the compensation effect, and reducing the difficulty of maintenance.

[0057] Furthermore, based on the four-quadrant switching control, the forward and reverse reactive power compensation of the photovoltaic power system can be realized; at the sixth level, remote control and other controls can be realized based on the terminal equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 A method flow chart of the reactive power refined compensation method according to an embodiment of the present application is shown;

[0060] Figure 2 The separate compensation capacitor bank and the common compensation capacitor bank displayed on the graphical user interface of the terminal device according to the embodiment of the present application are shown;

[0061] Figure 3 The circuit schematic diagram of the smart capacitor device according to the embodiment of the present application is shown;

[0062] Figure 4 Another circuit schematic diagram of the smart capacitor device according to an embodiment of the present application is shown;

[0063] Figure 5 A schematic diagram of an interface for viewing real-time data of the smart capacitor device in the terminal device is shown;

[0064] Figure 6 A schematic diagram of an interface for viewing and setting parameters of the smart capacitor device in the terminal device is shown;

[0065] Figure 7 A schematic diagram of a display module and an operation module of the smart capacitor device is shown;

[0066] Figure 8 Another flow chart of the reactive power refined compensation method is shown. DETAILED DESCRIPTION

[0067] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0068] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0069] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0070] In the user distribution network, there are a large number of inductive loads such as motors, transformers, reactors, fluorescent lamps, etc., and these loads require a large amount of capacitive reactive power to compensate. Existing reactive compensation devices are mainly divided into two categories: passive and active compensation. Passive compensation devices are mainly FC fixed compensation and static VAR compensator (SVC). Among them, capacitors are the main compensation power devices. However, conventional reactive compensation systems generally use a single capacitor (5-30kvar) of the same capacity. The large differential capacity may be too large or over-compensated or under-compensated, and the compensation accuracy is low. In addition, the reactive power in the user distribution network changes due to changes in working conditions and loads. The existing reactive compensation system only compensates for the user distribution network, rather than for specific reactive power requirements, which further leads to low compensation accuracy.

[0071] Based on this, in an embodiment of the present application, a method for fine-grained reactive power compensation and an intelligent capacitor device are provided; the intelligent capacitor device is used to provide reactive power compensation for a target power system; the intelligent capacitor device includes: a multi-channel capacitor group and a processor, each capacitor group includes multiple capacitors and a switching switch corresponding to each capacitor, and the control input end of the switching switch is connected to the control output end of the processor; based on the attributes and / or business requirements of the target power system, the device switching parameters of the intelligent capacitor device and the capacitor switching mode in the device switching parameters are configured; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching; when the capacitor switching mode is automatic switching, the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device are obtained; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power; the processor is based on the system power parameters of the target power system in the current round, the device power parameters The power compensation adjustment result is determined based on the power compensation adjustment result, and the capacitor switching result of the intelligent capacitor device in the current round is determined based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to the increase of power compensation, capacitor removal corresponding to the decrease of power compensation, and capacitor state corresponding to the maintenance of power compensation; the processor determines the target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the current round, and determines the target capacitor to be switched in the target capacitor group; when the time interval between the switching of the previous round reaches the preset switching time interval, the processor switches the target capacitor through the switching switch of the target capacitor, and enters the next round of switching after the switching is completed; in this way, the polling switching is set according to a specific mode, and the demand for reactive compensation is comprehensively judged according to parameters such as voltage and current, power factor, reactive power, and active power in each round of polling switching, and automatic compensation is performed to avoid switching oscillation and reduce compensation dead zone, and the principle of less compensation and more switching is adopted to make the switching compensation fine effect good, realize refined multi-level compensation, and improve compensation accuracy.

[0072] Please refer to Figure 1 , Figure 1 A method flow chart of a method for fine-grained reactive power compensation according to an embodiment of the present application is shown; the method for fine-grained reactive power compensation is applied to an intelligent capacitor device, and the intelligent capacitor device is used to provide reactive power compensation for a target power system; the intelligent capacitor device comprises: a multi-channel capacitor bank and a processor, each capacitor bank comprises a plurality of capacitors and a switching switch corresponding to each capacitor, and a control input end of the switching switch is connected to a control output end of the processor; the method comprises the following steps S101-S105:

[0073] S101, based on the properties and / or business requirements of the target power system, configuring the device switching parameters of the smart capacitor device and the capacitor switching mode in the device switching parameters; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching;

[0074] S102, when the capacitor switching mode is automatic switching, obtaining the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power;

[0075] S103, the processor determines a power compensation adjustment result based on the system power parameter, device power parameter and the switching power threshold of the target power system in the current round, and determines a capacitor switching result of the intelligent capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and capacitor state maintenance corresponding to maintaining power compensation;

[0076] S104, the processor determines a target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor group;

[0077] S105: When the time interval between the last switching round reaches the preset switching time interval, the processor switches the target capacitor through the switching switch of the target capacitor, and enters the next switching round after the switching is completed.

[0078] In an embodiment of the present application, the categories of the multi-channel capacitor group include separate compensation capacitor groups and common compensation capacitor groups; the multiple capacitors in the separate compensation capacitor group correspond to multiple phases of the target power system based on phase-to-ground compensation; the multiple capacitors in the common compensation capacitor group correspond to three phases of the target power system based on phase-to-phase compensation.

[0079] Common compensation refers to the use of three-phase capacitors to compensate the entire three-phase circuit simultaneously; separate compensation refers to the use of single-phase capacitors to compensate the A, B, and C phases independently.

[0080] Please refer to Figure 2 , Figure 2 The graphical user interface of the terminal device shows the separate compensation capacitor bank and the common compensation capacitor bank. Figure 2As shown, one of the separate compensation capacitor groups may include one or more capacitor groups; one of the common compensation capacitor groups may include one or more capacitor groups.

[0081] It should be noted that the capacitance of the capacitors in the multi-way capacitor group can be equal or unequal, and the multi-way capacitor group can be put into use together to form a multi-circuit step-type compensation capacity. In the embodiment of the present application, by reasonably designing the capacitance of the capacitors in the multi-way capacitor group, it is ensured that the small step difference accuracy of the compensation capacity at different levels reaches 2.5Kvar, the compensation ladder is small, and the principle of less compensation and more cutting is adopted to achieve a good switching compensation fine effect.

[0082] As an example only, the smart capacitor device includes 36 capacitor banks.

[0083] In terms of hardware, the switching switches corresponding to each capacitor in the intelligent capacitor device adopt a synchronous composite switch group, which has the advantage of realizing zero-crossing switching through the coding switch, achieving the functions of no inrush current, no arc light, and no harmonic pollution, and is suitable for refined multi-stage compensation.

[0084] Exemplarily, the switching switch may be a relay.

[0085] In some embodiments, each switching switch corresponds to a switching status indicator light, which displays the switching status of the corresponding capacitor.

[0086] The intelligent capacitor device also includes a component incoming switch and a surge protection, which organically combines the component incoming switch, surge protection and intelligent capacitor in a conventional capacitor cabinet, modularizes the reactive power compensation unit, greatly simplifies and facilitates the design and assembly of the complete set of equipment, reduces the overall cost, and is also convenient for the subsequent operation and maintenance of the equipment.

[0087] Please refer to Figure 3 and Figure 4 , Figure 3 A circuit schematic diagram of the smart capacitor device according to an embodiment of the present application is shown. Figure 4 Another circuit schematic diagram of the smart capacitor device described in the embodiment of the present application is shown; Figure 3 As shown, the intelligent capacitor device is arranged between the power supply side and the load of the target power system; the intelligent capacitor device collects the current signal of the target power system through the current transformer to obtain the system power parameter of the target power system; the processor controls the separate compensation capacitor group and / or the common compensation capacitor group to be put into the target power system to compensate the reactive power of the target power system; specifically, the separate compensation capacitor and the common compensation capacitor group are as follows Figure 4 As shown, the separate compensation capacitors are connected to the corresponding phases, and the common compensation capacitors are connected between phases.

[0088] In the step S101, based on the properties and / or business requirements of the target power system, the device switching parameters of the smart capacitor device and the capacitor switching mode in the device switching parameters are configured.

[0089] The capacitor switching mode includes manual switching and automatic switching. The manual switching is suitable for special situations (such as automatic switching failure), and the automatic switching is to automatically determine and adjust the capacitance value of the capacitor according to the real-time parameters of the target power system, such as voltage, current and power factor.

[0090] The capacitor switching refers to the switching on and off of the capacitor.

[0091] It should be noted that, in addition to the preset switching time interval and switching power threshold, the switching parameters of the smart capacitor device also include other parameters, which will not be described one by one here.

[0092] Please refer to Figure 8 , Figure 8 Another flow chart of the reactive power refined compensation method is shown; Figure 8 As shown, configuring the device switching parameters of the smart capacitor device and the capacitor switching mode in the device switching parameters based on the properties and / or business requirements of the target power system includes:

[0093] When the intelligent capacitor device is powered on, the power factor default value COS of the set switching power threshold is checked; if the power factor default value COS is within the first preset range, the switching power threshold COS is set set The setting value is equal to the power factor default value COS, otherwise, the switching power threshold COS set is a first specified value; exemplarily, the first preset range is [0.9, 1]; the first specified value is 0.94.

[0094] Check the setting value T of the preset switching time interval in the intelligent capacitor device. If the preset switching time interval T is within the second preset range, set the preset switching time interval T set Equal to T, otherwise, the preset switching time interval T set The second specified value.

[0095] That is, when the user sets the preset switching time interval and switching power threshold, the intelligent capacitor device automatically checks whether the preset switching time interval and switching power threshold set by the user are reasonable after powering on, and automatically adjusts them to the specified values ​​if they are unreasonable.

[0096] The automatic adjustment of the parameters ensures that the device can operate within a reasonable parameter range, avoids adverse effects on the power system due to improper parameter settings, improves the adaptability and reliability of the device, and contributes to the stable operation of the power system.

[0097] In step S102, when the capacitor switching mode is automatic switching, the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device are obtained; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power.

[0098] After setting the switching parameters of the device, select the capacitor switching mode as automatic or manual. If manual is selected, select the address number of the capacitor, manually issue a switching command to control the capacitor to switch, and the switching status indicator light corresponding to the capacitor will change accordingly.

[0099] If automatic is selected, the system power parameters of the target power system in the current round and the device power parameters of the smart capacitor device are automatically obtained, and subsequent steps are performed.

[0100] Specifically, in some embodiments, manually issuing a switching command to control the capacitor to switch includes:

[0101] When the capacitor switching mode is manual switching, each capacitor in the multi-channel capacitor group is displayed in the graphical user interface of the terminal device;

[0102] In response to a switching operation for a specific capacitor, generating a switching instruction for the specific capacitor, and sending the switching instruction to a processor of the smart capacitor device;

[0103] The processor of the intelligent capacitor device controls the specific capacitor to perform a switching operation based on the switching instruction.

[0104] The terminal device may be a mobile phone or a matching handheld terminal, computer or other device.

[0105] In some embodiments, the intelligent capacitor device is also provided with a communication module, through which the terminal device is connected to remotely control switching, view the device operation status and real-time data, view and modify the setting parameters, so that on-site operation and maintenance can be remotely operated without opening the device, which greatly reduces the workload of operation and maintenance and achieves truly intelligent operation and maintenance.

[0106] Exemplarily, the intelligent capacitor device is provided with an RS485 communication interface to realize remote operation and maintenance function.

[0107] Exemplarily, the smart capacitor device is provided with a Wifi module and a Bluetooth module, and can be remotely switched, the device operation status and real-time data can be viewed, and the set value can be viewed and modified through a matching handheld terminal near the device (for example, within 10m).

[0108] Please refer to Figure 5 and Figure 6 , Figure 5 A schematic diagram of an interface for viewing real-time data of the smart capacitor device in the terminal device is shown; Figure 6 A schematic diagram of an interface for viewing and setting parameters of the smart capacitor device in the terminal device is shown.

[0109] In some embodiments, the smart capacitor device includes a display module and an operation module for realizing local display and local operation. Figure 7 The display module adopts a digital tube display screen to display the current, voltage, active power, reactive power and other electric energy parameters of the intelligent capacitor device; the control operation for the capacitor group is realized through the operation module, and the control operation includes input, removal, confirmation and switching buttons.

[0110] Because the intelligent capacitor device is centralized compared to the traditional intelligent capacitor, a digital tube display screen is used on the intelligent capacitor device to replace various instruments in the original ordinary incoming line cabinet to realize intelligent integrated on-site display.

[0111] Exemplarily, the process of implementing the control operation on the capacitor bank through the operation module is described in detail below:

[0112] Press and hold the switch key for 3 seconds to enter the switching state: 1. The switching state indicator light flashes; 2. The equipment changes to manual mode, and the cursor of the corresponding switching relay flashes. Click the switching state key to switch the switching relay. After switching to the switching relay, you can click to switch on or off. Click the confirmation key to display them in turn (but the switching state indicator light keeps flashing). Press and hold the switch key for 3 seconds to exit the switching state: after exiting the switching state, the switching state indicator light does not flash and the equipment changes to automatic mode.

[0113] Click the confirmation button to switch the following four parameters in turn: 1. CT ratio setting; 2. GY overvoltage value setting; 3. qY undervoltage value setting; 4. Preset switching time interval setting (maximum 18s, minimum 0.5s).

[0114] In some embodiments, the obtaining of the system power parameters of the target power system in the current round and the device power parameters of the smart capacitor device includes:

[0115] When a preset query condition is met, a device query instruction is sent, and based on the return data of the device in response to the device query instruction, the reactive capacity of the device in the device power parameter is determined, and the switching state of the capacitor bank in the device is determined;

[0116] Obtain the system power parameters of the target power system in the current round.

[0117] For details, please refer to Figure 8 When the capacitor switching mode is automatic switching, the intelligent capacitor device detects whether the start signal of the APF in the target power system is working; if the start signal is working, the automatic program is started after a delay of 30s; a timed query command (device query instruction) is sent, for example, once every 0.5s, and a query is made once every 15s for capacitors 0-31; the reactive capacity Q and switching status of the intelligent capacitor device are extracted according to the returned data; the real-time system power factor COS from the APF is queried apf , Active capacity P apf and reactive capacity Q apf .

[0118] In the step S103, the processor determines the power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, and determines the capacitor switching result of the intelligent capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and maintaining capacitor state corresponding to maintaining power compensation.

[0119] Here, the power compensation adjustment result includes increasing power compensation, decreasing power compensation and maintaining power compensation.

[0120] Specifically, the processor determines a power compensation adjustment result based on the system power parameter, the device power parameter and the switching power threshold of the target power system in the current round, and determines the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result, including:

[0121] When the system reactive capacity is less than 0, the system power factor is updated to an opposite number to obtain an updated system power factor;

[0122] When the system active capacity is less than the preset active capacity threshold, or the system active capacity is greater than or equal to the preset active capacity threshold and the system power factor is less than the preset power factor threshold, it is determined that the power compensation adjustment result is to reduce the power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is capacitor removal;

[0123] When the system active capacity is greater than or equal to the preset active capacity threshold, and the system power factor is greater than or equal to the preset power factor threshold and less than the switching power threshold, comparing the device reactive capacity of the smart capacitor device with the system reactive capacity;

[0124] If the reactive capacity of the device is greater than or equal to the reactive capacity of the system, the power compensation adjustment result is determined to be maintaining power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is determined to be maintaining the capacitor state;

[0125] If the reactive capacity of the device is less than the reactive capacity of the system, it is determined whether the three-phase currents of the system current are all greater than the preset current threshold value;

[0126] If not, determining that the power compensation adjustment result is to maintain power compensation, and determining that the capacitor switching result of the intelligent capacitor device in the current round is to maintain the capacitor state;

[0127] If so, it is determined that the power compensation adjustment result is to increase the power compensation, and it is determined that the capacitor switching result of the intelligent capacitor device in the current round is capacitor switching.

[0128] For example, the preset active capacity threshold is 7.5KW, that is, the active capacity P is determined apf Is it greater than or equal to 7.5KW?

[0129] Exemplarily, the preset power factor threshold is approximately 0.2.

[0130] Exemplarily, the preset current threshold is 20A.

[0131] like Figure 8 As shown in the figure, after determining whether the capacitor is switched on or off, query the time interval t with the last switching on. When t ≥ T set , capacitor is put in or capacitor is removed.

[0132] In step S104, the processor determines a target capacitor bank to be switched from the capacitor bank based on the switching state of the capacitor bank and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor bank.

[0133] The processor determines the target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round. Specifically, the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and maintaining capacitor state corresponding to maintaining power compensation. The capacitor input determines to increase one or more target capacitor groups to increase the compensation capacity, the capacitor removal determines to remove one or more target capacitor groups to reduce the compensation capacity, and the maintaining capacitor state maintains the compensation capacity.

[0134] Add one or more target capacitor groups to increase the compensation capacity, that is, the compensation capacity of the smart capacitor device is increased by one level; remove one or more target capacitor groups to reduce the compensation capacity, that is, the compensation capacity of the smart capacitor device is reduced by one or more levels.

[0135] In the embodiment of the present application, a group of target capacitor banks is added or removed in one round, and refined reactive power compensation for the specific working conditions of the target power system is achieved through adjustment in multiple rounds. Since one round is a few seconds (usually 5-15s), the working condition changes of the target power system can be detected in time and refined compensation can be performed.

[0136] It should be noted that if the capacity and number of capacitors to be invested are calculated directly based on the compensation capacity required by the target power system, the algorithm will be more complicated. Due to the complexity of the target power system, the load in the power system is dynamically changing and may be affected by various external factors, such as weather, equipment failure, etc.; and the calculation process needs to consider many factors, such as the nonlinear characteristics of the capacitor and the harmonic content of the power system. The calculation is very complex, resulting in a long response time, and the calculation results often have a certain deviation from the actual operating conditions, which may lead to inaccurate switching of the capacitor group, thereby reducing the compensation accuracy.

[0137] The refined compensation method described in the embodiment of the present application adopts a method of multiple rounds of small-scale compensation, adopts the principle of less compensation and more cutting, and makes adjustments based on the actual situation of compensation, thereby improving the refined compensation effect.

[0138] In the refined compensation method described in the embodiment of the present application, based on the design of the separate compensation capacitor group and the common compensation capacitor group, reactive power compensation and three-phase unbalanced current regulation are taken into account, thereby further improving the refinement of reactive power compensation.

[0139] Specifically, the processor determines a target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor group, including:

[0140] The processor determines whether the three phases of the target power system meet the preset balance condition based on the system power parameters of the target power system in the current round, and determines the three-phase balance judgment result;

[0141] Based on the three-phase balance judgment result, determine the target category of the target capacitor group to be switched; wherein, when the three-phase balance judgment result is that the three-phase is balanced, the category of the corresponding capacitor group is a common compensation capacitor group; when the three-phase balance judgment result is that the three-phase is unbalanced, the category of the corresponding capacitor group is a separate compensation capacitor group;

[0142] Based on the switching state of the capacitor group and the capacitor switching result of the next round, the target capacitor group to be switched is determined from the capacitor groups of the target category according to the polling order of the preset capacitor group, and the target capacitor to be switched in the target capacitor group is determined.

[0143] Based on the three-phase balance judgment result, determining the target category of the target capacitor bank to be switched includes:

[0144] When the three-phase balance judgment result is three-phase balance and the capacitor switching result of the next round is capacitor switching; based on the switching state of the capacitor group, it is judged whether the common compensation capacitor groups are all in the compensation state;

[0145] If so, it is determined that the target category of the target capacitor bank to be switched is a split compensation capacitor bank.

[0146] That is to say, when the common compensation capacitor group is insufficient, the separate compensation capacitor groups are put into operation at the same time to provide reactive power compensation for the three-phase circuits of the target power system.

[0147] In the embodiment of the present application, since multiple capacitor banks are provided, and in each polling, whether it is the capacitor bank that needs to be increased or the capacitor bank that needs to be reduced, the capacitor bank can be replaced at the same time, and the capacitor that has been put into use can be replaced with the capacitor that has not been put into use, thereby extending the life of the capacitor. Moreover, the capacitor in the embodiment of the present application realizes zero-crossing switching through the coding switch, and there is no inrush current when it is put into use, no arc light when it is cut off, and no harmonic pollution when it is switched. The switching detection of the entire device is based on polling detection, so high-frequency switching can be performed without polluting the power system.

[0148] Specifically, based on the switching state of the capacitor group and the capacitor switching result of the next round, according to the polling order of the preset capacitor group, the target capacitor group to be switched is determined from the capacitor groups of the target category, including:

[0149] Determining a capacitor bank in a compensation state based on the switching state of the capacitor bank;

[0150] Based on the capacitor switching result of the current round, the capacitor bank to be put into operation in the current round is determined in sequence from the capacitor banks of the target category after the capacitor bank put into operation for compensation in the current round according to the polling order of the preset capacitor banks;

[0151] The capacitor bank in the compensation state is removed, and the capacitor bank to be put into use in the current round is put into use.

[0152] Combination Figure 2, the polling order of the capacitor group preset by the common compensation capacitor group is AB1 / BC1 / CA1, AB2 / BC2 / CA2, AB3 / BC3 / CA3, AB4 / BC4 / CA4; based on the switching state of the capacitor group, the capacitor group in the compensation state is determined to be AB1 / BC1 / CA1, and when the capacitor switching result of the next round is to maintain the capacitor state, AB2 / BC2 / CA2 is determined to be the capacitor group to be put into use in the current round, AB1 / BC1 / CA1 is removed, and AB2 / BC2 / CA2 is put into use.

[0153] For another example, based on the switching state of the capacitor group, it is determined that the capacitor group in the compensation state is AB1 / BC1 / CA1. When the capacitor switching result of the current round is to put the capacitor into operation, AB2 / BC2 / CA2 and AB3 / BC3 / CA3 are determined as the capacitor groups to be put into operation in the current round; AB1 / BC1 / CA1 is cut off, and AB2 / BC2 / CA2 and AB3 / BC3 / CA3 are put into operation.

[0154] For another example, based on the switching status of the capacitor groups, it is determined that the capacitor groups in the compensation state are AB1 / BC1 / CA1 and AB2 / BC2 / CA2. When the capacitor switching result of the current round is the removal of the capacitor, AB3 / BC3 / CA3 is determined as the capacitor group to be put into use in the current round; AB1 / BC1 / CA1 and AB2 / BC2 / CA2 are removed, and AB3 / BC3 / CA3 is put into use.

[0155] In the reactive power refined compensation method, determining the target capacitor to be switched in the target capacitor group includes:

[0156] For the split compensation capacitor group, the target capacitor to be switched in the target capacitor group is determined based on the phase to be compensated; when the three-phase balance judgment result is three-phase balance, the phase to be compensated is three-phase;

[0157] For the common compensation capacitor bank, it is determined that the three-phase capacitors in the target capacitor bank are all target capacitors.

[0158] In some embodiments, in the reactive power refined compensation method, the switching parameters include two sets of switching power thresholds, corresponding to the reactive power in the positive direction and the negative direction of the target power system respectively; the processor determines the power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, and determines the intelligent capacitor device before the capacitor switching result of the current round based on the power compensation adjustment result, and the method further includes:

[0159] Based on the photovoltaic power generation current signal collected by the intelligent capacitor device, determine the direction of the reactive power of the target power system; wherein, if the photovoltaic power generation current signal is collected, determine that the reactive power is negative, and if the photovoltaic power generation current signal is not collected, determine that the reactive power is positive;

[0160] Based on the determination of the direction of reactive power of the target power system, determining a switching power threshold with a matching direction from two sets of switching power thresholds;

[0161] Accordingly, the processor determines a power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, including:

[0162] The processor determines a power compensation adjustment result based on the system power parameters of the target power system in the current round, the device power parameters and the switching power threshold matched with the direction.

[0163] Specifically, forward active power: that is, input active power, is the power sent by the power grid to the user, and is the power used by the user; reverse active power: that is, output active power, is the power sent by the user to the power grid, and is the power generated by the user: forward reactive power: that is, input reactive power, is the reactive power sent by the power grid to the user, and is the reactive power used by the user; reverse reactive power: that is, output reactive power, is the reactive power sent by the user to the power grid, and is the reactive power generated by the user.

[0164] Correspondingly, quadrant 1 reactive power: input active power, input reactive power, the user is a resistive and inductive load; quadrant 2 reactive power: output active power, input reactive power, the user load is equivalent to an under-excited generator; quadrant 3 reactive power: output active power, output reactive power, the user load is equivalent to an over-excited generator; quadrant 4 reactive power: input active power, output reactive power, the user is a resistive and capacitive load.

[0165] In the photovoltaic environment, when the photovoltaic panels in the target power system supply power to the grid, the target power system will have reverse reactive power, which requires reverse reactive compensation. The existing technology mainly solves this problem by connecting photovoltaics as loads to current transformers or installing SVG. However, these two methods require on-site power outages, which is very troublesome, and SVG is expensive.

[0166] In the embodiment of the present application, the intelligent capacitor device is equipped with a hardware input terminal that can collect current signals of photovoltaic power generation, selects efficient photovoltaic modules and inverters, as well as reasonable distribution devices and transformers, etc., to collect photovoltaic power generation current signals, thereby determining the direction of reactive power of the target power system; two sets of switching power thresholds are set to adapt to the 2nd and 3rd quadrant compensation modes (negative reactive power compensation modes) and the 1st and 4th quadrant compensation modes (positive reactive power compensation modes), respectively, and support 4-quadrant control switching.

[0167] Specifically, in some embodiments, the configuration device switching parameters include:

[0168] Displaying a reactive power configuration control in a graphical user interface of a terminal device; the reactive power configuration control includes a 4-quadrant indicator symbol;

[0169] Based on the reactive power configuration control, two sets of switching power thresholds corresponding to reactive power in positive and negative directions of the target power system are configured with reference to the four-quadrant indicator symbol;

[0170] Among them, the two sets of switching power thresholds corresponding to the reactive power in the positive direction of the target power system are applicable to the 1st and 4th quadrant compensation modes; the two sets of switching power thresholds corresponding to the reactive power in the negative direction of the target power system are applicable to the 2nd and 3rd quadrant compensation modes.

[0171] Based on this, the reactive power fine compensation method described in the embodiment of the present application, at the first level, is based on the multi-channel capacitor group and polling mechanism in the intelligent capacitor device to achieve more cutting and less compensation, thereby improving the degree of refinement, and the calculation process is simple, and the compensation is more timely and accurate; at the second level, based on the design of the separate compensation capacitor group and the common compensation capacitor group, reactive compensation and three-phase unbalanced current regulation are taken into account, thereby further improving the degree of refinement of reactive compensation; at the third level, when the common compensation capacitor group is not enough, the separate compensation capacitor group is put into use at the same time to provide reactive compensation for the three-phase circuit of the target power system at the same time, give full play to the role of the capacitor, and the compensation strategy is more flexible; at the fourth level, the replacement of the capacitor group is realized at the same time in each polling, and the capacitor that has been put into use is replaced with the capacitor that has not been put into use, thereby extending the life of the capacitor, preventing a group of capacitors from failing in long-term operation and affecting the compensation effect, and reducing the difficulty of maintenance; at the fifth level, based on 4-quadrant switching control, forward and reverse reactive compensation for the power system using photovoltaics is realized; at the sixth level, remote control and other controls are realized based on terminal equipment.

[0172] Based on the same inventive concept, an intelligent capacitor device corresponding to the reactive power fine-grained compensation method is also provided in the embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned reactive power fine-grained compensation method in the embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0173] In some embodiments, a smart capacitor device is provided, which is used to provide reactive power compensation for a target power system; the smart capacitor device comprises: a multi-channel capacitor bank and a processor, each capacitor bank comprises a plurality of capacitors and a switching switch corresponding to each capacitor, and a control input end of the switching switch is connected to a control output end of the processor;

[0174] The smart capacitor device is used to configure the device switching parameters of the smart capacitor device and the capacitor switching mode in the device switching parameters based on the properties and / or business requirements of the target power system; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching;

[0175] The intelligent capacitor device is used to obtain the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device when the capacitor switching mode is automatic switching; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power;

[0176] The processor in the smart capacitor device is used to determine the power compensation adjustment result based on the system power parameter of the target power system in the current round, the device power parameter and the switching power threshold, and determine the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and maintaining capacitor state corresponding to maintaining power compensation;

[0177] The processor in the intelligent capacitor device is used to determine the target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determine the target capacitor to be switched in the target capacitor group;

[0178] The processor in the intelligent capacitor device is used to switch the target capacitor through the switching switch of the target capacitor when the time interval between the previous switching round reaches the preset switching time interval, and enter the next switching round after the switching is completed.

[0179] In some embodiments, in the smart capacitor device, the types of the multi-channel capacitor group include a separate compensation capacitor group and a common compensation capacitor group; the multiple capacitors in the separate compensation capacitor group correspond to multiple phases of the target power system based on phase-to-ground compensation; the multiple capacitors in the common compensation capacitor group correspond to three phases of the target power system based on phase-to-phase compensation;

[0180] The processor, when determining a target capacitor bank to be switched from the capacitor bank based on the switching state of the capacitor bank and the capacitor switching result of the next round, and determining a target capacitor to be switched in the target capacitor bank, is specifically used to:

[0181] The processor determines whether the three phases of the target power system meet the preset balance condition based on the system power parameters of the target power system in the current round, and determines the three-phase balance judgment result;

[0182] Based on the three-phase balance judgment result, determine the target category of the target capacitor group to be switched; wherein, when the three-phase balance judgment result is that the three-phase is balanced, the category of the corresponding capacitor group is a common compensation capacitor group; when the three-phase balance judgment result is that the three-phase is unbalanced, the category of the corresponding capacitor group is a separate compensation capacitor group;

[0183] Based on the switching state of the capacitor group and the capacitor switching result of the next round, the target capacitor group to be switched is determined from the capacitor groups of the target category according to the polling order of the preset capacitor group, and the target capacitor to be switched in the target capacitor group is determined.

[0184] In some embodiments, in the smart capacitor device, the processor determines the target capacitor bank to be switched from the target category of capacitor banks based on the switching state of the capacitor bank and the capacitor switching result of the next round according to the polling order of the preset capacitor bank, and is specifically used to:

[0185] Determining a capacitor bank in a compensation state based on the switching state of the capacitor bank;

[0186] Based on the capacitor switching result of the current round, the capacitor bank to be put into operation in the current round is determined in sequence from the capacitor banks of the target category after the capacitor bank put into operation for compensation in the current round according to the polling order of the preset capacitor banks;

[0187] The capacitor bank in the compensation state is removed, and the capacitor bank to be put into use in the current round is put into use.

[0188] In some embodiments, in the smart capacitor device, the processor, when determining the target category of the target capacitor bank to be switched based on the three-phase balance judgment result, is specifically used to:

[0189] When the three-phase balance judgment result is three-phase balance and the capacitor switching result of the next round is capacitor switching; based on the switching state of the capacitor group, it is judged whether the common compensation capacitor groups are all in the compensation state;

[0190] If so, it is determined that the target category of the target capacitor bank to be switched is a split compensation capacitor bank.

[0191] In some embodiments, in the smart capacitor device, the processor, when determining the target capacitor to be switched in the target capacitor group, is specifically used to:

[0192] For the split compensation capacitor group, the target capacitor to be switched in the target capacitor group is determined based on the phase to be compensated; when the three-phase balance judgment result is three-phase balance, the phase to be compensated is three-phase;

[0193] For the common compensation capacitor bank, it is determined that the three-phase capacitors in the target capacitor bank are all target capacitors.

[0194] In some embodiments, in the smart capacitor device, the switching parameters include two sets of switching power thresholds, which correspond to the reactive power in the positive direction and the negative direction of the target power system respectively; the processor determines the power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, and determines the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result, and the smart capacitor device is also used to:

[0195] Based on the photovoltaic power generation current signal collected by the intelligent capacitor device, determine the direction of the reactive power of the target power system; wherein, if the photovoltaic power generation current signal is collected, determine that the reactive power is negative, and if the photovoltaic power generation current signal is not collected, determine that the reactive power is positive;

[0196] Based on the determination of the direction of reactive power of the target power system, determining a switching power threshold with a matching direction from two sets of switching power thresholds;

[0197] Accordingly, the processor, when determining the power compensation adjustment result based on the system power parameter, the device power parameter and the switching power threshold of the target power system in the next round, is specifically used to:

[0198] The processor determines a power compensation adjustment result based on the system power parameters of the target power system in the current round, the device power parameters and the switching power threshold matched with the direction.

[0199] In some embodiments, in the smart capacitor device, the processor, when determining a power compensation adjustment result based on the system power parameter, the device power parameter and the switching power threshold of the target power system in the next round, and determining the capacitor switching result of the smart capacitor device in the next round based on the power compensation adjustment result, is specifically used to:

[0200] When the system reactive capacity is less than 0, the system power factor is updated to an opposite number to obtain an updated system power factor;

[0201] When the system active capacity is less than the preset active capacity threshold, or the system active capacity is greater than or equal to the preset active capacity threshold and the system power factor is less than the preset power factor threshold, it is determined that the power compensation adjustment result is to reduce the power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is capacitor removal;

[0202] When the system active capacity is greater than or equal to the preset active capacity threshold, and the system power factor is greater than or equal to the preset power factor threshold and less than the switching power threshold, comparing the device reactive capacity of the smart capacitor device with the system reactive capacity;

[0203] If the reactive capacity of the device is greater than or equal to the reactive capacity of the system, the power compensation adjustment result is determined to be maintaining power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is determined to be maintaining the capacitor state;

[0204] If the reactive capacity of the device is less than the reactive capacity of the system, it is determined whether the three-phase currents of the system current are all greater than the preset current threshold value;

[0205] If not, determining that the power compensation adjustment result is to maintain power compensation, and determining that the capacitor switching result of the intelligent capacitor device in the current round is to maintain the capacitor state;

[0206] If so, it is determined that the power compensation adjustment result is to increase the power compensation, and it is determined that the capacitor switching result of the intelligent capacitor device in the current round is capacitor switching.

[0207] In some embodiments, the smart capacitor device is further used for:

[0208] When the capacitor switching mode is manual switching, each capacitor in the multi-channel capacitor group is displayed in the graphical user interface of the terminal device;

[0209] In response to a switching operation for a specific capacitor, generating a switching instruction for the specific capacitor, and sending the switching instruction to a processor of the smart capacitor device;

[0210] The processor of the intelligent capacitor device controls the specific capacitor to perform a switching operation based on the switching instruction.

[0211] In some embodiments, the smart capacitor device, when configuring the switching parameters of the device, is specifically used to:

[0212] Displaying a reactive power configuration control in a graphical user interface of a terminal device; the reactive power configuration control includes a 4-quadrant indicator symbol;

[0213] Based on the reactive power configuration control, two sets of switching power thresholds corresponding to reactive power in positive and negative directions of the target power system are configured with reference to the four-quadrant indicator symbol;

[0214] Among them, the two sets of switching power thresholds corresponding to the reactive power in the positive direction of the target power system are applicable to the 1st and 4th quadrant compensation modes; the two sets of switching power thresholds corresponding to the reactive power in the negative direction of the target power system are applicable to the 2nd and 3rd quadrant compensation modes.

[0215] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0216] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0217] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0218] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a platform server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0219] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for fine reactive power compensation, characterized in that: Applied to an intelligent capacitor device, the intelligent capacitor device is used to provide reactive power compensation for a target power system; the intelligent capacitor device comprises: a multi-channel capacitor bank and a processor, each capacitor bank comprises a plurality of capacitors and a switching switch corresponding to each capacitor, and a control input end of the switching switch is connected to a control output end of the processor; The method comprises: Based on the properties and / or business requirements of the target power system, configuring the device switching parameters of the intelligent capacitor device and the capacitor switching mode in the device switching parameters; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching; When the capacitor switching mode is automatic switching, the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device are obtained; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power; The processor determines a power compensation adjustment result based on a system power parameter, a device power parameter and the switching power threshold of the target power system in the current round, and determines a capacitor switching result of the intelligent capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and capacitor state maintenance corresponding to maintaining power compensation; The processor determines a target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor group; When the time interval between the last switching round reaches the preset switching time interval, the processor switches the target capacitor through the switching switch of the target capacitor, and enters the next switching round after the switching is completed.

2. The reactive power refined compensation method according to claim 1, characterized in that: The types of the multi-channel capacitor group include a separate compensation capacitor group and a common compensation capacitor group; the multiple capacitors in the separate compensation capacitor group correspond to multiple phases of the target power system based on phase-to-ground separate compensation; the multiple capacitors in the common compensation capacitor group correspond to three phases of the target power system based on phase-to-phase common compensation; The processor determines a target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determines a target capacitor to be switched in the target capacitor group, including: The processor determines whether the three phases of the target power system meet the preset balance condition based on the system power parameters of the target power system in the current round, and determines the three-phase balance judgment result; Based on the three-phase balance judgment result, determine the target category of the target capacitor group to be switched; wherein, when the three-phase balance judgment result is that the three-phase is balanced, the category of the corresponding capacitor group is a common compensation capacitor group; when the three-phase balance judgment result is that the three-phase is unbalanced, the category of the corresponding capacitor group is a separate compensation capacitor group; Based on the switching state of the capacitor group and the capacitor switching result of the next round, the target capacitor group to be switched is determined from the capacitor groups of the target category according to the polling order of the preset capacitor group, and the target capacitor to be switched in the target capacitor group is determined.

3. The reactive power refined compensation method according to claim 2, characterized in that: Based on the switching state of the capacitor bank and the capacitor switching result of the next round, the target capacitor bank to be switched is determined from the capacitor banks of the target category according to the polling order of the preset capacitor banks, including: Determining a capacitor bank in a compensation state based on the switching state of the capacitor bank; Based on the capacitor switching result of the current round, the capacitor bank to be put into operation in the current round is determined in sequence from the capacitor banks of the target category after the capacitor bank put into operation for compensation in the current round according to the polling order of the preset capacitor banks; The capacitor bank in the compensation state is removed, and the capacitor bank to be put into use in the current round is put into use.

4. The method for refined reactive power compensation according to claim 2, characterized in that: Based on the three-phase balance judgment result, determining the target category of the target capacitor bank to be switched includes: When the three-phase balance judgment result is three-phase balance and the capacitor switching result of the next round is capacitor switching; based on the switching state of the capacitor group, it is judged whether the common compensation capacitor groups are all in the compensation state; If so, it is determined that the target category of the target capacitor bank to be switched is a split compensation capacitor bank.

5. The method for refined reactive power compensation according to claim 4, characterized in that: Determine the target capacitor to be switched in the target capacitor bank, including: For the split compensation capacitor group, the target capacitor to be switched in the target capacitor group is determined based on the phase to be compensated; when the three-phase balance judgment result is three-phase balance, the phase to be compensated is three-phase; For the common compensation capacitor bank, it is determined that the three-phase capacitors in the target capacitor bank are all target capacitors.

6. The reactive power refined compensation method according to claim 1, characterized in that: The switching parameters include two groups of switching power thresholds, which correspond to reactive power in the positive direction and the negative direction of the target power system respectively; the processor determines the power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, and determines the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result, and the method also includes: Based on the photovoltaic power generation current signal collected by the intelligent capacitor device, determine the direction of the reactive power of the target power system; wherein, if the photovoltaic power generation current signal is collected, determine that the reactive power is negative, and if the photovoltaic power generation current signal is not collected, determine that the reactive power is positive; Based on the determination of the direction of reactive power of the target power system, determining a switching power threshold with a matching direction from two sets of switching power thresholds; Accordingly, the processor determines a power compensation adjustment result based on the system power parameters, device power parameters and the switching power threshold of the target power system in the current round, including: The processor determines a power compensation adjustment result based on the system power parameters of the target power system in the current round, the device power parameters and the switching power threshold matched with the direction.

7. The method for refined reactive power compensation according to claim 1, characterized in that: The processor determines a power compensation adjustment result based on a system power parameter, a device power parameter and the switching power threshold of the target power system in the current round, and determines a capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result, including: When the system reactive capacity is less than 0, the system power factor is updated to an opposite number to obtain an updated system power factor; When the system active capacity is less than the preset active capacity threshold, or the system active capacity is greater than or equal to the preset active capacity threshold and the system power factor is less than the preset power factor threshold, it is determined that the power compensation adjustment result is to reduce the power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is capacitor removal; When the system active capacity is greater than or equal to the preset active capacity threshold, and the system power factor is greater than or equal to the preset power factor threshold and less than the switching power threshold, comparing the device reactive capacity of the smart capacitor device with the system reactive capacity; If the reactive capacity of the device is greater than or equal to the reactive capacity of the system, the power compensation adjustment result is determined to be maintaining power compensation, and the capacitor switching result of the intelligent capacitor device in the current round is determined to be maintaining the capacitor state; If the reactive capacity of the device is less than the reactive capacity of the system, it is determined whether the three-phase currents of the system current are all greater than the preset current threshold value; If not, determining that the power compensation adjustment result is to maintain power compensation, and determining that the capacitor switching result of the intelligent capacitor device in the current round is to maintain the capacitor state; If so, it is determined that the power compensation adjustment result is to increase the power compensation, and it is determined that the capacitor switching result of the intelligent capacitor device in the current round is capacitor switching.

8. The method for refined reactive power compensation according to claim 1, characterized in that: The method further comprises: When the capacitor switching mode is manual switching, each capacitor in the multi-channel capacitor group is displayed in the graphical user interface of the terminal device; In response to a switching operation for a specific capacitor, generating a switching instruction for the specific capacitor, and sending the switching instruction to a processor of the smart capacitor device; The processor of the intelligent capacitor device controls the specific capacitor to perform a switching operation based on the switching instruction.

9. The method for refined reactive power compensation according to claim 1, 6 or 8, characterized in that: The configuration device switching parameters include: Displaying a reactive power configuration control in a graphical user interface of a terminal device; the reactive power configuration control includes a 4-quadrant indicator symbol; Based on the reactive power configuration control, two sets of switching power thresholds corresponding to reactive power in positive and negative directions of the target power system are configured with reference to the four-quadrant indicator symbol; Among them, the two sets of switching power thresholds corresponding to the reactive power in the positive direction of the target power system are applicable to the 1st and 4th quadrant compensation modes; the two sets of switching power thresholds corresponding to the reactive power in the negative direction of the target power system are applicable to the 2nd and 3rd quadrant compensation modes.

10. A smart capacitor device, characterized in that: The intelligent capacitor device is used to provide reactive power compensation for the target power system; the intelligent capacitor device comprises: a multi-channel capacitor bank and a processor, each capacitor bank comprises a plurality of capacitors and a switching switch corresponding to each capacitor, and the control input end of the switching switch is connected to the control output end of the processor; The smart capacitor device is used to configure the device switching parameters of the smart capacitor device and the capacitor switching mode in the device switching parameters based on the properties and / or business requirements of the target power system; the device switching parameters also include a preset switching time interval and a switching power threshold; the capacitor switching mode includes manual switching and automatic switching; The intelligent capacitor device is used to obtain the system power parameters of the target power system in the current round and the device power parameters of the intelligent capacitor device when the capacitor switching mode is automatic switching; the system power parameters include: system power factor, system active capacity, system reactive capacity and system current; the device power parameters include device reactive power; The processor in the smart capacitor device is used to determine the power compensation adjustment result based on the system power parameter of the target power system in the current round, the device power parameter and the switching power threshold, and determine the capacitor switching result of the smart capacitor device in the current round based on the power compensation adjustment result; the capacitor switching result includes: capacitor input corresponding to increasing power compensation, capacitor removal corresponding to reducing power compensation, and maintaining capacitor state corresponding to maintaining power compensation; The processor in the intelligent capacitor device is used to determine the target capacitor group to be switched from the capacitor group based on the switching state of the capacitor group and the capacitor switching result of the next round, and determine the target capacitor to be switched in the target capacitor group; The processor in the intelligent capacitor device is used to switch the target capacitor through the switching switch of the target capacitor when the time interval between the previous switching round reaches the preset switching time interval, and enter the next switching round after the switching is completed.

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