CN114784821A - Intelligent switching control method and system for power capacitor - Google Patents

Intelligent switching control method and system for power capacitor Download PDF

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Publication number
CN114784821A
CN114784821A CN202210596442.1A CN202210596442A CN114784821A CN 114784821 A CN114784821 A CN 114784821A CN 202210596442 A CN202210596442 A CN 202210596442A CN 114784821 A CN114784821 A CN 114784821A
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capacitor
load
reactive power
phase
power
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CN114784821B (en
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龚钢
肖英
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Shenzhen Smart Energy Internet Technology Co ltd
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Shenzhen Smart Energy Internet Technology Co ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00001—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00002—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by monitoring
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
    • H02J13/00016—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/01—Arrangements for reducing harmonics or ripples

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Human Computer Interaction (AREA)
  • Control Of Electrical Variables (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention provides an intelligent switching control method and system for a power capacitor, and belongs to the technical field of power electronics. The method includes the steps that basic information of each branch capacitor is input through a monitoring and displaying unit; the rapid compensation unit responds to the change of the harmonic current and the reactive power of the load and sends the sampled reactive power and the harmonic current as well as the reactive power compensated by the harmonic current to the communication bus; the dry contact point board collects data information on the communication bus and makes a table; calculating reactive power and three-phase compensation capacity of a load at a certain moment; calculating the optimal combination of the common compensation capacitors according to the three-phase common compensation capacity, and filling and updating a tabulation; calculating the residual reactive power of each phase load in the three phases as the single-phase compensation capacity to calculate the optimal combination of each phase compensation capacitor, and filling and updating the tabulation; and the driving signal is sent to carry out switching on and off of each branch capacitor by combining tabulation information, so that harmonic waves and reactive power generated by the load can be quickly and effectively inhibited, and the stability of signals of the whole system is ensured.

Description

Intelligent switching control method and system for power capacitor
Technical Field
The invention relates to the technical field of power electronics, in particular to an intelligent switching control method and system for a power capacitor.
Background
In the power grid system, the reactive power generated by the user load can cause the loss of the power system to increase, thereby reducing the utilization rate of electric energy; and harmonic waves generated by the user load can pollute the power system and damage other electric equipment in the power system. For the power system, the harmonic wave and reactive power generated by the load need to be reasonably (reliably and economically) managed, so that the stable operation of the power system is ensured.
In low-voltage power distribution systems, Active Power Filters (APFs) are generally employed for harmonic suppression; aiming at reactive power management, the traditional scheme generally adopts a power capacitor to compensate the reactive power, but the dynamic characteristic of the power capacitor is poorer; or a Static Var Generator (SVG) is generally adopted for compensation at present, but the investment cost is higher. The researchers also propose to carry out hybrid compensation through a Static Var Generator (SVG) and a power capacitor, but the control of the power capacitor and the coupling of the SVG in the method are stronger, or the specific constraint is more, so that the selection of users is inconvenient, and the harmonic wave generated by the load cannot be effectively treated.
Therefore, how to provide a method for effectively treating the harmonic and reactive power generated by the load becomes a problem which needs to be solved urgently at present.
Disclosure of Invention
In view of the above, the present invention provides an intelligent switching control method and system for a power capacitor, and aims to solve the problem that the harmonic and reactive power generated by the existing load cannot be effectively controlled.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the invention provides an intelligent switching control method for a power capacitor, which is applied to an intelligent switching control system for the power capacitor, wherein the system comprises a power grid, a capacitor and a load, the load is connected with an A, B, C three-phase circuit, and the method comprises the following steps:
inputting basic information of each branch capacitor, and performing preliminary tabulation according to the input basic information of each branch capacitor;
responding to the change of harmonic current and reactive power generated by a load, compensating the generated harmonic current and reactive power, and simultaneously sending the acquired harmonic current and reactive power and self-compensated reactive power to a communication bus;
collecting data information on the communication bus;
calculating reactive power of a load at a certain moment;
calculating the three-phase co-compensation capacity of the load, and setting the minimum value of three phases of reactive power as the co-compensation capacity of the load;
calculating the optimal combination of the common compensation capacitors according to the three-phase common compensation capacity, and filling and updating the tabulation;
calculating the residual reactive power of each phase load in the three phases as the single-phase separate compensation capacity;
calculating the optimal combination of each phase compensation capacitor according to the compensation capacity of each phase in the three phases, and filling and updating the tabulation;
and sending a driving signal to switch each branch capacitor by combining the tabulation information.
In an embodiment, the logging of the basic information of each branch capacitor, and performing preliminary tabulation according to the logged basic information of each branch capacitor includes: classifying the power capacitors according to the types and the capacities of the power capacitors, wherein the power capacitors of the same type are divided into a group, and the group is arranged according to the sequence of the capacities of the power capacitors from large to small or from small to large; and power capacitors of the same capacity are divided into one unit.
In one embodiment, the data information includes: the CT detection point comprises reactive power, harmonic current and reactive power data compensated by the rapid compensation unit, and the communication bus is a CAN bus.
In an embodiment, the calculating the reactive power of the load at a certain time includes:
judging the position of a CT detection point in the system;
when the CT detection point is on the side of the power grid, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QAPF+QCap
QLoadrepresenting the reactive power of the load;
QSmprepresenting the reactive power detected by the CT, and Q when the reactive power actually compensated by the rapid compensation unit meets the requirementSmp＝0；
QAPFThe reactive power which is actually compensated by the rapid compensation unit is represented;
QCaprepresenting the reactive power compensated by the capacitor bank;
when the CT detection point is on the load side, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QCap
in one embodiment, the calculating the three-phase complementary capacity of the load, and the setting the minimum value of the three phases of reactive power as the complementary capacity of the load comprises an algorithm:
QT＝min(QLoad-A,QLoad-B,QLoad-C)
QTrepresenting three-phase co-compensation reactive power;
QLoad-Arepresenting the reactive power of the A phase of the load;
QLoad-Brepresenting the reactive power of the B phase of the load;
QLoad-Crepresenting the reactive power of the C phase of the load.
In an embodiment, the calculating the residual reactive power of each phase load as a single-phase complementary capacity and calculating the optimal combination of each phase complementary capacitor according to each phase complementary capacity in three phases includes the following algorithm:
QA＝QLoad-A-QT’
QB＝QLoad-B-QT’
QC＝QLoad-C-QT’
QArepresenting the reactive power of the phase A partial complement;
QBrepresenting the reactive power of the phase B fractional complement;
QCrepresenting the reactive power of the C-phase partial compensation;
QT’representation entityThe actual three-phase compensation capacity;
QLoad-Arepresenting the reactive power of the A phase of the load;
QLoad-Brepresenting the reactive power of the B phase of the load;
QLoad-Crepresenting the reactive power of the C phase of the load.
In one embodiment, the calculating the optimal combination of the co-compensation capacitors according to the three-phase co-compensation capacity and the optimal combination of the phase-to-phase compensation capacitors according to the three-phase-to-phase compensation capacity includes the following steps:
calculating actual three-phase co-compensation or sub-compensation capacity;
QX’＝QX0×N0+QX1×N1+QX2×N2+QX3×N3+…+QXn×N
QX’representing the actual three-phase co-or sub-complementary total capacity, symbol X representing one of the capacitor types T, A, B, C, Q when symbol X is replaced by TT’Representing the actual co-compensation capacity; when symbol X is replaced by A/B/C, QA’/QB’/QC’Respectively representing the actual separate compensation capacity of the A/B/C phase;
QXnthe actual capacity of a single capacitor in the nth unit in the three-phase co-compensation or sub-compensation capacitor is expressed, and the value is converted through the set rated capacity and standard voltage of the capacitor and the actual voltage at the common connection point of the system;
Nnthe number of capacitors which need to participate in compensation in the nth unit in the three-phase co-compensation or sub-compensation capacitor is represented;
obtaining the minimum value of the sum of the number of capacitors needing to participate in compensation in each unit in the three-phase common compensation or sub-compensation capacitor;
(N0,N1,N2,…Nn)＝min(N0+N1+N2+N3+…+Nn)
after the number of the power capacitors which are input into each unit is calculated, different mark values are used for identifying the re-input delay state, the input state and the action mark state of each branch capacitor and updating a tabulation.
In one embodiment, said identifying the re-throw delay status, throw status and action flag status of the branch capacitor with different flag values and updating said tabulation comprises:
if the re-throwing delay mark is 0 and the throwing state is 0, the current capacitor meets the throwing condition, and the action mark is marked as 1;
if the re-throwing delay mark is 0 and the throwing state is 1, the current capacitor is already put into use, and the capacitor action mark is marked as 0;
as long as the capacitor re-throwing delay mark is 1, the capacitor action mark is marked as 0, and the capacitor is skipped to inquire the re-throwing delay mark and the throwing state of the next capacitor;
by parity of reasoning, the N needed to be input by the nth unit is foundnAfter each capacitor, the remaining ones are the ones that need to be cut,
if the input state is 0, the capacitor is cut off, and the capacitor action mark is marked as 0; if the input state is 1, it indicates that the capacitor needs to be cut off, and the capacitor operation flag is marked as 1.
In one embodiment, further comprising the steps of: the residual capacity and harmonic current that the capacitor cannot compensate for are compensated by the fast compensation unit.
The second aspect of the invention also provides an intelligent switching control system for the power capacitor, which adopts the above intelligent switching control method for the power capacitor, and the system comprises a detection unit, a rapid compensation unit, a power capacitor cabinet, a dry contact plate, a monitoring and display unit and a communication unit which are electrically connected with each other,
the detection unit is used for detecting the voltage at the public connection point and detecting the current on the power grid side or the current on the load side;
the rapid compensation unit is used for calculating the reactive power and the harmonic current at the CT detection point according to the detected voltage and current information; the reactive power and the harmonic current are compensated in a fast response mode, and meanwhile the reactive power and the harmonic current at the CT detection point and the compensated reactive power data information are sent to a monitoring and displaying unit;
the power capacitor cabinet is used for receiving a driving signal sent by the dry contact point plate and then switching on and off a power capacitor so as to compensate the reactive power of the system;
the dry contact board is used for preliminarily making a table according to the basic information of each branch capacitor, receiving the reactive power, the harmonic current and the compensated reactive power which are sent to a CT detection point on a bus by the rapid compensation unit, judging the serial number of a branch of the capacitor needing to be switched by combining the capacity of the capacitor which is put into use and the capacity of the residual capacitor, and sending a driving signal to the corresponding branch to finish the switching of the capacitor;
a monitoring and display unit; the system is used for monitoring and displaying basic data information required by a user and inputting the basic information of each branch capacitor;
a communication unit; the data transmission and communication interaction device is used for data transmission and communication interaction among all the unit modules.
In one embodiment, the power capacitor cabinet comprises a driver and a power capacitor, wherein the driver is used for receiving a driving signal sent by the dry contact plate and then switching the power capacitor to compensate the reactive power of the system.
In an embodiment, the driver is a thyristor or a contactor, and the power capacitor cabinet further comprises a reactor.
In an embodiment, the fast compensation unit is an APF unit or an SVG unit or a combination thereof.
According to the intelligent switching control method and the intelligent switching control system for the power capacitor, provided by the embodiment of the invention, the system displays and inputs the basic information of each branch capacitor by using the monitoring and display unit; the rapid compensation unit rapidly responds to the change of the harmonic current and the reactive power of the load and sends the sampled reactive power and the harmonic current as well as the compensated reactive power to a communication bus; the method comprises the following steps that a dry contact board collects data information on a communication bus, preliminary tabulation is conducted according to basic information of each branch capacitor, and reactive power of a load at a certain moment is calculated; calculating the three-phase co-compensation capacity of the load, and setting the minimum value of the three phases of the reactive power as the co-compensation capacity of the load; calculating the optimal combination of the common compensation capacitors according to the three-phase common compensation capacity, and filling and updating the tabulation; calculating the residual reactive power of each phase load in the three phases as the single-phase separate compensation capacity; calculating the optimal combination of each phase compensation capacitor according to the compensation capacity of each phase in the three phases, and filling and updating the tabulation; and sending a driving signal to switch each branch capacitor by combining with the tabulation information, thereby quickly and effectively inhibiting harmonic waves and reactive power generated by a load, weakening the coupling between capacitor switching and a quick compensation unit and ensuring the stability of signals of the whole system.
Drawings
Fig. 1 is a flowchart of an embodiment of an intelligent switching control method for a power capacitor according to the present invention;
fig. 2 is a flowchart of another embodiment of an intelligent switching control method for a power capacitor according to an embodiment of the present invention;
fig. 3 is a flowchart of another embodiment of an intelligent switching control method for a power capacitor according to the embodiment of the present invention;
fig. 4 is a block diagram of a power capacitor intelligent switching control system according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a CT detection point of an intelligent switching control system for a power capacitor of an embodiment of the present invention, the CT detection point being located at a power grid side;
fig. 6 is a schematic circuit diagram of a CT detection point of an intelligent switching control system for a power capacitor according to an embodiment of the present invention, the CT detection point being located on a load side;
fig. 7 is a schematic diagram illustrating a change in capacitor capacity when a capacitor is put into the intelligent switching control system for a power capacitor according to an embodiment of the present invention and skipping over a resonant capacity;
fig. 8 is a schematic diagram illustrating a change of capacitor capacity when skipping over a resonant capacity when a capacitor is cut off in an intelligent switching control system for a power capacitor according to an embodiment of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects of the present invention more clear and obvious, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.
The first embodiment is as follows:
the invention provides an intelligent switching control method for a power capacitor, which is applied to an intelligent switching control system for the power capacitor, wherein the system comprises a power grid, the power capacitor and a load, the load is connected with an A, B, C three-phase circuit, please refer to fig. 1 to 3, and the method comprises the following steps:
s101, inputting basic information of each branch capacitor, and performing preliminary tabulation according to the input basic information of each branch capacitor;
specifically, the monitoring and display unit records basic information (such as a table 1-1) of the power capacitor and performs preliminary tabulation (such as a table 1-2); the tabulation comprises the steps that capacitors are classified according to the types and the capacities of the capacitors, the capacitors of the same type are divided into a group, and the capacitors in the group are arranged in the sequence from large to small or from small to large; the same capacity is divided into one unit as in tables 1-2.
TABLE 1-1 actual parameter table for three-phase co-compensation and single-phase sub-compensation capacitors
Branch numbering 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 1-12 1-13 1-14 1-15 1-16
Capacitor type T T T T T T T T T T T T T T T T
Capacity of capacitor 10k 30k 20k 40k 40k 10k 20k 30k 20k 10k 30k 40k 20k 40k 30k 10k
Branch numbering 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 2-11 2-12 2-13 2-14 2-15 2-16
Capacitor type A B C A C B B C A B B C A C A T
Capacity of capacitor 10k 5k 10k 5k 10k 5k 10k 5k 5k 10k 10k 5k 10k 10k 10k 10k
S102, responding to the change of harmonic current and reactive power generated by a load, compensating the generated harmonic current and reactive power, and simultaneously sending the acquired harmonic current and reactive power and the reactive power compensated by the harmonic current and reactive power to a communication bus;
specifically, the fast compensation unit calculates load harmonic current and reactive power according to sampled voltage and current data; compensating the load harmonic current and the reactive power in a quick response manner to offset the change of the load harmonic current and the reactive power; and meanwhile, the acquired harmonic current, reactive power and self-compensated reactive power are sent to a communication bus.
S103, collecting data information on the communication bus;
specifically, data information on the communication bus CAN is collected through the dry contact point board, and the data information includes: and the reactive power and the harmonic current at the CT detection point and the reactive power data sent by the rapid compensation unit.
S104, calculating reactive power of a load at a certain moment;
specifically, the reactive power of the load at a certain moment is calculated according to the reactive power at the CT detection point, the reactive power data sent by the fast compensation unit and the reactive power input by the capacitor, and before the reactive power of the load at a certain moment is calculated, the position of the CT detection point in the system needs to be judged; different reactive power calculation formulas are adopted according to different positions of the CT detection points, and the reactive power calculation formulas are as follows:
when the CT detection point is on the side of the power grid, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QAPF+QCap (1)
QLoadindicates no loadWork power;
QSmprepresenting the reactive power detected by the CT, Q when the reactive power actually compensated by the fast compensation unit meets the requirementSmp＝0；
QAPFThe reactive power which is actually compensated by the rapid compensation unit is represented;
QCaprepresenting the reactive power compensated by the capacitor bank;
when the CT detection point is on the load side, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QCap (2)
the meaning of the alphabet expression in the formula (2) is the same as that of the alphabet expression in the above formula (1).
S105, calculating the three-phase co-compensation capacity of the load, and setting the minimum value of three phases of reactive power as the co-compensation capacity of the load;
specifically, the method includes the steps of calculating the co-compensation capacity of an A, B, C three-phase circuit connected with a load, and setting the minimum value of three phases of reactive power as the co-compensation capacity of the load, and specifically includes the following algorithm:
QT＝min(QLoad-A,QLoad-B,QLoad-C) (3)
QTrepresenting three-phase co-compensation reactive power;
QLoad-Arepresenting the reactive power of the A phase of the load;
QLoad-Brepresenting the reactive power of the B phase of the load;
QLoad-Crepresenting the reactive power of the C phase of the load.
S106, calculating the optimal combination of the common compensation capacitors according to the three-phase common compensation capacity, and filling and updating the tabulation;
specifically, the method comprises the following steps:
s1061, calculating actual three-phase compensation capacity;
QT’＝QT0×N0+QT1×N1+QT2×N2+QT3×N3+…+QTn×Nn (4)
s1062, obtaining the minimum value of the sum of the number of capacitors needing to participate in compensation in each unit of the three-phase co-compensation capacitor;
(N0,N1,N2,…Nn)＝min(N0+N1+N2+N3+…+Nn) (5)
QT’representing the actual three-phase co-compensation capacity;
QTnthe actual capacity of a single capacitor in the nth unit in the three-phase co-compensation capacitor is expressed, and the value is converted through the set rated capacity and standard voltage of the capacitor and the actual voltage at the common connection point of the system;
Nnthe number of capacitors needed to participate in compensation of the nth unit in the three-phase co-compensation capacitor is shown.
S1063, after the number of the capacitors put into each unit is calculated, different mark values are used for marking the re-throwing delay state, the putting state and the action mark state of the branch capacitor and updating the tabulation;
the method specifically comprises the following steps:
if the re-throwing delay mark is 0 and the throwing state is 0, the current capacitor meets the throwing condition, and the action mark is marked as 1;
if the re-throwing delay mark is 0 and the throwing state is 1, the current capacitor is already put into use, and the capacitor action mark is marked as 0;
as long as the capacitor re-throwing delay mark is 1, the capacitor action mark is marked as 0, and the capacitor is skipped to inquire the re-throwing delay mark and the throwing state of the next capacitor;
by analogy, the N needed to be input by the nth unit is foundnAfter each capacitor, the remaining ones are the ones that need to be cut,
if the input state is 0, the capacitor is cut off, and the capacitor action mark is marked as 0; if the input state is 1, it indicates that the capacitor needs to be cut off, and the capacitor operation flag is marked as 1.
S107, calculating the residual reactive power of each phase load in the three phases as single-phase separate compensation capacity;
specifically, the calculating of the remaining reactive power of each phase load as the single-phase compensation capacity includes the following algorithm:
QA＝QLoad-A-QT’ (6)
QB＝QLoad-B-QT’ (7)
QC＝QLoad-C-QT’ (8)
QArepresenting the reactive power of the phase A partial complement;
QBrepresenting the reactive power of the phase B partial complement;
QCrepresenting the reactive power of the C-phase partial complement;
QT’representing the actual three-phase compensation capacity;
QLoad-Arepresenting the reactive power of the A phase of the load;
QLoad-Brepresenting the reactive power of the B phase of the load;
QLoad-Crepresenting the reactive power of the C phase of the load.
S108, calculating the optimal combination of each phase of the compensation capacitor according to the compensation capacity of each phase in the three phases; filling and updating the tabulation;
specifically, the optimal combination of the compensation capacitor banks is recalculated according to the respective phase compensation capacities of ABC, the calculation method is similar to the method for combining the compensation capacitors in step S106, and then the operation flags of the respective phase compensation capacitors are set and the tabulation is updated.
In this embodiment, the actual three-phase co-complement or sub-complement capacity formula may be unified as follows:
QX’＝QX0×N0+QX1×N1+QX2×N2+QX3×N3+…+QXn×N
QX’representing the actual three-phase total complementary or partial complementary capacity, and the symbol X represents the capacitanceOne of type T, A, B, C, Q when symbol X is replaced by TT’A method of combining the actual compensation capacity with the compensation capacitor in step S106; q when symbol X is replaced by A/B/CA’/QB’/QC’Respectively representing the actual separate compensation capacity of the A/B/C phase;
QXnthe actual capacity of a single capacitor in the nth unit in the three-phase co-compensation or sub-compensation capacitor is represented, and the value is converted through the set rated capacity and standard voltage of the capacitor and the actual voltage at the common connection point of the system;
Nnthe number of capacitors which need to participate in compensation in the nth unit in the three-phase co-compensation or sub-compensation capacitor is shown.
And S109, sending a driving signal to execute switching of each branch capacitor by combining the tabulation information.
Specifically, the capacitor state flag and the action flag in the following tables 1-2 are searched together; if the action flag is 0, the capacitor maintains the current status; if the action flag is 1 and the state flag is 0, the capacitor needs to be put into use, after the driving signal is sent, the delay flag is written into 0, the state flag is written into 1, and the action flag is written into 0; if the action mark is 1 and the state mark is 1, the capacitor needs to be cut off, the delay mark is written into 1 after the driving signal is sent, the state mark is written into 0, and the action mark is written into 0; when the delay time arrives, the delay flag is written to 0. The capacitance capacity at the time of major subharmonic resonance needs to be analyzed according to the received current harmonic information during the capacitor input or removal process, and when the total capacitor capacity after the capacitor is input or removed is comparable to the resonance capacity, the resonance capacity needs to be skipped to ensure the system stability, as shown in fig. 7, which is a schematic diagram of the change of the capacitor capacity skipping the resonance capacity when the capacitor is input, and fig. 8 is a schematic diagram of the change of the capacitor capacity skipping the resonance capacity when the capacitor is removed.
TABLE 1-2 TABLE FOR THREE-PHASE COUNTERMINAL AND SINGLE-PHASE QUANTITATIVE COMPENSATION CAPACITOR PARAMETERS
Figure BDA0003668252860000131
In one embodiment, further comprising the steps of:
s110, the residual capacity which cannot be compensated by the capacitor and the harmonic current are compensated by the rapid compensation unit.
In particular, the residual reactive power after the capacitor compensation (overcompensation or undercompensation) is taken up by the fast compensation unit, ensuring that the reactive power compensation net difference approaches the 0 value. In an embodiment, the fast compensation unit may be an APF unit or an SVG unit or a combination thereof.
According to the intelligent switching control method for the power capacitor, provided by the embodiment of the invention, the primary tabulation is carried out by inputting the basic information of each branch capacitor; quickly responding to changes of harmonic current and reactive power of a load; and the sampled reactive power and harmonic current and the compensated reactive power are sent to a communication bus; collecting data information on a communication bus; calculating reactive power of a load at a certain moment; calculating the three-phase co-compensation capacity of the load, and setting the minimum value of the three phases of the reactive power as the co-compensation capacity of the load; calculating the optimal combination of the common compensation capacitors according to the three-phase common compensation capacity, and filling and updating the tabulation; calculating the residual reactive power of each phase load in the three phases as the single-phase fractional compensation capacity; calculating the optimal combination of the phase compensation capacitors according to the phase compensation capacity in the three phases, and filling and updating the tabulation; and sending a driving signal to switch each branch capacitor by combining with the tabulation information, thereby quickly and effectively inhibiting harmonic waves and reactive power generated by a load, weakening the coupling between capacitor switching and a quick compensation unit and ensuring the stability of signals of the whole system.
According to the embodiment of the application, the communication bus adopts the CAN communication bus, so that the data CAN be processed in a multi-host mode, the power capacitor CAN be switched quickly and reliably, and the CAN communication bus has strong anti-jamming capability and good timeliness.
Example two:
referring to fig. 4, the system includes a detection unit 10, a fast compensation unit 20, a power capacitor cabinet 30, a dry contact plate 40, a monitoring and display unit 50, and a communication unit 60, which are electrically connected to each other.
The detection unit 10 is used for detecting the voltage at the common connection point and detecting the current at the power grid side or the current at the load side;
specifically, when the CT detection point is on the grid side, the detection unit 10 is configured to detect a current on the grid side, and when the CT detection point is on the load side, the detection unit 10 is configured to detect a current on the load side.
The rapid compensation unit 20 is configured to calculate the reactive power and the harmonic current at the CT detection point according to the detected voltage and current information; and fast response, compensating the reactive power and the harmonic current, and simultaneously sending the reactive power and the harmonic current at the CT detection point and the data information of the compensated reactive power to the monitoring and displaying unit 50;
the fast compensation unit 20 is an APF unit, an SVG unit, or a combination thereof, in this embodiment, the fast compensation unit 20 is an APF unit, and the application will be described below with an APF unit (APF for short) instead of the fast compensation unit 20.
Specifically, when the CT detection point is on the grid side, as shown in fig. 5, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QAPF+QCap (1)
QLoadrepresenting the reactive power of the load;
QSmprepresenting the reactive power detected by CT, and Q when the reactive power actually compensated by APF meets the requirementSmp＝0；
QAPFRepresenting the reactive power actually compensated by the APF;
QCaprepresenting the reactive power compensated by the capacitor bank;
when the CT detection point is on the load side, as shown in fig. 6, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QCap (2)
the data messages are also received by other nodes (e.g. dry circuit boards) on the CAN communication bus and are typically sent by the general purpose APF to the monitoring and display unit 50 for display or processing.
The power capacitor cabinet 30 is configured to perform switching of a power capacitor after receiving a driving signal sent by the dry contact plate 40, and compensate for reactive power of a system;
specifically, the power capacitor cabinet 30 includes a driver 301 and a power capacitor 302, and other auxiliary components; the driver 301 is used for switching the power capacitor after receiving the driving signal sent by the dry contact plate 40 to compensate the reactive power of the system, so as to improve the power factor of the system. In one embodiment, the driver 301 may be a thyristor or a contactor, and the auxiliary element may be a reactor.
And the dry contact plate 40 is used for performing preliminary tabulation according to the basic information of each branch capacitor, receiving the reactive power and the harmonic current which are sent to the CT detection point on the CAN communication bus by the APF unit and the reactive power sent by the APF unit, judging the serial number of the branch capacitor to be switched by combining the capacity of the capacitor which is put into use and the capacity of the residual capacitor, and sending a driving signal to the corresponding branch to finish the switching of the capacitor.
And the monitoring and displaying unit 50 is used for monitoring and displaying basic data information required by a user and inputting the basic information of each branch capacitor of the dry contact.
The communication unit 60 is configured to perform data transmission and communication interaction between the unit modules.
In the embodiment of the present application, a specific working process of the present application will be described by taking 32 capacitive branches as an example.
Each dry contact branch is numbered according to the branch sequence of 1-1 to 1-16, 2-1 to 2-16, and each branch actually connected to a capacitor can be a three-phase common compensation capacitor or a single-phase separate compensation capacitor; the basic information of each branch capacitor is recorded through the monitoring and display unit 50, and the dry contact plate 40 makes a table according to the basic information of the branch capacitor. Taking the following table 1-1 as an example, the capacitor type T represents that the current branch is connected to a 3-phase co-compensation capacitor; the type A of the capacitor represents that the current branch is connected into a single-phase differential compensation capacitor and is connected into an A phase; the capacitor type B represents that the current branch is connected into a single-phase differential compensation capacitor and is connected into a phase B; capacitor type C indicates that the current branch is connected into a single-phase differential compensation capacitor and into phase C.
TABLE 1-1 actual parameter table for three-phase co-compensation and single-phase sub-compensation capacitors
Branch numbering 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 1-12 1-13 1-14 1-15 1-16
Capacitor type T T T T T T T T T T T T T T T T
Capacity of capacitor 10k 30k 20k 40k 40k 10k 20k 30k 20k 10k 30k 40k 20k 40k 30k 10k
Branch numbering 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 2-11 2-12 2-13 2-14 2-15 2-16
Capacitor type A B C A C B B C A B B C A C A T
Capacity of capacitor 10k 5k 10k 5k 10k 5k 10k 5k 5k 10k 10k 5k 10k 10k 10k 10k
After data entry into the dry contact plate 40, the software re-tabulates the capacitors by capacitor capacity and type (see tables 1-2). The capacitor types are grouped according to the T-A-B-C sequence, and the capacitors of the same type are grouped into one group; the capacitors in the group are arranged in the order from large to small, and the capacitors with the same capacity are divided into one unit. In another embodiment, the capacitors in the group can be arranged in the order of the capacitor capacity from small to large. The capacitor types may also be grouped in other orders, such as a-B-C-T.
In the table, the delay mark value is 0 to indicate that the re-throwing delay is finished, and the value is 1 to indicate that the re-throwing delay is not finished; in the table, a value of 0 indicates that the arm is in the cut-off state, and a value of 1 indicates that the arm is in the input state. In the table, an action flag value of 0 indicates that the branch does not require action, and a value of 1 indicates that the branch requires action. The delay flag, the throw-in state and the action flag of each branch are initialized to 0 after power-on. The dry contact plate 40 receives the reactive power, the harmonic current and the reactive power sent by the APF unit to the CT detection point on the CAN communication bus, judges the serial number of the capacitor branch needing to be switched by combining the capacity of the capacitor which is put into use and the capacity of the residual capacitor, and sends a driving signal to the corresponding branch to complete the switching of the capacitor.
TABLE 1-2 TABLE FOR THREE-PHASE COUNTERMINAL AND SINGLE-PHASE QUANTITATIVE COMPENSATION CAPACITOR PARAMETERS
Figure BDA0003668252860000171
In the application of the invention, the dry contact board 40 judges the optimal combined capacity to be switched by the capacitor bank by using the reactive power and the harmonic current detected by the APF unit and the reactive power sent by the APF unit, thereby realizing the independence of switching control of the capacitor bank, reducing the coupling relation between a power capacitor and the APF unit, effectively inhibiting the harmonic generated by a load and compensating the reactive power of a system; and the user can conveniently select the brands of the APF unit (APF or SVG) and the power capacitor according to actual conditions.
In the application of the invention, the dry contact point plate 40 is connected with the monitoring and display unit 50 and the APF unit through a CAN communication bus; the dry contact plate 40 can be installed on the power capacitor cabinet 30 nearby, so that the driving signal wires can be effectively saved, the reliability of the driving signal is enhanced, and in addition, the installation and wiring are clear, and the wiring is simple and convenient.
In the application of the present invention, when the capacitor driving connection line is in a wrong connection, the disconnection and reconnection are not required, and only the wrong connection branch needs to be reconfigured according to the actual connection in the monitoring and display unit 50 (or the background).
According to the invention, the CAN bus communication is adopted for communication, and a multi-host mode CAN be adopted for processing data, so that the rapid and reliable switching of the power capacitor is realized.
The algorithm in the application of the invention does not need to carry out specific coding on the capacitor, the basic information of the capacitor configured for each branch is recorded into the storage unit of the dry contact plate 40 through the monitoring and display unit 50 (or other background tools), the capacitor is re-tabulated on a software algorithm, and the dry contact plate 40 determines the optimal switching combination of the capacitor according to the required capacity; the realization is simple and convenient, and the practicability is better.
In summary, in the intelligent switching control system for the power capacitor according to the embodiment of the present application, the dry contact plate 40 performs preliminary tabulation by using the basic information of the power capacitor recorded by the monitoring and display unit 50; compensating the harmonic current and reactive power generated by the load by using the fast dynamic characteristic of the fast compensation unit 20; the sampled reactive power, the sampled harmonic current and the compensated reactive power are sent to a communication bus CAN; the dry contact board 40 receives data information on the communication bus; the capacitor branch serial number needing to be switched is judged by combining the capacity of the capacitor which is already put into use and the capacity of the residual capacitor; and sending a driving signal to carry out switching on and off each branch capacitor by combining the tabulation information, so that harmonic waves and reactive power generated by a load can be quickly and effectively inhibited, the coupling between capacitor switching and a quick compensation unit 20 is weakened, and the stability of signals of the whole system is ensured.
Example three:
according to an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the above-mentioned intelligent switching control method for a power capacitor are implemented, and specific steps are as described in the first embodiment, and are not described herein again.
The memory in the present embodiment may be used to store software programs as well as various data. The memory may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function, and the like; the storage data area may store data created according to the use of the mobile phone, and the like. Further, the memory may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.
According to an example of this embodiment, all or part of the processes in the methods of the embodiments described above may be implemented by instructing relevant hardware by a computer program, where the program may be stored in a computer-readable storage medium, and in this embodiment of the present invention, the program may be stored in the storage medium of a computer system and executed by at least one processor in the computer system, so as to implement the processes including the embodiments of the methods described above. The storage medium includes, but is not limited to, a magnetic disk, a flash disk, an optical disk, a Read-Only Memory (ROM), and the like.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the description of the foregoing embodiments, it is clear to those skilled in the art that the method of the foregoing embodiments may be implemented by software plus a necessary general hardware platform, and certainly may also be implemented by hardware, but in many cases, the former is a better implementation. Based on such understanding, the technical solutions of the present invention or portions thereof contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the methods according to the embodiments of the present invention.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (13)

1. An intelligent switching control method for a power capacitor is applied to an intelligent switching control system for the power capacitor, the system comprises a power grid, the power capacitor and a load, and the load is connected with an A, B, C three-phase circuit, and the method is characterized by comprising the following steps:
inputting basic information of each branch capacitor, and performing preliminary tabulation according to the input basic information of each branch capacitor;
responding to the change of harmonic current and reactive power generated by a load, compensating the generated harmonic current and reactive power, and simultaneously sending the acquired harmonic current and reactive power and self-compensated reactive power to a communication bus;
collecting data information on the communication bus;
calculating reactive power of a load at a certain moment;
calculating the three-phase co-compensation capacity of the load, and setting the minimum value of three phases of reactive power as the co-compensation capacity of the load;
calculating the optimal combination of the common compensation capacitors according to the three-phase common compensation capacity, and filling and updating the tabulation;
calculating the residual reactive power of each phase load in the three phases as the single-phase fractional compensation capacity;
calculating the optimal combination of the phase compensation capacitors according to the phase compensation capacity in the three phases, and filling and updating the tabulation;
and sending a driving signal to switch each branch capacitor by combining the tabulation information.
2. The intelligent switching control method for the power capacitors according to claim 1, wherein the step of recording the basic information of each branch capacitor and the step of performing preliminary tabulation according to the recorded basic information of each branch capacitor comprises the steps of: classifying the power capacitors according to the types and the capacities of the power capacitors, wherein the power capacitors of the same type are divided into a group, and the group is arranged according to the sequence of the capacities of the power capacitors from large to small or from small to large; and power capacitors of the same capacity are divided into one unit.
3. The intelligent switching control method for the power capacitor according to claim 1 or 2, wherein the data information comprises: the CT detection point comprises reactive power, harmonic current and reactive power data compensated by the rapid compensation unit, and the communication bus is a CAN bus.
4. The intelligent switching control method for the power capacitor according to claim 3, wherein the calculating the reactive power of the load at a certain time comprises:
judging the position of a CT detection point in the system;
when the CT detection point is on the side of the power grid, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QAPF+QCap
QLoadrepresenting the reactive power of the load;
QSmprepresenting the reactive power detected by the CT, and Q when the reactive power actually compensated by the rapid compensation unit meets the requirementSmp＝0；
QAPFThe reactive power which is actually compensated by the rapid compensation unit is represented;
QCaprepresenting the reactive power compensated by the capacitor bank;
when the CT detection point is on the load side, the load reactive power calculation formula is as follows:
QLoad＝QSmp+QCap。
5. the power capacitor intelligent switching control method according to claim 4, wherein the calculating three-phase co-compensation capacity of the load, and setting the minimum value of three phases of reactive power as the co-compensation capacity of the load comprises an algorithm:
QT＝min(QLoad-A,QLoad-B,QLoad-C)
QTrepresenting three-phase co-compensation reactive power;
QLoad-Arepresenting the reactive power of the A phase of the load;
QLoad-Brepresenting the reactive power of the load phase B;
QLoad-Crepresenting the reactive power of the C phase of the load.
6. The intelligent switching control method for the power capacitor according to claim 4, wherein the calculation of the residual reactive power of each phase load as a single-phase complementary capacity and the calculation of the optimal combination of each phase complementary capacitor according to each phase complementary capacity of three phases comprises the following algorithm:
QA＝QLoad-A-QT’
QB＝QLoad-B-QT’
QC＝QLoad-C-QT’
QArepresenting the reactive power of the phase A partial complement;
QBrepresenting the reactive power of the phase B partial complement;
QCrepresenting the reactive power of the C-phase partial complement;
QT’representing the actual three-phase compensation capacity;
QLoad-Arepresenting the reactive power of the A phase of the load;
QLoad-Brepresenting the reactive power of the load phase B;
QLoad-Crepresenting the reactive power of the C phase of the load.
7. A power capacitor intelligent switching control method according to claim 5 or 6, wherein the calculation of the optimal combination of the co-compensation capacitors according to the three-phase co-compensation capacity and the calculation of the optimal combination of the phase-division compensation capacitors according to the phase-division compensation capacity in the three phases each comprise the following steps:
calculating actual three-phase co-compensation or sub-compensation capacity;
QX’＝QX0×N0+QX1×N1+QX2×N2+QX3×N3+…+QXn×N
QX’representing the actual total capacity of the three-phase co-or sub-compensation, the symbol X representing one of the capacitor types T, A, B, C, Q when the symbol X is replaced by TT’Representing the actual co-compensation capacity; when symbol X is replaced by A/B/C, QA’/QB’/QC’Respectively representing the actual separate compensation capacity of the A/B/C phase;
QXnthe actual capacity of a single capacitor in the nth unit in the three-phase co-compensation or sub-compensation capacitor is expressed, and the value is converted through the set rated capacity and standard voltage of the capacitor and the actual voltage at the common connection point of the system;
Nnthe number of capacitors which need to participate in compensation in the nth unit in the three-phase co-compensation or sub-compensation capacitor is represented;
obtaining the minimum value of the sum of the number of capacitors which are required to participate in compensation of each unit in the three-phase common compensation or sub-compensation capacitor;
(N0,N1,N2,…Nn)＝min(N0+N1+N2+N3+…+Nn)
after the number of the power capacitors which are put into each unit is calculated, different mark values are used for marking the re-putting delay state, the putting state and the action mark state of each branch capacitor and updating a tabulation.
8. The method according to claim 7, wherein said identifying the re-throw delay status, throw status and action flag status of the branch capacitor with different flag values and updating the tabulation comprises:
if the re-throwing delay mark is 0 and the throwing state is 0, the current capacitor meets the throwing condition, and the action mark is marked as 1;
if the re-throwing delay mark is 0 and the throwing state is 1, the current capacitor is already put into use, and the capacitor action mark is marked as 0;
as long as the capacitor re-throwing delay mark is 1, the capacitor action mark is marked as 0, and the capacitor is skipped to inquire the re-throwing delay mark and the throwing state of the next capacitor;
by analogy, the N needed to be input by the nth unit is foundnAfter each capacitor, the remaining ones are the ones that need to be cut,
if the input state is 0, the capacitor is cut off, and the capacitor action mark is marked as 0; if the input state is 1, it indicates that the capacitor needs to be cut off, and the capacitor operation flag is marked as 1.
9. The intelligent switching control method for the power capacitor according to claims 1-8, further comprising the steps of: the residual capacity and harmonic current that the capacitor cannot compensate for are compensated by the fast compensation unit.
10. An intelligent switching control system of a power capacitor, which is applied to the intelligent switching control method of the power capacitor of any one of the above 1-9, is characterized in that the system comprises a detection unit, a rapid compensation unit, a power capacitor cabinet, a dry contact plate, a monitoring and display unit and a communication unit which are electrically connected with each other,
the detection unit is used for detecting the voltage at the public connection point and detecting the current on the side of a power grid or the current on the side of a load;
the rapid compensation unit is used for calculating the reactive power and the harmonic current at the CT detection point according to the detected voltage and current information; the reactive power and the harmonic current are compensated in a fast response mode, and meanwhile the reactive power and the harmonic current at the CT detection point and the compensated reactive power data information are sent to a monitoring and displaying unit;
the power capacitor cabinet is used for switching on and off a power capacitor after receiving a driving signal sent by the dry contact point plate so as to compensate the reactive power of the system;
the dry contact board is used for preliminarily making a table according to the basic information of each branch capacitor, receiving the reactive power, the harmonic current and the compensated reactive power which are sent to a CT detection point on a bus by the rapid compensation unit, judging the serial number of a branch of the capacitor needing to be switched by combining the capacity of the capacitor which is put into use and the capacity of the residual capacitor, and sending a driving signal to the corresponding branch to finish the switching of the capacitor;
a monitoring and display unit; the system is used for monitoring and displaying basic data information required by a user and inputting the basic information of each branch capacitor;
a communication unit; the unit modules are used for data transmission and communication interaction among the unit modules.
11. The intelligent switching control device for power capacitors as claimed in claim 10, wherein the power capacitor cabinet comprises a driver and a power capacitor, and the driver is configured to switch the power capacitor after receiving a driving signal sent by the dry contact plate, so as to compensate the reactive power of the system.
12. A power capacitor intelligent switching control device according to claim 11, wherein the driver is a thyristor or a contactor, and the power capacitor cabinet further comprises a reactor.
13. The intelligent switching control device of power capacitors as claimed in claim 10, wherein the fast compensation unit is an APF unit or an SVG unit or a combination thereof.
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