CN111654034B - Park level voltage sag layered and graded treatment system and method and terminal equipment - Google Patents
Park level voltage sag layered and graded treatment system and method and terminal equipment Download PDFInfo
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- CN111654034B CN111654034B CN202010587488.8A CN202010587488A CN111654034B CN 111654034 B CN111654034 B CN 111654034B CN 202010587488 A CN202010587488 A CN 202010587488A CN 111654034 B CN111654034 B CN 111654034B
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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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/14—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading
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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
- H02J2310/00—The network for supplying or distributing electric power characterised by its spatial reach or by the load
- H02J2310/50—The network for supplying or distributing electric power characterised by its spatial reach or by the load for selectively controlling the operation of the loads
- H02J2310/56—The network for supplying or distributing electric power characterised by its spatial reach or by the load for selectively controlling the operation of the loads characterised by the condition upon which the selective controlling is based
- H02J2310/58—The condition being electrical
- H02J2310/60—Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
- Y02B70/3225—Demand response systems, e.g. load shedding, peak shaving
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
- Y04S20/20—End-user application control systems
- Y04S20/222—Demand response systems, e.g. load shedding, peak shaving
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Abstract
The embodiment of the invention relates to a park level voltage sag layered and graded management system, a park level voltage sag layered and graded management method and terminal equipment, wherein the park level voltage sag layered and graded management system is divided into a first type sensitive user and a second type sensitive user according to the voltage tolerance capacity of the sensitive users, the voltage sag of the first type sensitive user is managed by adopting a change-over switch device, the voltage sag of the second type sensitive user is managed by adopting a compensation device, the second type sensitive user is divided into three-level sensitive users according to the voltage sag amplitude tolerance capacity, and different compensation devices are selected according to the sensitive users of different levels to smoothly compensate the voltage of the sensitive users; the system also adopts the switching-on or switching-off of a switch in the change-over switch device to realize the rapid switching, solves the problem of the rapid switching between double power supplies, and also solves the technical problem of poor voltage sag treatment effect caused by poor coordination between the switch switching adopted for voltage sag treatment and the sag compensation device in the existing electric power park.
Description
Technical Field
The invention relates to the technical field of power quality, in particular to a park-level voltage sag layered grading treatment system, a park-level voltage sag layered grading treatment method and terminal equipment.
Background
With the rapid development of high and new technology industries and the adoption of computer management and automatic control means in traditional industries and modern businesses, the proportion of loads sensitive to power supply reliability and power quality is getting larger and larger, and more severe requirements on power supply quality are also provided. At present, a high-quality power park is adopted as an effective solution for power supply quality, the high-quality power park concentrates various sensitive loads within a certain range, can provide high-quality regional power supply aiming at various power quality problems, and the most common and serious power quality problem is voltage sag.
The voltage sag is also called voltage dip, voltage sag or voltage sag, and the voltage sag is an event that the root mean square value of the power supply voltage suddenly drops in a short time and then rapidly returns to a normal state, and the typical time is 0.5 to 30 cycles. Most current equipment is extremely sensitive to voltage sag, and the voltage sag lasting for a plurality of cycles can interrupt the operation of the equipment, thereby causing great economic loss.
At present, voltage sag occurring in a high-quality power park is solved by adopting a voltage sag compensation device, the existing voltage sag compensation devices are various, for example, a Solid State Transfer Switch (SSTS), an Uninterruptible Power Supply (UPS), a Dynamic Voltage Restorer (DVR), a distributed power supply (DG), and the like, and different compensation devices have certain differences in treatment cost and treatment effect. In addition to the above compensation device, a common method for dealing with voltage sag also includes temporarily switching the load in the sag occurrence region to other normal power supplies in a switch switching manner.
In the same high-quality electric power park, how to classify and manage the characteristics of voltage sag according to various sensitive loads, how to coordinate the switching and the sag compensation devices, how to match various voltage sag compensation devices and even how to smooth and compensate the voltage quality by various compensation devices are urgent problems of power supply quality and power supply cost.
Disclosure of Invention
The embodiment of the invention provides a park-level voltage sag layered grading treatment system, a park-level voltage sag layered grading treatment method and terminal equipment, which are used for solving the technical problem of poor voltage sag treatment effect caused by poor coordination between switch switching and sag compensation devices adopted for voltage sag treatment in the existing power park.
In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:
a park level voltage sag layered grading management method comprises a change-over switch device, a first power supply, a second power supply, a first type of sensitive users, a second type of sensitive users and a voltage and current sampling device; the first power supply is connected with the first type sensitive users through the change-over switch device, and the second power supply is connected with the second type sensitive users through the change-over switch device;
the change-over switch device is used for switching a power supply loop of the first power supply and the second power supply and selecting the first sensitive user or the second sensitive user, and comprises a first switch, a second switch and a solid-state switch, wherein a first end of the first switch is connected with the first power supply, a second end of the first switch is respectively connected with a first end of the solid-state switch and the first sensitive user, a first end of the second switch is connected with the second power supply, and a second end of the second switch is respectively connected with a second end of the solid-state switch and the second sensitive user;
the voltage and current sampling device is used for collecting the voltage output by the first power supply, the voltage output by the first switch, the current flowing into the first type of sensitive users, the voltage output by the second power supply, the voltage output by the second switch, the current flowing into the second type of sensitive users and the current of the solid-state switch.
Preferably, the second type of sensitive users comprises a first stage sensitive user, a second stage sensitive user and a third stage sensitive user which are connected in parallel with the change-over switch device; the first-stage sensitive users and the second-stage sensitive users are connected in parallel with an uninterruptible power supply as a compensation device, the third-stage sensitive users are connected in series with a dynamic voltage restorer as a compensation device, and the dynamic voltage restorer is connected with the change-over switch device.
The invention also provides a park level voltage sag layered and graded treatment method, which comprises the following steps:
s1, acquiring a voltage value of a park level power system, and starting a compensation device of an uninterruptible power supply or a dynamic voltage restorer in the park level voltage sag hierarchical treatment system according to claim 2 if the voltage value of the park level power system is not greater than a voltage threshold;
s2, detecting a first voltage output by a first power supply and a second voltage output by a second power supply through a voltage and current sampling device;
s3, if the first voltage is larger than the second voltage, the change-over switch device is not started, and a compensation device of an uninterruptible power supply or a dynamic voltage restorer in a second type of sensitive users is controlled to compensate the voltage to a voltage threshold value for the corresponding sensitive users;
s4, if the first voltage is smaller than the second voltage, starting the change-over switch device, and detecting the voltage output by the second power supply through the voltage and current sampling device again to be recorded as a third voltage;
s5, if the third voltage is larger than a voltage threshold value, locking the compensation devices of the uninterruptible power supply and the dynamic voltage restorer in the second type of sensitive users; if the third voltage is not greater than the voltage threshold, the compensation device of the uninterruptible power supply or the dynamic voltage restorer in the second type of sensitive users continuously compensates the voltage to the voltage threshold for the corresponding sensitive users;
wherein the voltage threshold is 75% of the voltage rating.
Preferably, the step of switching the operation of the switching means comprises:
if the first voltage is smaller than a voltage threshold and the second voltage is equal to the voltage threshold, the first switch is switched off, after waiting for a first time, the fourth voltage output by the first switch and the first current flowing into the first type of sensitive users are collected by the voltage and current sampling device;
and if the first switch is completely disconnected, the solid-state switch is conducted, and the change-over switch device completes the switching work.
Preferably, the change-over switch device is not activated if the first voltage is not less than a voltage threshold and the second voltage is not equal to the voltage threshold.
Preferably, after the solid-state switch is turned on or switched on, the step of switching the operation of the switching device includes:
continuously acquiring a fifth voltage output by the first power supply and a sixth voltage output by the second power supply through the voltage and current sampling device;
if the fifth voltage is not less than the voltage threshold, waiting for a second time and then acquiring a seventh voltage output by the first power supply through a voltage and current sampling device;
if the seventh voltage is greater than the voltage threshold, the first switch is switched on or switched on, and in a third time, second current of the solid-state switch is collected through the voltage and current sampling device;
if the second current is larger than the current threshold, the solid-state switch is switched off; and after waiting for the third time, if the second current is smaller than the current threshold, disconnecting the solid-state switch, and finishing the switching work of the change-over switch device.
Preferably, the first time is 3ms, the second time is 1min, and the third time is 15 ms.
Preferably, the compensation device for starting the uninterruptible power supply or the dynamic voltage restorer in the park level voltage sag hierarchical governing system specifically comprises:
if the voltage value of the park level power system is smaller than the voltage threshold value and larger than the 50% voltage rated value, starting an uninterrupted power supply of a first level sensitive user to supply power to the first level sensitive user for compensating voltage;
and if the voltage value of the park level power system is less than 50% of the voltage rated value, starting a dynamic voltage restorer to supply power to third-level sensitive users for compensating voltage.
The present invention also provides a computer-readable storage medium for storing computer instructions which, when run on a computer, cause the computer to perform the park-level voltage sag hierarchical governance method described above.
The invention also provides a terminal device, comprising a processor and a memory:
the memory is used for storing program codes and transmitting the program codes to the processor;
and the processor is used for executing the park-level voltage sag hierarchical management method according to the instructions in the program codes.
According to the technical scheme, the embodiment of the invention has the following advantages:
1. the park-level voltage sag hierarchical management system is divided into a first type of sensitive users and a second type of sensitive users according to the voltage tolerance capacity of the sensitive users, the voltage sag of the first type of sensitive users is managed by adopting a change-over switch device, the voltage sag of the second type of sensitive users is managed by adopting a compensation device, the second type of sensitive users are divided into three-level sensitive users according to the voltage sag amplitude tolerance capacity, and different compensation devices are selected according to the sensitive users of different levels to smoothly compensate the voltage of the sensitive users; the system also adopts the switching-on or switching-off of a switch in the change-over switch device to realize the rapid switching, solves the problem of the rapid switching between double power supplies, and also solves the technical problem of poor voltage sag treatment effect caused by poor coordination between the switch switching adopted for voltage sag treatment and the sag compensation device in the existing electric power park.
2. According to the park level voltage sag layered and graded management method, whether a compensation device is started or not is determined by comparing the acquired voltage value of the park level power system with a voltage threshold, whether a change-over switch device works or not is controlled according to the output voltage of a first power supply and a second power supply, then the voltage of a sensitive user is compensated to the voltage threshold by the compensation device, and the problem of voltage sag is solved. The method adopts the coordination and matching of the change-over switch device and the compensation device to jointly manage the voltage sag, the change-over switch device is used as a master control device, the compensation device is used as a slave control device, the introduction of the change-over switch device enables the sag time length required to be processed by the compensation device to be obviously shortened, the requirements of sensitive users on the energy storage unit can be effectively reduced, the sag management cost is saved, and the technical problem that the voltage sag management effect is poor due to the fact that the coordination and matching between the switch switching adopted for voltage sag management and the sag compensation device in the existing electric power park are poor is solved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a block diagram of a park-level voltage sag hierarchical treatment system according to an embodiment of the present invention.
Fig. 2 is a block diagram of a switching device of a park-level voltage sag hierarchical management system according to an embodiment of the present invention.
Fig. 3 is a flowchart of the steps of the park-level voltage sag hierarchical management method according to the embodiment of the present invention.
Fig. 4 is a flowchart of coordination control of the switching device and the compensation device in the park-level voltage sag hierarchical management method according to the embodiment of the present invention.
Fig. 5 is a flowchart of a park-level voltage sag hierarchical management method for switching off a mechanical switch and switching on a solid-state switch according to an embodiment of the present invention.
Fig. 6 is a flowchart of a park-level voltage sag hierarchical management method for closing a mechanical switch and opening a solid-state switch according to an embodiment of the present invention.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Interpretation of terms in the examples of the present invention:
voltage sag: the voltage effective value is reduced in a short time, which is the problem of voltage disturbance caused by power supply system faults, transformer excitation, large motor starting and the like. Voltage sag has two international definitions, one is the voltage sag named "voltage sag" by IEEE, which is defined as: the root mean square value of the voltage suddenly drops to 90-10% of the rated voltage, and the short-time disturbance phenomenon that the duration time is 0.5 cycle to 1 min; the other is that IEC names the voltage dip as "voltage dip," which is defined as 90% to 1% of the rated voltage.
Typical sensitive devices: when the voltage of a device sensitive to the supply voltage drops to a certain level, the device whose operation state is susceptible to influence is a sensitive device, also called a sensitive load.
Voltage sag tolerance of sensitive devices: when the effective voltage value is constant and equal to the rated voltage of the sensitive equipment, the sensitive equipment normally operates; for a voltage sag with a certain sag amplitude, the time length capacity that the sensitive device can maintain normal operation under the voltage sag is called the voltage sag tolerance capacity of the sensitive device.
Solid State Transfer switch ssts: the fast change-over switch based on the thyristor antiparallel and the fast switch structure is a high-speed switching device capable of completing the dual-power switching within 15-20 ms.
Dynamic Voltage restorer dvr (dynamic Voltage regulator): the inverter mainly comprises an inverter, a filter, a direct current energy storage unit and a transformer, wherein the inverter adopts a high-frequency switching device IGBT or IGCT to ensure the quick response characteristic of the DVR. The DVR is used in series in the distribution line, when the system supplies power normally, the dynamic voltage restorer is in a low-consumption standby state, and the current conversion side of the transformer is in short circuit; when voltage sag or fluctuation occurs on the system side, the DVR can respond quickly to generate alternating current compensation voltage and inject the alternating current compensation voltage into a power supply system through a transformer to compensate the difference between the fault voltage and the rated voltage and ensure the voltage quality of the load side.
Uninterruptible Power supply ups (uniterrupdable Power system): the system equipment is characterized in that a storage battery is connected with a converter, and direct current stored in the storage battery is converted into rated alternating current required by a load through the converter. The uninterruptible power supply is mainly used for providing stable and uninterrupted power supply for a single computer, a computer network system or other electronic equipment such as an electromagnetic valve, a pressure transmitter and the like. When the commercial power is interrupted (power failure in an accident), the UPS immediately converts the direct current electric energy of the storage battery into the alternating current electric energy required by the load, and the load keeps normal work and protects the software and hardware of the load from being damaged.
Distributed power supply dg (distributed generation): refers to a small modular, environmentally compatible, self-contained power supply with power of several kilowatts to 50MW (megawatts). These power sources are owned by the power department, the power consumer, or a third party to meet power system and consumer specific requirements. Such as peak regulation, power supply for remote users or business areas and residential areas, power transmission and transformation investment saving, power supply reliability improvement and the like.
Static Var compensator svc (static Var compensator): the dynamic reactive power compensation device is a rapid, smooth and controllable dynamic reactive power compensation device without a rotating component. The static reactive compensator is used by connecting a controllable reactor and a power capacitor (fixed or grouping switching) in parallel. The capacitor can emit reactive power (capacitive), the controllable reactor can absorb reactive power (inductive), the whole device can be smoothly changed from emitting reactive power to absorbing reactive power (or reversely), and the response is quick.
Phase jump: the phase jump is the change of the voltage phase angle before and after the voltage sag, and since each phase voltage is a complex number containing both amplitude and phase angle, not only the amplitude of the voltage changes before and after the voltage sag occurs, but also the voltage phase angle may change, and the phase change is called as phase jump. For voltage sags caused by three-phase faults, the difference of the impedance ratio X/R between the power supply system and the fault feeder line causes phase deviation of three-phase consistency; for voltage sags caused by asymmetric faults, phase jumps may occur even if there are no phase jumps in the voltage of the faulty phase or between faulty phases.
For the technical scheme of voltage sag treatment in the existing power park, for example, the invention patent of a comprehensive treatment method for voltage sag in a high-quality power park, which is disclosed by the intellectual property office of China in 2016, 9, 21, is published as CN105958478A, and the content of the comprehensive treatment method for voltage sag in the high-quality power park, which comprises the following steps of A) recording the abnormal voltage waveform of an electric energy quality monitoring point in the high-quality power park by using a wave recorder; B) analyzing the recorded abnormal voltage waveform of the power quality monitoring point to obtain the sag depth of the voltage waveform of the voltage sag; C) carrying out tolerance grading on sensitive users according to the tolerance of the sensitive users in the high-quality power park to the voltage sag; D) according to the analysis result, one voltage sag control measure which can meet the requirements of sensitive users and has the best economical efficiency is selected from multiple voltage sag control measures to control. The comprehensive treatment method for the voltage sag in the high-quality electric power park, disclosed by the invention, is used for rapidly responding to the generated voltage sag and treating the voltage sag, so that the safe and economic operation of voltage sag sensitive users is guaranteed, and the comprehensive treatment method has a good application prospect. The specific voltage compensation strategy in the method is as follows: the level-A sensitive user is represented by L1, the capability of bearing voltage sag is strongest, and an SVC is configured to be used as a voltage sag compensation device; class AA sensitive users, for which UPS is configured as a voltage sag compensation device, are denoted by L2; AAA-level sensitive users, for which the DVR is configured as a voltage sag compensation device, are denoted by L3; and controlling corresponding sensitive user phases to operate corresponding voltage sag treatment devices according to the sag depths of the voltage sag voltage waveforms, and uniformly treating the voltage sag. The method can be divided into the following two steps: if the voltage sag depth Usag is less than 50%, switching a solid-state switch, switching a power supply line to a standby feeder line, and further calculating the PPP bus voltage; if the voltage sag is 50% < Usag < 90%, the solid-state switch is not required to be switched, and the next step is directly carried out; if the sag voltage meets Usags of more than 90 percent, finishing voltage sag treatment if the sag voltage meets the Usags of more than 90 percent, and if the sag voltage does not meet the Usags of more than 90 percent, carrying out the next step; the other step is to calculate the voltage sag depth, if the sag voltage Usag is greater than 70%, the DVR is only put into the treatment of AAA level sensitive users, and the UPS and the SVC do not act; if the sag voltage is 50% < Usag < 70%, the DVR and the UPS are put into the system to respectively carry out voltage sag treatment on the AAA level user and the AA level user, and the SVC does not act; if Utag is less than 50%, the DVR, the UPS and the SVC are started to carry out voltage sag compensation on sensitive users of three levels. However, the comprehensive treatment method for voltage sag in the high-quality power park only divides the power supply grade by the voltage sag amplitude value to realize graded power supply, does not consider the voltage sag tolerance of typical sensitive equipment, so that the temporary sag treatment cost of the designed scheme is higher, and the capacity requirement of compensation equipment is increased and the treatment cost is increased due to the lack of a coordination strategy between a solid-state change-over switch and each treatment equipment. A switching control strategy lacking a solid-state switch exists, and if the switching fails, greater loss is caused; the problem of smooth switching of voltage sag management equipment (such as a DVR) is not considered, and particularly, phase jump caused by instantaneous switching-off of the DVR after compensation is finished causes certain influence on the operation of sensitive equipment.
The method comprises the steps that a park level voltage sag hierarchical management system, a park level voltage sag hierarchical management method and terminal equipment are provided, the park level voltage sag hierarchical management system is divided into a first type of sensitive users and a second type of sensitive users according to the voltage tolerance capacity of typical sensitive equipment, the equipment with short tolerance time is layered according to the sag tolerance time, the equipment with short tolerance time is further graded according to the sag tolerance amplitude, the load with high voltage sag tolerance capacity is managed in a centralized mode, the load with low voltage sag tolerance capacity is managed in a targeted mode, the logic control of a compensation device and a change-over switch device in the sensitive users is regulated and controlled comprehensively according to the hierarchical grading result, the voltage amplitude and the phase are considered comprehensively when the compensation device carries out voltage compensation, and phase jump caused when the compensation device is put into and taken out of the system is eliminated; the method is used for solving the technical problem that the coordination between the switch switching and sag compensation devices adopted for voltage sag treatment in the existing electric power park is poor, so that the voltage sag treatment effect is poor.
The first embodiment is as follows:
fig. 1 is a frame diagram of a park-level voltage sag hierarchical treatment system according to an embodiment of the present invention, and fig. 2 is a frame diagram of a switch device of the park-level voltage sag hierarchical treatment system according to an embodiment of the present invention.
As shown in fig. 1 and fig. 2, an embodiment of the present invention provides a park-level voltage sag hierarchical management system, which includes a switch device 10, a first power supply 1, a second power supply 2, a first type of sensitive users 30, a second type of sensitive users 40, and a voltage and current sampling device; the first power supply 1 is connected with a first type sensitive user 30 through a change-over switch device 10, and the second power supply 2 is connected with a second type sensitive user 40 through the change-over switch device 10;
the change-over switch device 10 is used for changing over the power supply circuits of the first power supply 1 and the second power supply 2 and selecting the first sensitive user 30 or the second sensitive user 40, the change-over switch device 10 comprises a first switch K1, a second switch K2 and a solid-state switch Kss, a first end of the first switch K1 is connected with the first power supply 1, a second end of the first switch K1 is respectively connected with a first end of the solid-state switch Kss and the first sensitive user 30, a first end of the second switch K2 is connected with the second power supply 2, and a second end of the second switch K2 is respectively connected with a second end of the solid-state switch Kss and the second sensitive user 40;
the voltage and current sampling device is used for collecting the voltage U output by the first power supply 11aVoltage U outputted from the first switch K11bCurrent I flowing into sensitive users of the first type 301Voltage U output by the second power supply 22aVoltage U outputted from the second switch K22bCurrent I flowing into sensitive users of the second type 402And current I of solid-state switch Kss12。
In an embodiment of the present invention, the second type of sensitive users 40 includes a first stage sensitive user 41, a second stage sensitive user 42 and a third stage sensitive user 43 connected in parallel with the diverter switch device 10; the first-stage sensitive users 41 and the second-stage sensitive users 42 are connected in parallel with an uninterruptible power supply UPS as a compensation device, the third-stage sensitive users 43 are connected in series with a dynamic voltage restorer DVR as a compensation device, and the dynamic voltage restorer DVR is connected with the change-over switch device 10.
The first switch K1 and the second switch K2 are preferably mechanical switches.
In the embodiment of the present invention, the tolerance capability of each typical sensitive device is detailed in table 1 below, the ACC and the trip unit are sensitive to the amplitude and the duration of the voltage sag, and are also susceptible to the phase jump, and if the upper limit of the amplitude tolerance and the lower limit of the duration tolerance are taken, as can be seen from table 1, the upper limit of the amplitude of the voltage sag is 75% of the rated voltage, and the lower limit of the duration is 10ms, so the objective of the hierarchical governing range of the campus level voltage sag is that the amplitude of the voltage sag suffered by each sensitive device is below 75%, and the duration is above 10 ms.
TABLE 1 upper and lower limit values of voltage sag tolerance of sensitive equipment
| Type of sensitive device | Upper and lower limits of tolerance curve amplitude and duration |
| Tripping device | {[30％，45％]，[10ms，20ms]} |
| PC | {[29％，31％]，[97ms，92ms]} |
| ACC | {[30％，60％]，[10ms，120ms]} |
| ASD | {[55％，75％]，[10ms，35ms]} |
| PLC | {[15％，32％]，[20ms，433ms]} |
As can be seen from table 1 above, the sensing device has a certain voltage tolerance capability, and has different tolerance degrees for the duration of the voltage sag, and both the switching device 10 and the compensation device can cope with the voltage sag with a longer duration. However, the compensation arrangement requires additional time-dependent investment in sensitive equipment to cope with the more permanent voltage sag; the voltage sag phenomenon of any duration can be dealt with after the switch switching in the switching device 10 is completed. Therefore, for voltage sags of longer duration, fast switching on devices should be a priority in a reasonable design scenario. The mainstream technology for switching the switch in the switch device 10 can realize 20-30ms action completion, and in this embodiment, the upper limit of the voltage amplitude tolerance capability of the sensitive equipment is 75% of the rated voltage UNFor long-term endurance of voltage sags exceeding 30msSensitive equipment adopts a change-over switch device 10 for centralized treatment; for sensitive equipment with the voltage sag time endurance capacity of less than 30ms, a compensation device with the action time within 5-10ms can be adopted for governing. And the sensitive equipment with the voltage sag duration endurance capability exceeding 30ms is used as a first class of sensitive users, and the sensitive equipment with the voltage sag duration endurance capability less than 30ms is used as a second class of sensitive users.
In the embodiment of the present invention, according to different tolerance degrees of the sensitive device to the voltage sag amplitude and the phase jump, the second class of sensitive users are classified into three classes, specifically: the voltage sag amplitude endurance capacity is 50 percent UNThe above is defined as a first-level sensitive user, such as an ASD sensitive device; the voltage sag amplitude endurance capacity is 50 percent UNThe following definition without being influenced by phase jump is a second-level sensitive user, such as sensitive equipment like PLC; the voltage sag amplitude endurance capacity is 50 percent UNThe following devices which are sensitive to phase jump are defined as third-stage sensitive users, such as low-voltage release devices and the like. For the first-stage sensitive users and the second-stage sensitive users, an Uninterrupted Power Supply (UPS) is configured as a compensation device of the sensitive users to quickly compensate the voltage amplitude of the sensitive users to 75 percent UN(ii) a For third-level sensitive users, the DVR is configured as a compensation device of the sensitive users, and the voltage amplitude and the phase angle of the sensitive users are smoothly compensated to 75 percent UNAnd the influence on the operation of the second-level sensitive user caused by phase jump generated in the switching and exiting processes of the compensation device is avoided.
It should be noted that the park-level voltage sag hierarchical management system is divided into two types of sensitive users from two levels of voltage sag duration and voltage sag amplitude according to the voltage tolerance capability of each sensitive device to comprehensively manage the voltage sag, firstly centralizedly manage the sensitive devices with strong tolerance capability during the sag duration, and manage the high-sensitive devices in a targeted configuration compensation device. And the voltage sag is managed by three-level sensitive users according to the tolerance degree of the sensitive equipment to the voltage sag amplitude and the phase jump, so that the compensation of the voltage amplitude is ensured to the maximum extent, the sensitive equipment is prevented from being influenced by the phase jump, and meanwhile, the sag management cost is reduced.
The park-level voltage sag hierarchical management system provided by the invention is divided into a first type of sensitive users and a second type of sensitive users according to the voltage tolerance capacity of the sensitive users, the voltage sag of the first type of sensitive users is managed by adopting a change-over switch device, the voltage sag of the second type of sensitive users is managed by adopting a compensation device, the second type of sensitive users is divided into three-level sensitive users according to the voltage sag amplitude tolerance capacity, and different compensation devices are selected according to the sensitive users of different levels to smoothly compensate the voltage of the sensitive users; the system also adopts the switching-on or switching-off of a switch in the change-over switch device to realize the rapid switching, solves the problem of the rapid switching between double power supplies, and also solves the technical problem of poor voltage sag treatment effect caused by poor coordination between the switch switching adopted for voltage sag treatment and the sag compensation device in the existing electric power park.
It should be noted that, the park-level voltage sag hierarchical management system adopts the change-over switch device to manage the voltage sag with longer duration of voltage sag tolerance of the sensitive equipment, and adopts the compensation device corresponding to the sensitive user to manage the sag event with shorter duration of voltage sag tolerance and overlarge voltage sag amplitude. The change-over switch device can realize the avoidance of long-time sag, the introduction of the change-over switch device obviously shortens the sag time length required to be processed by the compensation device, the dependence of the compensation device on the energy storage unit can be effectively reduced, and the economy is better.
Example two:
fig. 3 is a flowchart of steps of a park-level voltage sag hierarchical management method according to an embodiment of the present invention, and fig. 4 is a flowchart of coordinated control of a change-over switch device and a compensation device of the park-level voltage sag hierarchical management method according to an embodiment of the present invention.
As shown in fig. 3 and 4, an embodiment of the present invention provides a park-level voltage sag hierarchical management system, including the following steps:
s1, acquiring a voltage value of a park level power system, and starting a compensation device of an uninterruptible power supply or a dynamic voltage restorer in the park level voltage sag hierarchical management system if the voltage value of the park level power system is not greater than a voltage threshold;
s2, detecting a first voltage output by a first power supply and a second voltage output by a second power supply through a voltage and current sampling device;
s3, if the first voltage is larger than the second voltage, the change-over switch device is not started, and the compensation device of the uninterrupted power supply or the dynamic voltage restorer in the second type of sensitive users is controlled to compensate the voltage to the voltage threshold value for the corresponding sensitive users;
s4, if the first voltage is smaller than the second voltage, starting a change-over switch device, and detecting the voltage output by the second power supply through the voltage and current sampling device again to be recorded as a third voltage;
s5, if the third voltage is larger than a voltage threshold value, locking a compensation device of an uninterrupted power supply and a dynamic voltage restorer in a second type of sensitive users; if the third voltage is not greater than the voltage threshold, the compensation device of the uninterruptible power supply or the dynamic voltage restorer in the second type of sensitive users continuously compensates the voltage to the voltage threshold for the corresponding sensitive users;
wherein the voltage threshold is 75% of the voltage rating.
In step S1 of the embodiment of the present invention, the voltage value of the campus level power system of the power system connected to the campus level voltage sag hierarchical governance system is mainly obtained, whether the voltage value of the campus level power system is not greater than a voltage threshold is determined, and if the voltage value of the campus level power system is greater than the voltage threshold, neither the change-over switch device in the campus level voltage sag hierarchical governance system nor the compensation device connected to the sensitive user is activated. And if the voltage value of the park level power system is not greater than the voltage threshold, starting a compensation device connected with a sensitive user in the park level voltage sag hierarchical treatment system.
It should be noted that, according to the voltage endurance of the sensitive device in table 1 in the first embodiment, the voltage threshold is set to 75% of the rated voltage. The voltage value of the park level power system is greater than 75% of the rated voltage and is defined as a sag level 1, namely, a change-over switch device and a compensation device connected with a sensitive user in the park level voltage sag hierarchical treatment system do not work; the voltage value of the park level power system is less than or equal to 75% of the rated voltage and is defined as a sag level 2, namely, a compensation device connected with a sensitive user in the park level voltage sag hierarchical treatment system is started. And determining whether the switching switch device and a compensation device connected with a sensitive user are started and the specific action time sequence according to the voltage sag grade. In order to increase the overall flexibility, a part of the functions of the compensation device connected to sensitive users are concentrated on the controller of the change-over switching device, i.e. the switch in the change-over switching device acts as a master control device and the compensation device acts as a slave control device.
In steps S2, S3, and S4 of the embodiment of the present invention, after the compensation device connected to the sensitive user in the campus level voltage sag hierarchical management system is activated, the voltage and current sampling device detects the first voltage U output by the first power supply1aAnd a second voltage U output by a second power supply2a. A first voltage U obtained by detection1aAnd a second voltage U2aAnd comparing, and adopting different governing modes for the voltage sag according to a comparison result. The coordination strategy of the change-over switch device and the compensation device is realized by detecting the voltage output by the first power supply and the second power supply, and is more scientific and reasonable than the existing coordination strategy by the sag depth, so that the sag treatment efficiency can be effectively improved, and the switching of the power supplies can be reduced.
Note that, as shown in fig. 4, if the first voltage U is set to be the first voltage U1aGreater than the second voltage U2aThen, the change-over switch device is not started, so that the compensation device connected with the second type of sensitive users compensates the voltage of the corresponding sensitive users to the voltage threshold value; if the first voltage U is1aIs less than or equal to the second voltage U2aStarting the change-over switch device, supplying power to the sensitive equipment by the second power supply and the first power supply together, realizing that the power supply for the sensitive equipment is switched to a standby power supply (namely the second power supply), if the fault of the first power supply is eliminated, starting the change-over switch device after waiting for 1 minute in order to prevent multiple times of sag generation in a short time, and judgingWhether or not the interruption satisfies the switching condition of the change-over switch device (first voltage U)1aNot less than the voltage threshold) and if satisfied will switch back to the first power supply. And after the switching device to be switched is finished, detecting whether the voltage output by the second power supply is normal or not through the current and voltage sampling device, if so, locking the compensation device connected with a sensitive user, and enabling the park-level voltage sag layered and graded treatment system to exit from a compensation mode.
In step S5 of the embodiment of the present invention, the voltage output by the second power supply is detected by the voltage and current sampling device according to step S4 and is recorded as a third voltage, where the third voltage is not greater than the voltage threshold, so that the compensation device of the uninterruptible power supply or the dynamic voltage restorer in the second type of sensitive users continues to compensate the voltage to the voltage threshold for the corresponding sensitive users.
It should be noted that the park-level voltage sag layered and graded management method adopts the coordination and cooperation of the change-over switch device and the compensation device to jointly manage the voltage sag, the change-over switch device serves as the master control device, the compensation device serves as the slave control device, and the introduction of the change-over switch device enables the sag time length required to be processed by the compensation device to be obviously shortened, so that the requirements of sensitive users on the energy storage unit can be effectively reduced, and the sag management cost is saved.
According to the park-level voltage sag layered and graded management method, whether the compensation device is started or not is determined by comparing the acquired voltage value of the park-level power system with the voltage threshold, whether the change-over switch device works or not is controlled according to the output voltage of the first power supply and the second power supply, then the compensation device is adopted to compensate the voltage of a sensitive user to the voltage threshold, and the problem of voltage sag is solved. The method adopts the coordination and matching of the change-over switch device and the compensation device to jointly manage the voltage sag, the change-over switch device is used as a master control device, the compensation device is used as a slave control device, the introduction of the change-over switch device enables the sag time length required to be processed by the compensation device to be obviously shortened, the requirements of sensitive users on the energy storage unit can be effectively reduced, the sag management cost is saved, and the technical problem that the voltage sag management effect is poor due to the fact that the coordination and matching between the switch switching adopted for voltage sag management and the sag compensation device in the existing electric power park are poor is solved.
Fig. 5 is a flowchart of a park-level voltage sag hierarchical management method for switching off a mechanical switch and switching on a solid-state switch according to an embodiment of the present invention.
In one embodiment of the invention, as shown in fig. 5, the step of switching the operation of the switching means comprises:
if the first voltage is smaller than the voltage threshold and the second voltage is equal to the voltage threshold, the first switch is switched off, and after waiting for the first time, a fourth voltage output by the first switch and a first current flowing into a first type of sensitive users are collected by the voltage and current sampling device;
if the first switch is completely disconnected, the solid-state switch is switched on or switched on, and the switching device completes switching work.
In the embodiment of the invention, if the first voltage is not less than the voltage threshold and the second voltage is not equal to the voltage threshold, the switch device is not activated.
The condition that the first switch is completely turned off is that the fourth voltage is 0V and the first current is 0A. The first switch and the second switch are both preferably mechanical switches, the solid-state switches are preferably fully-controlled solid-state switches, and the time required for the mechanical switches and the solid-state switches to open and close the gates is as shown in table 2 below.
| Type of device | Speed of opening | Closing speed |
| Quick mechanical switch | 3ms | 15ms |
| Full-control solid-state switch | 10μs | 1～3ms |
In this embodiment, for example, when the power supply loop of the first power supply fails, if the solid-state switch is closed and then the mechanical switch is opened when a voltage sag occurs, the power supply loop of the first power supply and the power supply loop of the second power supply are connected in parallel, which may generate a high short-circuit current and damage the solid-state switch. Therefore, the park-level voltage sag layered grading management method firstly triggers the mechanical switch to be disconnected, the solid-state switch can be closed after the mechanical switch is completely separated, the short circuit of the line between the power supply loop of the first power supply and the power supply loop of the second power supply can be effectively avoided, the whole switching time does not exceed 3.5ms as the disconnection time of the mechanical switch is 3ms, although the delay triggering scheme can cause the voltage interruption of about 3.5ms, the method can be completely accepted for sensitive equipment with the sag tolerance time of more than 30 ms. Specifically, as shown in fig. 5, when the line is operating normally, the voltage-current sampling device monitors the voltage U output from the first power supply1aAnd the voltage U output by the second power supply1bTo determine whether a voltage sag occurs in a line of the first power supply output voltage; if a voltage sag occurs, i.e. U1a<Uref，UrefIf the voltage threshold is the voltage threshold, starting to execute the switching action; firstly triggering the first switch K1 to be switched off, waiting for 3ms due to the slow switching-off speed of the mechanical switch, and simultaneously detecting the current I flowing into the first sensitive user by the voltage and current sampling device1And the first switch outputs a fourth voltage U1bTo determine whether the first switch K1 is fully open; when the first K1 is completely turned off, that is, the fourth voltage is 0V and the first current is 0A, the solid-state switch Kss is triggered to be turned on to supply power to the sensitive user, so that the switching process is completed, and the whole switching process does not exceed 3.5 ms.
Fig. 6 is a flowchart of a park-level voltage sag hierarchical management method for closing a mechanical switch and opening a solid-state switch according to an embodiment of the present invention.
In the embodiment of the present invention, after the solid-state switch is turned on or switched on, the step of switching the operation of the switching device includes:
continuously acquiring a fifth voltage output by the first power supply and a sixth voltage output by the second power supply through the voltage and current sampling device;
if the fifth voltage is not less than the voltage threshold, waiting for a second time and then acquiring a seventh voltage output by the first power supply through the voltage and current sampling device;
if the seventh voltage is larger than the voltage threshold, the first switch is conducted or switched on, and in a third time, the second current of the solid-state switch is collected through the voltage and current sampling device;
if the second current is larger than the current threshold, the solid-state switch is switched off; and after waiting for the third time, if the second current is smaller than the current threshold, disconnecting the solid-state switch, and finishing the switching work of the switch device.
It should be noted that, as shown in fig. 6, the fifth voltage U output by the first power supply is monitored by the voltage current sampling device1a' and a sixth voltage U output from the second power supply2a"value of, judgment U1aWhether or not less than Uref(ii) a Waiting for 1 minute is needed to prevent multiple sags in a short time, if no sag occurs in the 1 minute, the seventh voltage U output by the first power supply is output1a"always greater than UrefThen the first power supply requirement begins to resume power supply. When power supply is recovered, the first switch is triggered to be switched on firstly, the switching-on speed of the mechanical switch is low, the mechanical switch can be switched on only in 15ms, and the solid-state switch cannot be switched off at the moment in order to ensure that a sensitive user cannot drop power in the period of time; continuing to monitor current I of solid state switch via voltage current sampling device12If I is detected12Greater than a current threshold IrefAnd the current of the solid-state switch generates overcurrent, which proves that the mechanical switch is successfully switched on, and the solid-state switch needs to be immediately switched off. If the current I of the solid-state switch is not detected all the time within 15ms12When overcurrent occurs, the solid-state switch is automatically turned off at the moment of 15ms, and the power supply loop of the first power supply and the power supply loop of the second power supply are prevented from being connected until the switching process is finishedThe indirect wire power supply is connected in parallel, and short circuit accidents occur. According to the park-level voltage sag layered grading treatment method, the delay trigger switch device is adopted, the phenomenon that overcurrent damages a switch device due to wrong switching is avoided, correct switching between the first power supply and the second power supply can be guaranteed, and the reliability of sag treatment is improved.
In an embodiment of the invention, the first time is 3ms, the second time is 1min, and the third time is 15 ms.
In an embodiment of the present invention, the compensation device for starting the uninterruptible power supply or the dynamic voltage restorer in the park level voltage sag hierarchical management system specifically includes:
if the voltage value of the park level power system is smaller than the voltage threshold value and larger than 50% of the voltage rated value, starting an uninterrupted power supply of a first level sensitive user to supply power to the first level sensitive user for compensating voltage;
and if the voltage value of the park level power system is less than 50% of the voltage rated value, starting a dynamic voltage restorer to supply power to third level sensitive users for compensating voltage.
Note that, if 50% UN<Voltage value Usag of park level power system<75％UNThe UPS is started to supply power to the first-level sensitive users, and the voltage amplitude is quickly compensated to 75 percent UN. If Usag<50％UNStarting the dynamic voltage restorer DVR to manage sag for the third-level sensitive users, and flatly compensating the voltage amplitude and the phase angle to 75 percent UNAvoiding phase jump in the compensation process; the UPS is started to supply power to the first-stage sensitive users and the second-stage sensitive users, and the voltage amplitude is quickly compensated to 75 percent UN。UNIs the voltage rating.
Example three:
the embodiment of the invention also provides a computer-readable storage medium, which is used for storing computer instructions, and when the computer instructions run on a computer, the computer is enabled to execute the park-level voltage sag hierarchical management method.
Example four:
the embodiment of the present invention further provides a terminal device, which is characterized by comprising a processor and a memory:
a memory for storing the program code and transmitting the program code to the processor;
and the processor is used for executing the park-level voltage sag hierarchical management method according to instructions in the program codes.
Illustratively, a computer program may be partitioned into one or more modules/units, which are stored in a memory and executed by a processor to accomplish the present application. One or more modules/units may be a series of computer program instruction segments capable of performing certain functions, the instruction segments describing the execution of a computer program in a device.
The device may be a computing device such as a desktop computer, a notebook, a palm top computer, a cloud server, and the like. The device may include, but is not limited to, a processor, a memory. Those skilled in the art will appreciate that the device is not limited and may include more or fewer components than those shown, or some components may be combined, or different components, e.g., the device may also include input output devices, network access devices, buses, etc.
The Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The storage may be an internal storage unit of the computer device, such as a hard disk or a memory of the computer device. The memory may also be an external storage device of the computer device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the computer device. Further, the memory may also include both internal and external storage units of the computer device. The memory is used for storing computer programs and other programs and data required by the computer device. The memory may also be used to temporarily store data that has been output or is to be output.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, methods and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system and method may be implemented in other ways. For example, the above-described system embodiments are merely illustrative, and for example, the division of the units is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, systems or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. A park level voltage sag layered hierarchical management method is applied to a park level voltage sag layered hierarchical management system and is characterized in that the park level voltage sag layered hierarchical management system comprises a change-over switch device, a first power supply, a second power supply, a first type of sensitive users, a second type of sensitive users and a voltage and current sampling device; the first power supply is connected with the first type sensitive users through the change-over switch device, and the second power supply is connected with the second type sensitive users through the change-over switch device;
the change-over switch device is used for switching a power supply loop of the first power supply and the second power supply and selecting the first sensitive user or the second sensitive user, and comprises a first switch, a second switch and a solid-state switch, wherein a first end of the first switch is connected with the first power supply, a second end of the first switch is respectively connected with a first end of the solid-state switch and the first sensitive user, a first end of the second switch is connected with the second power supply, and a second end of the second switch is respectively connected with a second end of the solid-state switch and the second sensitive user;
the voltage and current sampling device is used for collecting the voltage output by the first power supply, the voltage output by the first switch, the current flowing into the first type of sensitive users, the voltage output by the second power supply, the voltage output by the second switch, the current flowing into the second type of sensitive users and the current of the solid-state switch;
the second type of sensitive users comprise first-stage sensitive users, second-stage sensitive users and third-stage sensitive users which are connected with the change-over switch device in parallel; the first-stage sensitive users and the second-stage sensitive users are connected in parallel with an uninterruptible power supply as a compensation device, the third-stage sensitive users are connected in series with a dynamic voltage restorer as a compensation device, and the dynamic voltage restorer is connected with the change-over switch device;
the park level voltage sag layered and graded treatment method comprises the following steps:
s1, acquiring a voltage value of a park level power system, and starting a compensation device of an uninterruptible power supply or a dynamic voltage restorer in a park level voltage sag hierarchical management system if the voltage value of the park level power system is not greater than a voltage threshold;
s2, detecting a first voltage output by a first power supply and a second voltage output by a second power supply through a voltage and current sampling device;
s3, if the first voltage is larger than the second voltage, the change-over switch device is not started, and a compensation device of an uninterruptible power supply or a dynamic voltage restorer in a second type of sensitive users is controlled to compensate the voltage to a voltage threshold value for the corresponding sensitive users;
s4, if the first voltage is smaller than the second voltage, starting the change-over switch device, and detecting the voltage output by the second power supply through the voltage and current sampling device again to be recorded as a third voltage;
s5, if the third voltage is larger than a voltage threshold value, locking the compensation devices of the uninterruptible power supply and the dynamic voltage restorer in the second type of sensitive users; if the third voltage is not greater than the voltage threshold, the compensation device of the uninterruptible power supply or the dynamic voltage restorer in the second type of sensitive users continuously compensates the voltage to the voltage threshold for the corresponding sensitive users;
wherein the voltage threshold is 75% of the voltage rating.
2. The park-level voltage sag stratified charge management method according to claim 1, wherein the step of switching the switching means comprises:
if the first voltage is smaller than a voltage threshold and the second voltage is equal to the voltage threshold, the first switch is switched off, after waiting for a first time, the fourth voltage output by the first switch and the first current flowing into the first type of sensitive users are collected by the voltage and current sampling device;
and if the first switch is completely disconnected, the solid-state switch is switched on or switched on, and the switching switch device completes switching work.
3. The park-level voltage sag stratified charge management method according to claim 2, wherein the diverter switch device is not activated if the first voltage is not less than a voltage threshold and the second voltage is not equal to a voltage threshold.
4. The park-level voltage sag layered and graded treatment method according to claim 2, wherein the step of switching the operation of the switching device after the solid-state switch is turned on or switched off comprises:
continuously acquiring a fifth voltage output by the first power supply and a sixth voltage output by the second power supply through the voltage and current sampling device;
if the fifth voltage is not less than the voltage threshold, waiting for a second time and then acquiring a seventh voltage output by the first power supply through a voltage and current sampling device;
if the seventh voltage is greater than the voltage threshold, the first switch is switched on or switched on, and in a third time, second current of the solid-state switch is collected through the voltage and current sampling device;
if the second current is larger than the current threshold, the solid-state switch is switched off; and after waiting for the third time, if the second current is smaller than the current threshold, disconnecting the solid-state switch, and finishing the switching work of the change-over switch device.
5. The park-level voltage sag stratified charge management method according to claim 4, wherein the first time is 3ms, the second time is 1min, and the third time is 15 ms.
6. The park-level voltage sag layered and hierarchical governance method according to claim 1, wherein the compensation device for starting an uninterruptible power supply or a dynamic voltage restorer in the park-level voltage sag layered and hierarchical governance system specifically comprises:
if the voltage value of the park level power system is smaller than the voltage threshold value and larger than the 50% voltage rated value, starting an uninterrupted power supply of a first level sensitive user to supply power to the first level sensitive user for compensating voltage;
and if the voltage value of the park level power system is less than 50% of the voltage rated value, starting a dynamic voltage restorer to supply power to third-level sensitive users for compensating voltage.
7. A computer-readable storage medium for storing computer instructions which, when executed on a computer, cause the computer to perform the park-level voltage sag hierarchical remediation method of any one of claims 1 to 6.
8. A terminal device, comprising a processor and a memory:
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is used for executing the park level voltage sag hierarchical governance method according to any one of claims 1 to 6 according to instructions in the program code.
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