CN109167393B - Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system - Google Patents

Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system Download PDF

Info

Publication number
CN109167393B
CN109167393B CN201811187510.9A CN201811187510A CN109167393B CN 109167393 B CN109167393 B CN 109167393B CN 201811187510 A CN201811187510 A CN 201811187510A CN 109167393 B CN109167393 B CN 109167393B
Authority
CN
China
Prior art keywords
bus voltage
voltage
reactor
distribution network
limit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811187510.9A
Other languages
Chinese (zh)
Other versions
CN109167393A (en
Inventor
孙峰
李胜辉
戈阳阳
张潇桐
张钊
谢赐戬
赵清松
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Liaoning Electric Power Co Ltd
Original Assignee
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Liaoning Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by State Grid Corp of China SGCC, Electric Power Research Institute of State Grid Liaoning Electric Power Co Ltd filed Critical State Grid Corp of China SGCC
Priority to CN201811187510.9A priority Critical patent/CN109167393B/en
Publication of CN109167393A publication Critical patent/CN109167393A/en
Application granted granted Critical
Publication of CN109167393B publication Critical patent/CN109167393B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H02J3/383—
    • 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
    • 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
    • H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30—Reactive power compensation

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a distribution network pivot point voltage regulation method and system based on a distributed photovoltaic power generation system. The voltage regulating method comprises the following steps: collecting 380V bus voltage of a power distribution network of a distributed photovoltaic power generation system in real time; when the bus voltage of 380V is greater than a voltage threshold value, timing is started; when the timing time is greater than a time threshold, acquiring the current season; acquiring reactors in a corresponding preset capacity range according to the current season; a reactor is connected in parallel on a central point 10kV bus; judging whether the reduced 380V bus voltage acquired in real time exceeds the limit; when the lowered 380V bus voltage is out of limit, adjusting parameters of the reactor until the lowered 380V bus voltage is not out of limit; regulating the bus voltage of 380V is stopped. According to the voltage regulating method, under the fluctuation of photovoltaic output of the distributed photovoltaic power generation system, an active power distribution network load flow calculation method is adopted to analyze the bus overvoltage condition of the power distribution network, and finally, the bus voltage of the center point is dynamically regulated.

Description

Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system
Technical Field
The invention relates to the technical field of photovoltaic power generation, in particular to a distribution network pivot point voltage regulation method and system based on photovoltaic power generation fluctuation.
Background
The basic equipment of the existing distributed photovoltaic power generation system mainly comprises a photovoltaic cell assembly, a grid-connected inverter and other equipment, and the wiring is directly connected to a user side.
However, with the rapid development of distributed photovoltaic power generation, the problem that the voltage of a power distribution network is out of limit due to high-permeability photovoltaic power generation cannot be ignored. At present, students generally start with photovoltaic inverter control, energy storage device increase and transformer tap voltage regulation to improve the situation of out-of-limit of the distribution network voltage. The photovoltaic inverter control has limited capability of regulating voltage out-of-limit, and the photovoltaic inverter is difficult to adopt uniform manufacturers and to be uniformly allocated; the voltage out-of-limit can be adjusted to a certain extent by adding the energy storage device, but the cost is increased inevitably; and aiming at the current situation of equipment in a domestic power distribution network, only a small number of adjustable transformer taps are arranged, and the adjusting range and the flexibility are poor.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art or the related art.
Therefore, the first purpose of the invention is to provide a distribution network pivot point voltage regulating method based on a distributed photovoltaic power generation system.
The invention also provides a distribution network pivot point voltage regulating system based on the distributed photovoltaic power generation system.
In order to achieve the above object, according to a technical solution of a first aspect of the present invention, there is provided a distribution network pivot voltage regulation method based on a distributed photovoltaic power generation system, the voltage regulation method including: collecting 380V bus voltage of a power distribution network of the distributed photovoltaic power generation system in real time; when the bus voltage of 380V is greater than a voltage threshold value, timing is started; when the timing time is greater than a time threshold, acquiring the current season; acquiring a reactor in a corresponding preset capacity range according to the current season; the reactor is connected in parallel to a central point 10kV bus, so that the reactor absorbs the reactive power of the power distribution network in real time to reduce the 380V bus voltage; judging whether the reduced 380V bus voltage acquired in real time is out of limit or not; when the reduced 380V bus voltage is out of limit, adjusting parameters of the reactor, and continuously judging whether the reduced 380V bus voltage acquired in real time is out of limit or not until the reduced 380V bus voltage is not out of limit; and stopping regulating the 380V bus voltage.
Preferably, the distribution network center point voltage regulation method based on the distributed photovoltaic power generation system further includes: when the 380V bus voltage is less than or equal to the voltage threshold, stopping regulating the 380V bus voltage; when the timing time is less than or equal to the time threshold, stopping regulating the 380V bus voltage; and when the lowered bus voltage of 380V is not out of limit, stopping regulating the bus voltage of 380V.
Preferably, the step of obtaining the reactor within the corresponding preset capacity range according to the current season specifically includes: when the current season is spring, acquiring a reactor with the capacity of 2000 to 3000 kvar; when the current season is summer, acquiring a reactor with the capacity of 3500 kvar-5000 kvar; when the current season is autumn, acquiring a reactor with the capacity of 2000 to 3500 kvar; and when the current season is winter, acquiring the reactors with the capacity of 1000-2500 kvar.
Preferably, the step of judging whether the reduced 380V bus voltage collected in real time exceeds the limit specifically includes: judging whether the reduced 380V bus voltage meets a constraint condition Uimin≤Ui≤Uimax(ii) a When the reduced 380V bus voltage meets the constraint condition Uimin≤Ui≤UimaxWhen the bus voltage of 380V is reduced, the out-of-limit does not occur; otherwise, the bus bar power of 380V is reducedThe pressure is out of limit; wherein, UiFor reduced bus voltage of 380V, UiminAnd UimaxThe bus voltage limit value is a lower limit value and an upper limit value of the bus voltage limit value of 380V after reduction.
Preferably, the voltage threshold is 1.07UNSaid UNThe rated voltage of a 380V bus of the distributed photovoltaic power generation system is obtained; the time threshold ranges from 60s to 70 s; and the parameter of the reactor comprises equivalent impedance of the reactor.
The technical scheme of the second aspect of the invention provides a distribution network pivot point voltage regulating system based on a distributed photovoltaic power generation system, which comprises: the acquisition unit is used for acquiring 380V bus voltage of a power distribution network of the distributed photovoltaic power generation system in real time; the timing unit is used for starting timing when the 380V bus voltage is greater than a voltage threshold; the acquisition unit is used for acquiring the current season when the timing time is greater than a time threshold; the acquisition unit is further used for acquiring the reactors in the corresponding preset capacity range according to the current season; the regulating unit is used for connecting the reactor in parallel on a central point 10kV bus, so that the reactor can absorb the reactive power of the power distribution network in real time to reduce the 380V bus voltage; the judging unit is used for judging whether the reduced 380V bus voltage acquired in real time exceeds the limit; the adjusting unit is further configured to adjust parameters of the reactor when the reduced 380V bus voltage is out of limit, and the judging unit is further configured to continuously judge whether the reduced 380V bus voltage acquired in real time is out of limit until the reduced 380V bus voltage is not out of limit; the adjusting unit is further used for stopping adjusting the 380V bus voltage.
Preferably, the adjusting unit is further configured to stop adjusting the 380V bus voltage when the 380V bus voltage is less than or equal to the voltage threshold; the adjusting unit is further used for stopping adjusting the 380V bus voltage when the timing time is less than or equal to the time threshold; and the adjusting unit is also used for stopping adjusting the 380V bus voltage when the lowered 380V bus voltage is not out of limit.
Preferably, the obtaining unit is specifically configured to: when the current season is spring, acquiring a reactor with the capacity of 2000 to 3000 kvar; when the current season is summer, acquiring a reactor with the capacity of 3500 kvar-5000 kvar; when the current season is autumn, acquiring a reactor with the capacity of 2000 to 3500 kvar; and when the current season is winter, acquiring the reactors with the capacity of 1000-2500 kvar.
Preferably, the determining unit is specifically configured to: judging whether the reduced 380V bus voltage meets a constraint condition Uimin≤Ui≤Uimax(ii) a When the reduced 380V bus voltage meets the constraint condition Uimin≤Ui≤UimaxWhen the bus voltage of 380V is reduced, the out-of-limit does not occur; otherwise, the reduced 380V bus voltage is out-of-limit; wherein, UiFor reduced bus voltage of 380V, UiminAnd UimaxThe bus voltage limit value is a lower limit value and an upper limit value of the bus voltage limit value of 380V after reduction.
Preferably, the voltage threshold is 1.07UNSaid UNThe rated voltage of a 380V bus of the distributed photovoltaic power generation system is obtained; the time threshold ranges from 60s to 70 s; and the parameter of the reactor comprises equivalent impedance of the reactor.
The invention has the beneficial effects that:
according to the distribution network pivot point voltage regulating method based on the distributed photovoltaic power generation system, a proper active distribution network load flow calculation method is adopted under the fluctuation of photovoltaic output of the distributed photovoltaic power generation system so as to analyze the bus overvoltage condition of the distribution network, and finally, the bus voltage of the pivot point is dynamically regulated. Specifically, 380V bus voltage of the distributed photovoltaic power generation system is collected in real time, when the condition that the 380V bus voltage is larger than a voltage threshold value continuously exceeds a time threshold value, a current season is obtained, then a reactor in a corresponding preset capacity range is obtained according to the current season, so that the reactor is connected in parallel on a central point 10kV bus to absorb reactive power of a power distribution network in real time through a power supply reactor, the 380V bus voltage can be reduced based on an active power distribution network flow calculation method, when the reduced 380V bus voltage is out of limit, parameters of the reactor are adjusted, whether the reduced 380V bus voltage is out of limit or not is continuously judged, the 380V bus voltage is not adjusted until the reduced 380V bus voltage is out of limit, and the purpose of reducing the 380V bus voltage to be in a corresponding preset range is achieved, the voltages of all nodes of the power distribution network are controlled within the corresponding preset range, and the problem that the voltage of the power distribution network is out of limit when the distributed photovoltaic power generation system with high permeability is connected to the power distribution network is solved; further, compared with the prior art that the problem that the voltage of the power distribution network is out of limit is solved by adopting the technical means of photovoltaic inverter control, energy storage device increase and transformer tap voltage regulation, the voltage regulation method provided by the invention can greatly reduce the cost, and meanwhile, the voltage regulation range of the pivot point is wider, so that the flexibility of voltage regulation of the pivot point is improved.
Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1 shows a schematic flow diagram of a distribution network hub voltage regulation method based on a distributed photovoltaic power generation system according to an embodiment of the present invention;
FIG. 2a shows a solar photovoltaic output curve of a distributed photovoltaic power generation system with an installed capacity of 200kW in a Shenyang region under 4 different weather conditions of sunny days, cloudy days, rainy days and gusty rain to cloudy days typical in summer according to an embodiment of the present invention;
FIG. 2b shows load characteristics curves for a rural area, a mall, an enterprise business and an industry over a 24 hour time period for one embodiment of the present invention;
FIG. 3 illustrates a schematic diagram of a distributed photovoltaic power generation system based distribution grid in an area of the Shenyang of one embodiment of the present invention;
FIG. 4a shows a graph of 380V bus voltage deviation before reactor addition and 380V bus voltage deviation after reactor addition according to one embodiment of the invention;
figure 4b shows a graph of the 10kV bus voltage deviation before reactor addition and the 10kV bus voltage deviation after reactor addition in accordance with an embodiment of the present invention.
Fig. 5 shows a schematic block diagram of a distribution grid hub voltage regulation system based on a distributed photovoltaic power generation system according to an embodiment of the present invention.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.
Fig. 1 shows a schematic flow chart of a distribution network hub voltage regulation method based on a distributed photovoltaic power generation system according to an embodiment of the present invention. Wherein, UNFor a 380V bus rated voltage 380V of a distributed photovoltaic power generation system, as shown in fig. 1, a distribution network center point voltage regulation method based on the distributed photovoltaic power generation system includes:
step 102, collecting 380V bus voltage of a power distribution network of a distributed photovoltaic power generation system in real time;
104, judging whether the bus voltage is more than 1.07UN(ii) a When the bus voltage is more than 1.07UNThen, go to step 106; when the bus voltage is less than or equal to 1.07UNThen, go to step 120;
step 106, starting timing;
step 108, judging whether the timing time is greater than a time threshold value; when the timing time is greater than the time threshold, performing step 110; when the timing time is less than or equal to the time threshold, performing step 120;
step 110, obtaining the current season;
step 112, acquiring reactors in a corresponding preset capacity range according to the current season;
step 114, the reactor is connected in parallel with the central point 10kV bus, so that the reactor can absorb the reactive power of the power distribution network in real time to reduce 380V bus voltage;
step 116, judging whether the lowered 380V bus voltage collected in real time exceeds the limit; when the bus voltage of 380V after the reduction is out of limit, the step 118 is carried out, and the step 116 is returned to, until the bus voltage of 380V after the reduction is not out of limit, the step 120 is carried out;
step 118, adjusting parameters of the reactor;
and step 120, stopping regulating the 380V bus voltage.
According to the distribution network pivot point voltage regulating method based on the distributed photovoltaic power generation system, a proper active distribution network load flow calculation method is adopted under the fluctuation of photovoltaic output of the distributed photovoltaic power generation system so as to analyze the bus overvoltage condition of the distribution network, and finally, the bus voltage of the pivot point is dynamically regulated. Specifically, 380V bus voltage of the distributed photovoltaic power generation system is collected in real time, when the condition that the 380V bus voltage is larger than a voltage threshold value continuously exceeds a time threshold value, a current season is obtained, then a reactor in a corresponding preset capacity range is obtained according to the current season, so that the reactor is connected in parallel on a central point 10kV bus, a power reactor absorbs reactive power of a power distribution network in real time, based on an active power distribution network power flow calculation method, the 380V bus voltage can be reduced, when the reduced 380V bus voltage is out of limit, parameters of the reactor are adjusted, whether the reduced 380V bus voltage is out of limit or not is continuously judged, the 380V bus voltage is not adjusted until the reduced 380V bus voltage is out of limit, and the purpose of reducing both the 380V bus voltage and the 10kV bus voltage to the corresponding preset ranges is achieved, the voltages of all nodes of the power distribution network are controlled within the corresponding preset range, and the problem that the voltage of the power distribution network is out of limit when the distributed photovoltaic power generation system with high permeability is connected to the power distribution network is solved; further, compared with the prior art that the problem that the voltage of the power distribution network is out of limit is solved by adopting the technical means of photovoltaic inverter control, energy storage device increase and transformer tap voltage regulation, the voltage regulation method provided by the invention can greatly reduce the cost, and meanwhile, the voltage regulation range of the pivot point is wider, so that the flexibility of voltage regulation of the pivot point is improved.
Further, when the bus voltage of 380V is less than or equal to the voltage threshold, the timing time is less than or equal to the time threshold, or the new value of the bus voltage is not out-of-limit, it indicates that the power distribution network does not have the voltage out-of-limit problem, or the acquired bus voltage may be a transient voltage out-of-limit problem caused by some interfering electrical signals, or when the new value of the bus voltage is not out-of-limit, the bus voltage of 380V is directly stopped from being adjusted, so that the purpose of intelligently adjusting the bus voltage of 380V is achieved, and the working reliability of the voltage adjusting method is ensured. In this embodiment, a switch may be disposed on a control loop of the reactor, and the reactor may be disabled by turning off the switch, so as to stop adjusting the 380V bus voltage.
In the embodiment, the power distribution network is divided into three voltage levels, namely 66kV, 10kV and 380V, the photovoltaic output characteristic and the load characteristic of a typical area are combined, and an active power distribution network power flow calculation method is adopted to determine that the bus voltage of the power distribution network exceeds the limit under the fluctuation of the photovoltaic output of the distributed photovoltaic power generation system.
In the active power distribution network load flow calculation, any complex power system can be summarized as the following components (parameters) consisting of a generator (injecting current or power), a load (injecting negative current or power), a transmission line branch (resistance, reactance), a transformer branch (resistance, reactance, transformation ratio), a grounding branch (impedance and admittance) on a bus, and a grounding branch (generally, line charging point admittance);
using admittance matrices YBWhen the node injects current
Figure GDA0002604539080000061
And node voltage
Figure GDA0002604539080000062
Node voltage equation (1) constituting a linear equation system, i.e., a power network:
Figure GDA0002604539080000063
wherein the content of the first and second substances,
Figure GDA0002604539080000064
developed to obtain formula (2):
Figure GDA0002604539080000071
since the node injection amount measured in an actual distribution network is not current but power in general, the node injection current in the formula must be expressed by the node injection power. Obtaining a mathematical model of power flow calculation of the power system according to the relation between the node injection power and the node injection current and the transformation of the admittance matrix, namely a power flow equation (3):
Figure GDA0002604539080000072
wherein the content of the first and second substances,
Figure GDA0002604539080000073
Piand QiRespectively node voltage, injected active power and injected reactive power of the node i. Based on the power flow equation (3), it can be obtained that the photovoltaic output (i.e. P in the power flow equation) is generated in a certain time period of a day in a certain areai) If the voltage is too high, even if a certain load is consumed in the area, the bus voltage of the low voltage 380V also has the out-of-limit problem, and at the moment, the pair is obtained according to the current seasonThe reactor in the preset capacity range is connected in parallel with the 10kV bus with the pivot point of 66kV/10kV, and can absorb the reactive power Q of the power distribution network in real timeiFurther, the bus voltage of 380V is reduced.
Further, because the photovoltaic output has the characteristics of randomness and intermittence, in order to effectively reduce the influence of the fluctuation on the operation stability of the power distribution network, the photovoltaic output probability distribution characteristics of several typical days in summer in the sunward region are analyzed. Fig. 2a shows a solar photovoltaic output curve of a distributed photovoltaic power generation system with an installed capacity of 200kW in a sunny region in a 24-hour period under 4 different weather conditions of sunny days, cloudy days, rainy days and gusts of rain turning cloudy days, which are typical in summer. As shown in fig. 2a, in sunny days, the air temperature is 14 to 24 ℃, and the average value of solar photovoltaic output is 64 kW; in cloudy days, the temperature is 17-24 ℃, and the average value of solar photovoltaic output is 78 kW; in rainy days, the temperature is 15 to 26 ℃, and the average value of the solar photovoltaic output is 48 kW; when the gust rain changes into cloudy rain, the air temperature is 19-26 ℃, and the average value of the solar photovoltaic output is 60 kW.
Further, the loads of different typical functional areas (rural, commercial, business and industrial) have different fluctuating characteristics. FIG. 2b shows the load characteristics of a rural area, a mall, an enterprise business and an industry over a 24 hour period. As shown in fig. 2b, the rural load fluctuates most obviously around six to eight hours at night; the market load begins to fluctuate around six points in the morning and shows a continuously increasing trend until ten points in the evening show a descending trend; the load of the enterprise and public institution fluctuates maximally around two points of ten am and two points of afternoon; the industrial load basically has a stable change trend all day.
Further, an ETAP (ETAP is an abbreviation of an integrated analysis software system for power electrical analysis and power management) software is adopted to simulate the distribution network based on the distributed photovoltaic power generation system in a certain area of the shenyang shown in fig. 3, and as shown in fig. 2a and fig. 2b, the following analysis results are obtained: in a market in the Shenyang area, the photovoltaic output is the greatest during the day between 11 o 'clock and 14 o' clock in summer, which is about 200kW, and the load characteristic of the market is about the same during the time period from 11 o 'clock to 14 o' clock20kW, based on the model of the power flow equation (3), the low-voltage 380V bus voltage is inevitably over-limited due to the overhigh photovoltaic output. The bus voltage of 380V of the distribution network based on the distributed photovoltaic power generation system is 1.3U which can be collected through the distribution network in FIG. 3NTherefore, a 3750kvar capacity reactor is selected, and the 3750kvar capacity reactor is connected in parallel to the 10kV bus to perform reactive power regulation so as to absorb redundant reactive power in the power distribution network, so that the voltage on the 380V bus is reduced to 1.05UNThe bus voltage after the reduction was confirmed to be 1.05UNThe 380V bus voltage is not regulated, the 380V low-voltage bus voltage index of the power distribution network is met, and therefore the operation stability of the power distribution network based on the distributed photovoltaic power generation system is improved.
Fig. 4a shows a graph of 380V bus voltage deviation before reactor addition and 380V bus voltage deviation after reactor addition according to an embodiment of the invention. Figure 4b shows a graph of the 10kV bus voltage deviation before reactor addition and the 10kV bus voltage deviation after reactor addition in accordance with an embodiment of the present invention. As shown in fig. 4a and 4b, compared with the bus voltage deviation of each node before the reactor is added, the voltage regulating method of the present invention reduces both the 380V bus voltage deviation of each node after the reactor is added and the 10kV bus voltage deviation of each node, which further illustrates that the voltage regulating method of the present invention solves the problem of out-of-limit distribution network voltage generated when the distributed photovoltaic power generation system with high permeability is connected to the distribution network.
In an embodiment of the present invention, the step of obtaining the reactor in the corresponding preset capacity range according to the current season specifically includes: when the current season is spring, acquiring a reactor with the capacity of 2000 to 3000 kvar; when the current season is summer, acquiring a reactor with the capacity of 3500 kvar-5000 kvar; when the current season is autumn, acquiring a reactor with the capacity of 2000 to 3500 kvar; and when the current season is winter, acquiring the reactors with the capacity of 1000-2500 kvar.
In this embodiment, the reactors within the corresponding preset capacity range are obtained through the current season, so that reactors with different capacities are put into the pivot point, the reactors with different capacities conform to the photovoltaic output characteristics of the current season, 380V bus voltage can be quickly and accurately reduced when parameters of the reactors are adjusted, the reduced 380V bus voltage meets constraint conditions as soon as possible, the reduced 380V bus voltage is determined not to be out of limit, and the adjustment sensitivity of the 380V bus voltage is improved.
In an embodiment of the present invention, the step of determining whether the reduced 380V bus voltage collected in real time exceeds a limit specifically includes: judging whether the reduced 380V bus voltage meets a constraint condition Uimin≤Ui≤Uimax(ii) a When the reduced 380V bus voltage meets the constraint condition Uimin≤Ui≤UimaxWhen the bus voltage of 380V is reduced, the out-of-limit does not occur; otherwise, the reduced 380V bus voltage is out-of-limit; wherein, UiFor reduced bus voltage of 380V, UiminAnd UimaxThe bus voltage limit value is a lower limit value and an upper limit value of the bus voltage limit value of 380V after reduction.
In this embodiment, to ensure stable operation of the power system, the reduced 380V bus voltage needs to satisfy the constraint condition Uimin≤Ui≤Uimax. In a specific embodiment, UiminAnd UimaxUsually set in advance, UiminIs 0.93UN，UimaxIs 1.07UNSaid UNThe voltage is the rated voltage of a 380V bus of the distributed photovoltaic power generation system, namely 380V.
In one embodiment of the present invention, the voltage threshold is 1.07UNSaid UNThe rated voltage of a 380V bus of the distributed photovoltaic power generation system is obtained; the time threshold ranges from 60s to 70 s; and the parameter of the reactor comprises equivalent impedance of the reactor.
In this embodiment, the parameters of the reactor include equivalent impedance of the reactor, so adjusting the parameters of the reactor mainly changes the parameters of the reactorThe equivalent impedance of the reactor. In the specific embodiment, the reactor drives a winding in the reactor to generate relative angular displacement through a transmission mechanism of the adjustable reactor so as to change the synthetic effective turn number of the winding in the reactor and change the equivalent impedance of the reactor, thereby achieving the purpose of adjusting the reactive power of the power distribution network within a certain range while adjusting the reactance value. In a specific embodiment, UN380V and the time threshold is 60S, 65S or 70S.
Fig. 5 shows a schematic block diagram of a distribution grid hub voltage regulation system based on a distributed photovoltaic power generation system according to an embodiment of the present invention. As shown in fig. 5, the distribution network central point voltage regulation system 500 based on the distributed photovoltaic power generation system includes:
the acquisition unit 502 is used for acquiring 380V bus voltage of a power distribution network of the distributed photovoltaic power generation system in real time;
the timing unit 504 is used for starting timing when the 380V bus voltage is greater than a voltage threshold;
an obtaining unit 506, configured to obtain a current season when the timing time is greater than a time threshold;
the obtaining unit 506 is further configured to obtain the reactors within the corresponding preset capacity range according to the current season;
the adjusting unit 508 is used for connecting the reactor in parallel on a central point 10kV bus, so that the reactor absorbs the reactive power of the power distribution network in real time to reduce the 380V bus voltage;
the judging unit 510 is configured to judge whether the reduced 380V bus voltage acquired in real time exceeds a limit;
the adjusting unit 508 is further configured to adjust parameters of the reactor when the lowered bus voltage of 380V is out of limit, and
the determining unit 510 is further configured to continue to determine whether the reduced 380V bus voltage collected in real time exceeds the limit until the reduced 380V bus voltage does not exceed the limit;
the adjusting unit 508 is further configured to stop adjusting the 380V bus voltage.
According to the distribution network pivot point voltage regulating system 500 based on the distributed photovoltaic power generation system, under the fluctuation of photovoltaic output of the distributed photovoltaic power generation system, a proper active distribution network load flow calculation method is adopted to analyze the bus overvoltage condition of the distribution network, and finally, the bus voltage of the pivot point is dynamically regulated; specifically, 380V bus voltage of the distributed photovoltaic power generation system is collected in real time through the collection unit 502, when the duration time of the condition that the bus voltage recorded by the timing unit 504 is greater than the voltage threshold exceeds the time threshold, the current season is obtained through the obtaining unit 506, then the reactor in the corresponding preset capacity range is obtained through the obtaining unit 506 according to the current season, so that the reactor is connected in parallel on the central point 10kV bus through the adjusting unit 508 to allow the reactor to absorb the reactive power of the power distribution network in real time, based on the active power distribution network flow calculation method, the 380V bus voltage can be reduced, when the reduced bus voltage is determined to be out of limit through the judgment unit 510, the parameter of the reactor is adjusted through the adjusting unit 508, and whether the reduced bus voltage is out of limit or not is continuously judged through the judgment unit 510 until the reduced bus voltage is not out of limit, the bus voltage of 380V is stopped being adjusted, the purpose that both the bus voltage of 380V and the bus voltage of 10kV are reduced to be within the corresponding preset range is achieved, and then all node voltages of the power distribution network are controlled to be within the corresponding preset range, so that the problem that the power distribution network voltage is out of limit when the distributed photovoltaic power generation system with high permeability is connected to the power distribution network is solved; further, compared with the prior art that the problem that the voltage of the power distribution network is out of limit is solved by adopting the technical means of photovoltaic inverter control, energy storage device increase and transformer tap voltage regulation, the voltage regulation method provided by the invention can greatly reduce the cost, and meanwhile, the voltage regulation range of the pivot point is wider, so that the flexibility of voltage regulation of the pivot point is improved.
In an embodiment of the present invention, the adjusting unit 508 is further configured to stop adjusting the 380V bus voltage when the 380V bus voltage is less than or equal to the voltage threshold; the adjusting unit 508 is further configured to stop adjusting the 380V bus voltage when the timing time is less than or equal to the time threshold; and the adjusting unit 508 is further configured to stop adjusting the 380V bus voltage when the lowered 380V bus voltage does not exceed the limit.
In this embodiment, when the bus voltage of 380V is less than or equal to the voltage threshold, the timing time is less than or equal to the time threshold, or the new value of the bus voltage is not out-of-limit, it indicates that the power distribution network does not have the voltage out-of-limit problem, or the acquired bus voltage may be a transient voltage out-of-limit problem caused by some interfering electrical signals, or when the new value of the bus voltage is not out-of-limit, the adjustment of the bus voltage of 380V is directly stopped through the adjustment unit 508, so that the intelligent adjustment of the voltage regulation system on the bus voltage of 380V is achieved, and the working stability of the voltage regulation system is ensured.
In an embodiment of the present invention, the obtaining unit 506 is specifically configured to: when the current season is spring, acquiring a reactor with the capacity of 2000 to 3000 kvar; when the current season is summer, acquiring a reactor with the capacity of 3500 kvar-5000 kvar; when the current season is autumn, acquiring a reactor with the capacity of 2000 to 3500 kvar; and when the current season is winter, acquiring the reactors with the capacity of 1000-2500 kvar.
In this embodiment, the reactors in the preset capacity range corresponding to the current season are obtained through the obtaining unit 506, so that reactors with different capacities are put in the pivot point, the reactors with different capacities conform to the photovoltaic output characteristics of the current season, the 380V bus voltage can be quickly and accurately reduced when the parameters of the reactor are adjusted, the reduced 380V bus voltage meets the constraint condition as soon as possible, the reduced 380V bus voltage is determined not to be out of limit, and the adjustment sensitivity of the 380V bus voltage is improved.
In an embodiment of the present invention, the determining unit 510 is specifically configured to: judging whether the reduced 380V bus voltage meets a constraint condition Uimin≤Ui≤Uimax(ii) a When lowered downThe 380V bus voltage meets the constraint condition Uimin≤Ui≤UimaxWhen the bus voltage of 380V is reduced, the out-of-limit does not occur; otherwise, the reduced 380V bus voltage is out-of-limit; wherein, UiFor reduced bus voltage of 380V, UiminAnd UimaxThe bus voltage limit value is a lower limit value and an upper limit value of the bus voltage limit value of 380V after reduction.
In this embodiment, to ensure that the power system operates stably, the judgment unit 510 determines that the reduced 380V bus voltage needs to satisfy the constraint condition Uimin≤Ui≤Uimax. In a specific embodiment, UiminAnd UimaxUsually set in advance, UiminIs 0.93UN，UimaxIs 1.07UNSaid UNThe voltage is the rated voltage of a 380V bus of the distributed photovoltaic power generation system, namely 380V.
In one embodiment of the present invention, the voltage threshold is 1.07UNSaid UNThe rated voltage of a 380V bus of the distributed photovoltaic power generation system is obtained; the time threshold ranges from 60s to 70 s; and the parameter of the reactor comprises equivalent impedance of the reactor.
In this embodiment, the parameter of the reactor includes an equivalent impedance of the reactor, and thus adjusting the parameter of the reactor mainly changes the equivalent impedance of the reactor. In the specific embodiment, the reactor drives a winding in the reactor to generate relative angular displacement through a transmission mechanism of the adjustable reactor so as to change the synthetic effective turn number of the winding in the reactor and change the equivalent impedance of the reactor, thereby achieving the purpose of adjusting the reactive power of the power distribution network within a certain range while adjusting the reactance value. In a specific embodiment, UN380V and the time threshold is 60S, 65S or 70S.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A distribution network pivot point voltage regulation method based on a distributed photovoltaic power generation system is characterized by comprising the following steps:
collecting 380V bus voltage of a power distribution network of the distributed photovoltaic power generation system in real time;
when the bus voltage of 380V is greater than a voltage threshold value, timing is started;
when the timing time is greater than a time threshold, acquiring the current season;
acquiring a reactor in a corresponding preset capacity range according to the current season;
the reactor is connected in parallel to a central point 10kV bus, so that the reactor absorbs the reactive power of the power distribution network in real time to reduce the 380V bus voltage;
judging whether the reduced 380V bus voltage acquired in real time is out of limit or not;
when the lowered bus voltage of 380V is out of limit, adjusting parameters of the reactor, and
continuously judging whether the reduced 380V bus voltage acquired in real time is out-of-limit or not until the reduced 380V bus voltage is not out-of-limit;
and stopping regulating the 380V bus voltage.
2. The distributed photovoltaic power generation system based distribution network hub voltage regulation method of claim 1, further comprising:
when the 380V bus voltage is less than or equal to the voltage threshold, stopping regulating the 380V bus voltage; when the timing time is less than or equal to the time threshold, stopping regulating the 380V bus voltage; and stopping regulating the 380V bus voltage when the lowered 380V bus voltage is not out of limit.
3. The distribution network pivot point voltage regulation method based on the distributed photovoltaic power generation system according to claim 1, wherein the step of obtaining the corresponding reactor within the preset capacity range according to the current season specifically comprises:
when the current season is spring, acquiring a reactor with the capacity of 2000 to 3000 kvar;
when the current season is summer, acquiring a reactor with the capacity of 3500 kvar-5000 kvar;
when the current season is autumn, acquiring a reactor with the capacity of 2000 to 3500 kvar;
and when the current season is winter, acquiring the reactors with the capacity of 1000-2500 kvar.
4. The distribution network pivot point voltage regulating method based on the distributed photovoltaic power generation system according to claim 1, wherein the step of judging whether the reduced 380V bus voltage collected in real time exceeds the limit specifically comprises:
judging whether the reduced 380V bus voltage meets a constraint condition Uimin≤Ui≤Uimax(ii) a When the reduced 380V bus voltage meets the constraint condition Uimin≤Ui≤UimaxWhen the bus voltage of 380V is reduced, the out-of-limit does not occur; otherwise, the reduced 380V bus voltage is out-of-limit;
wherein, UiFor reduced bus voltage of 380V, UiminAnd UimaxThe bus voltage limit value is a lower limit value and an upper limit value of the bus voltage limit value of 380V after reduction.
5. The distribution network hub voltage regulation method based on the distributed photovoltaic power generation system according to any one of claims 1 to 4,
the voltage threshold value is 1.07UNSaid UNThe rated voltage of a 380V bus of the distributed photovoltaic power generation system is obtained;
the time threshold ranges from 60s to 70 s; and
the parameters of the reactor comprise equivalent impedance of the reactor.
6. The utility model provides a distribution network pivot pressure regulating system based on distributed photovoltaic power generation system which characterized in that includes:
the acquisition unit is used for acquiring 380V bus voltage of a power distribution network of the distributed photovoltaic power generation system in real time;
the timing unit is used for starting timing when the 380V bus voltage is greater than a voltage threshold;
the acquisition unit is used for acquiring the current season when the timing time is greater than a time threshold;
the acquisition unit is further used for acquiring the reactors in the corresponding preset capacity range according to the current season;
the regulating unit is used for connecting the reactor in parallel on a central point 10kV bus, so that the reactor can absorb the reactive power of the power distribution network in real time to reduce the 380V bus voltage;
the judging unit is used for judging whether the reduced 380V bus voltage acquired in real time exceeds the limit;
the regulating unit is also used for adjusting the parameters of the reactor when the lowered 380V bus voltage exceeds the limit, and
the judging unit is further configured to continuously judge whether the reduced 380V bus voltage acquired in real time is out-of-limit until the reduced 380V bus voltage is not out-of-limit;
the adjusting unit is further used for stopping adjusting the 380V bus voltage.
7. The distribution network hub voltage regulation system based on distributed photovoltaic power generation system of claim 6,
the adjusting unit is further configured to stop adjusting the 380V bus voltage when the 380V bus voltage is less than or equal to the voltage threshold;
the adjusting unit is further used for stopping adjusting the 380V bus voltage when the timing time is less than or equal to the time threshold; and
the adjusting unit is further configured to stop adjusting the 380V bus voltage when the lowered 380V bus voltage does not exceed the limit.
8. The distribution network hub voltage regulation system based on the distributed photovoltaic power generation system of claim 6, wherein the obtaining unit is specifically configured to:
when the current season is spring, acquiring a reactor with the capacity of 2000 to 3000 kvar;
when the current season is summer, acquiring a reactor with the capacity of 3500 kvar-5000 kvar;
when the current season is autumn, acquiring a reactor with the capacity of 2000 to 3500 kvar;
and when the current season is winter, acquiring the reactors with the capacity of 1000-2500 kvar.
9. The distribution network center point voltage regulation system based on the distributed photovoltaic power generation system of claim 6, wherein the determination unit is specifically configured to:
judging whether the reduced 380V bus voltage meets a constraint condition Uimin≤Ui≤Uimax(ii) a When the reduced 380V bus voltage meets the constraint condition Uimin≤Ui≤UimaxWhen the bus voltage of 380V is reduced, the out-of-limit does not occur; otherwise, the reduced 380V bus voltage is out-of-limit;
wherein, UiFor reduced bus voltage of 380V, UiminAnd UimaxThe bus voltage limit value is a lower limit value and an upper limit value of the bus voltage limit value of 380V after reduction.
10. The distribution network hub voltage regulation system based on distributed photovoltaic power generation system of any one of claims 6 to 9,
the voltage threshold value is 1.07UNSaid UNThe rated voltage of a 380V bus of the distributed photovoltaic power generation system is obtained;
the time threshold ranges from 60s to 70 s; and
the parameters of the reactor comprise equivalent impedance of the reactor.
CN201811187510.9A 2018-10-12 2018-10-12 Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system Active CN109167393B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811187510.9A CN109167393B (en) 2018-10-12 2018-10-12 Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811187510.9A CN109167393B (en) 2018-10-12 2018-10-12 Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system

Publications (2)

Publication Number Publication Date
CN109167393A CN109167393A (en) 2019-01-08
CN109167393B true CN109167393B (en) 2020-10-27

Family

ID=64877952

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811187510.9A Active CN109167393B (en) 2018-10-12 2018-10-12 Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system

Country Status (1)

Country Link
CN (1) CN109167393B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009254167A (en) * 2008-04-08 2009-10-29 Tokyo Electric Power Co Inc:The Method and apparatus for adjusting voltage of power distribution line
CN101697474A (en) * 2009-11-10 2010-04-21 华北电网有限公司 Remote automatic control method of high-voltage shut reactor considering safety of system voltage
CN103094913A (en) * 2013-01-12 2013-05-08 华南理工大学 Optimal configuration of 10 kV power distribution network parallel reactor and compensation method of 10 kV power distribution network parallel reactor
CN106911134A (en) * 2017-04-24 2017-06-30 许继集团有限公司 A kind of method and system for stabilizing distribution network load busbar voltage fluctuation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009254167A (en) * 2008-04-08 2009-10-29 Tokyo Electric Power Co Inc:The Method and apparatus for adjusting voltage of power distribution line
CN101697474A (en) * 2009-11-10 2010-04-21 华北电网有限公司 Remote automatic control method of high-voltage shut reactor considering safety of system voltage
CN103094913A (en) * 2013-01-12 2013-05-08 华南理工大学 Optimal configuration of 10 kV power distribution network parallel reactor and compensation method of 10 kV power distribution network parallel reactor
CN106911134A (en) * 2017-04-24 2017-06-30 许继集团有限公司 A kind of method and system for stabilizing distribution network load busbar voltage fluctuation

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
分布式光伏发电特性与气象影响因子诊断分析;曹英丽,方诗琦,王洋 等;《沈阳农业大学学报》;20180615;第49卷(第3期);363-370 *

Also Published As

Publication number Publication date
CN109167393A (en) 2019-01-08

Similar Documents

Publication Publication Date Title
CN110224393B (en) New energy consumption assessment method based on minimum load shedding model
CN109802396B (en) Photovoltaic transformer area electric energy quality control system based on voltage sensitivity configuration
CN103259267A (en) Mold splitting type voltage control method for wind power plant cluster
CN110829408B (en) Multi-domain scheduling method considering energy storage power system based on power generation cost constraint
CN113285451A (en) Black start coordination control method based on photovoltaic energy storage system
CN107370172B (en) Battery energy storage system integrated operation control system and method in high permeability photovoltaic distribution
CN112736973A (en) Battery energy storage capacity configuration method and system for stabilizing output fluctuation of wind power and photovoltaic power station
CN115036963A (en) Two-stage demand response strategy for improving toughness of power distribution network
CN116470513A (en) Multi-type photo-thermal power station coordinated scheduling operation method responding to power grid requirements
CN117810974A (en) AI prediction-based light Chu Zhirou micro-grid control method and device
CN102005807B (en) Method for regulating photovoltaic power generation system through super capacitor energy storage system
CN105490279A (en) Dichotomy-based local voltage control method for distributed power supply
CN109167393B (en) Distribution network pivot point voltage regulation method and system based on distributed photovoltaic power generation system
CN116961204A (en) Intelligent photovoltaic commercial power hybrid energy-saving charging control method
CN115719973A (en) Distributed photovoltaic grid-connected voltage comprehensive treatment method and system
CN104779622B (en) The idle difference control method of medium voltage distribution network distributed power source based on staircase chart
CN109617183A (en) A kind of intelligent power supply method of multiple battery systems
CN210725435U (en) PID solar street lamp controller based on incremental algorithm
CN113346506A (en) Rapid reactive power control method for large photovoltaic power station
CN106300443B (en) A kind of three for reducing abandonment layer cogeneration microgrid energy control method
Jing et al. Multi-time-scale coordinative and complementary reactive power and voltage control strategy for wind farms cluster
CN115117937B (en) Highway roadside grid-connected type optical storage micro-grid system and power supply method
CN114154279B (en) Opportunity constraint assessment method for distribution network bearing capacity of heat accumulating type electric heating access
CN112751370B (en) Distributed photovoltaic multi-source reactive power absorption power factor control method
CN108155664B (en) Photovoltaic local multi-mode switching control method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant