CN109888843B - Power adjusting method and system for large-scale new energy to be accessed into direct-current power grid - Google Patents
Power adjusting method and system for large-scale new energy to be accessed into direct-current power grid Download PDFInfo
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Abstract
The invention discloses a power regulation method and a power regulation system for accessing large-scale new energy into a direct current power grid, wherein the method comprises the following steps: acquiring a section active power value at a new energy power collection position in real time; calculating to obtain an adjusting key parameter; the adjusting key parameters comprise a threshold interval consisting of an adjusting upper threshold and an adjusting lower threshold; judging whether the section active power value exceeds the threshold interval in real time; if the active power exceeds the threshold interval, sending a power regulation instruction to each sub-field station according to a preset power regulation quantity value to complete the active power regulation of the cross section; according to the method and the system, when the new energy power exceeds the rated capacity of the converter, the large power loss and disturbance caused by the locking of a generator tripping or the converter are avoided; the method and the system improve the output of new energy and the utilization rate of the converter, and simultaneously can reduce the fluctuation rate of active power and improve the operation safety of a direct current power grid on the premise of ensuring the safety of the converter by dynamically adjusting the active power of the section.
Description
Technical Field
The invention relates to the technical field of electric power, in particular to a power adjusting method and system for accessing large-scale new energy into a direct-current power grid.
Background
Traditional fossil energy is gradually being exhausted as a non-renewable resource. Environmental problems such as global warming and air pollution caused by the large consumption of fossil energy pose a great threat to human survival. The development of clean and renewable new energy sources has become a necessary choice for the sustainable development of human beings. As a new energy source which is the most mature and promising in development at present, wind power generation and photovoltaic power generation have been rapidly developed in recent years. In 2017, the wind power installation reaches 1.54 hundred million kilowatts and the photovoltaic power generation installation reaches 1.02 hundred million kilowatts in China, and the total proportion of the wind power installation and the photovoltaic power generation installation accounts for more than 13 percent of the national power generation installation. The new energy source has fluctuation and intermittency. The consumption of large-scale new energy has become a main problem to be solved urgently at present. The flexible direct-current transmission technology based on the modular multilevel converter has the advantages of low harmonic content, active and reactive decoupling control, capability of connecting a weak power grid or a passive network, easiness in forming a direct-current power grid and the like, and is a world-recognized optimal technical scheme for large-scale new energy grid connection and consumption.
In consideration of the fluctuation of the new energy, in practical engineering, the total installed capacity of the new energy is usually larger than the rated power of the converter at the collection. Taking the demonstration project of a four-end annular flexible direct-current power grid of a renewable energy source in Zhang Bei as an example, the rated capacities of two collecting converter stations in Kangbao and Zhang Bei are 1500MW and 3000MW respectively, and the planned capacities of new energy sources are 2250MW and 4500MW respectively. When the new energy power exceeds the rated capacity of the converter, the safe and stable operation of the converter and even a direct current power grid can be threatened. In addition, when the new energy output is out of limit in the system safety control strategy, a tripping strategy is usually adopted, and great disturbance is caused to the system. Conventional power regulation methods set a single power limit. When the total generated power of the new energy exceeds the limit, a power reduction instruction is issued; and then, distributing the power reduction command to the new energy substation for execution according to a preset execution sequence. When the new energy power is reduced and the traditional control method returns, the output power of the new energy station can generate large fluctuation near the power limit value.
Disclosure of Invention
In order to solve the problems that the blocking converter or the generator tripping causes disturbance to a system when the section active power exceeds the rated capacity of the converter in the background technology and the output power of a new energy station generates large fluctuation near a power limit value when a traditional control method returns, the invention provides a power regulation method and a system for accessing a large-scale new energy into a direct current power grid, wherein the method and the system collect the section active power at the convergence position of the large-scale new energy in real time by setting the upper limit threshold value and the lower limit threshold value of power regulation, and adaptively regulate the power of the new energy which is converged into the direct current power grid to be kept within the upper limit threshold value and the lower limit threshold value when the output of the new energy is close to the rated capacity of the converter; the power regulation method for accessing the large-scale new energy into the direct current power grid comprises the following steps:
collecting the active power value of the section at the power collection position of each new energy sub-field station in real time;
calculating to obtain an adjusting key parameter according to the characteristics of the new energy, the parameters of the current converter at the convergence part and the precision of the section active power acquisition and measurement device; the adjusting key parameters comprise a threshold interval consisting of an adjusting upper threshold and an adjusting lower threshold;
judging whether the section active power value exceeds the threshold interval in real time;
and if the active power exceeds the threshold interval, sending a power regulation instruction to each sub-field station according to a preset power regulation quantity value to finish the active power regulation of the cross section.
Further, the setting formula of the adjustment upper limit threshold is as follows:
Pth_up＝PconN-Tdelay_maxVup_max-PconNεPowerM％-5TcVup_max
wherein, Pth_upFor power regulation of the upper threshold, PconNRated power, T, of converters at the junctionsdelay_maxIs the sum of the control system delay and the maximum power response time of the new energy sub-station, Vup_maxFor maximum rate of increase of output of new energy station, epsilonPowerM% error of the power measuring device, TcA power regulation control period;
the setting formula of the adjustment lower limit threshold is as follows:
Pth_down＝Pth_up-ΝΔP
wherein, Pth_downFor the lower threshold of power adjustment, N is a preset interval constant, and Δ P is a preset power adjustment value.
Further, the preset power regulation quantity value is larger than the product of the maximum increase speed processed by the new energy station and the power regulation control period.
Further, the value range of the power regulation control period is a time interval formed by the response times of the two new energy sub-field stations with the highest power response speed.
Further, if the section active power value is higher than the upper regulation threshold, sending a power down-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value;
and if the active power value of the section is lower than the lower regulation threshold, sending a power up-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value.
Further, before the sending of the power adjustment command to each subfield station according to the preset power adjustment value, the method further includes:
determining one or more sub-field stations capable of implementing power regulation;
sending a power regulation instruction to the one or more sub-field stations capable of implementing power regulation according to a preset power regulation value;
the method for determining one or more sub-field stations capable of implementing power regulation comprises the step of selecting one or more sub-field stations with response speed higher than a preset speed value and actual power higher than a preset power value as the sub-field stations capable of implementing power regulation in the sub-field stations which operate normally.
Further, setting a power regulation input flag bit;
when a power regulation instruction is sent to each sub-field station, setting a power regulation input flag bit as 1;
and after the active power of the section is adjusted, when the active power value of the section is recovered to be within a threshold interval, setting a power adjustment input flag bit to be 0.
The power regulation system for accessing the large-scale new energy into the direct current power grid comprises:
the power acquisition unit is used for acquiring the active power value of the section at the power collection position of each new energy sub-field station in real time;
the parameter setting unit is used for calculating and obtaining an adjusting key parameter according to the characteristics of the new energy, the parameters of the current converter at the collecting part and the precision of the section active power acquisition and measurement device; the adjusting key parameters comprise a threshold interval consisting of an adjusting upper threshold and an adjusting lower threshold;
the power monitoring unit is used for judging whether the section active power value acquired by the power acquisition unit exceeds the threshold interval in real time;
and the adjusting and executing unit is used for sending a power adjusting instruction to each sub-field station according to a preset power adjusting value when the power monitoring unit monitors whether the active power value of the section exceeds the threshold interval, so as to complete the active power adjustment of the section.
Further, the formula for adjusting the upper threshold setting by the parameter setting unit is as follows:
Pth_up＝PconN-Tdelay_maxVup_max-PconNεPowerM％-5TcVup_max
wherein, Pth_upFor power regulation of the upper threshold, PconNRated power, T, of converters at the junctionsdelay_maxIs the sum of the control system delay and the maximum power response time of the new energy sub-station, Vup_maxFor maximum rate of increase of output of new energy station, epsilonPowerM% error of the power measuring device, TcA power regulation control period;
the formula for adjusting the lower limit threshold setting by the parameter setting unit is as follows:
Pth_down＝Pth_up-ΝΔP
wherein, Pth_downFor power regulation lower threshold, N is a preset interval constant, and Δ P is a preset power regulationMagnitude.
Further, the parameter setting unit is used for presetting a power regulation value; the preset power regulation value is larger than the product of the maximum increase speed processed by the new energy station and the power regulation control period.
Further, the value range of the power regulation control period is a time interval formed by the response times of the two new energy sub-field stations with the highest power response speed.
Further, if the power monitoring unit monitors that the active power value of the section is higher than the upper regulation threshold, the regulation execution unit sends a power down instruction to each sub-field station according to a preset rule according to a preset power regulation value;
and if the power monitoring unit monitors that the active power value of the section is lower than the lower regulation threshold, the regulation execution unit sends a power up-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value.
Further, the adjusting execution unit is used for determining one or more sub-field stations capable of implementing power adjustment; sending a power regulation instruction to the one or more sub-field stations capable of implementing power regulation according to a preset power regulation value;
the adjusting execution unit is used for selecting one or more sub-field stations with response speed higher than a preset speed value and actual power larger than a preset power value from the sub-field stations which operate normally as the sub-field stations capable of implementing power adjustment.
Further, the power monitoring unit is configured to set a power adjustment input flag bit;
when a power regulation instruction is sent to each sub-field station, setting a power regulation input flag bit as 1;
and after the active power of the section is adjusted, when the active power value of the section is recovered to be within a threshold interval, setting a power adjustment input flag bit to be 0.
The invention has the beneficial effects that: the technical scheme of the invention provides a power regulation method and a system for accessing large-scale new energy into a direct current power grid, wherein the method and the system collect the active power of the section at the convergence position of the large-scale new energy in real time by setting the upper limit threshold and the lower limit threshold of power regulation, and adaptively regulate the power of the new energy which is converged into the direct current power grid to be kept within the upper limit threshold and the lower limit threshold when the output of the new energy is close to the rated capacity of a current converter; according to the method and the system, when the new energy power exceeds the rated capacity of the converter, the problem that the system is greatly disturbed due to large power loss caused by the fact that the converter is cut off or the converter is locked is avoided. The method and the system for setting the upper and lower limit thresholds of the power regulation can improve the output of new energy and the utilization rate of the converter. Meanwhile, the method and the system can reduce the fluctuation rate of the active power on the premise of ensuring the safety of the converter and improve the operation safety of the direct-current power grid by dynamically adjusting the active power of the section.
Drawings
A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
fig. 1 is a flowchart of a power regulation method for accessing a large-scale new energy into a dc power grid according to an embodiment of the present invention;
fig. 2 is a structural diagram of a power regulation system of a large-scale new energy source connected to a dc power grid according to an embodiment of the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a flowchart of a power regulation method for accessing a large-scale new energy into a dc power grid according to an embodiment of the present invention; as shown in fig. 1, the method and the system collect the active power of the section at the position where the large-scale new energy is collected in real time by setting the upper and lower limit thresholds of power regulation, and adaptively adjust the power of the new energy which is converged into the direct current power grid to keep within the upper and lower limit thresholds when the output of the new energy is close to the rated capacity of a converter; the method comprises the following steps:
the technical effect of this embodiment is to solve a series of problems caused when the active power of the cross section generated by the large-scale new energy accessed to the dc power grid exceeds the rated capacity of the converter, and monitoring by acquiring the active power value of the cross section is a necessary prerequisite measure, and the acquisition modes of the active power value of the cross section are various and are not described herein.
in the embodiment, the adjusting key parameters are set by acquiring the wind and photovoltaic power response characteristics of the new energy station, the transmission delay of the control system, the power fluctuation characteristics of the new energy and the precision of the measurement system.
Further, the key parameter is adjusted to an upper threshold, a lower threshold, a power adjustment value, and an intermediate value, i.e. a power adjustment control period, for calculating the key parameter;
and the value range of the power regulation control period is a time interval formed by the response time of the two new energy sub-field stations with the highest power response speed.
The setting formula of the adjusting upper limit threshold value is as follows:
Pth_up＝PconN-Tdelay_maxVup_max-PconNεPowerM％-5TcVup_max
wherein, Pth_upFor power regulation of the upper threshold, PconNRated power, T, of converters at the junctionsdelay_maxIs the sum of the control system delay and the maximum power response time of the new energy sub-station, Vup_maxFor maximum rate of increase of output of new energy station, epsilonPowerM% error of the power measuring device, TcA power regulation control period;
in the setting formula of the adjusting upper limit threshold value, the first half part PconN-Vup_maxTdelay_maxThe theoretical threshold value represents an upper regulation limit, and the theoretical threshold value is required for ensuring that the maximum output increasing speed of the new energy field station is met under the conditions of the control system delay and the maximum power response time of the new energy sub-field station; in practice, however, a certain amount of margin must be taken into account, i.e. including the error P due to the power measurementconNεPowerM%, and control margin; the control margin is V for the new energy station within 5 power regulation control periods (namely 5Tc)up_max(ii) a boosted power;
on the basis of the theoretical threshold, the margin is comprehensively considered, and the power regulation upper limit threshold can be obtained.
For example, assuming that the installed capacity of the new energy is 2250MW, the rated power P of the converter at the collection pointconN1500MW, the control system delays for 100ms, the maximum power response time of the new energy sub-station is 700ms, and the maximum output increasing speed V of the new energy stationup_max30% of installed capacity/min, the upper limit theoretical threshold value of the power regulation strategy is Pth_theory1494.6 MW. In engineering, a certain margin Δ P is usually consideredth. The margin includes a margin P left when power measurement errors are taken into accountconNεPowerM%, the power measurement error is typically 0.5%; control margin, i.e. new energy station at V for 5 control cycles (i.e. 5Tc)up_maxRising power control period Tc300 ms. Hence, powerAdjusting the actual upper threshold value Pth_up＝Pth_theory-PconNεPowerM％-5TcVup_max＝1477.0MW。
Further, the power regulation lower limit threshold is determined according to the power regulation upper limit threshold and a preset threshold interval width; the width of the preset threshold interval is N times of a preset power regulation value;
in this example, N is 1.5; therefore, the setting formula of the adjustment lower limit threshold is as follows:
Pth_down＝Pth_up-1.5ΔP。
further, before calculating the lower limit threshold of power regulation, the power regulation value needs to be set; the preset power regulation value is larger than the product of the maximum increase speed processed by the new energy station and the power regulation control period.
determining a threshold interval according to the set power regulation upper limit threshold and the power regulation lower limit threshold; and comparing the threshold interval with the real-time section active power value to judge whether the abnormal condition exceeding the threshold interval exists.
And step 140, if the threshold interval is exceeded, sending a power regulation instruction to each sub-field station according to a preset power regulation value, and completing the section active power regulation.
Beyond the threshold interval, there are two cases:
if the active power value of the section is higher than the upper regulation threshold, sending a power down-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value;
and if the active power value of the section is lower than the lower regulation threshold, sending a power up-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value.
Further, before the sending of the power adjustment command to each subfield station according to the preset power adjustment value, the method further includes:
determining one or more sub-field stations capable of implementing power regulation;
sending a power regulation instruction to the one or more sub-field stations capable of implementing power regulation according to a preset power regulation value;
the method for determining one or more sub-field stations capable of implementing power regulation comprises the step of selecting one or more sub-field stations with response speed higher than a preset speed value and actual power higher than a preset power value as the sub-field stations capable of implementing power regulation in the sub-field stations which operate normally.
Namely, the sub-field station capable of implementing power regulation needs to comprise three conditions, namely normal operation, high response speed and large real-time power; selecting sub-field stations which can be used for real-time power regulation by setting a preset response speed threshold and a preset power threshold; the magnitude of the power adjustment magnitude may also be coordinated by tightening or relaxing the magnitudes of the response speed threshold and the power threshold.
In this embodiment, the power threshold is selected to be 0.2 times of the power adjustment value.
The distribution of the power regulation value in the selected plurality of sub-field stations capable of carrying out power regulation can be average distribution or can be distributed according to a preset rule and weight; in this embodiment, the weight may be calculated according to the response speed and the real transmission power.
Furthermore, in order to confirm the current regulation state conveniently, a power regulation input flag bit can be set;
when a power regulation instruction is sent to each sub-field station, setting a power regulation input flag bit as 1;
and after the active power of the section is adjusted, when the active power value of the section is recovered to be within a threshold interval, setting a power adjustment input flag bit to be 0.
According to the method, the section active power at the convergence position of large-scale new energy is used as a controlled object, and when the output of the new energy is close to the rated capacity of the converter, the section active power is dynamically regulated through the upper limit threshold value and the lower limit threshold value so as to be not more than the rated value of the converter, so that the safe operation of the converter is ensured, the disturbance of a system caused by a power cutter or the locking of the converter due to power out-of-limit is avoided, and the safety and the reliability of a direct-current power grid are improved.
Fig. 2 is a structural diagram of a power regulation system of a large-scale new energy source connected to a dc power grid according to an embodiment of the present invention. As shown in fig. 2, the system includes:
the power acquisition unit 210 is used for acquiring a section active power value at a power collection position of each new energy sub-field station in real time;
the parameter setting unit 220 is used for calculating and obtaining a regulating key parameter according to the characteristics of the new energy, the parameters of the current converter at the collecting position and the accuracy of the section active power acquisition and measurement device; the adjusting key parameters comprise a threshold interval consisting of an adjusting upper threshold and an adjusting lower threshold;
further, the formula for the parameter setting unit 220 to adjust the upper threshold is as follows:
Pth_up＝PconN-Tdelay_maxVup_max-PconNεPowerM％-5TcVup_max
wherein, Pth_upFor power regulation of the upper threshold, PconNRated power, T, of converters at the junctionsdelay_maxIs the sum of the control system delay and the maximum power response time of the new energy sub-station, Vup_maxFor maximum rate of increase of output of new energy station, epsilonPowerM% error of the power measuring device, TcA power regulation control period;
the formula for the parameter setting unit 220 to adjust the lower limit threshold is as follows:
Pth_down＝Pth_up-ΝΔP
wherein, Pth_downFor the lower threshold of power adjustment, N is a preset interval constant, and Δ P is a preset power adjustment value.
Further, the parameter setting unit 220 is configured to preset a power adjustment value; the preset power regulation value is larger than the product of the maximum increase speed processed by the new energy station and the power regulation control period.
Further, the value range of the power regulation control period is a time interval formed by the response times of the two new energy sub-field stations with the highest power response speed.
A power monitoring unit 230, where the power monitoring unit 230 is configured to determine whether the section active power value acquired by the power acquisition unit 210 exceeds the threshold interval in real time;
and an adjusting and executing unit 240, where the adjusting and executing unit 240 is configured to send a power adjusting instruction to each sub-field station according to a preset power adjusting value when the power monitoring unit 230 monitors whether the cross-section active power value exceeds the threshold interval, so as to complete cross-section active power adjustment.
Further, if the power monitoring unit 230 monitors that the section active power value is higher than the upper regulation threshold, the regulation execution unit 240 sends a power down instruction to each sub-field station according to a preset rule according to a preset power regulation value;
if the power monitoring unit 230 monitors that the section active power value is lower than the lower regulation threshold, the regulation execution unit 240 sends a power up-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value.
Further, the adjustment performing unit 240 is configured to determine one or more sub-field stations capable of performing power adjustment; sending a power regulation instruction to the one or more sub-field stations capable of implementing power regulation according to a preset power regulation value;
the adjustment execution unit 240 is configured to select one or more sub-field stations, among the sub-field stations that operate normally, having a response speed higher than a preset speed value and an actual power value higher than a preset power value as sub-field stations that can perform power adjustment.
Further, the power monitoring unit 230 is configured to set a power adjustment input flag;
when a power regulation instruction is sent to each sub-field station, setting a power regulation input flag bit as 1;
and after the active power of the section is adjusted, when the active power value of the section is recovered to be within a threshold interval, setting a power adjustment input flag bit to be 0.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Reference to step numbers in this specification is only for distinguishing between steps and is not intended to limit the temporal or logical relationship between steps, which includes all possible scenarios unless the context clearly dictates otherwise.
Moreover, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the disclosure and form different embodiments. For example, any of the embodiments claimed in the claims can be used in any combination.
Various component embodiments of the disclosure may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The present disclosure may also be embodied as device or system programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present disclosure may be stored on a computer-readable medium or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.
It should be noted that the above-mentioned embodiments illustrate rather than limit the disclosure, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several systems, several of these systems may be embodied by one and the same item of hardware.
The foregoing is directed to embodiments of the present disclosure, and it is noted that numerous improvements, modifications, and variations may be made by those skilled in the art without departing from the spirit of the disclosure, and that such improvements, modifications, and variations are considered to be within the scope of the present disclosure.
Claims (12)
1. A power regulation method for accessing large-scale new energy into a direct current power grid comprises the following steps:
collecting the active power value of the section at the power collection position of each new energy sub-field station in real time;
calculating to obtain an adjusting key parameter according to the characteristics of the new energy, the parameters of the current converter at the convergence part and the precision of the section active power acquisition and measurement device; the adjusting key parameters comprise a threshold interval consisting of an adjusting upper threshold and an adjusting lower threshold;
the setting formula of the adjusting upper limit threshold value is as follows:
Pth_up＝PconN-Tdelay_maxVup_max-PconNεPowerM％-5TcVup_max
wherein, Pth_upFor power regulation of the upper threshold, PconNRated power, T, of converters at the junctionsdelay_maxIs the sum of the control system delay and the maximum power response time of the new energy sub-station, Vup_maxFor maximum rate of increase of output of new energy station, epsilonPowerM% error of the power measuring device, TcA power regulation control period;
the setting formula of the adjustment lower limit threshold is as follows:
Pth_down＝Pth_up-NΔP
wherein, Pth_downSetting the value as a power regulation lower limit threshold, wherein N is a preset interval constant, and delta P is a preset power regulation quantity value;
judging whether the section active power value exceeds the threshold interval in real time;
and if the active power exceeds the threshold interval, sending a power regulation instruction to each sub-field station according to a preset power regulation quantity value to finish the active power regulation of the cross section.
2. The method of claim 1, wherein: the preset power regulation value is larger than the product of the maximum increase speed processed by the new energy station and the power regulation control period.
3. The method according to claim 1 or 2, characterized in that: and the value range of the power regulation control period is a time interval formed by the response time of the two new energy sub-field stations with the highest power response speed.
4. The method of claim 1, wherein:
if the active power value of the section is higher than the upper regulation threshold, sending a power down-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value;
and if the active power value of the section is lower than the lower regulation threshold, sending a power up-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value.
5. The method according to claim 1 or 4, wherein before sending power adjustment commands to each sub-field station according to the preset power adjustment value, the method further comprises:
determining one or more sub-field stations capable of implementing power regulation;
sending a power regulation instruction to the one or more sub-field stations capable of implementing power regulation according to a preset power regulation value;
the method for determining one or more sub-field stations capable of implementing power regulation comprises the step of selecting one or more sub-field stations with response speed higher than a preset speed value and actual power higher than a preset power value as the sub-field stations capable of implementing power regulation in the sub-field stations which operate normally.
6. The method of claim 1, wherein:
setting a power regulation input flag bit;
when a power regulation instruction is sent to each sub-field station, setting a power regulation input flag bit as 1;
and after the active power of the section is adjusted, when the active power value of the section is recovered to be within a threshold interval, setting a power adjustment input flag bit to be 0.
7. A power conditioning system for large scale new energy access to a DC power grid, the system comprising:
the power acquisition unit is used for acquiring the active power value of the section at the power collection position of each new energy sub-field station in real time;
the parameter setting unit is used for calculating and obtaining an adjusting key parameter according to the characteristics of the new energy, the parameters of the current converter at the collecting part and the precision of the section active power acquisition and measurement device; the adjusting key parameters comprise a threshold interval consisting of an adjusting upper threshold and an adjusting lower threshold;
the formula for adjusting the upper limit threshold setting by the parameter setting unit is as follows:
Pth_up＝PconN-Tdelay_maxVup_max-PconNεPowerM％-5TcVup_max
wherein, Pth_upFor power regulation of the upper threshold, PconNRated power, T, of converters at the junctionsdelay_maxIs the sum of the control system delay and the maximum power response time of the new energy sub-station, Vup_maxFor maximum rate of increase of output of new energy station, epsilonPowerM% error of the power measuring device, TcA power regulation control period;
the formula for adjusting the lower limit threshold setting by the parameter setting unit is as follows:
Pth_down＝Pth_up-NΔP
wherein, Pth_downSetting the value as a power regulation lower limit threshold, wherein N is a preset interval constant, and delta P is a preset power regulation quantity value;
the power monitoring unit is used for judging whether the section active power value acquired by the power acquisition unit exceeds the threshold interval in real time;
and the adjusting and executing unit is used for sending a power adjusting instruction to each sub-field station according to a preset power adjusting value when the power monitoring unit monitors whether the active power value of the section exceeds the threshold interval, so as to complete the active power adjustment of the section.
8. The system of claim 7, wherein: the parameter setting unit is used for presetting a power regulation value; the preset power regulation value is larger than the product of the maximum increase speed processed by the new energy station and the power regulation control period.
9. The system according to claim 7 or 8, characterized in that: and the value range of the power regulation control period is a time interval formed by the response time of the two new energy sub-field stations with the highest power response speed.
10. The system of claim 7, wherein:
if the power monitoring unit monitors that the section active power value is higher than the adjustment upper limit threshold, the adjustment execution unit sends a power down instruction to each sub-field station according to a preset rule according to a preset power adjustment value;
and if the power monitoring unit monitors that the active power value of the section is lower than the lower regulation threshold, the regulation execution unit sends a power up-regulation instruction to each sub-field station according to a preset rule according to a preset power regulation value.
11. The system according to claim 7 or 10, characterized in that:
the regulation execution unit is used for determining one or more sub-field stations capable of implementing power regulation; sending a power regulation instruction to the one or more sub-field stations capable of implementing power regulation according to a preset power regulation value;
the adjusting execution unit is used for selecting one or more sub-field stations with response speed higher than a preset speed value and actual power larger than a preset power value from the sub-field stations which operate normally as the sub-field stations capable of implementing power adjustment.
12. The system of claim 7, wherein: the power monitoring unit is used for setting a power regulation input flag bit;
when a power regulation instruction is sent to each sub-field station, setting a power regulation input flag bit as 1;
and after the active power of the section is adjusted, when the active power value of the section is recovered to be within a threshold interval, setting a power adjustment input flag bit to be 0.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439596A (en) * | 2013-08-05 | 2013-12-11 | 东北电网有限公司 | Method for detecting safe operation steady-state performance of power transmission network |
| CN104348190A (en) * | 2014-10-27 | 2015-02-11 | 国家电网公司 | Active power adjusting method of wind power plant group collection system |
| CN108599192A (en) * | 2018-03-30 | 2018-09-28 | 中国电力科学研究院有限公司 | A kind of out-of-limit fast control method of power and system of isolated island current conversion station connected with passive power grid |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108418228A (en) * | 2018-03-28 | 2018-08-17 | 许继电气股份有限公司 | A kind of active power controller method when converter fault and flexible direct current power grid |
-
2019
- 2019-02-28 CN CN201910153202.2A patent/CN109888843B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439596A (en) * | 2013-08-05 | 2013-12-11 | 东北电网有限公司 | Method for detecting safe operation steady-state performance of power transmission network |
| CN104348190A (en) * | 2014-10-27 | 2015-02-11 | 国家电网公司 | Active power adjusting method of wind power plant group collection system |
| CN108599192A (en) * | 2018-03-30 | 2018-09-28 | 中国电力科学研究院有限公司 | A kind of out-of-limit fast control method of power and system of isolated island current conversion station connected with passive power grid |
Non-Patent Citations (3)
| Title |
|---|
| ±500 kV柔直电网与新能源和常规发电机组的协调控制研究;王炳辉等;《全球能源互联网》;20180925(第04期);471-477页 * |
| Enhancement of power system stability with VSC-HVDC transmission;H. S. Kang等;《2016 North American Power Symposium (NAPS)》;20160920;1-5页 * |
| 抽蓄电站和经多端柔性直流电网接入的大规模新能源间的协调互补优化控制方案;李文锋等;《电力系统保护与控制》;20171201(第23期);130-135页 * |
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