CN115684815B - Method and device for detecting oscillation source of direct-current power distribution network - Google Patents

Method and device for detecting oscillation source of direct-current power distribution network Download PDF

Info

Publication number
CN115684815B
CN115684815B CN202211704819.7A CN202211704819A CN115684815B CN 115684815 B CN115684815 B CN 115684815B CN 202211704819 A CN202211704819 A CN 202211704819A CN 115684815 B CN115684815 B CN 115684815B
Authority
CN
China
Prior art keywords
power
power module
psd
distribution network
module
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
CN202211704819.7A
Other languages
Chinese (zh)
Other versions
CN115684815A (en
Inventor
刘晓
苏善诚
任志刚
胥明凯
赵子达
彭克
于光远
肖传亮
瞿寒冰
董春发
刘宝
申文伟
贾玉健
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.)
Shandong University of Technology
Jinan Power Supply Co of State Grid Shandong Electric Power Co Ltd
Original Assignee
Shandong University of Technology
Jinan Power Supply Co of State Grid Shandong 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 Shandong University of Technology, Jinan Power Supply Co of State Grid Shandong Electric Power Co Ltd filed Critical Shandong University of Technology
Priority to CN202211704819.7A priority Critical patent/CN115684815B/en
Publication of CN115684815A publication Critical patent/CN115684815A/en
Application granted granted Critical
Publication of CN115684815B publication Critical patent/CN115684815B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Landscapes

  • Direct Current Feeding And Distribution (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a method and a device for detecting an oscillation source of a direct-current power distribution network, wherein the method comprises the following steps: based on a unit connection method, the switching state of each switch and the unlocking state of a converter device are obtained from a direct current power distribution network, and an equivalent model of a double-end power supply direct current power distribution network taking a power module as a basic unit is established; calculating input signals of each power module by using the equivalent model; calculating PSD of the input signals of each power module by utilizing the input signals to obtain autocorrelation functions of the input signals; calculating the PSD of the output signals of each power module by using the transfer function of the equivalent model and the PSD of the input signals; and calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module, and judging whether the power module is an oscillation source. The invention can detect the oscillation source of the direct current distribution network, effectively eliminate system oscillation in time and reduce the loss caused by direct current bus oscillation.

Description

Method and device for detecting oscillation source of direct-current power distribution network
Technical Field
The invention relates to a method and a device for detecting an oscillation source of a direct-current power distribution network based on PSD (Power Spectral density ), and belongs to the technical field of stable operation monitoring of power distribution systems.
Background
In order to achieve the aim of carbon peak and carbon neutralization, new energy mainly comprising clean energy such as solar energy, wind energy and the like is greatly developed. Compared with an alternating current power grid, the direct current power grid does not need to track the frequency of the voltage of the bus, so that the running controllability and reliability of the direct current system are greatly improved, and meanwhile, the distributed power supply and the multi-element load are more suitable for being connected. On one hand, the direct-current distribution system does not need a current conversion link of an alternating-current system, so that the new energy acceptance capability and the utilization rate of a power grid can be effectively improved, on the other hand, the novel direct-current system introduces a large number of power electronic converters, the independent decoupling control of the active power and the reactive power of the converters can be effectively realized, and meanwhile, the power conversion is faster and more flexible when the alternating-current power grid and the direct-current system interact. However, with the sustainable utilization of energy, energy storage devices and the access of various types of alternating current and direct current loads, the structure of a direct current distribution network is also greatly changed, and the static operation structure of a traditional power system is changed into a novel intelligent structure of the power system, which is flexible and autonomous.
For the direct current distribution network, reactive power does not exist in the direct current distribution network, so that whether the direct current voltage is stable or not becomes the only index for measuring whether the direct current system can safely and stably operate. And with the access of high-proportion power electronic equipment, the voltage oscillation problem of the direct-current power distribution system also gradually appears. On the one hand, because equipment such as a synchronous generator is absent in the direct-current power distribution network, and meanwhile, new power sources such as a photovoltaic power supply, a fan and the like which are connected cannot provide inertia support for the system, the total amount of inertia in the system is smaller; on the other hand, the interconnection device of the alternating current power grid and the direct current power distribution network is mainly a power electronic converter, so that the inertia of the alternating current power grid and the direct current power distribution network are relatively isolated, and the problem of oscillation is easy to cause.
With the strong development of dc distribution networks in recent years, the problem of oscillation is also receiving more attention. For the oscillation problem of the direct current distribution network, a large number of students mainly study the mechanism of the direct current distribution network. For the detection method of the oscillation source, the current research is mainly focused on the aspect of an alternating current system, and the detection method of the oscillation source of the direct current power distribution network is relatively deficient. When the direct current distribution network oscillates, if the source causing the oscillation can be located in time, the system oscillation can be eliminated more timely and effectively, and the loss caused by the direct current bus oscillation is reduced. Therefore, the problem of detecting the oscillation source is a problem which needs to be solved in the aspect of the research of the direct current power distribution network at present.
Disclosure of Invention
In order to solve the problems, the invention provides a method and a device for detecting an oscillation source of a direct current power distribution network, which can detect the oscillation source of the direct current power distribution network, timely and effectively eliminate system oscillation and reduce loss caused by direct current bus oscillation.
The technical scheme adopted for solving the technical problems is as follows:
on one hand, the method for detecting the oscillation source of the direct-current power distribution network provided by the embodiment of the invention comprises the following steps:
based on a unit connection method, acquiring the switching state of each switch and the unlocking state of a converter device from a direct current power distribution network, and establishing an equivalent model of the double-end power supply direct current power distribution network taking a power module as a basic unit according to the switching state of each switch and the unlocking state of the converter device;
calculating input signals of each power module by using the equivalent model;
calculating PSD of the input signals of each power module by utilizing the input signals to obtain autocorrelation functions of the input signals;
calculating the PSD of the output signals of each power module by using the transfer function of the equivalent model and the PSD of the input signals;
and calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module, and judging whether the power module is an oscillation source.
As one possible implementation manner of this embodiment, the equivalent model includes a power supply end equivalent model of the dual-end power supply dc power distribution network and a constant power load end equivalent model of the dual-end power supply dc power distribution network.
As a possible implementation manner of this embodiment, the power supply end equivalent model of the dual-end power supply dc power distribution network is expressed as:
Figure SMS_1
Figure SMS_2
wherein
Figure SMS_3
in the formula
Figure SMS_15
、/>
Figure SMS_5
For power module->
Figure SMS_17
Closed loop transfer function and output impedance of reference values to respective output signals, +.>
Figure SMS_8
,/>
Figure SMS_16
Respectively power module->
Figure SMS_9
The direct-current droop control inner loop proportional-integral regulator has proportional and integral coefficients, +.>
Figure SMS_13
,/>
Figure SMS_6
Respectively power module->
Figure SMS_18
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure SMS_4
Is equivalent gain of converter->
Figure SMS_14
、/>
Figure SMS_7
、/>
Figure SMS_12
Respectively the inductance, the resistance and the capacitance of the filter circuit,sfor Laplace operator>
Figure SMS_19
For the d-axis component of the ac side voltage, +.>
Figure SMS_21
Is equivalent to three-phase power supply voltage->
Figure SMS_11
、/>
Figure SMS_20
The current controller and the voltage controller are respectively adopted, and proportional integral control and ++are adopted in the equivalent model>
Figure SMS_10
Is a positive integer.
As a possible implementation manner of this embodiment, the constant power load end equivalent model of the double-end power supply dc power distribution network is expressed as:
Figure SMS_22
Figure SMS_23
wherein ,
Figure SMS_24
/>
Figure SMS_25
Figure SMS_26
Figure SMS_27
in the formula ,
Figure SMS_29
,/>
Figure SMS_37
norton equivalent admittance and closed loop transfer function of constant power load power module, G j,d (s) is a voltage controller, +.>
Figure SMS_38
,/>
Figure SMS_31
Constant power load modules respectively>
Figure SMS_35
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure SMS_36
For PWM duty cycle, +.>
Figure SMS_39
For filtering inductor current->
Figure SMS_28
Is equivalent gain of converter->
Figure SMS_32
Is equivalent to output resistance>
Figure SMS_33
,/>
Figure SMS_34
,/>
Figure SMS_30
The inductance, capacitance and resistance of the filter circuit are respectively.
As a possible implementation manner of this embodiment, a calculation formula of the input signal of each power module is:
Figure SMS_40
in the formula
Figure SMS_41
For power module->
Figure SMS_42
Input signal of>
Figure SMS_43
,/>
Figure SMS_44
Respectively power module->
Figure SMS_45
Reference voltage and reference current of>
Figure SMS_46
The number of the power modules of the direct-current distribution network is the number of the power modules of the direct-current distribution network.
As a possible implementation manner of this embodiment, a calculation formula of the PSD of the input signal of each power module is:
Figure SMS_47
/>
in the formula
Figure SMS_48
For input signal +.>
Figure SMS_49
PSD of->
Figure SMS_50
For input signal +.>
Figure SMS_51
Is an autocorrelation function of>
Figure SMS_52
Is the self-signal of the derived autocorrelation function.
As a possible implementation manner of this embodiment, a calculation formula of the PSD of the output signal of each power module is:
Figure SMS_53
in the formula
Figure SMS_56
For power module->
Figure SMS_57
Output signal of>
Figure SMS_59
For power module->
Figure SMS_55
PSD, & gt of output signal>
Figure SMS_58
For power module->
Figure SMS_61
Transfer function of->
Figure SMS_62
Is (are) mould>
Figure SMS_54
For power module->
Figure SMS_60
Transfer function of->
Figure SMS_63
Is a mold of (a).
As a possible implementation manner of this embodiment, the calculation formula of the oscillation source detection index is:
Figure SMS_64
in the formula
Figure SMS_65
For power module->
Figure SMS_66
PSD measured values of>
Figure SMS_67
For measuring power module->
Figure SMS_68
An indicator of the degree of deviation of the PSD theoretical value from the measured value.
On the other hand, the device for detecting the oscillation source of the direct-current power distribution network provided by the embodiment of the invention comprises the following components:
the equivalent model building module is used for obtaining the switching state of each switch and the unlocking state of the converter device from the direct current power distribution network based on the unit connection method, and building an equivalent model of the double-end power supply direct current power distribution network taking the power module as a basic unit according to the switching state of each switch and the unlocking state of the converter device;
the input signal calculation module is used for calculating the input signals of the power modules by using the equivalent model;
the input signal PSD calculation module is used for calculating the PSD of the input signals of each power module by utilizing the input signals to obtain the autocorrelation function of the input signals;
the output signal PSD calculation module is used for calculating the PSD of the output signals of each power module by utilizing the transfer function of the equivalent model and the PSD of the input signals;
and the oscillation source judging module is used for calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module and judging whether the power module is an oscillation source or not.
As a possible implementation manner of this embodiment, the equivalent model established by the equivalent model establishing module includes a power supply end equivalent model of the double-end power supply dc power distribution network and a constant power load end equivalent model of the double-end power supply dc power distribution network.
As a possible implementation manner of this embodiment, the power supply end equivalent model of the dual-end power supply dc power distribution network is expressed as:
Figure SMS_69
Figure SMS_70
wherein
Figure SMS_71
in the formula
Figure SMS_79
、/>
Figure SMS_77
For power module->
Figure SMS_86
Closed loop transfer function and output impedance of reference values to respective output signals, +.>
Figure SMS_73
,/>
Figure SMS_82
Respectively power module->
Figure SMS_78
The direct-current droop control inner loop proportional-integral regulator has proportional and integral coefficients, +.>
Figure SMS_81
,/>
Figure SMS_83
Respectively power module->
Figure SMS_85
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure SMS_72
Is equivalent gain of converter->
Figure SMS_89
、/>
Figure SMS_76
、/>
Figure SMS_87
Respectively the inductance, the resistance and the capacitance of the filter circuit,sfor Laplace operator>
Figure SMS_75
For the d-axis component of the ac side voltage, +.>
Figure SMS_80
Is equivalent to three-phase power supply voltage->
Figure SMS_74
、/>
Figure SMS_88
The current controller and the voltage controller are respectively adopted, and proportional integral control and ++are adopted in the equivalent model>
Figure SMS_84
Is a positive integer.
As a possible implementation manner of this embodiment, the constant power load end equivalent model of the double-end power supply dc power distribution network is expressed as:
Figure SMS_90
Figure SMS_91
wherein ,
Figure SMS_92
Figure SMS_93
Figure SMS_94
/>
Figure SMS_95
in the formula ,
Figure SMS_99
,/>
Figure SMS_101
norton equivalent admittance and closed loop transfer function of constant power load power module, G j,d (s) is a voltage controller, +.>
Figure SMS_103
,/>
Figure SMS_97
Constant power load modules respectively>
Figure SMS_102
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure SMS_105
For PWM duty cycle, +.>
Figure SMS_107
For filtering inductor current->
Figure SMS_96
Is equivalent gain of converter->
Figure SMS_100
Is equivalent to output resistance>
Figure SMS_104
,/>
Figure SMS_106
,/>
Figure SMS_98
The inductance, capacitance and resistance of the filter circuit are respectively.
As a possible implementation manner of this embodiment, the calculation formula of the input signal calculation module for calculating the input signal of each power module is:
Figure SMS_108
in the formula
Figure SMS_109
For power module->
Figure SMS_110
Input signal of>
Figure SMS_111
,/>
Figure SMS_112
Respectively power module->
Figure SMS_113
Reference voltage and reference current of>
Figure SMS_114
The number of the power modules of the direct-current distribution network is the number of the power modules of the direct-current distribution network.
The calculation formula for calculating the PSD of the input signals of each power module by the input signal PSD calculation module is as follows:
Figure SMS_115
in the formula
Figure SMS_116
For input signal +.>
Figure SMS_117
PSD of->
Figure SMS_118
For input signal +.>
Figure SMS_119
Is an autocorrelation function of>
Figure SMS_120
Is the self-signal of the derived autocorrelation function.
The calculation formula for calculating the PSD of the output signals of each power module by the output signal PSD calculation module is as follows:
Figure SMS_121
in the formula
Figure SMS_123
For power module->
Figure SMS_126
Output signal of>
Figure SMS_129
For power module->
Figure SMS_124
PSD, & gt of output signal>
Figure SMS_127
For power module->
Figure SMS_130
Transfer function of->
Figure SMS_131
Is (are) mould>
Figure SMS_122
For power module->
Figure SMS_125
Transfer function of->
Figure SMS_128
Is a mold of (a).
The calculation formula for calculating the oscillation source detection index by the oscillation source judging module is as follows:
Figure SMS_132
in the formula
Figure SMS_133
For power module->
Figure SMS_134
PSD measured values of>
Figure SMS_135
For measuring power module->
Figure SMS_136
An indicator of the degree of deviation of the PSD theoretical value from the measured value.
The technical scheme of the embodiment of the invention has the following beneficial effects:
according to the invention, an equivalent model of the direct-current power distribution network is established through a unit connection method, the PSD of an output signal is obtained based on the input signals and transfer functions of all power modules in the equivalent model, and the deviation degree of the obtained PSD and the PSD actual measurement value of the output signal of each power module is considered to detect the oscillation source of the direct-current power distribution network.
In the invention, in the process of establishing the equivalent model of the direct-current power distribution network by combining the unit connection method, the two-port model is established by separating the node impedance of the system and each power module, so that the calculation pressure of the system is effectively reduced, and the detection of the oscillation source of equipment accessed to the direct-current power distribution network is facilitated.
In the process of positioning the DC power distribution network oscillation source by using PSD, the invention obtains the PSD theoretical value of the output signal of each power module through the input signal and the transfer function of each power module, and proposes a judgment index based on the theoretical value and the actual measured value of the output signal of each power module; the detection of the oscillation source can be accurately and rapidly carried out on each power module of the direct-current power distribution network through judging indexes, and the problem of direct-current voltage oscillation can be effectively solved in time.
Drawings
FIG. 1 is a flowchart illustrating a method of DC power distribution network oscillation source detection, according to an exemplary embodiment;
FIG. 2 is a block diagram illustrating an apparatus for DC power distribution network oscillation source detection according to an exemplary embodiment;
FIG. 3 is a flow chart of a method for detecting an oscillation source of a PSD-based direct current power distribution network by using the device of the invention;
FIG. 4 is a schematic diagram of a simulated verified DC power distribution network model topology, according to an exemplary embodiment;
FIG. 5 is a schematic diagram of the voltage oscillation curve of the DC bus in the calculation example 1;
FIG. 6 is a graph showing the PSD measured value of the power module 1 in the calculation example 1;
FIG. 7 is a graph showing the PSD measured value of the power module 2 in example 1;
FIG. 8 is a histogram of the oscillation source detection index of example 1;
FIG. 9 is a schematic diagram of voltage oscillation curves of the DC bus in the example 2;
FIG. 10 is a graph showing the PSD measured value of the power module 3 in the calculation example 2;
FIG. 11 is a graph showing the PSD measured value of the power module 4 in the calculation example 2;
fig. 12 is a histogram of the oscillation source detection index in example 2.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings:
in order to clearly illustrate the technical features of the present solution, the present invention will be described in detail below with reference to the following detailed description and the accompanying drawings. The following disclosure provides many different embodiments, or examples, for implementing different structures of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. It should be noted that the components illustrated in the figures are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and processes are omitted so as to not unnecessarily obscure the present invention.
As shown in fig. 1, the method for detecting the oscillation source of the direct-current power distribution network provided by the embodiment of the invention comprises the following steps:
the method comprises the steps of obtaining the switching state of each switch and the unlocking state of a converter device from a direct current power distribution network based on a unit connection method, and establishing an equivalent model of a double-end power supply direct current power distribution network taking a power module as a basic unit according to the switching state of each switch and the unlocking state of the converter device, wherein the equivalent model comprises a power supply end equivalent model of the double-end power supply direct current power distribution network and a constant power load end equivalent model of the double-end power supply direct current power distribution network;
calculating input signals of each power module by using the equivalent model;
calculating PSD of the input signals of each power module by utilizing the input signals to obtain autocorrelation functions of the input signals;
calculating the PSD of the output signals of each power module by using the transfer function of the equivalent model and the PSD of the input signals;
and calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module, and judging whether the power module is an oscillation source.
The basic parameters of the direct current distribution network comprise a direct current distribution network topological structure, converter station parameters (full-bridge MMC/half-bridge MMC), line parameters and short circuit fault positions, wherein the direct current distribution network topological parameters represent the number of stations and interconnection relations of the half-bridge MMC, the full-bridge MMC and the direct current transformers, and according to the Thevenin equivalent circuit principle, the circuit parameters are related to circuit topology and short circuit fault points and directly influence the short circuit current values of the fault points.
As a possible implementation manner of this embodiment, the power supply end equivalent model of the dual-end power supply dc power distribution network is expressed as:
Figure SMS_137
Figure SMS_138
wherein
Figure SMS_139
in the formula
Figure SMS_156
、/>
Figure SMS_143
Closed loop transfer function and output impedance for reference value to respective output signal in equivalent model of power module,/>
Figure SMS_152
,/>
Figure SMS_142
Respectively power module->
Figure SMS_149
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure SMS_147
,/>
Figure SMS_155
Respectively power module->
Figure SMS_154
The direct-current droop control inner loop proportional-integral regulator has proportional and integral coefficients, +.>
Figure SMS_157
,/>
Figure SMS_140
For the proportionality and sagging coefficients, +.>
Figure SMS_150
Is equivalent gain of converter->
Figure SMS_145
、/>
Figure SMS_151
、/>
Figure SMS_146
Respectively the inductance, the resistance and the capacitance of the filter circuit,sfor Laplace operator>
Figure SMS_148
For the d-axis component of the ac side voltage, +.>
Figure SMS_141
、/>
Figure SMS_153
The current controller and the voltage controller are respectively adopted, and proportional integral control and ++are adopted in the equivalent model>
Figure SMS_144
Is a positive integer.
As a possible implementation manner of this embodiment, the constant power load end equivalent model of the double-end power supply dc power distribution network is expressed as:
Figure SMS_158
/>
Figure SMS_159
wherein ,
Figure SMS_160
Figure SMS_161
Figure SMS_162
Figure SMS_163
in the formula ,
Figure SMS_166
,/>
Figure SMS_167
norton equivalent admittance and closed loop transfer function of constant power load power module, G j,d (s) is a voltage controller, +.>
Figure SMS_172
For PWM duty cycle, +.>
Figure SMS_165
Is equivalent gain of converter->
Figure SMS_169
Is equivalent to output resistance>
Figure SMS_170
,/>
Figure SMS_171
,/>
Figure SMS_164
The inductance, the capacitance and the resistance of the filter circuit are respectively +.>
Figure SMS_168
To filter the inductor current.
As a possible implementation manner of this embodiment, a calculation formula of the input signal of each power module is:
Figure SMS_173
in the formula
Figure SMS_174
For power module->
Figure SMS_175
Input signal of>
Figure SMS_176
,/>
Figure SMS_177
Respectively power module->
Figure SMS_178
Reference voltage and reference current of>
Figure SMS_179
The number of the power modules of the direct-current distribution network is the number of the power modules of the direct-current distribution network. />
As a possible implementation manner of this embodiment, a calculation formula of the PSD of the input signal of each power module is:
Figure SMS_180
in the formula
Figure SMS_181
For input signal +.>
Figure SMS_182
PSD of->
Figure SMS_183
For input signal +.>
Figure SMS_184
Is an autocorrelation function of>
Figure SMS_185
Is the self-signal of the derived autocorrelation function.
As a possible implementation manner of this embodiment, a calculation formula of the PSD of the output signal of each power module is:
Figure SMS_186
in the formula
Figure SMS_188
For power module->
Figure SMS_194
Output signal of>
Figure SMS_195
For power module->
Figure SMS_189
PSD, & gt of output signal>
Figure SMS_192
For power module->
Figure SMS_193
Transfer function of->
Figure SMS_196
Is (are) mould>
Figure SMS_187
For power module->
Figure SMS_190
Transfer function of->
Figure SMS_191
Is a mold of (a).
As a possible implementation manner of this embodiment, the calculation formula of the oscillation source detection index is:
Figure SMS_197
in the formula
Figure SMS_198
For power module->
Figure SMS_199
PSD measured values of>
Figure SMS_200
For measuring power module->
Figure SMS_201
An indicator of the degree of deviation of the PSD theoretical value from the measured value.
As shown in fig. 2, a device for detecting an oscillation source of a dc power distribution network according to an embodiment of the present invention includes:
the equivalent model building module is used for obtaining the switching state of each switch and the unlocking state of the converter device from the direct current power distribution network based on the unit connection method, and building an equivalent model of the double-end power supply direct current power distribution network taking the power module as a basic unit according to the switching state of each switch and the unlocking state of the converter device, wherein the equivalent model comprises a power supply end equivalent model of the double-end power supply direct current power distribution network and a constant power load end equivalent model of the double-end power supply direct current power distribution network;
the input signal calculation module is used for calculating the input signals of the power modules by using the equivalent model;
the input signal PSD calculation module is used for calculating the PSD of the input signals of each power module by utilizing the input signals to obtain the autocorrelation function of the input signals;
the output signal PSD calculation module is used for calculating the PSD of the output signals of each power module by utilizing the transfer function of the equivalent model and the PSD of the input signals;
and the oscillation source judging module is used for calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module and judging whether the power module is an oscillation source or not.
As shown in fig. 3, the process of detecting the oscillation source of the direct-current power distribution network based on the PSD by using the device of the invention comprises the following steps:
step 1, establishing an equivalent model of the double-end power supply direct current power distribution network based on a unit connection method.
When an equivalent model is built for the double-end power supply direct current distribution network, the double-end power supply direct current distribution network is divided into a power supply end power module and a constant power load power module according to the characteristics of the access direct current bus equipment, and the parameters of the equivalent model of the power supply end power module can be expressed as follows:
Figure SMS_202
Figure SMS_203
wherein
Figure SMS_204
in the formula
Figure SMS_216
、/>
Figure SMS_209
Closed loop transfer function and output impedance for reference value to respective output signal in equivalent model of power module,/>
Figure SMS_217
,/>
Figure SMS_212
Respectively power module->
Figure SMS_221
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure SMS_211
,/>
Figure SMS_215
Respectively power module->
Figure SMS_210
The direct-current droop control inner loop proportional-integral regulator has proportional and integral coefficients, +.>
Figure SMS_218
,/>
Figure SMS_205
For the proportionality and sagging coefficients, +.>
Figure SMS_219
Is equivalent gain of converter->
Figure SMS_208
、/>
Figure SMS_220
、/>
Figure SMS_207
Respectively comprises a filter circuit inductor, a resistor and a capacitor,sfor Laplace operator>
Figure SMS_213
For the d-axis component of the ac side voltage, +.>
Figure SMS_206
、
Figure SMS_214
The current controller and the voltage controller are respectively adopted, and proportional integral control is adopted in the model.
The equivalent model parameters of the constant power load power module can be expressed as:
Figure SMS_222
Figure SMS_223
wherein ,
Figure SMS_224
Figure SMS_225
/>
Figure SMS_226
Figure SMS_227
in the formula
Figure SMS_230
,/>
Figure SMS_232
Norton equivalent admittance and closed loop transfer function of constant power load power module, G j,d (s) is a voltage controller, +.>
Figure SMS_233
For PWM duty cycle, +.>
Figure SMS_229
Is equivalent gain of converter->
Figure SMS_234
Is equivalent to output resistance>
Figure SMS_235
,/>
Figure SMS_236
,/>
Figure SMS_228
The inductance, the capacitance and the resistance of the filter circuit are respectively +.>
Figure SMS_231
To filter the inductor current.
And 2, obtaining input signals of each power module by using the obtained equivalent model parameters.
For a double-end power supply direct current power distribution network, a power module at a power supply end in an equivalent model is a power module
Figure SMS_237
,/>
Figure SMS_238
The constant-power load power module is a power module +.>
Figure SMS_239
The input signal for each power module can thus be expressed as:
Figure SMS_240
in the formula
Figure SMS_241
For power module->
Figure SMS_242
Input signal of>
Figure SMS_243
,/>
Figure SMS_244
Respectively power module->
Figure SMS_245
Reference voltage and reference current of>
Figure SMS_246
The number of the power modules of the direct-current distribution network is the number of the power modules of the direct-current distribution network.
And step 3, obtaining PSD of the input signals of each power module by using the obtained input signals.
And obtaining the autocorrelation function according to the obtained input signal expression. For a dc power distribution network, the oscillation process is a generalized stationary random process, and in this process, the autocorrelation function and the PSD of the process are fourier transforms, so the PSD of the input signal of each power module can be expressed as:
Figure SMS_247
in the formula
Figure SMS_248
For input signal +.>
Figure SMS_249
PSD of->
Figure SMS_250
For input signal +.>
Figure SMS_251
Is an autocorrelation function of>
Figure SMS_252
Is the self-signal of the derived autocorrelation function.
And 4, obtaining the PSD of the output signal by utilizing the relation between the input signal and the output signal of the power module.
For a direct current system, the input signals of each power module can be decomposed into superposition of impulse signals with different time delays, and then under the condition of known input signals, the power module can be obtained by using a continuous domain convolution method
Figure SMS_253
And combining the transfer function of the obtained equivalent model with the PSD of the input signal, the PSD of the output signal of each power module obtained can be expressed as:
Figure SMS_254
in the formula
Figure SMS_257
For power module->
Figure SMS_259
Output signal of>
Figure SMS_263
For power module->
Figure SMS_256
PSD, & gt of output signal>
Figure SMS_261
For power module->
Figure SMS_262
Transfer function of->
Figure SMS_264
Is (are) mould>
Figure SMS_255
For power module->
Figure SMS_258
Transfer function of->
Figure SMS_260
Is a mold of (a).
And step 5, utilizing the theoretical value and the actual measurement value of each power module PSD to provide an oscillation source detection index.
In an ideal situation, the PSD theoretical value of the power module of the non-oscillation source is strictly equal to the actual measurement value, so that for a certain power module, if the PSD theoretical value is equal to the actual measurement value, the power module is not an oscillation source; if the PSD theoretical value and the actual measurement value are not equal, the power module is indicated to have a disturbance source. However, since a large number of power electronic elements are introduced into the direct current system, nonlinear factors, interference noise and the like exist in the direct current system, and differences exist between theoretical values and actual measurement values of PSDs. The index for measuring the deviation degree of the PSD theoretical value and the measured value is provided by considering the factors, and is as follows:
Figure SMS_265
in the formula
Figure SMS_266
For power module->
Figure SMS_267
PSD measured values of>
Figure SMS_268
For measuring power module->
Figure SMS_269
An indicator of the degree of deviation of the PSD theoretical value from the measured value.
The method for detecting the oscillation source of the direct-current distribution network based on the PSD is specifically described through two calculation examples, wherein in the calculation examples, the effectiveness of the method for detecting the oscillation source of the direct-current distribution network based on the PSD is specifically described through direct-current voltage oscillation scenes caused by two conditions of external disturbance access to a direct-current system and sudden increase of load consumption power in the system.
Fig. 4 shows a topology of the double-end power supply dc distribution network constructed by the simulation case. In the figure, the voltage class of a direct current bus is 600V, alternating current sources G1 and G2 are connected into a direct current system through a converter, the converter adopts droop control, the alternating current source G1 and a converter part thereof are power modules 1, the alternating current source G2 and a converter part thereof are power modules 2, a variable load 1 and a converter part thereof are power modules 3, and the load 2 and a converter part thereof are power modules 4.
Calculation example 1: in order to verify the effectiveness of the detection method provided herein under the condition that the external disturbance is connected to cause the oscillation of the direct current bus, the consumed power of the power modules 3 and 4 is kept to be 24 kW, the external disturbance is connected to the power module 1 during 1.4S, the voltage of the direct current bus is affected by the external disturbance to oscillate as shown in fig. 5, the oscillation frequency is 7.93Hz, and the power module 1 is an oscillation source in the condition.
As shown in fig. 6 and 7, the actual values of the PSDs of the power modules 1 and 2 are respectively shown, the histogram of the oscillation source detection indexes of the power modules 1 and 2 obtained by using the obtained actual values and theoretical values of the PSDs is shown in fig. 8, and it is known from the graph that the oscillation source detection index of the power module 1 as the oscillation source satisfies the following condition
Figure SMS_270
Instead of the oscillation source power module 2 satisfying +.>
Figure SMS_271
Consistent with the oscillation source detection methods presented herein.
Calculation example 2: to verify the effectiveness of the detection method provided herein in the case of oscillation of the dc bus caused by sudden increase of power consumption of the power module in the system, the power consumption of the power module 4 is kept to be 60kW, the initial power consumption of the power module 3 is 24 kW, the sudden change of power consumption is 60kW at 0.5S, and at this time, the voltage oscillation of the dc bus is as shown in fig. 9, and the oscillation frequency is 42.504Hz. Since the system oscillation is caused by the abrupt power change of the power module 3, the power module 3 is an oscillation source.
As shown in fig. 10 and 11, which are actual measurement values of the PSDs of the power modules 3 and 4, respectively, and a histogram of the oscillation source detection indexes of the power modules 3 and 4 obtained by using the obtained actual measurement values and theoretical values of the PSDs is shown in fig. 12, it is known from the graph that the oscillation source detection indexes of the power module 3 as the oscillation source satisfy the following conditions
Figure SMS_272
Instead of the oscillation source power module 4 satisfying +.>
Figure SMS_273
The obtained result is consistent with the theoretical analysis of the oscillation source detection method.
Compared with the prior art, the invention has the following advantages:
in the method for establishing the equivalent model of the direct-current power distribution network by combining the unit connection method, the two-port model is established by separating the node impedance of the system and each power module, so that the calculation pressure of the system is effectively reduced, and the detection of the oscillation source of equipment accessed to the direct-current power distribution network is facilitated.
In the process of positioning the DC power distribution network oscillation source by using PSD, the PSD theoretical value of the output signal is obtained through the input signal and the transfer function of each power module, and a judgment index is provided based on the theoretical value and the actual measured value of the output signal of each power module. The detection of the oscillation source can be accurately and rapidly carried out on each power module of the direct-current power distribution network through judging indexes, and the problem of direct-current voltage oscillation can be effectively solved in time.
Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.

Claims (10)

1. The method for detecting the oscillation source of the direct-current power distribution network is characterized by comprising the following steps of:
based on a unit connection method, acquiring the switching state of each switch and the unlocking state of a converter device from a direct current power distribution network, and establishing an equivalent model of the double-end power supply direct current power distribution network taking a power module as a basic unit according to the switching state of each switch and the unlocking state of the converter device; the equivalent model comprises a power supply end equivalent model of the double-end power supply direct current power distribution network and a constant power load end equivalent model of the double-end power supply direct current power distribution network;
calculating input signals of each power module by using the equivalent model;
calculating PSD of the input signals of each power module by utilizing the input signals to obtain autocorrelation functions of the input signals;
calculating the PSD of the output signals of each power module by using the transfer function of the equivalent model and the PSD of the input signals;
calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module, and judging whether the power module is an oscillation source or not;
the power supply end equivalent model of the double-end power supply direct current power distribution network is expressed as:
Figure QLYQS_1
Figure QLYQS_2
wherein
Figure QLYQS_3
in the formula
Figure QLYQS_11
、/>
Figure QLYQS_10
For power module->
Figure QLYQS_20
Closed loop transfer function and output impedance of reference values to respective output signals, +.>
Figure QLYQS_9
,/>
Figure QLYQS_13
Respectively power module->
Figure QLYQS_17
The direct-current droop control inner loop proportional-integral regulator has proportional and integral coefficients, +.>
Figure QLYQS_21
,/>
Figure QLYQS_6
Respectively power module->
Figure QLYQS_12
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure QLYQS_4
Is equivalent gain of converter->
Figure QLYQS_16
、/>
Figure QLYQS_5
、/>
Figure QLYQS_14
Respectively the inductance, the resistance and the capacitance of the filter circuit,sfor Laplace operator>
Figure QLYQS_7
For the d-axis component of the ac side voltage, +.>
Figure QLYQS_19
Is equivalent to three-phase power supply voltage->
Figure QLYQS_8
、/>
Figure QLYQS_15
The current controller and the voltage controller are respectively adopted, and proportional integral control and ++are adopted in the equivalent model>
Figure QLYQS_18
Is a positive integer;
the constant power load end equivalent model of the double-end power supply direct current power distribution network is expressed as:
Figure QLYQS_22
Figure QLYQS_23
wherein ,
Figure QLYQS_24
/>
Figure QLYQS_25
Figure QLYQS_26
Figure QLYQS_27
in the formula ,
Figure QLYQS_31
,/>
Figure QLYQS_32
norton equivalent admittance and closed loop transfer function of constant power load power module, G j,d (s) is a voltage controller, +.>
Figure QLYQS_35
,/>
Figure QLYQS_30
Constant power load modules respectively>
Figure QLYQS_34
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure QLYQS_37
For PWM duty cycle, +.>
Figure QLYQS_38
For filtering inductor current->
Figure QLYQS_28
Is equivalent gain of converter->
Figure QLYQS_33
Is equivalent to output resistance>
Figure QLYQS_36
,/>
Figure QLYQS_39
,/>
Figure QLYQS_29
The inductance, capacitance and resistance of the filter circuit are respectively.
2. The method for detecting an oscillation source of a direct current power distribution network according to claim 1, wherein the calculation formula of the input signal of each power module is:
Figure QLYQS_40
in the formula
Figure QLYQS_41
For power module->
Figure QLYQS_42
Input signal of>
Figure QLYQS_43
,/>
Figure QLYQS_44
Respectively power module->
Figure QLYQS_45
Reference voltage and reference current of>
Figure QLYQS_46
The number of the power modules of the direct-current distribution network is the number of the power modules of the direct-current distribution network.
3. The method for detecting an oscillation source of a direct current power distribution network according to claim 1, wherein a calculation formula of the PSD of the input signal of each power module is:
Figure QLYQS_47
/>
in the formula
Figure QLYQS_48
For input signal +.>
Figure QLYQS_49
PSD of->
Figure QLYQS_50
For input signal +.>
Figure QLYQS_51
Is an autocorrelation function of>
Figure QLYQS_52
Is the self-signal of the derived autocorrelation function.
4. The method for detecting an oscillation source of a direct current power distribution network according to claim 1, wherein a calculation formula of the PSD of the output signal of each power module is:
Figure QLYQS_53
in the formula
Figure QLYQS_55
For power module->
Figure QLYQS_60
Output signal of>
Figure QLYQS_62
For power module->
Figure QLYQS_56
PSD, & gt of output signal>
Figure QLYQS_57
For power module->
Figure QLYQS_59
Transfer function of->
Figure QLYQS_63
Is (are) mould>
Figure QLYQS_54
For power module->
Figure QLYQS_58
Transfer function of->
Figure QLYQS_61
Is a mold of (a).
5. The method for detecting an oscillation source of a direct current power distribution network according to claim 1, wherein the calculation formula of the oscillation source detection index is:
Figure QLYQS_64
in the formula
Figure QLYQS_65
For power module->
Figure QLYQS_66
PSD measured values of>
Figure QLYQS_67
For measuring power module->
Figure QLYQS_68
An indicator of the degree of deviation of the PSD theoretical value from the measured value.
6. The utility model provides a device that direct current distribution network oscillation source detected which characterized in that includes:
the equivalent model building module is used for obtaining the switching state of each switch and the unlocking state of the converter device from the direct current power distribution network based on the unit connection method, and building an equivalent model of the double-end power supply direct current power distribution network taking the power module as a basic unit according to the switching state of each switch and the unlocking state of the converter device; the equivalent model established by the equivalent model establishing module comprises a power supply end equivalent model of the double-end power supply direct current power distribution network and a constant power load end equivalent model of the double-end power supply direct current power distribution network;
the input signal calculation module is used for calculating the input signals of the power modules by using the equivalent model;
the input signal PSD calculation module is used for calculating the PSD of the input signals of each power module by utilizing the input signals to obtain the autocorrelation function of the input signals;
the output signal PSD calculation module is used for calculating the PSD of the output signals of each power module by utilizing the transfer function of the equivalent model and the PSD of the input signals;
the oscillation source judging module is used for calculating an oscillation source detection index based on the PSD actual measurement value and the PSD theoretical value of each power module and judging whether the power module is an oscillation source or not;
the power supply end equivalent model of the double-end power supply direct current power distribution network is expressed as:
Figure QLYQS_69
Figure QLYQS_70
wherein
Figure QLYQS_71
in the formula
Figure QLYQS_81
、/>
Figure QLYQS_78
For power module->
Figure QLYQS_84
Closed loop transfer function and output impedance of reference values to respective output signals, +.>
Figure QLYQS_75
,/>
Figure QLYQS_85
Respectively power module->
Figure QLYQS_87
The direct-current droop control inner loop proportional-integral regulator has proportional and integral coefficients, +.>
Figure QLYQS_89
,/>
Figure QLYQS_74
Respectively power module->
Figure QLYQS_82
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure QLYQS_72
Is equivalent gain of converter->
Figure QLYQS_80
、/>
Figure QLYQS_77
、/>
Figure QLYQS_83
Respectively the inductance, the resistance and the capacitance of the filter circuit,sfor Laplace operator>
Figure QLYQS_79
For the d-axis component of the ac side voltage, +.>
Figure QLYQS_88
Is equivalent to three-phase power supply voltage->
Figure QLYQS_73
、/>
Figure QLYQS_86
The current controller and the voltage controller are respectively adopted, and proportional integral control and ++are adopted in the equivalent model>
Figure QLYQS_76
Is a positive integer;
the constant power load end equivalent model of the double-end power supply direct current power distribution network is expressed as:
Figure QLYQS_90
Figure QLYQS_91
wherein ,
Figure QLYQS_92
Figure QLYQS_93
Figure QLYQS_94
/>
Figure QLYQS_95
in the formula ,
Figure QLYQS_98
,/>
Figure QLYQS_103
norton equivalent admittance and closed loop transfer function of constant power load power module, G j,d (s) is a voltage controller, +.>
Figure QLYQS_106
,/>
Figure QLYQS_99
Constant power load modules respectively>
Figure QLYQS_101
Controlling the proportional and integral coefficients of the outer loop proportional-integral regulator, +.>
Figure QLYQS_104
For PWM duty cycle, +.>
Figure QLYQS_107
For filtering inductor current->
Figure QLYQS_96
Is equivalent gain of converter->
Figure QLYQS_100
Is equivalent to output resistance>
Figure QLYQS_102
,/>
Figure QLYQS_105
,/>
Figure QLYQS_97
The inductance, capacitance and resistance of the filter circuit are respectively.
7. The apparatus for detecting an oscillation source of a dc power distribution network according to claim 6, wherein the calculation formula for calculating the input signal of each power module by the input signal calculation module is:
Figure QLYQS_108
in the formula
Figure QLYQS_109
For power module->
Figure QLYQS_110
Input signal of>
Figure QLYQS_111
,/>
Figure QLYQS_112
Respectively power module->
Figure QLYQS_113
Reference voltage and reference current of>
Figure QLYQS_114
The number of the power modules of the direct-current distribution network is the number of the power modules of the direct-current distribution network.
8. The apparatus for detecting an oscillation source of a dc power distribution network according to claim 6, wherein the calculation formula for calculating the PSD of the input signal of each power module by the input signal PSD calculation module is:
Figure QLYQS_115
in the formula
Figure QLYQS_116
For input signal +.>
Figure QLYQS_117
PSD of->
Figure QLYQS_118
For input signal +.>
Figure QLYQS_119
Is an autocorrelation function of>
Figure QLYQS_120
Is the self-signal of the derived autocorrelation function.
9. The apparatus for detecting an oscillation source of a dc power distribution network according to claim 6, wherein the calculation formula for calculating the PSD of the output signal of each power module by the output signal PSD calculation module is:
Figure QLYQS_121
in the formula
Figure QLYQS_124
For power module->
Figure QLYQS_126
Output signal of>
Figure QLYQS_128
For power module->
Figure QLYQS_123
PSD, & gt of output signal>
Figure QLYQS_125
For power module->
Figure QLYQS_129
Transfer function of->
Figure QLYQS_131
Is (are) mould>
Figure QLYQS_122
For power module->
Figure QLYQS_127
Transfer function of->
Figure QLYQS_130
Is a mold of (a).
10. The device for detecting an oscillation source of a dc power distribution network according to claim 6, wherein the calculation formula for calculating the oscillation source detection index by the oscillation source judging module is as follows:
Figure QLYQS_132
in the formula
Figure QLYQS_133
For power module->
Figure QLYQS_134
PSD measured values of>
Figure QLYQS_135
For measuring power module->
Figure QLYQS_136
An indicator of the degree of deviation of the PSD theoretical value from the measured value. />
CN202211704819.7A 2022-12-29 2022-12-29 Method and device for detecting oscillation source of direct-current power distribution network Active CN115684815B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211704819.7A CN115684815B (en) 2022-12-29 2022-12-29 Method and device for detecting oscillation source of direct-current power distribution network

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211704819.7A CN115684815B (en) 2022-12-29 2022-12-29 Method and device for detecting oscillation source of direct-current power distribution network

Publications (2)

Publication Number Publication Date
CN115684815A CN115684815A (en) 2023-02-03
CN115684815B true CN115684815B (en) 2023-05-12

Family

ID=85055355

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211704819.7A Active CN115684815B (en) 2022-12-29 2022-12-29 Method and device for detecting oscillation source of direct-current power distribution network

Country Status (1)

Country Link
CN (1) CN115684815B (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022122100A1 (en) * 2020-12-07 2022-06-16 Vestas Wind Systems A/S A method for damping power oscillations in a power grid

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102820673B (en) * 2012-08-10 2014-10-08 沈阳工业大学 Multiterminal flexible direct current power transmission system included power grid operation control system and method
CN106410825B (en) * 2016-10-26 2019-05-28 华北电力大学 The method for predicting electric system electromechanical oscillations mode after MTDC transmission system accesses
CN110649642B (en) * 2019-09-29 2021-09-17 山东理工大学 Voltage coordination control method for alternating current and direct current power distribution system and alternating current and direct current power distribution system
CN113612262B (en) * 2021-07-15 2024-05-31 国网江苏省电力有限公司电力科学研究院 Method and system for inhibiting direct-current side low-frequency oscillation

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022122100A1 (en) * 2020-12-07 2022-06-16 Vestas Wind Systems A/S A method for damping power oscillations in a power grid

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Wei Gao等.《Augmented random search based inter-area oscillation damping using high voltage DC transmission》.《Electric Power Systems Research》.2022,全文. *
李海荣等.《直流配电系统直流电压控制时间尺度的低频振荡机理分析》.《高电压技术》.2021,全文. *

Also Published As

Publication number Publication date
CN115684815A (en) 2023-02-03

Similar Documents

Publication Publication Date Title
CN106787707A (en) Embedded accumulation energy type multimode tandem photovoltaic DC booster converter and application process
CN105870953B (en) A kind of light storage joint grid-connected system and its control method
CN104135030B (en) Flexible island grid-connection control device and method for smart power grids
CN107994606A (en) Grid-connected inverter system method for analyzing stability under a kind of multi-frequency coupling factor Coexistence Situation
CN109802406B (en) Method for analyzing resonance stability of flexible direct-current transmission access system
CN110556871B (en) Aggregation equivalence method for large-scale photovoltaic power generation system based on structure keeping method
CN104638668B (en) A kind of photovoltaic power generation grid-connecting control method and system
CN106950512B (en) Energy storage converter grid-connected and grid-disconnected characteristic integrated detection system and method
CN103259287B (en) Bi-directional grid-connected inversion device and bi-directional grid-connected inversion method for distributed type new energy power generation system
CN103259282B (en) A kind of non-isolation type and the soft combination method of isolated form photovoltaic combining inverter
CN102148501B (en) Disturbance generation device for wind power station
CN107104431A (en) A kind of MMC HVDC transmission systems MMC module Approach for Modeling of Small-Signal
CN109459615A (en) High pressure impedance measurement device and control method based on cascade multi-level converter
CN102608468B (en) Testing system for detecting characteristics of offshore wind power flexible direct current transmission converter
CN108959780A (en) The big signal simulation model of Monophase electric power electronic transformer
CN108880316A (en) The grid-connection converter Predictive Control System and control method of compensation with voltage
CN115684815B (en) Method and device for detecting oscillation source of direct-current power distribution network
CN110336302A (en) Light storage joint grid-connected system and its control method with virtual synchronous characteristic
CN104953590A (en) Harmonic analysis method for unified power flow controller based on topological structure of MMC (modular Multilevel Converter)
CN104638634A (en) Direct current micro-grid oscillation suppression method based on band-pass filter in master-slave mode
CN204465352U (en) The intelligent voltage disturbing generating device that module differentiation controls
Boi et al. Evaluation of sic-based three phase power converter for microgrid applications
CN113742907A (en) Photovoltaic power station short-circuit current unified calculation method
CN113937791B (en) Photovoltaic power station transient model suitable for broadband oscillation analysis of large power grid
Cho et al. Design of LCL filter using hybrid intelligent optimization for photovoltaic system

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