Model construction method, voltage cross-border suppression method, system, equipment and medium

Abstract

The invention relates to a model construction method, a voltage cross-border suppression method, a system, equipment and a medium. According to the model construction method, a zero voltage drop equation is solved to finally obtain a voltage out-of-limit suppression model, and the voltage out-of-limit suppression model can determine reactive power enabling rising voltage caused by active power to be minimum according to the actual operation condition of the distributed power supply. The reactive power can control the voltage output by the distributed power supply to be within a certain voltage range, thereby ensuring that the active power injection of the generator does not cause significant voltage rise, and effectively solving the problem of voltage crossing of the power distribution network.

Description

Technical Field

[0001] The present invention relates to the technical field of active power response of a distribution network energy supply system, and in particular to a model building method, a voltage out-of-bounds suppression method, a system, a device and a medium. Background Art

[0002] Distributed Generation (DG) (such as photovoltaics) has become an important part of future energy due to its unique environmental friendliness, economy, and flexibility in power generation. However, due to the randomness, intermittency, and volatility of its output and the access of a large number of DGs, it will cause a reversal of the flow, resulting in a rise in voltage and voltage crossing, affecting the safe and stable operation of the power system. The control of distribution network operators (DNOs) cannot effectively cope with it. Summary of the invention

[0003] In order to solve the technical defects in the prior art, the present invention provides a model building method, a voltage crossing suppression method, a system, a device and a medium.

[0004] The present invention provides a model building method, the method comprising:

[0005] Analyze the topological structure of the distribution network where voltage crossing is to be suppressed and construct the feeder model of the distribution network;

[0006] Based on the feeder model, a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in the feeder of the distribution network is established to determine a zero voltage drop equation caused by a complex current injected into the distribution network;

[0007] Solving the zero voltage drop equation to obtain a reactive power expression for minimizing the voltage rise caused by suppressing the active power in the distribution network;

[0008] The reactive power expression is determined as a model for voltage out-of-bounds suppression.

[0009] Optionally, the step of establishing a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in a feeder of the distribution network based on the feeder model to determine a zero voltage drop equation caused by a complex current injected into the distribution network comprises:

[0010] Determining the complex current injected into the distribution network based on the power and voltage output by the distributed power source;

[0011] Based on the complex current injected into the distribution network, the voltage output by the distributed power source and the voltage output by the secondary side of the transformer, a voltage drop equation from the connection point of the distributed power source in the feeder to the connection point of the secondary side of the transformer is established;

[0012] Based on the voltage drop equation, a zero voltage drop equation caused by the complex current injected into the power distribution network is determined.

[0013] Optionally, the complex current injected into the distribution network is determined in a manner that satisfies the following formula:

[0014]

[0015] in, is the complex current injected into the distribution network, V G is the voltage output by the distributed power supply, is the complex voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between them, V0 is the voltage output by the secondary side of the transformer, is the complex voltage output on the secondary side of the transformer, and j is the imaginary coefficient of the complex number.

[0016] Optionally, the voltage drop equation from the connection point of the distributed power source in the feeder to the connection point of the secondary side of the transformer is established based on the complex current injected into the distribution network, the voltage output by the distributed power source, and the voltage output by the secondary side of the transformer, including:

[0017] Determine the voltage drop equation based on the voltage output by the distributed power source, the voltage output by the secondary side of the transformer, the complex current injected into the distribution network and the impedance of the feeder;

[0018] The real and imaginary parts of the pressure drop equation satisfy the following formula:

[0019]

[0020] Among them, V G is the voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between is the complex voltage output by the distributed power source, is the complex voltage outputted by the secondary side of the transformer, V0 is the voltage outputted by the secondary side of the transformer, R is the resistance of the feeder, X is the reactance of the feeder, and the impedance of the feeder is R+jX, where j is the imaginary coefficient of the complex number.

[0021] Optionally, determining a zero voltage drop equation caused by the complex current injected into the distribution network based on the voltage drop equation includes:

[0022] Based on the fact that the voltage output by the distributed power source is approximately equal to the voltage output by the secondary side of the transformer, the voltage drop equation is simplified to obtain a standby zero voltage drop equation caused by the complex current injected into the distribution network;

[0023] Based on the voltage output by the distributed power source being the reference voltage of the distributed power source, simplifying the standby zero voltage drop equation, and determining the zero voltage drop equation caused by the complex current injected into the distribution network;

[0024] The zero pressure drop equation satisfies the following formula:

[0025]

[0026] Among them, P G is the active power of distributed generation, Q G is the reactive power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0027] Optionally, the reactive power expression satisfies the following formula:

[0028]

[0029] in, P is the reactive power in the distribution network that minimizes the voltage rise caused by the active power. G is the active power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0030] Based on the same inventive structure, the present invention also provides a model building system, the system comprising:

[0031] A feeder model building unit is used to analyze the topological structure of the distribution network to be subjected to voltage over-limit suppression and build a feeder model of the distribution network;

[0032] A zero voltage drop equation determination unit, configured to establish a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in a feeder of the distribution network based on the feeder model, so as to determine a zero voltage drop equation caused by a complex current injected into the distribution network;

[0033] A reactive power expression determination unit, used for solving the zero voltage drop equation to obtain a reactive power expression that minimizes the voltage rise caused by suppressing the active power in the distribution network;

[0034] The model determination unit is used to determine the reactive power expression as a model for voltage out-of-bounds suppression.

[0035] Optionally, the zero pressure drop equation determining unit includes:

[0036] A complex current determination module, used to determine the complex current injected into the distribution network based on the power and voltage output by the distributed power source;

[0037] A voltage drop equation establishment module, used to establish a voltage drop equation from a distributed power source connection point in a feeder to a transformer secondary side connection point based on the complex current injected into the distribution network, the voltage output by the distributed power source, and the voltage output by the transformer secondary side;

[0038] The zero voltage drop equation determination module is used to determine the zero voltage drop equation caused by the complex current injected into the power distribution network based on the voltage drop equation.

[0039] Optionally, the complex current injected into the distribution network is determined in a manner that satisfies the following formula:

[0040]

[0041] in, is the complex current injected into the distribution network, V G is the voltage output by the distributed power supply, is the complex voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between them, V0 is the voltage output by the secondary side of the transformer, is the complex voltage output on the secondary side of the transformer, and j is the imaginary coefficient of the complex number.

[0042] Optionally, the pressure drop equation establishing module is specifically used for:

[0043] Determine the voltage drop equation based on the voltage output by the distributed power source, the voltage output by the secondary side of the transformer, the complex current injected into the distribution network and the impedance of the feeder;

[0044] The real and imaginary parts of the pressure drop equation satisfy the following formula:

[0045]

[0046] Among them, V G is the voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between is the complex voltage output by the distributed power source, is the complex voltage outputted by the secondary side of the transformer, V0 is the voltage outputted by the secondary side of the transformer, R is the resistance of the feeder, X is the reactance of the feeder, and the impedance of the feeder is R+jX, where j is the imaginary coefficient of the complex number.

[0047] Optionally, the zero pressure drop equation determination module is specifically used for:

[0048] Based on the fact that the voltage output by the distributed power source is approximately equal to the voltage output by the secondary side of the transformer, the voltage drop equation is simplified to obtain a standby zero voltage drop equation caused by the complex current injected into the distribution network;

[0049] Based on the voltage output by the distributed power source being the reference voltage of the distributed power source, simplifying the standby zero voltage drop equation, and determining the zero voltage drop equation caused by the complex current injected into the distribution network;

[0050] The zero pressure drop equation satisfies the following formula:

[0051]

[0052] Among them, P G is the active power of distributed generation, Q G is the reactive power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0053] Optionally, the reactive power expression satisfies the following formula:

[0054]

[0055] in, P is the reactive power in the distribution network that minimizes the voltage rise caused by the active power. G is the active power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0056] Based on the same inventive concept, the present invention provides a voltage out-of-bounds suppression method, the method comprising:

[0057] Obtaining resistance and reactance of feeders in a distribution network whose voltage is to be suppressed from crossing a boundary, and active power of distributed power sources connected to the distribution network;

[0058] Solving the model of the resistance and reactance of the feeder and the active power input voltage out-of-bounds suppression of the distributed power source, to obtain the reactive power in the distribution network that minimizes the voltage rise caused by suppressing the active power;

[0059] Based on the reactive power, performing reactive power control on the voltage output by the distributed power source;

[0060] The voltage out-of-bounds suppression model is a model constructed based on the above-mentioned model construction method.

[0061] Optionally, the performing reactive power control on the voltage output by the distributed power source based on the reactive power includes:

[0062] The reactive power that minimizes the voltage rise caused by the active power in the distribution network is injected into the distributed power source, and the reactive power output by the distributed power source is adjusted to perform reactive power control on the voltage output by the distributed power source.

[0063] Optionally, after performing reactive power control on the voltage output by the distributed power source based on the reactive power, the method further includes:

[0064] Determine a non-nominal turns ratio based on a nominal turns ratio, a transformer short-circuit impedance, a preset voltage value on the secondary side of the transformer, and a complex voltage and a complex current injected into the transformer main busbar by the distribution network;

[0065] Based on the non-nominal turns ratio, a voltage outputted from the secondary side of a transformer in the distribution network is controlled.

[0066] Optionally, the non-nominal turns ratio satisfies the following formula:

[0067]

[0068] Where M is the non-nominal turns ratio set, m is the non-nominal turns ratio, r is the nominal turns ratio, m * is the non-rated turns ratio corresponding to the minimum absolute value of the difference between m and r, is the transformer short-circuit impedance, The complex voltage injected into the transformer main busbar of the distribution network, The complex current injected into the transformer main busbar of the distribution network, V 0,set It is the preset voltage of the secondary side of the transformer.

[0069] Optionally, the controlling the voltage outputted by the secondary side of the transformer in the distribution network based on the non-nominal turns ratio includes:

[0070] Based on the non-nominal turns ratio, the on-load tap changer of the transformer is adjusted to control the voltage outputted by the secondary side of the transformer in the distribution network.

[0071] Based on the same inventive concept, the present invention also provides a voltage cross-limit suppression system, the system comprising:

[0072] An impedance and active power acquisition unit, used to acquire the resistance and reactance of a feeder in a distribution network whose voltage crossing is to be suppressed, and the active power of a distributed power source connected to the distribution network;

[0073] A reactive power determination unit, used to obtain a reactive power in the distribution network that minimizes voltage rise caused by suppressing active power by using a model for suppressing voltage cross-boundary of the resistance and reactance of the feeder and the active power input voltage of the distributed power source;

[0074] A distributed power supply voltage control unit, used to perform reactive power control on the voltage output by the distributed power supply based on the reactive power;

[0075] The voltage out-of-bounds suppression model is a model constructed based on the above-mentioned model construction method.

[0076] Optionally, the distributed power supply voltage control unit is specifically used to: inject reactive power in the distribution network that suppresses the active power and causes the smallest voltage rise into the distributed power supply, and adjust the reactive power output by the distributed power supply to perform reactive power control on the voltage output by the distributed power supply.

[0077] Optionally, the system further comprises:

[0078] a non-nominal turns ratio determination unit, configured to determine the non-nominal turns ratio based on the nominal turns ratio, the short-circuit impedance of the transformer, a preset voltage value of the secondary side of the transformer, and a complex voltage and a complex current injected into the main busbar of the transformer by the distribution network;

[0079] A transformer secondary side voltage control unit is used to control the voltage outputted by the secondary side of the transformer in the distribution network based on the non-nominal turns ratio.

[0080] Optionally, the non-nominal turns ratio satisfies the following formula:

[0081]

[0082] Where M is the non-nominal turns ratio set, m is the non-nominal turns ratio, r is the nominal turns ratio, m * is the non-rated turns ratio corresponding to the minimum absolute value of the difference between m and r, is the transformer short-circuit impedance, The complex voltage injected into the transformer main busbar of the distribution network, The complex current injected into the transformer main busbar of the distribution network, V 0,set It is the preset voltage of the secondary side of the transformer.

[0083] Optionally, the transformer secondary side voltage control unit is specifically used for:

[0084] Based on the non-nominal turns ratio, the on-load tap changer of the transformer is adjusted to control the voltage outputted by the secondary side of the transformer in the distribution network.

[0085] The present invention also provides a computing device, comprising: one or more processors;

[0086] a processor for executing one or more programs;

[0087] When the one or more programs are executed by the one or more processors, the model building method as described above or the voltage out-of-bounds suppression method as described above is implemented.

[0088] The present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the model building method as described above or the voltage crossing suppression method as described above is implemented.

[0089] Compared with the prior art, the present invention has the following beneficial effects:

[0090] The present invention provides a model construction method, which finally obtains a model for voltage out-of-bounds suppression by solving a zero voltage drop equation. The model for voltage out-of-bounds suppression can determine the reactive power that minimizes the voltage rise caused by active power according to the actual operating conditions of the distributed power source. The voltage output by the distributed power source can be controlled to be within a certain voltage range through the reactive power, thereby ensuring that the active power injection of the generator will not cause a significant voltage rise, and effectively solving the problem of voltage out-of-bounds in the distribution network.

[0091] The present invention also provides a voltage out-of-bounds suppression method, which can effectively determine the reactive power that minimizes the voltage rise caused by active power through a voltage out-of-bounds suppression model. The reactive power can be used to control the voltage output by the distributed power source, thereby avoiding a significant voltage rise caused by the active power injection of the generator, and effectively solving the problem of voltage out-of-bounds in the distribution network.

[0092] In addition, the method can also control the voltage output on the secondary side of the transformer in the distribution network through a non-nominal turns ratio, thereby avoiding the injection of active power from distributed power sources, which affects the voltage distribution of the distribution network, thereby avoiding interference with the voltage regulation of the distribution network operator caused by the injection of distributed power sources in a large range of load changes, making the distributed power sources a disturbance-free supply, effectively avoiding disturbances in the voltage distribution in the distribution network, and ensuring the normal operation of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 A flow chart of a model building method provided by the present invention;

[0094] Figure 2 A schematic diagram of a single-line model of an upstream feeder of a distributed power source provided by the present invention;

[0095] Figure 3A schematic diagram of the relationship between the bus voltage and injected power of the distributed power supply provided by the present invention;

[0096] Figure 4 A schematic diagram showing a comparison of bus voltage variation with load demand when there is constant generation of DGs and when there is no zero generation of DGs under the reactive power control strategy provided by the present invention;

[0097] Figure 5 A flowchart of another model building method provided by the present invention;

[0098] Figure 6 A block diagram of a model building system provided by the present invention;

[0099] Figure 7 A flow chart of a voltage crossing suppression method provided by the present invention;

[0100] Figure 8 A flow chart of another voltage crossing suppression method provided by the present invention;

[0101] Fig. 9 A block diagram of a voltage out-of-bounds suppression system provided by the present invention;

[0102] Fig.10 A block diagram of another voltage crossing suppression system provided by the present invention;

[0103] Fig.11 A block diagram of a computer device provided by the present invention. DETAILED DESCRIPTION

[0104] Most DNOs require DG to operate at zero reactive power at a fixed power factor to limit installed capacity in order to ensure acceptable voltage distribution in the worst case. The main reasons are: the capacity of a single DG unit is usually too small to control the grid voltage; automatic DG voltage control will interfere with DNOs control, that is, interfere with the operation of the on-load tap-changer transformer, resulting in an increase in the risk of islanding.

[0105] To solve the problem of voltage crossing caused by DG penetration in the power grid, the existing technologies have proposed centralized and distributed voltage control methods. For example, centralized solutions that increase the overall DG installed capacity through wide-area voltage control and reactive power management, and other dispatching methods that consider voltage support through multi-agent-based optimization, but centralized methods require a large investment in sensors, communications, and control systems, which makes their application in large-scale DG situations difficult to implement. Distributed voltage control methods can limit the voltage rise of feeders where loads and generators are continuously distributed. More complex distributed control methods have also been used to control the target voltage of automatic voltage control relays at the main substation and combine fixed power factors with automatic voltage control. However, the purpose of the existing technologies is to let DG control the bus voltage: either centrally coordinated by the DNO, autonomously controlled, or limiting the voltage control range.

[0106] The present invention provides a model building method and system, which suppresses the voltage rise caused by active power injection through a proposed voltage over-limit suppression model (i.e., a distributed automatic control method). The purpose of the proposed method is not to control the bus voltage, but to ensure that the generator active power injection itself does not cause a significant voltage rise on the basis of DNOs maintaining their traditional load demand voltage regulation tasks. The implementation of the model building method can be illustrated by the following examples.

[0107] Embodiment 1:

[0108] Figure 1 A flow chart of a model building method provided by the present invention, such as Figure 1 As shown, the method may include the following steps:

[0109] In step 101, the topological structure of the distribution network to be suppressed from crossing the voltage limit is analyzed, and a feeder model of the distribution network is constructed.

[0110] The distribution network topology can be understood as a circuit diagram including the connection relationship between each node, feeder and device in the distribution network. Generally, the node can be a substation (or transformer), load, resistor, inductor or distributed power source in the distribution network. The feeder model can include the connection relationship between feeder parameters and feeder nodes. Generally, the feeder parameters can include impedance (i.e. resistance and reactance) and voltage, current, active power or reactive power injected into the distribution network. The distribution network topology can be a radial chain distribution network topology.

[0111] In this step, a possible implementation method may include: analyzing the topological structure of the distribution network to be suppressed from voltage crossing through a preset analysis algorithm, obtaining the electrical parameters and connection relationship of each node in the distribution network, and determining the feeder parameters of the feeder and the connection relationship of the feeder nodes from the electrical parameters and connection relationship of each node in the distribution network to construct a feeder model of the distribution network. For example, the feeder parameters of the feeder and the connection relationship of the feeder nodes may be used as the feeder model of the distribution network. The preset analysis algorithm may be one or more algorithms such as a power flow calculation algorithm, a pre-trained topological structure analysis model, or an optimal distribution network reconstruction algorithm.

[0112] In this step, another possible implementation method can be: based on the radial chain distribution network topology, analyze the power flow and node voltage change law of the distribution network caused by the access of distributed power sources, and build a distribution feeder model

[0113] It should be noted that the radial chain distribution network topology has been widely used in the actual production process of power systems due to its advantages of good economy, easy capacity expansion, easy relay setting coordination, simple wiring, etc. The feeder in the distribution network (i.e., distribution feeder) is on the secondary side of the transformer, usually composed of a tree structure. The feeder can be connected to an on-load tap transformer with on-load tap switching voltage regulation. The on-load tap transformer is responsible for maintaining the grid voltage within the allowable range (+ / -6% of the rated voltage). The distribution network operator can set the transformer secondary voltage close to the maximum value to ensure that the voltage is higher than the minimum value at the end of the long feeder.

[0114] Optionally, after constructing the feeder model of the distribution network, power system software (such as MATLAB / Simulink, etc.) can be used for simulation to calculate the comparison accuracy between the simulation results and the actual measurement data information, and adjust the feeder model based on the comparison accuracy. For example, when the comparison accuracy between the simulation results and the actual measurement data information is less than a preset comparison accuracy threshold, adjust the feeder model to improve the accuracy of the feeder model.

[0115] In step 102, based on the feeder model, a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in a feeder of the distribution network is established to determine a zero voltage drop equation caused by a complex current injected into the distribution network.

[0116] The feeder model may include the power and voltage output by the distributed power source, the voltage output by the secondary side of the transformer, etc. The complex current may be understood as the current input by the distributed power source to the distribution network when the distributed power source is connected to the feeder of the distribution network. The zero voltage drop equation may be understood as the equation in which the voltage drop between the connection point of the distributed power source in the feeder and the connection point of the secondary side of the transformer is zero.

[0117] It should be noted that the voltage drop equation from the connection point of the distributed power source to the secondary side connection point of the transformer in the feeder of the distribution network can be established through the feeder parameters in the feeder model, the connection relationship of the feeder nodes and Kirchhoff's voltage law. The voltage drop equation is simplified by voltage initialization to obtain the zero voltage drop equation caused by the complex current injected into the distribution network. Among them, the voltage initialization can include the voltage drop between the distributed power source connection point and the transformer secondary side connection point being zero, and the voltage output by the distributed power source being the reference voltage of the distributed power source. Based on the distribution feeder analysis, the optimal reactive power is sought mainly to find a suitable Q G The value of P G Minimize the voltage rise caused by

[0118] In step 103, the zero voltage drop equation is solved to obtain a reactive power expression for minimizing the voltage rise caused by suppressing the active power in the distribution network.

[0119] The reactive power expression can be understood as an equation for the reactive power in the distribution network that minimizes the voltage rise caused by the active power, expressed by the active power of the distributed generation, the resistance and reactance of the feeder.

[0120] A specific implementation method of this step may be to solve the zero voltage drop equation by taking the reactive power in the equation as the unknown quantity to obtain the reactive power expression that minimizes the voltage rise caused by suppressing the active power in the distribution network.

[0121] In step 104, the reactive power expression is determined as a model for voltage out-of-bounds suppression.

[0122] It should be noted that the model construction method provided by the present invention suppresses the voltage rise caused by active power injection through the voltage over-boundary suppression model. The purpose of the proposed model is not to control the bus voltage, but to ensure that the active power injection of the generator itself does not cause a significant voltage rise on the basis of DNOs maintaining their traditional load demand voltage regulation tasks. The voltage over-boundary suppression model and the power factor control method can be simulated to obtain the change trend of the voltage (bus voltage) in the distribution network with active power when the voltage over-boundary suppression model control (i.e., reactive power control strategy) and the power factor control method are respectively obtained, and the change trend of the bus voltage with load demand when there is constant power generation of DGs and when there is no DG zero power generation under the reactive power control strategy is compared to verify the effectiveness of the proposed method.

[0123] For example, Figure 2 A schematic diagram of a single-line model of an upstream feeder of a distributed power source provided by the present invention is shown in FIG. Figure 2 As shown in Figure 2, when distributed generation is connected to the feeder, the voltage distribution of the distribution network may increase. The voltage V output by the distributed generation GIt can be approximated as V0+R+X (i.e. V0+R P +X Q ), where V0 is the voltage output on the secondary side of the transformer, and the power generated by the distributed power source is P G +jQ G , the power of the system load can be S L =P L +jQ L (P L is the active power of the system load, Q L is the reactive power of the system load), P=P G -P L and Q = Q G -Q L are the active power and reactive power injected into the distributed generation bus, respectively, and R and X are the resistance and reactance of the feeder, respectively. In order to be able to inject active power, a higher bus voltage is usually required unless the generator can absorb a large amount of reactive power.

[0124] Among them, the power factor control method is a method to suppress the voltage over-limit caused by voltage rise, which is mainly to suppress the voltage over-limit caused by voltage rise by keeping the P / Q (active power / reactive power) ratio constant. In order to make the reactive power (i.e. Q) compensate for the rise in feeder voltage caused by the active power (i.e. P), that is, for V G ≈V0, it is necessary to make Q=-R P / X. However, high loads require a lot of reactive power, which the generator capacity cannot support, making the power factor control method difficult to implement. In addition, in order to keep the power factor constant at the injection point, the generator settings must be changed when the load changes, which needs to be achieved by observing the load size and power factor. For the above reasons, most DNOs do not want DG to adjust the power factor, but to keep it constant.

[0125] Figure 3 The schematic diagram of the relationship between the distributed power supply bus voltage and the injected power provided by the present invention compares the influence of reactive power control and power factor control on voltage rise. Figure 2 The selected R+jX=14.6+j7.6Ω and compared the high load (load parameter is P L +jQ L =5+j2MW / Mvar) and no-load conditions, the constant power factor selects the lagging power factor (P F =0.5). The results show that under the reactive power control strategy, the voltage rise is significantly suppressed regardless of high load or zero load.

[0126] Figure 4The following is a schematic diagram comparing the changing trends of bus voltage with load demand when there is constant generation of DGs and when there is no zero generation of DGs under the reactive power control strategy provided by the present invention, as shown in FIG. Figure 4 As shown, the constant power generation is 5+jQ*, Q* is -7.88MVar, and when there is no DG zero power generation, only the load is considered, and two cases with short-circuit power of 250MVA and 500MVA are compared. The results show that the change law under the proposed reactive power control method is basically similar to the curve when there is no DG zero power generation, indicating that the proposed reactive power control method will not interfere with the DNOs voltage regulation of load changes.

[0127] The present invention provides a model construction method, which finally obtains a model for voltage out-of-bounds suppression by solving a zero voltage drop equation. The model for voltage out-of-bounds suppression can determine the reactive power that minimizes the voltage rise caused by active power according to the actual operating conditions of the distributed power source. The voltage output by the distributed power source can be controlled to be within a certain voltage range through the reactive power, thereby ensuring that the active power injection of the generator will not cause a significant voltage rise, and effectively solving the problem of voltage out-of-bounds in the distribution network.

[0128] Figure 5 A flowchart of another model building method provided by the present invention, such as Figure 5 As shown above Figure 1 Step 102 in the model building method shown may include the following steps:

[0129] In step 1021, the complex current injected into the power distribution network is determined based on the power and voltage output by the distributed power source.

[0130] It should be noted that the complex current injected into the distribution network may be the current input by the distributed power source into the distribution network. The complex current injected into the distribution network is determined in a manner that satisfies the following formula:

[0131]

[0132] in, is the complex current injected into the distribution network, V G is the voltage output by the distributed power supply, is the complex voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between them, V0 is the voltage output by the secondary side of the transformer, is the complex voltage output on the secondary side of the transformer, and j is the imaginary coefficient of the complex number.

[0133] In step 1022, a voltage drop equation from a connection point of the distributed power source in a feeder to a connection point of the secondary side of the transformer is established based on the complex current injected into the distribution network, the voltage output by the distributed power source, and the voltage output by the secondary side of the transformer.

[0134] A specific implementation of this step may be to determine the voltage drop equation based on the voltage output by the distributed power source, the voltage output by the secondary side of the transformer, the complex current injected into the distribution network, and the impedance of the feeder.

[0135] It should be noted that according to Kirchhoff's law, it can be determined that the feeder line is (i.e. the voltage output by the distributed power supply) to The voltage drop equation (i.e., voltage equation) of the node (voltage output on the secondary side of the transformer) is:

[0136]

[0137] Formula (1) (i.e. the complex current injected into the distribution network ) is substituted into formula (2), and the voltage drop equation (i.e., voltage equation) is simplified to obtain the following equation:

[0138]

[0139] The real and imaginary parts of the pressure drop equation satisfy the following formula:

[0140]

[0141] Among them, V G is the voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between is the complex voltage output by the distributed power source, is the complex voltage outputted by the secondary side of the transformer, V0 is the voltage outputted by the secondary side of the transformer, R is the resistance of the feeder, X is the reactance of the feeder, and the impedance of the feeder is R+jX, where j is the imaginary coefficient of the complex number.

[0142] In step 1023, based on the voltage drop equation, a zero voltage drop equation caused by the complex current injected into the power distribution network is determined.

[0143] A possible implementation of this step may be to simplify the voltage drop equation based on the fact that the voltage output by the distributed power source is approximately equal to the voltage output by the secondary side of the transformer, and obtain a standby zero voltage drop equation caused by the complex current injected into the distribution network; based on the fact that the voltage output by the distributed power source is a reference voltage of the distributed power source, simplify the standby zero voltage drop equation and determine the zero voltage drop equation caused by the complex current injected into the distribution network.

[0144] It should be noted that by squaring both sides of formula (3) and then adding them together, we get the following formula:

[0145]

[0146] in,

[0147] For zero pressure drop, Solving formula (4) yields the following equation:

[0148]

[0149] Initialize the voltage output by the distributed power supply to the reference voltage of the distributed power supply (i.e. V G ≈1p.u.), and the zero pressure drop equation is obtained. The zero pressure drop equation satisfies the following formula:

[0150]

[0151] Among them, P G is the active power of distributed generation, Q G is the reactive power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0152] The reactive power Q of distributed generation G As the unknown quantity, equation (5) is solved to obtain the reactive power expression. The reactive power expression satisfies the following formula:

[0153]

[0154] in, P is the reactive power in the distribution network that minimizes the voltage rise caused by the active power. G is the active power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0155] It should be noted that based on the obtained Reactive power control can effectively solve the voltage rise problem caused by the active power injected by distributed power sources, and its effect is superior to constant power factor (leading or lagging) control (refer to Figure 3 ).

[0156] The present invention provides a model construction method, which finally obtains a model for voltage out-of-bounds suppression by solving a zero voltage drop equation. The model for voltage out-of-bounds suppression can determine the reactive power that minimizes the voltage rise caused by active power according to the actual operating conditions of the distributed power source. The voltage output by the distributed power source can be controlled to be within a certain voltage range through the reactive power, thereby ensuring that the active power injection of the generator will not cause a significant voltage rise, and effectively solving the problem of voltage out-of-bounds in the distribution network.

[0157] Embodiment 2:

[0158] Based on the same invention, Figure 6 A block diagram of a model building system provided by the present invention, the system may include:

[0159] A feeder model building unit 601 is used to analyze the topological structure of the distribution network for which voltage crossing is to be suppressed, and to build a feeder model of the distribution network;

[0160] A zero voltage drop equation determination unit 602 is used to establish a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in a feeder of the distribution network based on the feeder model, so as to determine a zero voltage drop equation caused by a complex current injected into the distribution network;

[0161] A reactive power expression determination unit 603 is used to solve the zero voltage drop equation to obtain a reactive power expression that minimizes the voltage rise caused by suppressing the active power in the distribution network;

[0162] The model determination unit 604 is used to determine the reactive power expression as a model for voltage out-of-bounds suppression.

[0163] Optionally, the zero pressure drop equation determining unit 602 includes:

[0164] A complex current determination module, used to determine the complex current injected into the distribution network based on the power and voltage output by the distributed power source;

[0165] A voltage drop equation establishment module, used to establish a voltage drop equation from a distributed power source connection point in a feeder to a transformer secondary side connection point based on the complex current injected into the distribution network, the voltage output by the distributed power source, and the voltage output by the transformer secondary side;

[0166] The zero voltage drop equation determination module is used to determine the zero voltage drop equation caused by the complex current injected into the power distribution network based on the voltage drop equation.

[0167] Optionally, the complex current injected into the distribution network is determined in a manner that satisfies the following formula:

[0168]

[0169] in, is the complex current injected into the distribution network, V G is the voltage output by the distributed power supply, is the complex voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between them, V0 is the voltage output by the secondary side of the transformer, is the complex voltage output on the secondary side of the transformer, and j is the imaginary coefficient of the complex number.

[0170] Optionally, the pressure drop equation establishing module is specifically used for:

[0171] Determine the voltage drop equation based on the voltage output by the distributed power source, the voltage output by the secondary side of the transformer, the complex current injected into the distribution network and the impedance of the feeder;

[0172] The real and imaginary parts of the pressure drop equation satisfy the following formula:

[0173]

[0174] Among them, V G is the voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between is the complex voltage output by the distributed power source, is the complex voltage outputted by the secondary side of the transformer, V0 is the voltage outputted by the secondary side of the transformer, R is the resistance of the feeder, X is the reactance of the feeder, and the impedance of the feeder is R+jX, where j is the imaginary coefficient of the complex number.

[0175] Optionally, the zero pressure drop equation determination module is specifically used for:

[0176] Based on the fact that the voltage output by the distributed power source is approximately equal to the voltage output by the secondary side of the transformer, the voltage drop equation is simplified to obtain a standby zero voltage drop equation caused by the complex current injected into the distribution network;

[0177] Based on the voltage output by the distributed power source being the reference voltage of the distributed power source, simplifying the standby zero voltage drop equation, and determining the zero voltage drop equation caused by the complex current injected into the distribution network;

[0178] The zero pressure drop equation satisfies the following formula:

[0179]

[0180] Among them, P G is the active power of distributed generation, Q G is the reactive power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0181] Optionally, the reactive power expression satisfies the following formula:

[0182]

[0183] in, P is the reactive power in the distribution network that minimizes the voltage rise caused by the active power. G is the active power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

[0184] Embodiment 3:

[0185] Based on the same inventive concept, Figure 7 A flow chart of a voltage crossing suppression method provided by the present invention, such as Figure 7 As shown, the method may include the following steps:

[0186] In step 701, the resistance and reactance of a feeder in a distribution network whose voltage crossing is to be suppressed, and the active power of a distributed power source connected to the distribution network are obtained.

[0187] It should be noted that the resistance and reactance of the feeder in the distribution network whose voltage crossing is to be suppressed and the active power of the distributed power source connected to the distribution network can be obtained by receiving manual input through a preset interface.

[0188] In step 702, the resistance and reactance of the feeder and the model of the active power input voltage out-of-bounds suppression of the distributed power source are solved to obtain the reactive power in the distribution network that minimizes the voltage rise caused by suppressing the active power.

[0189] The voltage out-of-bounds suppression model is a model constructed based on the model construction method of the above-mentioned embodiment.

[0190] It should be noted that the obtained resistance and reactance of the feeder and the active power of the distributed power source can be input into the voltage over-bounds suppression model, and the reactive power that minimizes the voltage rise caused by suppressing the active power in the distribution network can be obtained by solving the voltage over-bounds suppression model.

[0191] In step 703, reactive power control is performed on the voltage output by the distributed power source based on the reactive power.

[0192] A possible implementation method of this step is to inject reactive power in the distribution network that minimizes the voltage rise caused by the active power into the distributed power source, adjust the reactive power output by the distributed power source, and perform reactive power control on the voltage output by the distributed power source.

[0193] Among them, based on the obtained Reactive power control can effectively solve the voltage rise problem caused by the active power injected by distributed power sources, and its effect is superior to constant power factor (leading or lagging) control (refer to Figure 4 ), the voltage rise suppression effect is more significant under both zero load and high load conditions. The voltage over-limit suppression method can effectively determine the reactive power that minimizes the voltage rise caused by active power through the voltage over-limit suppression model, and the voltage output by the distributed power source can be controlled through the reactive power, thereby avoiding the significant voltage rise caused by the active power injection of the generator, and effectively solving the problem of voltage over-limit in the distribution network.

[0194] It should be noted that the voltage over-limit suppression method is simulated and verified. Through power flow calculation and analysis, the variation trend of bus voltage with active power during reactive power control strategy and power factor control proposed by the present invention can be compared (refer to Figure 3 ), it can be clearly found that under this reactive power control strategy, the voltage rise is significantly suppressed. Under the reactive power control strategy, the bus voltage change trend with load demand can be compared when there is constant DG power generation and when there is no DG zero power generation (reference Figure 4 ), the results clearly show that the proposed control method will not interfere with the voltage regulation of DNOs. Therefore, it is shown that the reactive power control strategy proposed in the present invention can be used to turn a large number of DGs into disturbance-free power supplies, and DG can inject a wide range of active power without obvious voltage rise; in a wide range of load changes, DG injection will not cause obvious interference to the voltage regulation of DNOs. The reactive power injected by the distributed power source follows the above formula (6) (that is, the injection amount of the generator follows formula (6) (that is, the reactive power control method)), and the voltage distribution in the distribution network (that is, the network voltage) is almost independent of the active power generated by the distributed power source. This is also an aspect of the voltage out-of-bounds suppression method (that is, reactive power control method) proposed in the present invention. The voltage out-of-bounds suppression method (reactive power control method) of the present invention mainly lies in finding a suitable QG value to minimize the voltage rise caused by PG.

[0195] The voltage over-limit suppression method provided by the present invention can suppress the voltage rise caused by active power injection through a distributed automatic control method. The purpose of the proposed method is not to control the bus voltage, but to ensure that the generator active power injection itself does not cause a significant voltage rise on the basis of DNOs maintaining their traditional load demand voltage regulation tasks.

[0196] Figure 8 A flowchart of another voltage crossing suppression method provided by the present invention is shown in FIG. Figure 8 As shown, after the reactive power control is performed on the voltage output by the distributed power source based on the reactive power, the method may further include the following steps:

[0197] In step 704, a non-nominal turns ratio is determined based on the nominal turns ratio, the transformer short-circuit impedance, a preset voltage value on the secondary side of the transformer, and a complex voltage and a complex current injected into the transformer main busbar by the distribution network.

[0198] Wherein, optionally, the non-nominal turns ratio satisfies the following formula:

[0199]

[0200] Where M is the non-nominal turns ratio set, m is the non-nominal turns ratio, r is the nominal turns ratio, m * is the non-rated turns ratio corresponding to the minimum absolute value of the difference between m and r, is the transformer short-circuit impedance, The complex voltage injected into the transformer main busbar of the distribution network, The complex current injected into the transformer main busbar of the distribution network, V 0,set It is the preset voltage of the secondary side of the transformer.

[0201] It should be noted that DNOs set a secondary voltage target value V for the transformer. 0，set , and use on-load tap change to achieve the goal. 0，set The mismatch between the voltage output on the secondary side of the transformer (i.e., the actual secondary voltage) V0 is minimized, and a suitable non-rated turns ratio m is selected. In practical applications, the voltage output on the secondary side of the transformer (i.e., the transformer secondary voltage) V0 is regulated by DNOs to compensate for voltage fluctuations at the grid supply point and voltage drops within the transformer.

[0202] In step 705, based on the non-nominal turns ratio, the voltage outputted by the secondary side of the transformer in the distribution network is controlled.

[0203] A specific implementation of this step may be to adjust the on-load tap changer of the transformer based on the non-nominal turns ratio to control the voltage outputted by the secondary side of the transformer in the distribution network.

[0204] It should be noted that the above formula (6) is based on V0 = V G ≈1p.u, but when different loads are connected to the distributed power bus, the voltage V G There will be different degrees of decline (ref. Figure 4 ). Although the suppression effect on voltage rise is consistent, when the distribution network faces different load demands and injects different distributed power sources, the voltage distribution will change. The deviation between the preset voltage on the secondary side of the transformer (i.e., the target voltage on the secondary side of the transformer) and the voltage output on the secondary side of the transformer (i.e., the actual voltage) can be minimized by reasonably selecting the non-nominal turns ratio, and the voltage control strategy of the distribution network operator can be constructed to ensure that the voltage distribution is not affected by the active power, and the simulation verification is carried out. The voltage V0 output on the secondary side of the transformer is adjusted by DNOs, and the on-load tap-changing transformer can adjust the voltage V0 to ensure that the voltage amplitude at the feeder load bus is within an acceptable range to compensate for the voltage fluctuation at the power supply point of the power grid and the voltage drop in the transformer. The voltage output on the secondary side of the transformer in the distribution network can be adjusted by the non-nominal turns ratio to avoid the injection of distributed power sources, which affects the voltage distribution of the distribution network, thereby avoiding the injection of distributed power sources in a large range of load changes, causing interference to the voltage regulation of the distribution network operator, making the distributed power sources become disturbance-free supply, effectively avoiding disturbances in the voltage distribution in the distribution network, and ensuring the normal operation of the distribution network.

[0205] Another voltage over-limit suppression method provided by the present invention above minimizes the deviation between the target voltage on the secondary side of the transformer and the actual voltage by reasonably selecting a non-nominal turns ratio (i.e., based on this, a reactive power control method is studied to seek the optimal reactive power to minimize the voltage rise caused by the active power, and the deviation between the target voltage on the secondary side of the transformer and the actual voltage is minimized by reasonably selecting a non-nominal turns ratio), and the voltage control strategy of the distribution network operator is constructed to ensure that the voltage distribution is not affected by the active power. The voltage over-limit suppression model is solved to obtain the voltage output of the distributed power source in the distribution network by controlling the reactive power that minimizes the voltage rise caused by the active power (i.e., using the reactive control method), which can effectively suppress the voltage rise; at the same time, the voltage dependence on the load is basically unchanged, and the DG injection will not cause obvious interference to the DNO voltage regulation in a large range of load changes.

[0206] Embodiment 4:

[0207] Based on the same inventive concept, Fig. 9 A block diagram of a voltage out-of-bounds suppression system provided by the present invention, such as Fig. 9 As shown, the system may include:

[0208] The impedance and active power acquisition unit 901 is used to acquire the resistance and reactance of the feeder in the distribution network whose voltage crossing is to be suppressed, and the active power of the distributed power source connected to the distribution network;

[0209] A reactive power determination unit 902 is used to obtain a reactive power that minimizes the voltage rise caused by suppressing the active power in the distribution network by using the resistance and reactance of the feeder and the model for suppressing the active power input voltage out of bounds of the distributed power source;

[0210] A distributed power supply voltage control unit 903, configured to perform reactive power control on the voltage output by the distributed power supply based on the reactive power;

[0211] The voltage out-of-bounds suppression model is a model constructed based on the model construction method of the above embodiment.

[0212] Optionally, the distributed power supply voltage control unit 903 is specifically used to: inject reactive power in the distribution network that minimizes the voltage rise caused by suppressing active power into the distributed power supply, and adjust the reactive power output by the distributed power supply to perform reactive power control on the voltage output by the distributed power supply.

[0213] Optionally, Fig.10 A block diagram of another voltage crossing suppression system provided by the present invention, such as Fig.10 As shown, the system may also include:

[0214] A non-nominal turns ratio determination unit 904, configured to determine the non-nominal turns ratio based on the nominal turns ratio, the short-circuit impedance of the transformer, a preset voltage value of the secondary side of the transformer, and a complex voltage and a complex current injected into the main busbar of the transformer by the distribution network;

[0215] The transformer secondary side voltage control unit 905 is used to control the voltage outputted by the secondary side of the transformer in the distribution network based on the non-nominal turns ratio.

[0216] Optionally, the non-nominal turns ratio satisfies the following formula:

[0217]

[0218] Where M is the non-nominal turns ratio set, m is the non-nominal turns ratio, r is the nominal turns ratio, m * is the non-rated turns ratio corresponding to the minimum absolute value of the difference between m and r, is the transformer short-circuit impedance, The complex voltage injected into the transformer main busbar of the distribution network, The complex current injected into the transformer main busbar of the distribution network, V 0,set It is the preset voltage of the secondary side of the transformer.

[0219] Optionally, the transformer secondary side voltage control unit 905 is specifically used for:

[0220] Based on the non-nominal turns ratio, the on-load tap changer of the transformer is adjusted to control the voltage outputted by the secondary side of the transformer in the distribution network.

[0221] Embodiment 5:

[0222] Based on the same inventive concept, the present invention also provides a computer device, such as Fig.11 As shown, the computer device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits, or other processors.

[0223] (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, and are suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a computer storage medium to implement a corresponding method flow or a corresponding function, so as to implement a model building method in the above-mentioned embodiment, or a step of a voltage out-of-bounds suppression method.

[0224] Embodiment 4:

[0225] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It can be understood that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement a model building method or a step of a voltage out-of-bounds suppression method in the above-mentioned embodiment.

[0226] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0227] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0228] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0229] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0230] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A model building method, characterized in that: The method comprises: Analyze the topological structure of the distribution network where voltage crossing is to be suppressed and construct the feeder model of the distribution network; Based on the feeder model, a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in the feeder of the distribution network is established to determine a zero voltage drop equation caused by a complex current injected into the distribution network; Solving the zero voltage drop equation to obtain a reactive power expression for minimizing the voltage rise caused by suppressing the active power in the distribution network; The reactive power expression is determined as a model for voltage out-of-bounds suppression.

2. The method according to claim 1, characterized in that The method of establishing a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in a feeder of the distribution network based on the feeder model to determine a zero voltage drop equation caused by a complex current injected into the distribution network includes: Determining the complex current injected into the distribution network based on the power and voltage output by the distributed power source; Based on the complex current injected into the distribution network, the voltage output by the distributed power source and the voltage output by the secondary side of the transformer, a voltage drop equation from the connection point of the distributed power source in the feeder to the connection point of the secondary side of the transformer is established; Based on the voltage drop equation, a zero voltage drop equation caused by the complex current injected into the power distribution network is determined.

3. The method according to claim 2, characterized in that The complex current injected into the distribution network is determined in a manner that satisfies the following formula: in, is the complex current injected into the distribution network, V G is the voltage output by the distributed power supply, is the complex voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between them, V0 is the voltage output by the secondary side of the transformer, is the complex voltage output on the secondary side of the transformer, and j is the imaginary coefficient of the complex number.

4. The method according to claim 2, characterized in that: The voltage drop equation from the connection point of the distributed power source in the feeder to the connection point of the secondary side of the transformer is established based on the complex current injected into the distribution network, the voltage output by the distributed power source and the voltage output by the secondary side of the transformer, including: Determine the voltage drop equation based on the voltage output by the distributed power source, the voltage output by the secondary side of the transformer, the complex current injected into the distribution network and the impedance of the feeder; The real and imaginary parts of the pressure drop equation satisfy the following formula: Among them, V G is the voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between is the complex voltage output by the distributed power supply, is the complex voltage outputted by the secondary side of the transformer, V0 is the voltage outputted by the secondary side of the transformer, R is the resistance of the feeder, X is the reactance of the feeder, and the impedance of the feeder is R+jX, where j is the imaginary coefficient of the complex number.

5. The method according to claim 2, characterized in that: The step of determining the zero voltage drop equation caused by the complex current injected into the distribution network based on the voltage drop equation includes: Based on the fact that the voltage output by the distributed power source is approximately equal to the voltage output by the secondary side of the transformer, the voltage drop equation is simplified to obtain a standby zero voltage drop equation caused by the complex current injected into the distribution network; Based on the voltage output by the distributed power source being the reference voltage of the distributed power source, simplifying the standby zero voltage drop equation, and determining the zero voltage drop equation caused by the complex current injected into the distribution network; The zero pressure drop equation satisfies the following formula: Among them, P G is the active power of distributed generation, Q G is the reactive power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

6. The method according to claim 1, characterized in that The reactive power expression satisfies the following formula: in, P is the reactive power in the distribution network that minimizes the voltage rise caused by the active power. G is the active power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

7. A model building system, characterized in that: The system comprises: A feeder model building unit is used to analyze the topological structure of the distribution network to be subjected to voltage over-limit suppression and build a feeder model of the distribution network; A zero voltage drop equation determination unit, configured to establish a voltage drop equation from a distributed power source connection point to a transformer secondary side connection point in a feeder of the distribution network based on the feeder model, so as to determine a zero voltage drop equation caused by a complex current injected into the distribution network; A reactive power expression determination unit, used for solving the zero voltage drop equation to obtain a reactive power expression that minimizes the voltage rise caused by suppressing the active power in the distribution network; The model determination unit is used to determine the reactive power expression as a model for voltage out-of-bounds suppression.

8. The system according to claim 7, characterized in that The zero pressure drop equation determination unit comprises: A complex current determination module, used to determine the complex current injected into the distribution network based on the power and voltage output by the distributed power source; A voltage drop equation establishment module, used to establish a voltage drop equation from a distributed power source connection point in a feeder to a transformer secondary side connection point based on the complex current injected into the distribution network, the voltage output by the distributed power source, and the voltage output by the transformer secondary side; The zero voltage drop equation determination module is used to determine the zero voltage drop equation caused by the complex current injected into the power distribution network based on the voltage drop equation.

9. The system according to claim 8, characterized in that The complex current injected into the distribution network is determined in a manner that satisfies the following formula: in, is the complex current injected into the distribution network, V G is the voltage output by the distributed power supply, is the complex voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between them, V0 is the voltage output by the secondary side of the transformer, is the complex voltage output on the secondary side of the transformer, and j is the imaginary coefficient of the complex number.

10. The system according to claim 8, characterized in that The pressure drop equation establishment module is specifically used for: Determine the voltage drop equation based on the voltage output by the distributed power source, the voltage output by the secondary side of the transformer, the complex current injected into the distribution network and the impedance of the feeder; The real and imaginary parts of the pressure drop equation satisfy the following formula: Among them, V G is the voltage output by the distributed power supply, P G is the active power of distributed generation, Q G is the reactive power of distributed generation, δ is and The angle between is the complex voltage output by the distributed power supply, is the complex voltage outputted by the secondary side of the transformer, V0 is the voltage outputted by the secondary side of the transformer, R is the resistance of the feeder, X is the reactance of the feeder, and the impedance of the feeder is R+jX, where j is the imaginary coefficient of the complex number.

11. The system according to claim 8, characterized in that The zero pressure drop equation determination module is specifically used for: Based on the fact that the voltage output by the distributed power source is approximately equal to the voltage output by the secondary side of the transformer, the voltage drop equation is simplified to obtain a standby zero voltage drop equation caused by the complex current injected into the distribution network; Based on the voltage output by the distributed power source being the reference voltage of the distributed power source, simplifying the standby zero voltage drop equation, and determining the zero voltage drop equation caused by the complex current injected into the distribution network; The zero pressure drop equation satisfies the following formula: Among them, P G is the active power of distributed generation, Q G is the reactive power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

12. The system according to claim 7, characterized in that The reactive power expression satisfies the following formula: Among them, Q * G P is the reactive power in the distribution network that minimizes the voltage rise caused by the active power. G is the active power of the distributed generation, R is the resistance of the feeder, and X is the reactance of the feeder.

13. A voltage out-of-bounds suppression method, characterized in that: The method comprises: Obtaining resistance and reactance of feeders in a distribution network whose voltage is to be suppressed from crossing a boundary, and active power of distributed power sources connected to the distribution network; Solving the model of the resistance and reactance of the feeder and the active power input voltage out-of-bounds suppression of the distributed power source, to obtain the reactive power in the distribution network that minimizes the voltage rise caused by suppressing the active power; Based on the reactive power, performing reactive power control on the voltage output by the distributed power source; The voltage out-of-bounds suppression model is a model constructed based on the model construction method described in any one of claims 1 to 6.

14. The method according to claim 13, characterized in that The reactive power control of the voltage output by the distributed power source based on the reactive power includes: The reactive power that minimizes the voltage rise caused by the active power in the distribution network is injected into the distributed power source, and the reactive power output by the distributed power source is adjusted to perform reactive power control on the voltage output by the distributed power source.

15. The method according to claim 13, characterized in that After performing reactive power control on the voltage output by the distributed power source based on the reactive power, the method further includes: Determine a non-nominal turns ratio based on a nominal turns ratio, a transformer short-circuit impedance, a preset voltage value on the secondary side of the transformer, and a complex voltage and a complex current injected into the transformer main busbar by the distribution network; Based on the non-nominal turns ratio, a voltage outputted from the secondary side of a transformer in the distribution network is controlled.

16. The method according to claim 15, characterized in that The non-nominal turns ratio satisfies the following formula: Where M is the non-nominal turns ratio set, m is the non-nominal turns ratio, r is the nominal turns ratio, m * is the non-rated turns ratio corresponding to the minimum absolute value of the difference between m and r, is the transformer short-circuit impedance, The complex voltage injected into the transformer main busbar of the distribution network, The complex current injected into the transformer main busbar of the distribution network, V 0,set It is the preset voltage of the secondary side of the transformer.

17. The method according to claim 15, characterized in that The controlling of the voltage outputted from the secondary side of the transformer in the distribution network based on the non-nominal turns ratio includes: Based on the non-nominal turns ratio, the on-load tap changer of the transformer is adjusted to control the voltage outputted by the secondary side of the transformer in the distribution network.

18. A voltage out-of-bounds suppression system, characterized in that: The system comprises: An impedance and active power acquisition unit, used to acquire the resistance and reactance of a feeder in a distribution network whose voltage crossing is to be suppressed, and the active power of a distributed power source connected to the distribution network; A reactive power determination unit, used to obtain a reactive power in the distribution network that minimizes voltage rise caused by suppressing active power by using a model for suppressing voltage cross-boundary of the resistance and reactance of the feeder and the active power input voltage of the distributed power source; A distributed power supply voltage control unit, used to perform reactive power control on the voltage output by the distributed power supply based on the reactive power; The voltage out-of-bounds suppression model is a model constructed based on the model construction method described in any one of claims 1 to 6.

19. The system according to claim 18, characterized in that The distributed power supply voltage control unit is specifically used to: inject reactive power that minimizes the voltage rise caused by active power in the distribution network into the distributed power supply, adjust the reactive power output by the distributed power supply, and perform reactive power control on the voltage output by the distributed power supply.

20. The system according to claim 18, characterized in that The system further comprises: a non-nominal turns ratio determination unit, configured to determine the non-nominal turns ratio based on the nominal turns ratio, the short-circuit impedance of the transformer, a preset voltage value of the secondary side of the transformer, and a complex voltage and a complex current injected into the main busbar of the transformer by the distribution network; A transformer secondary side voltage control unit is used to control the voltage outputted by the secondary side of the transformer in the distribution network based on the non-nominal turns ratio.

21. The system according to claim 20, characterized in that The non-nominal turns ratio satisfies the following formula: Where M is the non-nominal turns ratio set, m is the non-nominal turns ratio, r is the nominal turns ratio, m * is the non-rated turns ratio corresponding to the minimum absolute value of the difference between m and r, is the transformer short-circuit impedance, The complex voltage injected into the transformer main busbar of the distribution network, The complex current injected into the transformer main busbar of the distribution network, V 0,set It is the preset voltage of the secondary side of the transformer.

22. The system according to claim 20, characterized in that The transformer secondary side voltage control unit is specifically used for: Based on the non-nominal turns ratio, the on-load tap changer of the transformer is adjusted to control the voltage outputted by the secondary side of the transformer in the distribution network.

23. A computer device, characterized in that: include: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the model building method according to any one of claims 1 to 6 or the voltage out-of-bounds suppression method according to any one of claims 13 to 17 is implemented.

24. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the model building method according to any one of claims 1 to 6 or the voltage crossing suppression method according to any one of claims 13 to 17 is implemented.

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