Energy consumption device construction method, energy consumption device construction system, equipment and medium

Abstract

The invention relates to an energy consumption device construction method, an energy consumption device construction system, equipment and a medium. According to the energy consumption device construction method, energy consumption device capacity is directly constructed relative to new energy sending rated power, the rated active power of a sending end and reactive power of the sending end under different working conditions are processed through system power flow, the maximum surplus active power of a converter station is obtained, and the energy consumption device capacity is calculated based on the maximum surplus active power and the capacitor charging and discharging rate. The energy storage capacity of the energy consumption device can be accurately determined, the power absorption accuracy of the energy consumption device is improved, the resistance value of the energy consumption device is accurately calculated, meanwhile, the energy consumption device is constructed based on the resistance value of the energy consumption device, the switching precision of the energy consumption device is improved, the frequency of energy consumption actions in the fault period is reduced, and the system stability is improved. And the possibility of new energy offline during the fault ride-through period is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, specifically to a method for constructing an energy-consuming device, an energy-consuming device construction system, equipment, and medium. Background Technology

[0002] With the rapid development of low-frequency power transmission, scenarios such as direct low-frequency transmission of renewable energy followed by frequency conversion and integration into the industrial frequency grid, and flexible low-frequency interconnection of regional power grids are gradually gaining acceptance. Low-frequency converter stations employ cascaded sub-module converters. In the event of a receiving-end fault, the surplus power may cause DC overvoltage. To address this issue, energy-consuming devices are widely used to absorb the surplus power generated by renewable energy. However, in low-frequency power transmission scenarios, the electrical distance between the low-frequency converter station and the sending end is generally large, resulting in significant losses on the transmission lines. Designing the capacity of energy-consuming devices based on the rated power of renewable energy transmission leads to a decrease in the accuracy of power absorption by these devices. Furthermore, the repeated switching of energy-consuming devices causes repeated impacts on the system. Summary of the Invention

[0003] To address the problem that directly constructing energy-consuming device capacity using rated power from renewable energy sources leads to a decrease in the accuracy of power absorption by the energy-consuming device, this invention provides a method for constructing an energy-consuming device, applicable to low-frequency power transmission systems. The method includes: Based on the rated active power of the sending end in the low-frequency transmission system and the reactive power of the sending end under different operating conditions, the maximum surplus active power of the converter station in the low-frequency transmission system is obtained by using a pre-built system power flow model. Based on the submodule capacitor of the energy-consuming device, the capacitor charging and discharging rate is obtained; The resistance value of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate. The energy-consuming device is constructed based on its resistance value.

[0004] Optionally, the step of obtaining the maximum surplus active power of the converter station in the low-frequency transmission system based on the rated active power of the sending end and the reactive power of the sending end under different operating conditions, using a pre-built system power flow model, includes: Based on the rated active power of the sending end and the reactive power of the sending end under different operating conditions, the system power flow model is iteratively solved using the Newton-Lager iteration method to obtain the voltage and phase angle of the converter station. Based on the voltage and phase angle of the converter station, the maximum surplus active power of the converter station is obtained.

[0005] Optionally, the process of constructing the system power flow model includes: Based on the node admittance matrix of the low-frequency power transmission system, the power expression of each node in the low-frequency power transmission system is obtained. The power expressions of each node in the low-frequency power transmission system are decomposed to obtain the active power expression and reactive power expression of each node in the low-frequency power transmission system. The active power expression and reactive power expression of each node in the low-frequency power transmission system are used as the power flow model of the system.

[0006] Optionally, the power expression of each node in the low-frequency transmission system satisfies the following formula:

[0007] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, Y ij The first node in the admittance matrix i The node to the first j Admittance between nodes For the first j Complex voltages at nodes, For the first i The conjugate voltage of each node n The number of nodes.

[0008] Optionally, the system power flow model satisfies the following formula:

[0009] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, G ij For the first i The node to the first j The real part of the admittance between nodes. B ij For the first i The node to the first j The imaginary part of the admittance between nodes δ ij For the first i The node to the first j Phase angle between nodes U j For the first j The voltage of each node, Ui For the first i The voltage of each node, n The number of nodes.

[0010] Optionally, the submodule capacitor based on the energy-consuming device is used to obtain the capacitor charge / discharge rate, including: Based on the sub-module capacitor of the energy-consuming device, the upper threshold of the capacitor voltage when the energy-consuming device operates, and the lower threshold of the capacitor voltage, the energy stored in the capacitor of the energy-consuming device is obtained. The capacitor charge / discharge rate is obtained based on the energy stored in the capacitor and the maximum fault time of the energy-consuming device.

[0011] Optionally, the capacitor's charge / discharge rate satisfies the following formula:

[0012] Where, Δ P This refers to the capacitor's charge and discharge rate. C For submodule capacitors, U C1 The upper threshold of the capacitor voltage. U C2 The threshold voltage is the voltage across the capacitor. t This represents the maximum downtime.

[0013] Optionally, obtaining the resistance value of the energy-consuming device based on the maximum surplus active power and the capacitor charging and discharging rate includes: The capacity of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate. Based on the capacity of the energy-consuming device and the effective voltage output from the low-frequency side of the energy-consuming device, the resistance value of the energy-consuming device is obtained, and the low-frequency side of the energy-consuming device adopts network control.

[0014] Optionally, the resistance of the energy-consuming device satisfies the following formula:

[0015] in, P 0 represents the maximum surplus active power, Δ P This refers to the capacitor's charge and discharge rate. U Lrms The effective voltage output from the low-frequency side of the energy-consuming device. R ´ represents the resistance value of the energy-consuming device.

[0016] Optionally, after constructing the energy-consuming device based on its resistance value, the method further includes: The energy-consuming device is tested under different operating conditions or different power frequency side faults in the low-frequency power transmission system, and the test results of the energy-consuming device are obtained. Based on the test results of the energy-consuming device, the energy-consuming device is optimized and adjusted.

[0017] Based on the same inventive concept, the present invention also provides an energy-consuming device construction system suitable for low-frequency power transmission systems, the system comprising: The maximum surplus active power determination unit is used to obtain the maximum surplus active power of the converter station in the low-frequency transmission system based on the rated active power of the sending end in the low-frequency transmission system and the reactive power of the sending end under different operating conditions, using a pre-built system power flow model. A capacitor charge / discharge rate determination unit is used to obtain the capacitor charge / discharge rate based on the sub-module capacitor of the energy-consuming device. The energy-consuming device resistance value determination unit is used to obtain the resistance value of the energy-consuming device based on the maximum surplus active power and the capacitor charging and discharging rate. An energy-consuming device construction unit is used to construct the energy-consuming device based on its resistance value.

[0018] Optionally, the maximum surplus active power determination unit is specifically used for: Based on the rated active power of the sending end and the reactive power of the sending end under different operating conditions, the system power flow model is iteratively solved using the Newton-Lager iteration method to obtain the voltage and phase angle of the converter station. Based on the voltage and phase angle of the converter station, the maximum surplus active power of the converter station is obtained.

[0019] Optionally, the system further includes: a system power flow model construction unit; The system power flow model construction unit is used for: Based on the node admittance matrix of the low-frequency power transmission system, the power expression of each node in the low-frequency power transmission system is obtained. The power expressions of each node in the low-frequency power transmission system are decomposed to obtain the active power expression and reactive power expression of each node in the low-frequency power transmission system. The active power expression and reactive power expression of each node in the low-frequency power transmission system are used as the power flow model of the system.

[0020] Optionally, the power expression of each node in the low-frequency transmission system satisfies the following formula:

[0021] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node,Y ij The first node in the admittance matrix i The node to the first j Admittance between nodes For the first j Complex voltages at nodes, For the first i The conjugate voltage of each node n The number of nodes.

[0022] Optionally, the system power flow model satisfies the following formula:

[0023] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, G ij For the first i The node to the first j The real part of the admittance between nodes. B ij For the first i The node to the first j The imaginary part of the admittance between nodes δ ij For the first i The node to the first j Phase angle between nodes U j For the first j The voltage of each node, U i For the first i The voltage of each node, n The number of nodes.

[0024] Optionally, the capacitor charge / discharge rate determining unit is specifically used for: Based on the sub-module capacitor of the energy-consuming device, the upper threshold of the capacitor voltage when the energy-consuming device operates, and the lower threshold of the capacitor voltage, the energy stored in the capacitor of the energy-consuming device is obtained. The capacitor charge / discharge rate is obtained based on the energy stored in the capacitor and the maximum fault time of the energy-consuming device.

[0025] Optionally, the capacitor's charge / discharge rate satisfies the following formula:

[0026] Where, Δ P This refers to the capacitor's charge and discharge rate. C For submodule capacitors, UC1 The upper threshold of the capacitor voltage. U C2 The threshold voltage is the voltage across the capacitor. t This represents the maximum downtime.

[0027] Optionally, the energy-consuming device resistance value determination unit is specifically used for: The capacity of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate. Based on the capacity of the energy-consuming device and the effective voltage output from the low-frequency side of the energy-consuming device, the resistance value of the energy-consuming device is obtained, and the low-frequency side of the energy-consuming device adopts network control.

[0028] Optionally, the resistance of the energy-consuming device satisfies the following formula:

[0029] in, P 0 represents the maximum surplus active power, Δ P This refers to the capacitor's charge and discharge rate. U Lrms The effective voltage output from the low-frequency side of the energy-consuming device. R ´ represents the resistance value of the energy-consuming device.

[0030] Optionally, the system further includes: The test structure determination unit is used to test the energy-consuming device under different operating conditions or different power frequency side faults in the low-frequency power transmission system, and obtain the test results of the energy-consuming device. An optimization and adjustment unit is used to optimize and adjust the energy-consuming device based on the test results of the energy-consuming device.

[0031] Based on the same inventive concept, the present invention also provides an electronic device, comprising: one or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, an energy-consuming device construction method as described above is implemented.

[0032] Based on the same inventive concept, the present invention also provides an electronically readable storage medium having a computer program stored thereon, wherein when the computer program is executed, it implements a method for constructing an energy-consuming device as described above.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method, system, equipment, and medium for constructing an energy-consuming device. The method directly constructs the energy-consuming device capacity relative to the rated power of the renewable energy transmission. By processing the rated active power and reactive power of the transmitting end under different operating conditions using system power flow, the maximum surplus active power of the converter station is obtained. Based on the maximum surplus active power and the capacitor charging and discharging rate, the energy storage capacity of the energy-consuming device can be accurately determined, improving the accuracy of power absorption by the device. The resistance value of the energy-consuming device is also accurately calculated. Furthermore, constructing the energy-consuming device based on its resistance value improves the accuracy of switching on and off, reduces the number of energy-consuming actions during faults, enhances system stability, and significantly reduces the possibility of renewable energy disconnection during fault ride-through. Attached Figure Description

[0034] Figure 1 A flowchart of a method for constructing an energy-consuming device provided by the present invention; Figure 2 A schematic diagram of a low-frequency power transmission system provided by the present invention; Figure 3 A schematic diagram of DC voltage under an optimized energy-consuming device design method provided by the present invention; Figure 4 A schematic diagram of DC voltage under a conventional energy-consuming device design method provided by the present invention; Figure 5 A block diagram of an energy-consuming device construction system provided by the present invention. Figure 6 A block diagram of an electronic device provided by the present invention. Detailed Implementation

[0035] Example 1: Figure 1 A flowchart of a method for constructing an energy-consuming device provided by the present invention, applicable to low-frequency power transmission systems, such as... Figure 1 As shown, the method may include the following steps 101 to 104: In step 101, based on the rated active power of the sending end in the low-frequency transmission system and the reactive power of the sending end under different operating conditions, the maximum surplus active power of the converter station in the low-frequency transmission system is obtained using a pre-built system power flow model.

[0036] In step 102, the capacitor charge / discharge rate is obtained based on the submodule capacitor of the energy-consuming device.

[0037] In step 103, the resistance value of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate.

[0038] In step 104, the energy-consuming device is constructed based on its resistance value.

[0039] It should be noted that, in some scenarios, a method for constructing an energy-consuming device can also be referred to as an optimized design method for energy-consuming devices applicable to low-frequency power transmission. This invention discloses an optimized design method for energy-consuming devices applicable to low-frequency power transmission, including receiving-end power flow analysis (i.e., system power flow model), submodule capacitor charging and discharging rate analysis (i.e., capacitor charging and discharging rate), fault duration, and energy-consuming device design scheme. This invention improves the accuracy of energy-consuming device switching and reduces the number of energy-consuming actions during faults through optimized design of the resistance value of the energy-consuming device, thereby improving system stability and significantly reducing the possibility of renewable energy disconnection during fault ride-through.

[0040] The above Figure 1 Possible implementations of step 101 shown may include the following steps 1011 to 1012: In step 1011, based on the rated active power of the sending end and the reactive power of the sending end under different operating conditions, the system power flow model is iteratively solved using the Newton-Laurel iterative method to obtain the voltage and phase angle of the converter station.

[0041] In step 1012, the maximum surplus active power of the converter station is obtained based on the voltage and phase angle of the converter station.

[0042] It should be noted that by using the Newton-Lager iteration method to iteratively solve the system power flow model, the voltage and phase angle of each node can be obtained, and thus the power of each node can be obtained, so as to obtain the maximum surplus active power of the converter station.

[0043] The above Figure 1 Possible implementations of step 102 shown may include the following steps 1021 to 1022: In step 1021, the energy stored in the capacitor of the energy-consuming device is obtained based on the sub-module capacitor of the energy-consuming device, the upper threshold of the capacitor voltage when the energy-consuming device operates, and the lower threshold of the capacitor voltage.

[0044] In step 1022, the capacitor charge / discharge rate is obtained based on the energy stored in the capacitor and the maximum fault time of the energy-consuming device.

[0045] It should be noted that, based on this characteristic, the energy-consuming device switching strategy is designed as follows: when the capacitor voltage is too high, the energy-consuming device is activated, and the power flow is from the converter valve to the energy-consuming device, causing the submodule capacitor to discharge and the capacitor voltage to decrease; when the capacitor voltage is too low, the energy-consuming device is deactivated, and the power flow is from the converter valve, causing the submodule capacitor to charge and the capacitor voltage to increase, thus achieving a dynamic balance of the capacitor voltage within the allowable range. Therefore, the capacitor charging and discharging rate can be determined to satisfy the following formula:

[0046] Where, Δ P This refers to the capacitor's charge and discharge rate. C For submodule capacitors, U C1 The upper threshold of the capacitor voltage. U C2 The threshold voltage is the voltage across the capacitor. t This represents the maximum downtime. In some scenarios, U C1 This can be expressed as the initial value of the capacitor voltage. U C2 This can be expressed as the remaining capacitor voltage after a certain discharge time. t It can be expressed as the duration of continuous discharge.

[0047] The above Figure 1 Possible implementations of step 103 shown may include the following steps 1031 to 1032: In step 1031, the capacity of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate.

[0048] In step 1032, the resistance value of the energy-consuming device is obtained based on the capacity of the energy-consuming device and the effective voltage output on the low-frequency side of the energy-consuming device. The low-frequency side of the energy-consuming device is controlled by a network.

[0049] It should be noted that the resistance value of the energy-consuming device in step 1032 above can satisfy the following formula:

[0050] in, P 0 represents the maximum surplus active power, Δ P This refers to the capacitor's charge and discharge rate. U Lrms The effective voltage output from the low-frequency side of the energy-consuming device. R ´ represents the resistance value of the energy-consuming device.

[0051] The active power flowing into the converter station varies depending on the reactive power output at the sending end. Therefore, the energy-consuming device should be able to absorb the maximum surplus active power flowing into the converter station, which is defined as... P 0. Energy-consuming device configuration as follows Figure 2 As shown, M3C is the converter station.

[0052] During steady-state operation, the energy-consuming devices are not activated, and all power generated at the sending end flows into the converter station after transmission losses. When a fault occurs on the grid side, the energy-consuming devices are activated, and all power generated at the sending end flows into them after transmission losses. The low-frequency side of the converter station uses V / F control (i.e., grid-based control), where V is the voltage on the low-frequency side and F is the frequency. Assuming DC voltage fluctuations are within allowable limits, the converter station output voltage can be considered a constant value. Therefore, the active power consumed by the energy-consuming devices can be expressed as:

[0053] in P R represents the power absorbed by the energy-consuming device, and R is the energy-consuming resistor. U Lrms This represents the effective value of the output voltage on the low-frequency side. It is easy to see that the power absorbed by the energy-consuming device varies depending on the energy-consuming resistance value.

[0054] Let the resistance of the energy-consuming device when it absorbs P0 be R0. Then, when the designed R is less than R0, the power consumed by the energy-consuming device is greater than the active power flowing into the converter station before the energy-consuming device is put into operation. The insufficient power after the energy-consuming device is put into operation is made up by the converter station, which is expressed as follows: (i.e., capacitor charge / discharge rate), this The flow direction is from the converter station to the energy-consuming device, thereby causing the capacitor voltage of the converter valve submodule to discharge. In some scenarios, this process can be represented as the calculation of the resistance value of the energy-consuming device:

[0055] in This refers to the capacity of energy-consuming devices.

[0056] For example, U C1 The upper limit of the capacitor voltage of the converter submodule for a given energy-consuming device is illustrated in Figure 3, where the value is approximately 2.4. U C2 To illustrate the target value of the submodule capacitor voltage after time t, Figure 3 is used as an example. After 0.6s of discharge, U C2 The value is approximately 2.15 in the figure. The formula for calculating the capacitor's charge and discharge rate can be rearranged and transformed to obtain...

[0057] Substituting the values ​​into the resistance calculation of the energy-consuming device, we can obtain:

[0058] P 0、 C , U Lrms All are constant values.U C1 Given a maximum upper limit, the longest timeframe for fault clearing can be taken as... t Since the time is 0.625s, the energy dissipation device designed within 0.625s does not repeatedly operate, therefore... U C2 It can take a suitable value greater than the given lower limit; thus, the equation is only about... A simple linear equation in one variable. It can be seen that... U C1 , U C2 and t This directly determines the resistance value of the energy-consuming device, and U C1 , U C2 and t This represents the discharge rate of the submodule capacitor. Wherein t Take 0.625s as a reference value, which can be changed according to requirements.

[0059] in, Figure 4 This invention provides a DC voltage schematic diagram based on a traditional energy-consuming device design method, where the design is based solely on the rated power of the sending end. Figure 3 This invention provides a DC voltage schematic diagram under an optimized energy-consuming device design method, which simultaneously considers power flow and capacitor charging / discharging rates. It is evident that under the same operating conditions, this optimized energy-consuming device design method achieves accurate judgment of surplus power, significantly reduces the number of energy-consuming switching operations, and enhances system stability.

[0060] The above Figure 1 The process of constructing the system power flow model in step 101 may include the following steps S1 to S3: In step S1, based on the node admittance matrix of the low-frequency transmission system, the power expression of each node in the low-frequency transmission system is obtained.

[0061] In step S2, the power expression of each node in the low-frequency power transmission system is decomposed to obtain the active power expression and reactive power expression of each node in the low-frequency power transmission system.

[0062] In step S3, the active power expression and reactive power expression of each node in the low-frequency power transmission system are used as the system power flow model.

[0063] It should be noted that the power expressions for each node in the low-frequency transmission system described in step S1 above can satisfy the following formula:

[0064] in, Pi For the first i The active power of each node. Q i For the first i The reactive power of each node, Y ij The first node in the admittance matrix i The node to the first j Admittance between nodes For the first j Complex voltages at nodes, For the first i The conjugate voltage of each node n The number of nodes.

[0065] The system power flow model described in step S3 above can satisfy the following formula:

[0066] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, G ij For the first i The node to the first j The real part of the admittance between nodes. B ij For the first i The node to the first j The imaginary part of the admittance between nodes δ ij For the first i The node to the first j Phase angle between nodes U j For the first j The voltage of each node, U i For the first i The voltage of each node, n The number of nodes.

[0067] For example, assuming the rated active power at the sending end is fixed, the voltage at the sending end will change with different reactive power outputs, thus affecting power loss. The converter station is a balancing node, and the sending end is a PQ node. The system power flow can be solved based on the transmission line impedance to obtain the active power flowing into the converter station.

[0068] Complex power can be calculated using the following formula.

[0069] in, For complex voltages, It is the conjugate current.

[0070] Complex power S Expressed as complex numbers for active and reactive power, and node currents are also included. I This can be obtained from the nodal admittance matrix:

[0071] in Y ij For the first i The node and the first j Admittance between nodes, Then we have:

[0072] in For the first i Complex voltages at nodes, U i For the first i The voltage of each node, δ i For the first i The phase angles of each node, where G and B are the real and imaginary parts of the node admittance matrix, respectively.

[0073] Optionally, in the above Figure 1 Following step 104, the method may further include the following steps 105-106: In step 105, the energy-consuming device is tested under different operating conditions or different power frequency side faults of the low-frequency power transmission system to obtain the test results of the energy-consuming device.

[0074] In step 106, the energy-consuming device is optimized and adjusted based on the test results of the energy-consuming device.

[0075] It should be noted that, based on the initial design of the resistance value of the energy-consuming device, the operating conditions at the sending end were changed, and the performance of the energy-consuming device under different operating conditions was tested. Since the power flowing into the converter and the power output at the sending end have a non-linear relationship, the use of an equal division design in the group design of the energy-consuming device may result in the inability to effectively absorb all the power output at the sending end under certain operating conditions. The maximum capacity of the energy-consuming device can be fine-tuned based on the test results, and the grouping range can also be fine-tuned based on the test results.

[0076] For example, an optimization design method for energy-consuming devices suitable for low-frequency power transmission may include the following steps: System power flow calculation; submodule capacitor charging and discharging rate calculation; energy-consuming device resistance design; verification under different operating conditions and faults. Specifically, the rated active power of the sending end and the corresponding reactive power under different operating conditions are predetermined. System power flow calculation (i.e., system power flow model) is used to calculate the rated active and reactive power to obtain the maximum input active power of the converter station. Based on the maximum input active power, the resistance value of the energy-consuming device is calculated. The energy-consuming device is then designed based on the resistance value, and the designed energy-consuming device is verified.

[0077] The system power flow calculation includes the following steps: calculating the active and reactive power output of the sending system under different active and reactive power outputs; calculating the active power flowing into the receiving end under different active and reactive power outputs of the sending system; and recording the maximum active power flowing into the receiving end.

[0078] The calculation of the capacitor charging and discharging rate in the submodule includes: calculating the capacitor charging and discharging rate based on the energy stored in the capacitor.

[0079] Calculating the charge / discharge rate of a capacitor based on its stored energy involves the following steps: Identify the capacitors in the submodules; determine the maximum failure time; identify the upper and lower thresholds of the capacitor voltage at which the energy-consuming device operates; and calculate the capacitor discharge power.

[0080] The design of the resistance value of the energy-consuming device includes: calculating the capacity of the energy-consuming device based on the capacitor discharge power and the surplus power to be absorbed; and designing the resistance value of the energy-consuming device based on the capacity of the energy-consuming device.

[0081] Among them, the energy-consuming device should be able to effectively absorb surplus power; the energy-consuming device should have the ability to reduce DC voltage; the number of energy-consuming devices in groups is not fixed.

[0082] Fault verification under different operating conditions includes the following steps: Test the performance of energy-consuming devices under different operating conditions and faults; make appropriate adjustments to the energy-consuming devices based on the test results.

[0083] Embodiment 1 of the present invention provides an optimization design method for energy-consuming devices in low-frequency power transmission. By optimizing the resistance value of the energy-consuming device, the accuracy of switching of the energy-consuming device is improved, the number of energy-consuming actions during faults is reduced, the system stability is improved, and the possibility of new energy sources being disconnected from the grid during fault ride-through is greatly reduced.

[0084] Example 2: Based on the same inventive concept Figure 5 A block diagram of an energy-consuming device construction system provided by the present invention is shown below. Figure 5 As shown, this is applicable to low-frequency power transmission systems, and the system may include: The maximum surplus active power determination unit is used to obtain the maximum surplus active power of the converter station in the low-frequency transmission system based on the rated active power of the sending end in the low-frequency transmission system and the reactive power of the sending end under different operating conditions, using a pre-built system power flow model. A capacitor charge / discharge rate determination unit is used to obtain the capacitor charge / discharge rate based on the sub-module capacitor of the energy-consuming device. The energy-consuming device resistance value determination unit is used to obtain the resistance value of the energy-consuming device based on the maximum surplus active power and the capacitor charging and discharging rate. An energy-consuming device construction unit is used to construct the energy-consuming device based on its resistance value.

[0085] Optionally, the maximum surplus active power determination unit is specifically used for: Based on the rated active power of the sending end and the reactive power of the sending end under different operating conditions, the system power flow model is iteratively solved using the Newton-Lager iteration method to obtain the voltage and phase angle of the converter station. Based on the voltage and phase angle of the converter station, the maximum surplus active power of the converter station is obtained.

[0086] Optionally, the system further includes: a system power flow model construction unit; The system power flow model construction unit is used for: Based on the node admittance matrix of the low-frequency power transmission system, the power expression of each node in the low-frequency power transmission system is obtained. The power expressions of each node in the low-frequency power transmission system are decomposed to obtain the active power expression and reactive power expression of each node in the low-frequency power transmission system. The active power expression and reactive power expression of each node in the low-frequency power transmission system are used as the power flow model of the system.

[0087] Optionally, the power expression of each node in the low-frequency transmission system satisfies the following formula:

[0088] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, Y ij The first node in the admittance matrix i The node to the first j Admittance between nodes For the first j Complex voltages at nodes, For the first i The conjugate voltage of each node.

[0089] Optionally, the system power flow model satisfies the following formula:

[0090] in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, G ij For the first i The node to the first j The real part of the admittance between nodes. B ij For the first i The node to the first j The imaginary part of the admittance between nodes δ ij For the first i The node to the first j Phase angle between nodes U j For the first j The voltage of each node, U i For the first i The voltage of each node.

[0091] Optionally, the capacitor charge / discharge rate determining unit is specifically used for: Based on the sub-module capacitor of the energy-consuming device, the upper threshold of the capacitor voltage when the energy-consuming device operates, and the lower threshold of the capacitor voltage, the energy stored in the capacitor of the energy-consuming device is obtained. The capacitor charge / discharge rate is obtained based on the energy stored in the capacitor and the maximum fault time of the energy-consuming device.

[0092] Optionally, the capacitor's charge / discharge rate can satisfy the following formula:

[0093] Where, Δ P This refers to the capacitor's charge and discharge rate. C For submodule capacitors, U C1 The upper threshold of the capacitor voltage. U C2 The threshold voltage is the voltage across the capacitor. t Maximum downtime Optionally, the energy-consuming device resistance value determination unit is specifically used for: The capacity of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate. Based on the capacity of the energy-consuming device and the effective voltage output from the low-frequency side of the energy-consuming device, the resistance value of the energy-consuming device is obtained, and the low-frequency side of the energy-consuming device adopts network control.

[0094] Optionally, the resistance of the energy-consuming device satisfies the following formula:

[0095] in, P 0 represents the maximum surplus active power, Δ P This refers to the capacitor's charge and discharge rate. U Lrms The effective voltage output from the low-frequency side of the energy-consuming device. R ´ represents the resistance value of the energy-consuming device.

[0096] Optionally, the system further includes: The test structure determination unit is used to test the energy-consuming device under different operating conditions or different power frequency side faults in the low-frequency power transmission system, and obtain the test results of the energy-consuming device. An optimization and adjustment unit is used to optimize and adjust the energy-consuming device based on the test results of the energy-consuming device.

[0097] Example 3: Based on the same inventive concept, the present invention also provides an electronic device, such as... Figure 6 As shown, the computer device includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes 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 (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to realize the steps of the energy-consuming device construction method in the above embodiment.

[0098] Example 4: Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the energy-consuming device construction method in the above embodiments.

[0099] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied 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.

[0100] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0101] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0102] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0103] 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 within the scope of the claims of the present invention pending approval.

Claims

1. A method for constructing an energy-consuming device, characterized in that, Applicable to low-frequency power transmission systems, the method includes: Based on the rated active power of the sending end in the low-frequency transmission system and the reactive power of the sending end under different operating conditions, the maximum surplus active power of the converter station in the low-frequency transmission system is obtained by using a pre-built system power flow model. Based on the submodule capacitor of the energy-consuming device, the capacitor charging and discharging rate is obtained; The resistance value of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate. The energy-consuming device is constructed based on its resistance value.

2. The method according to claim 1, characterized in that, Based on the rated active power at the sending end of the low-frequency transmission system and the reactive power at the sending end under different operating conditions, the maximum surplus active power of the converter station in the low-frequency transmission system is obtained using a pre-built system power flow model, including: Based on the rated active power of the sending end and the reactive power of the sending end under different operating conditions, the system power flow model is iteratively solved using the Newton-Laurel iterative method to obtain the voltage and phase angle of the converter station. Based on the voltage and phase angle of the converter station, the maximum surplus active power of the converter station is obtained.

3. The method according to claim 1, characterized in that, The process of constructing the system power flow model includes: Based on the node admittance matrix of the low-frequency power transmission system, the power expression of each node in the low-frequency power transmission system is obtained. The power expressions of each node in the low-frequency power transmission system are decomposed to obtain the active power expressions and reactive power expressions of each node in the low-frequency power transmission system. The active power expression and reactive power expression of each node in the low-frequency power transmission system are used as the power flow model of the system.

4. The method according to claim 3, characterized in that, The power expression of each node in the low-frequency power transmission system satisfies the following formula: in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, Y ij The first node in the admittance matrix i The node to the first j Admittance between nodes For the first j Complex voltages at nodes, For the first i The conjugate voltage of each node n The number of nodes.

5. The method according to claim 3, characterized in that, The system power flow model satisfies the following formula: in, P i For the first i The active power of each node. Q i For the first i The reactive power of each node, G ij For the first i The node to the first j The real part of the admittance between nodes. B ij For the first i The node to the first j The imaginary part of the admittance between nodes δ ij For the first i The node to the first j Phase angle between nodes U j For the first j The voltage of each node, U i For the first i The voltage of each node, n The number of nodes.

6. The method according to claim 1, characterized in that, The capacitor in the submodule based on the energy-consuming device is used to obtain the capacitor charge / discharge rate, including: Based on the sub-module capacitor of the energy-consuming device, the upper threshold of the capacitor voltage when the energy-consuming device operates, and the lower threshold of the capacitor voltage, the energy stored in the capacitor of the energy-consuming device is obtained. The capacitor charge / discharge rate is obtained based on the energy stored in the capacitor and the maximum fault time of the energy-consuming device.

7. The method according to claim 6, characterized in that, The charging and discharging rate of the capacitor satisfies the following formula: Where, Δ P This refers to the capacitor's charge and discharge rate. C For submodule capacitors, U C1 The upper threshold of the capacitor voltage. U C2 The threshold voltage is the voltage across the capacitor. t This represents the maximum downtime.

8. The method according to claim 1, characterized in that, The process of obtaining the resistance value of the energy-consuming device based on the maximum surplus active power and the capacitor charging and discharging rate includes: The capacity of the energy-consuming device is obtained based on the maximum surplus active power and the capacitor charging and discharging rate. Based on the capacity of the energy-consuming device and the effective voltage output from the low-frequency side of the energy-consuming device, the resistance value of the energy-consuming device is obtained, and the low-frequency side of the energy-consuming device adopts network control.

9. The method according to claim 8, characterized in that, The resistance value of the energy-consuming device satisfies the following formula: in, P 0 represents the maximum surplus active power, Δ P This refers to the capacitor's charge and discharge rate. U Lrms The effective voltage output from the low-frequency side of the energy-consuming device. R ´ represents the resistance value of the energy-consuming device.

10. The method according to claim 1, characterized in that, After constructing the energy-consuming device based on its resistance value, the method further includes: The energy-consuming device is tested under different operating conditions or different power frequency side faults in the low-frequency power transmission system, and the test results of the energy-consuming device are obtained. Based on the test results of the energy-consuming device, the energy-consuming device is optimized and adjusted.

11. A system for constructing an energy-consuming device, characterized in that, Suitable for low-frequency power transmission systems, the system comprising: The maximum surplus active power determination unit is used to obtain the maximum surplus active power of the converter station in the low-frequency transmission system based on the rated active power of the sending end in the low-frequency transmission system and the reactive power of the sending end under different operating conditions, using a pre-built system power flow model. A capacitor charge / discharge rate determination unit is used to obtain the capacitor charge / discharge rate based on the sub-module capacitor of the energy-consuming device. The energy-consuming device resistance value determination unit is used to obtain the resistance value of the energy-consuming device based on the maximum surplus active power and the capacitor charging and discharging rate. An energy-consuming device construction unit is used to construct the energy-consuming device based on its resistance value.

12. An electronic 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, a method for constructing an energy-consuming device as described in any one of claims 1 to 10 is implemented.

13. An electronically readable storage medium, characterized in that, It contains a computer program, which, when executed, implements a method for constructing an energy-consuming device as described in any one of claims 1 to 10.

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