Method for determining the range of values of equalizing resistors of energy consumption sub-modules of direct current energy consumption devices

Abstract

The application relates to a method for determining the value range of a voltage-sharing resistor of an energy consumption submodule of a direct-current energy consumption device. The method comprises the following steps: obtaining a time parameter, a resistor parameter, a safety factor and an energy consumption factor, wherein the time parameter is the minimum value of the allowable input time of a single energy consumption switching period submodule of the direct-current energy consumption device; determining the upper limit value of the value range of the voltage-sharing resistor of the energy consumption submodule according to the time parameter and the energy consumption factor; and determining the lower limit value of the value range of the voltage-sharing resistor of the energy consumption submodule according to the safety factor and the resistor parameter. The method can conveniently determine the value range of the voltage-sharing resistor of the energy consumption submodule of the direct-current energy consumption device, thereby meeting the design requirements and safety requirements.

Description

Technical Field

[0001] This application relates to the field of DC energy-consuming device technology, and in particular to a method for determining the range of values ​​for the voltage equalization resistor of the energy-consuming submodule of a DC energy-consuming device. Background Technology

[0002] With the development of power transmission technology, in order to achieve fault ride-through in the power transmission system, it is necessary to use DC energy dissipation devices to consume the surplus power of the DC bus voltage in the power transmission system in order to ensure the safe operation of the equipment.

[0003] Currently, in order to balance factors such as equipment cost and component manufacturing level, DC energy consumption devices in power transmission systems mostly adopt hybrid DC energy consumption devices. Hybrid DC energy consumption devices mostly use centralized energy consumption resistors combined with voltage equalization resistors of energy consumption sub-modules to achieve energy consumption.

[0004] However, there is no systematic method to determine the range of values ​​for the voltage equalization resistors of the energy-consuming submodules, which makes it difficult to design corresponding DC energy-consuming devices when facing the energy consumption requirements of different power transmission systems. Summary of the Invention

[0005] Therefore, it is necessary to provide a method for determining the range of values ​​for the voltage equalization resistors of the energy-consuming submodules of a DC energy-consuming device, which can easily determine the above-mentioned technical problems.

[0006] In a first aspect, this application provides a method for determining the value range of the voltage equalization resistor of the energy-consuming submodule of a DC energy-consuming device, the method comprising:

[0007] Obtain time parameters, resistance parameters, safety factor and energy consumption factor. The time parameter is the minimum allowable time for a single energy consumption switching cycle submodule of the DC energy consumption device.

[0008] Based on the time parameters and energy consumption coefficient, determine the upper limit of the range of values ​​for the voltage equalization resistor of the energy consumption submodule;

[0009] Based on the safety factor and resistance parameters, determine the lower limit of the voltage equalization resistor range for the energy-consuming submodule.

[0010] In one embodiment, the step of determining the time parameter includes:

[0011] Obtain the structural parameters and power consumption of the DC power consumption device;

[0012] Determine a power transfer coefficient based on the structural parameters;

[0013] Calculate the target surplus power when the ratio of surplus power to energy consumption is consistent with the power transfer coefficient;

[0014] The allowable input time for a single energy consumption switching cycle submodule corresponding to the target surplus power is determined as a time parameter.

[0015] In one embodiment, calculating the target surplus power when the ratio of surplus power to energy dissipation power matches the power transfer coefficient includes:

[0016]

[0017] Among them, P s For surplus power, P r Where n is the power consumption, and n and N are the structural parameters of the DC power consumption device. Specifically, n is the number of redundant power consumption sub-modules, and N is the number of rated power consumption sub-modules.

[0018] In one embodiment, determining the allowable input time of a single energy consumption switching cycle submodule corresponding to the target surplus power as a time parameter includes:

[0019]

[0020] Among them, T Rsm (P s C represents the allowed activation time for a single energy consumption switching cycle submodule. eq C is the total capacitance of the DC power-consuming device. sm For the capacitor of the energy-consuming submodule of the DC energy-consuming device, U u U is the DC bus voltage when the DC power consumption device is put into operation. d P is the DC bus voltage when the DC power-consuming device is disconnected. s For surplus power, P r Where n is the power consumption, and n and N are the structural parameters of the DC power consumption device. Specifically, n is the number of redundant power consumption sub-modules, and N is the number of rated power consumption sub-modules.

[0021] In one embodiment, the upper limit of the range of values ​​for the voltage equalization resistor of the submodule is determined based on time parameters and energy consumption coefficients, including:

[0022]

[0023] Among them, R sm_min T represents the upper limit of the range of values. Rsm_min For time parameters, U is the energy consumption coefficient, where U smp U represents the peak capacitor voltage of the energy-consuming submodule. sm Where N is the rated operating voltage of the energy-consuming submodule, and C is the rated number of energy-consuming submodules. sm The capacitor is the energy-consuming submodule of the DC energy-consuming device.

[0024] In one embodiment, the lower limit of the voltage equalization resistor value range for the energy-consuming submodule is determined based on the safety factor and resistance parameters, including:

[0025]

[0026] Among them, R sm_min K represents the lower limit of the range of values, and K is the safety factor. U is a resistance parameter. smp I represents the peak capacitor voltage of the energy-consuming submodule. peak This is the peak allowable turn-off current of the switching transistor connected in parallel with the energy-consuming resistor in the energy-consuming submodule.

[0027] Secondly, this application provides a device for determining the range of values ​​for the voltage equalization resistor of the energy-consuming submodule of a DC energy-consuming device, the device comprising:

[0028] The acquisition module is used to acquire time parameters, resistance parameters, safety factor and energy consumption factor. The time parameter is the minimum allowable time for the sub-module of a single energy consumption switching cycle of the DC energy consumption device.

[0029] The upper limit determination module is used to determine the upper limit of the range of values ​​for the voltage equalization resistor of the energy-consuming submodule based on the time parameter and the energy consumption coefficient.

[0030] The lower limit determination module is used to determine the lower limit of the voltage equalization resistor value range of the energy-consuming submodule based on the safety factor and resistance parameters.

[0031] Thirdly, this application provides a controller, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described above.

[0032] Fourthly, this application provides a DC power dissipation device, comprising:

[0033] Multiple energy-consuming sub-modules are connected in series between the live wire and the neutral wire of the DC bus;

[0034] As in the above embodiment, the controller is connected to the switching switch and the switching transistor in the energy-consuming submodule. The controller is used to control the on / off state of the switching switch and the switching transistor according to the value range of the voltage equalization resistor of the energy-consuming submodule, so as to consume the surplus power of the DC bus.

[0035] Fifthly, this application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the methods described above.

[0036] The method for determining the range of equalizing resistor values ​​for the energy-consuming submodules of the aforementioned DC energy-consuming device involves acquiring time parameters, resistance parameters, a safety factor, and an energy consumption factor. The time parameter represents the minimum allowable operating time for the submodule during a single energy-consuming switching cycle of the DC energy-consuming device. Based on the time parameter and the energy consumption factor, the upper limit of the equalizing resistor value range is determined. This ensures that the energy consumed by the submodule during a single switching operation does not exceed its capacity, preventing overload and damage. It also avoids excessively high resistance leading to excessive energy consumption, ensuring the safety and controllability of the energy-consuming device. Based on the safety factor and resistance parameters, the lower limit of the equalizing resistor value range is determined. This ensures that the submodule can withstand the minimum resistance value, guaranteeing its normal operation and safety, while avoiding excessively low resistance that could cause malfunction or damage. In summary, by acquiring the time parameter, resistance parameter, safety factor, and energy consumption factor, the upper and lower limits of the equalizing resistor value range for the energy-consuming submodule can be determined, thus achieving a comprehensive consideration of the stability, performance, and safety of the energy-consuming device. By reasonably selecting and calculating these parameters, the upper and lower limits of the voltage equalization resistor value range of the energy-consuming submodule can be determined, thereby meeting the design requirements and safety considerations. Attached Figure Description

[0037] Figure 1 This is an application environment diagram of a method for determining the value range of the voltage equalization resistor of the energy-consuming submodule of a DC energy-consuming device in one embodiment.

[0038] Figure 2 This is a flowchart illustrating a method for determining the range of values ​​for the voltage equalization resistor in the energy-consuming submodule of a DC energy-consuming device in one embodiment.

[0039] Figure 3 This is a flowchart illustrating the steps for determining time parameters in one embodiment;

[0040] Figure 4 This is an equivalent circuit diagram of a DC transmission system under a receiving-end fault condition in one embodiment;

[0041] Figure 5 This is a waveform diagram of the voltage change of the energy-consuming submodule during a single energy-consuming switching cycle in one embodiment.

[0042] Figure 6 The simulation diagram shows the energy consumption effect of an energy-consuming submodule in implementation when the voltage equalization resistor is 12.7Ω.

[0043] Figure 7 This is a structural block diagram of a device for determining the range of equalizing resistor values ​​for a DC energy-consuming submodule in one embodiment.

[0044] Figure 8 This is a diagram of the internal structure of the controller in one embodiment. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0046] The method for determining the range of voltage equalization resistor values ​​for the energy-consuming submodule of a DC energy-consuming device provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, a DC energy dissipation device is installed between the live and neutral wires of the DC bus. This device comprises multiple energy dissipation sub-modules connected in series between the live and neutral wires of the DC bus. Controller A is connected to the switching switches and switching transistors within each of the energy dissipation sub-modules. Controller A acquires time parameters, resistance parameters, a safety factor, and an energy dissipation factor. The time parameter represents the minimum allowable operating time for a single energy dissipation switching cycle sub-module. Based on the time parameter and energy dissipation factor, the upper limit of the voltage equalization resistor value range for each energy dissipation sub-module is determined. Similarly, based on the safety factor and resistance parameter, the lower limit of the voltage equalization resistor value range is determined. Controller A then controls the on / off state of the switching switches and switching transistors according to the voltage equalization resistor value range of the energy dissipation sub-modules to dissipate the excess power of the DC bus.

[0047] As mentioned in the background section, DC power dissipation devices are often the primary means of enabling fault ride-through in power transmission systems. For example, in offshore wind power flexible DC transmission systems, due to the inertial power characteristics of wind farms, when a fault occurs in the AC system of the onshore converter station, the wind farm power cannot be cut off in a short time. The surplus power accumulates in the DC system, causing the DC bus voltage to rise. If this exceeds the insulation withstand capacity of the equipment, the system faces the risk of disintegration. Considering construction costs, DC power dissipation devices are generally installed at the onshore station to limit the bus overvoltage level under AC system faults and ensure the safe operation of the equipment.

[0048] DC power dissipation devices can be classified into three types according to their topology: centralized, distributed, and hybrid. Centralized DC power dissipation devices consist of direct-flow power dissipation valves and centralized power dissipation resistors. This approach offers high technical and economic efficiency but requires high consistency in power device parameters. It also experiences significant system impact during commissioning and decommissioning, further emphasizing the need for high device consistency. Distributed DC power dissipation devices integrate power dissipation resistors into each valve module. This approach offers smooth control and system friendliness but requires water cooling, resulting in higher equipment costs and larger footprints. To address the shortcomings of centralized and semi-centralized technologies in engineering applications, domestic and international scholars have proposed hybrid DC power dissipation device technologies. This approach balances factors such as equipment cost and device manufacturing capabilities, and has become one of the important research directions in the field of DC power dissipation device technology.

[0049] A typical structure of a hybrid DC power consumption device is as follows: Figure 1 As shown, it includes N rated energy-consuming sub-modules (sm1, sm2...sm... n ) and a centralized energy-consuming resistor Rs, and an internal DC capacitor C for each energy-consuming submodule. sm It is connected in parallel with the static voltage equalization resistor R0, and the voltage equalization resistor R sm After being connected in series with switch T1, it is connected in parallel with diode D1. The ports of the energy-consuming submodule are the two ends of switch T2. Switch T2 is connected in parallel with bypass switch K and then in series with diode D1.

[0050] When a fault occurs at the receiving end of the system, the hybrid DC power dissipation device is activated. The hybrid DC power dissipation device mainly absorbs surplus power through centralized power dissipation resistors, and there are relatively mature calculation methods for the value of centralized power dissipation resistors.

[0051] Currently, there is no systematic method to obtain the value range of the equalizing resistor in the submodule. Traditional methods involve modeling, simulation, and parameter iteration, which are cumbersome and labor-intensive in determining the value range. The traditional method can be summarized as follows: First, based on the device selection results of the power module, estimate the initial value of the equalizing resistor; second, build a model based on the system fault conditions and the amount of surplus power, and conduct simulation verification; third, based on the simulation results, perform parameter iteration optimization to determine the value range of the equalizing resistor that meets the system operation requirements.

[0052] For the reasons stated above, in one embodiment, such as Figure 2 As shown, this application provides a method for determining the value range of the voltage equalization resistor in the energy-consuming submodule of a DC energy-consuming device, which can be applied to... Figure 1 Taking the controller in the example, the following steps are included:

[0053] S202, obtain time parameters, resistance parameters, safety factor and energy consumption factor. The time parameter is the minimum allowable time for a single energy consumption switching cycle submodule of the DC energy consumption device.

[0054] The time parameter refers to the minimum allowable activation time for a single power consumption switching cycle submodule of the DC power consumption device. It represents the minimum time that the DC power consumption device can complete in one switching cycle. A single power consumption switching cycle refers to the time interval required after the DC power consumption device performs one power consumption operation before it can perform the next. Within this time cycle, the DC power consumption device completes one complete power consumption process, including charging, discharging, and power consumption. It should be noted that the length of the power consumption switching cycle depends on specific application requirements and design specifications. For example, some applications may require a shorter switching cycle to achieve more frequent power consumption operations, while others may require a longer switching cycle to meet system stability and power consumption device performance requirements. The resistance parameter describes the resistance characteristics of the power consumption submodule, representing its resistance magnitude. The safety factor is used to consider safety factors in the design of the DC power consumption device, such as... Figure 1 In the DC power dissipation device shown, to ensure the safe operation of switch T1 and prevent it from being damaged due to peak turn-off current, it is necessary to select the voltage equalization resistor R of the power dissipation submodule during the design process of the DC power dissipation device. SM (At time) By introducing a safety factor, the safe operation of the device is ensured. The energy consumption factor represents the energy that the energy-consuming submodule can consume per unit time.

[0055] S204 determines the upper limit of the voltage equalization resistor range for the energy-consuming submodule based on the time parameter and energy consumption coefficient.

[0056] Specifically, firstly, based on the time parameter, the minimum allowable operating time for a single power-switching cycle submodule of the DC power-consuming device is determined. This minimum value represents the minimum time the DC power-consuming device can complete in one switching cycle. Then, based on the energy consumption coefficient, the energy consumed by the submodule per unit time is calculated. Next, the time parameter is divided by the energy consumption coefficient to obtain the maximum energy consumed by the submodule in one power-switching cycle. Finally, based on the resistance characteristics of the submodule and the maximum energy consumption, the upper limit of the voltage-equalizing resistor for the submodule is calculated.

[0057] By following the steps above, the upper limit of the voltage equalization resistor value for the energy-consuming submodule can be determined to meet design requirements and safety considerations. This upper limit represents the maximum resistance the energy-consuming submodule can withstand; exceeding this value may cause the energy-consuming device to malfunction or be damaged. Therefore, when selecting the resistor value, it should be ensured that it does not exceed this upper limit.

[0058] S206, based on the safety factor and resistance parameters, determine the lower limit of the range of values ​​for the voltage equalization resistor of the energy-consuming submodule.

[0059] Specifically, first, determine the value of the safety factor. The safety factor is a multiplicative factor used to consider the safety and reliability of the energy-consuming submodule. A larger safety factor implies higher safety and reliability requirements. Next, based on design requirements and safety considerations, select appropriate resistance parameters. These parameters may include the rated resistance value and maximum current handling capacity of the energy-consuming submodule. For example, to ensure that the switching transistor in the energy-consuming submodule operates within a safe current range, a larger resistor needs to be selected to ensure that the energy-consuming submodule generates a smaller current at higher voltages. In addition, heat dissipation requirements can be considered. For example, the energy-consuming resistor generates heat during operation, and higher power consumption leads to higher heat generation. If the energy-consuming submodule has high requirements for heat dissipation, a larger resistance value needs to be selected to reduce the heat generated per unit resistance. Then, multiply the resistance parameters by the safety factor to obtain the minimum resistance required by the energy-consuming submodule during energy consumption, considering the safety factor. Finally, use the minimum resistance determined above as the lower limit value of the voltage equalization resistor of the energy-consuming submodule.

[0060] By following the steps above, the lower limit of the voltage equalization resistor value for the energy-consuming submodule can be determined to meet design requirements and safety considerations. This lower limit represents the minimum resistance required for the energy-consuming submodule; values ​​below this may cause the energy-consuming device to malfunction or be damaged. Therefore, when selecting a resistor value, it should be ensured that it is not lower than this lower limit.

[0061] The method for determining the range of equalizing resistor values ​​for the energy-consuming submodules of the aforementioned DC energy-consuming device involves acquiring time parameters, resistance parameters, a safety factor, and an energy consumption factor. The time parameter represents the minimum allowable operating time for the submodule during a single energy-consuming switching cycle of the DC energy-consuming device. Based on the time parameter and the energy consumption factor, the upper limit of the equalizing resistor value range is determined. This ensures that the energy consumed by the submodule during a single switching operation does not exceed its capacity, preventing overload and damage. It also avoids excessively high resistance leading to excessive energy consumption, ensuring the safety and controllability of the energy-consuming device. Based on the safety factor and resistance parameters, the lower limit of the equalizing resistor value range is determined. This ensures that the submodule can withstand the minimum resistance value, guaranteeing its normal operation and safety, while avoiding excessively low resistance that could cause malfunction or damage. In summary, by acquiring the time parameter, resistance parameter, safety factor, and energy consumption factor, the upper and lower limits of the equalizing resistor value range for the energy-consuming submodule can be determined, thus achieving a comprehensive consideration of the stability, performance, and safety of the energy-consuming device. By reasonably selecting and calculating these parameters, the upper and lower limits of the voltage equalization resistor value range of the energy-consuming submodule can be determined, thereby meeting the design requirements and safety considerations.

[0062] In one embodiment, such as Figure 3 As shown, the steps for determining the time parameter include:

[0063] S302, obtain the structural parameters and power consumption of the DC power consumption device.

[0064] Structural parameters refer to the structural parameters of a DC power-consuming device, including the number of power-consuming sub-modules, the device's size, shape, and materials. These parameters play a crucial role in determining the device's external form and internal structure. By obtaining structural parameters, we can understand the device's physical characteristics, such as its size, heat dissipation capacity, and current path, thus providing a basis for resistance selection and energy consumption calculation. Power consumption refers to the energy consumed by the DC power-consuming device per unit time. It is an important indicator for evaluating the device's energy consumption capacity and performance. By obtaining power consumption, we can understand the device's energy consumption during actual operation, thus providing a basis for resistance selection and energy consumption calculation. Power consumption can be obtained through experimental measurement or calculation based on the device's design parameters and operating conditions.

[0065] By obtaining the structural parameters and power consumption of a DC power-consuming device, a comprehensive understanding of its design and performance characteristics can be achieved, providing accurate data and basis for subsequent resistance value selection and energy consumption calculation. This ensures that the DC power-consuming device has stable energy consumption capability and good performance during operation.

[0066] S304, determine a power transfer coefficient based on structural parameters.

[0067] The power transfer coefficient refers to the ratio between the energy transferred from the power source to the energy-consuming device per unit time and the total energy supplied by the power source. It reflects the energy transfer efficiency and energy loss of the energy-consuming device.

[0068] Specifically, based on the structural parameters of a DC power-consuming device, its resistance, current, voltage, and other characteristics can be determined, allowing for the calculation of the energy transferred from the power source to the device per unit time. Simultaneously, the structural parameters also provide the device's power consumption, i.e., the energy consumed by the device per unit time. By comparing the energy transferred from the power source to the power-consuming device per unit time with the total energy supplied by the power source, a power transfer coefficient can be determined. A higher coefficient indicates that the power-consuming device utilizes the energy supplied by the power source more efficiently, with less energy loss. Conversely, a lower coefficient indicates lower energy transfer efficiency and greater energy loss.

[0069] Therefore, determining a power transfer coefficient based on the structural parameters of a DC power-consuming device can help evaluate the device's energy transfer efficiency and energy loss. This helps optimize the device design and select appropriate resistor values ​​to improve the device's energy utilization efficiency and performance.

[0070] S306, calculate the target surplus power when the ratio of surplus power to energy consumption power is consistent with the power transfer coefficient.

[0071] In this context, surplus power refers to the difference between the energy transmitted at the transmitting end and the energy received at the receiving end in a DC transmission system. For example, taking a DC transmission system as an example, such as... Figure 4 As shown, under fault conditions, the DC transmission system is equivalent to the sending end, and the receiving end is equivalent to a constant power consumption source, with powers Pi and Po respectively. Based on the power magnitudes of the sending and receiving ends after the fault, the system surplus power Ps is Ps = Pi - Po. The target surplus power refers to the actual surplus power achieved when the power transfer coefficient and the ratio of surplus power to energy consumption are consistent. Specifically, assuming the power transfer coefficient is j and the energy consumption is Pe, the target surplus power can be calculated by multiplying the energy consumption by the power transfer coefficient, i.e., the target surplus power is Ps = j * Pe. By multiplying the power transfer coefficient by the energy consumption, the target surplus power consistent with the ratio of surplus power to energy consumption can be obtained.

[0072] S308, determine the allowable input time of a single energy consumption switching cycle submodule corresponding to the target surplus power as a time parameter.

[0073] Specifically, by determining the allowable operating time of a single energy-consuming sub-module corresponding to the target surplus power as a time parameter, the operating time of each energy-consuming sub-module can be controlled, thereby controlling the amount of surplus power consumed by the energy-consuming sub-module on the DC bus. This ensures that the system can maintain the required target surplus power during operation.

[0074] In the above embodiments, the time parameters are determined based on the relationship between structural parameters, power consumption, and surplus power, ensuring that the determined time parameters accurately reflect the power consumption capacity of the DC power consumption device.

[0075] In one embodiment, calculating the target surplus power when the ratio of surplus power to energy dissipation power matches the power transfer coefficient includes:

[0076]

[0077] Among them, P s For surplus power, P r Where n is the power consumption, and n and N are the structural parameters of the DC power consumption device. Specifically, n is the number of redundant power consumption sub-modules, and N is the number of rated power consumption sub-modules.

[0078] The above embodiments provide a specific implementation method for calculating the target surplus power, which can accurately determine the target surplus power, thereby providing a data basis for determining the time parameters.

[0079] In one embodiment, determining the allowable operating time of a single energy consumption switching cycle submodule corresponding to the target surplus power as a time parameter includes:

[0080]

[0081] Among them, T Rsm (P s C represents the maximum allowable activation time of the submodule voltage equalization resistor in a single energy consumption switching cycle. eq C is the total capacitance of the DC power-consuming device. sm For the capacitor of the energy-consuming submodule of the DC energy-consuming device, U u U is the DC bus voltage when the DC power consumption device is put into operation. d P is the DC bus voltage when the DC power-consuming device is disconnected. s For surplus power, P r Where n is the power consumption, and n and N are the structural parameters of the DC power consumption device. Specifically, n is the number of redundant power consumption sub-modules, and N is the number of rated power consumption sub-modules.

[0082] In one specific embodiment, the steps for determining the allowable activation time of a single energy consumption switching cycle submodule include:

[0083] The time of a single energy consumption switching cycle is divided into four stages for separate calculation, as follows:

[0084] First tier deployment time T1:

[0085]

[0086] Second energy input duration T2:

[0087]

[0088] Third-step resection time T3:

[0089]

[0090] The fourth energy-consuming resection duration, T4:

[0091]

[0092] Single energy consumption switching cycle time T0:

[0093]

[0094] The DC-side equivalent capacitance is the sum of the capacitances of the energy-consuming device submodules, i.e. Uu is the DC bus voltage when the energy-consuming device is in operation, Ud is the DC bus voltage when the energy-consuming device is disconnected, Ceq is the DC-side equivalent capacitance, Pr is the energy-consuming power, Ps is the surplus power, Usm is the submodule's rated operating voltage, Usmp is the submodule's peak capacitor voltage, Csm is the submodule's rated capacitance, and Rs is the value of the centralized energy-consuming resistor. Based on the established flexible DC system, all of the above parameters are known quantities.

[0095] like Figure 1 and 5 As shown, the equalizing resistor is Rsm in the energy-consuming submodule. The purpose of Rsm is to discharge the overvoltage generated on capacitor Csm during the operation of the energy-consuming device. Therefore, only when transistor T2 of the energy-consuming submodule is turned on can transistor T1 discharge the overvoltage of capacitor Csm. In the above four working stages: in stage 2, transistor T2 is always turned on, and Rsm can be activated in this stage. In stage 4, N rated energy-consuming submodules are locked out, and n redundant energy-consuming submodules are removed, that is, T2 of n redundant energy-consuming submodules is turned on. On average, the time for Rsm to be activated should be n*T4 / (n+N). Since stages 1 and 3 are gradually activated or deactivated, the average calculation is used. The total time for Rsm to be activated in the two stages should be (T1+T3) / 2.

[0096] Based on the analytical expressions for the duration of the four stages in a single energy consumption switching cycle of a DC energy consumption device, the expression for the allowable activation time of a sub-module in a single energy consumption switching cycle is as follows:

[0097]

[0098] In one embodiment, determining the upper limit of the range of values ​​for the voltage equalization resistor in the submodule based on time parameters and energy consumption coefficients includes:

[0099]

[0100] Among them, R sm_min T represents the upper limit of the range of values. Rsm_min For time parameters, U is the energy consumption coefficient, where U smp U represents the peak capacitor voltage of the energy-consuming submodule. sm Where N is the rated operating voltage of the energy-consuming submodule, and C is the rated number of energy-consuming submodules. sm The capacitor is the energy-consuming submodule of the DC energy-consuming device.

[0101] The above embodiments provide a specific implementation method for calculating the upper limit of the range of values ​​for the voltage equalization resistor of the submodule, which can accurately determine the upper limit of the range of values ​​for the voltage equalization resistor of the submodule.

[0102] In one embodiment, the lower limit of the voltage equalization resistor value range for the energy-consuming submodule is determined based on the safety factor and resistance parameters, including:

[0103]

[0104] Among them, R sm_min K represents the lower limit of the range of values, and K is the safety factor. U is a resistance parameter. smp I represents the peak capacitor voltage of the energy-consuming submodule. peak This is the peak allowable turn-off current of the switching transistor connected in parallel with the energy-consuming resistor in the energy-consuming submodule.

[0105] The above embodiments provide a specific implementation method for calculating the lower limit of the voltage equalization resistor value range of the energy-consuming submodule, which can accurately determine the lower limit of the voltage equalization resistor value range of the energy-consuming submodule.

[0106] In one embodiment, this application provides a DC power dissipation device, comprising:

[0107] Multiple energy-consuming sub-modules are connected in series between the live wire and the neutral wire of the DC bus;

[0108] As in the above embodiment, the controller is connected to the switching switch and the switching transistor in the energy-consuming submodule. The controller is used to control the on / off state of the switching switch and the switching transistor according to the value range of the voltage equalization resistor of the energy-consuming submodule, so as to consume the surplus power of the DC bus.

[0109] In the above embodiments, the meaning and function of the energy-consuming submodule and the controller can be referred to the description in the above embodiments, and will not be repeated here. By controlling the on / off state of the switching switch and the switching transistor, the controller can adjust the load of the energy-consuming submodule, thereby consuming the surplus power on the DC bus and avoiding equipment damage.

[0110] To describe the scheme of this application in more detail, the following is in conjunction with the appendix. Figure 1-6 The solution described in this application is described in detail.

[0111] This application provides a typical hybrid DC power consumption device topology, such as Figure 1 As shown, it includes N rated energy-consuming sub-modules (sm1, sm2...smn) and a centralized energy-consuming resistor Rs. Each energy-consuming sub-module has an internal DC capacitor Csm and a static voltage equalization resistor R0 connected in parallel. The voltage equalization resistor Rsm is connected in series with the T1 switch and then in parallel with the diode D1. The energy-consuming sub-module port is the two ends of the T2 switch. The T2 switch is connected in parallel with the bypass switch K and then in series with the diode D1.

[0112] After the hybrid DC power dissipation device is put into operation, the voltage change waveform of the power dissipation submodule during one power dissipation switching cycle is as follows: Figure 5As shown, based on the structure of the energy-consuming device and the waveform diagram during the energy consumption process, the range of values ​​for the voltage equalization resistor of the energy-consuming submodule can be calculated using the following steps:

[0113] Step 1, as follows Figure 4 As shown, an equivalent circuit model of the DC transmission system under fault conditions is established, and the expression for the switching time of a single energy consumption device of the DC energy consumption device is solved. The specific implementation method is as follows:

[0114] The equivalent circuit of a DC transmission system under receiving-end fault conditions is as follows: Figure 4 As shown, the DC-side equivalent capacitance is the sum of the capacitances of the energy-consuming device submodules, and its expression is:

[0115]

[0116] Under fault conditions, the DC transmission system is equivalent to a sending end and a receiving end, both with constant power sources, Pi and Po respectively. Based on the power levels at the sending and receiving ends after the fault, the expression for the system's surplus power is:

[0117] P s =P i -P o

[0118] The time of a single energy consumption switching cycle is divided into four stages for separate calculation, specifically including the following steps:

[0119] Calculate the first-stage input time T1:

[0120]

[0121] Calculate the duration T2 of the second energy input:

[0122]

[0123] Calculate the time T3 for the third-step resection:

[0124]

[0125] Calculate the duration T4 of the fourth energy-consuming resection:

[0126]

[0127] Calculate the energy consumption of a single switching cycle T0:

[0128]

[0129] Among them, U u U is the DC bus voltage when the energy-consuming device is put into operation. d C is the DC bus voltage when the energy-consuming device is disconnected. eq P is the DC-side equivalent capacitance.r For energy consumption, P s For surplus power, U sm Here, Usmp is the rated operating voltage of the submodule, Csm is the peak voltage of the submodule capacitor, and Rs is the rated capacitance of the submodule. Based on the established flexible DC system, all of the above parameters are known quantities.

[0130] Step 2: Based on the DC power consumption switching control strategy and combined with the analytical expression of the switching cycle, solve the expression for the maximum allowable activation time of the sub-module voltage equalization resistor;

[0131] The DC power consumption switching control strategy is as follows: The purpose of the equalizing resistor Rsm is to discharge the overvoltage generated on capacitor Csm during the operation of the power consumption device. Therefore, only when transistor T2 of the submodule is turned on can transistor T1 discharge the overvoltage of capacitor Csm. In the above four working stages: In stage 2, transistor T2 is always turned on, and Rsm can be applied in this stage. In stage 4, N submodules are locked and n submodules are cut off, that is, T2 of n submodules is turned on. The average time that Rsm can be applied should be n*T4 / (n+N). Since stages 1 and 3 are gradually applied or cut off, the average calculation is used. The total time that Rsm can be applied in the two stages should be (T1+T3) / 2.

[0132] Based on the analytical expression for the duration of the four stages in a single switching cycle of a DC power consumption device, the expression for the maximum allowable switching time of the submodule voltage equalization resistor is:

[0133]

[0134] Where n is the number of redundant sub-modules of the DC power consumption device, and N is the number of rated sub-modules.

[0135] Step 3: Based on the overvoltage limit indicators of the comprehensive power module, determine the upper limit of the voltage equalization resistor value. In the expression for the maximum allowable activation time of the sub-module voltage equalization resistor, only the surplus power Ps is a variable, with a value range of 0 to Pr. When in... Time. T Rsm To obtain the minimum value, the minimum value T can be calculated. Rsm_min Based on the law of conservation of energy, to maintain voltage stability in the submodule, the voltage increment of the capacitor within one switching cycle must be entirely absorbed by the voltage equalization resistor. According to the voltage equalization control strategy of the DC energy-consuming device, the maximum allowable switching time of the voltage equalization resistor in a single cycle is determined to be T. Rsm_min The upper limit of the value of the voltage equalizing resistor is determined as follows:

[0136]

[0137] Step 4: Determine the lower limit of the voltage equalization resistor value based on the current withstand capability requirements. Determine the lower limit of the voltage equalization resistor value:

[0138]

[0139] Where K is the safety factor, I peak This is the peak value of the allowable turn-off current for switch T1.

[0140] Step 5: Determine the range of values ​​for the voltage equalizing resistor based on the determined upper and lower limits: [R] sm_min ,R sm_max ]

[0141] Based on the above calculation method, taking a ±500kV / 2000MW DC energy-consuming device as an example, according to the system parameters, the nominal DC voltage U dc ±500kV, rated power P r 2000MW, centralized energy-consuming resistor R s Ω, submodule rated operating voltage Usm: 2kV, rated number of submodules N: 500, redundant submodules n: 40, power consumption module capacitor C sm 4mF, maximum turn-off current Inon of device T1: 4000A.

[0142] According to the method provided in this application, the DC bus overvoltage and power module overvoltage limiting indicators are combined to determine the DC bus voltage U when the energy-consuming device is put into operation. u The DC bus voltage is taken as 1030kV based on a rating of less than or equal to 1.06. The DC bus voltage U when the energy-consuming device is disconnected... d The DC bus voltage is set at 1040kV, with a rating of ≥1.02. Considering the submodule's rated operating voltage of 2kV, the peak voltage Usmp of the submodule capacitor is set at 2600V, not exceeding the capacitor's rated DC voltage, and the safety factor K is set at 1.5. Substituting the system parameters, the minimum allowable activation time T of the submodule equalizing resistor is obtained. Rsm_min Substituting the specific parameters mentioned above into the formula for calculating the upper and lower limits of the voltage equalization resistor value, the final value range of the voltage equalization resistor is obtained as [1.05Ω, 12.7Ω]. Based on the above value range, a voltage equalization resistor of 12.7Ω is randomly selected and substituted into the simulation system. The simulation results are as follows... Figure 6 As shown, the fluctuations in DC bus voltage and submodule voltage are within the allowable range, achieving the design effect.

[0143] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0144] Based on the same inventive concept, this application also provides a device for determining the range of equalizing resistor values ​​for the power consumption submodule of a DC power consumption device, used to implement the method for determining the range of equalizing resistor values ​​for the power consumption submodule of a DC power consumption device as described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations in the embodiments of the device for determining the range of equalizing resistor values ​​for the power consumption submodule of a DC power consumption device provided below can be found in the limitations of the method for determining the range of equalizing resistor values ​​for the power consumption submodule of a DC power consumption device described above, and will not be repeated here.

[0145] In one embodiment, such as Figure 7 As shown, this application provides a device for determining the range of voltage equalization resistor values ​​for an energy-consuming submodule of a DC energy-consuming device. The device includes:

[0146] The acquisition module 702 is used to acquire time parameters, resistance parameters, safety factor and energy consumption factor. The time parameter is the minimum allowable time for the sub-module of a single energy consumption switching cycle of the DC energy consumption device.

[0147] The upper limit determination module 704 is used to determine the upper limit of the range of values ​​for the voltage equalization resistor of the energy consumption submodule based on the time parameter and the energy consumption coefficient.

[0148] The lower limit determination module 706 is used to determine the lower limit of the voltage equalization resistor range of the energy-consuming submodule based on the safety factor and resistance parameters.

[0149] In one embodiment, the acquisition module 702 further includes:

[0150] The acquisition unit is used to acquire the structural parameters and power consumption of the DC power consumption device.

[0151] The coefficient determination unit is used to determine a power transfer coefficient based on structural parameters;

[0152] The power determination unit is used to calculate the target surplus power when the ratio of surplus power to energy consumption power is consistent with the power transfer coefficient.

[0153] The time parameter determination unit is used to determine the allowable input time of a single energy consumption switching cycle submodule corresponding to the target surplus power as a time parameter.

[0154] The range of voltage equalization resistor values ​​for the energy-consuming submodules of the aforementioned DC energy-consuming device can be determined by all or part of the modules within the device through software, hardware, or a combination thereof. These modules can be embedded in hardware or independent of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0155] In one embodiment, a controller is provided, which may be a server, and its internal structure diagram may be as follows: Figure 8 As shown, the controller includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores energy consumption data. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for determining the range of voltage equalization resistor values ​​for the energy-consuming submodule of a DC energy-consuming device.

[0156] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0157] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0158] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0159] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0160] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0161] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0162] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for determining the value range of the voltage equalization resistor in the energy-consuming submodule of a DC energy-consuming device, characterized in that, The DC power dissipation device includes several power dissipation sub-modules; the power dissipation sub-module voltage equalization resistor in each power dissipation sub-module is connected in series with the first switching transistor and in parallel with the first diode; the second switching transistor in each power dissipation sub-module is connected in parallel with the bypass switch and in series with the first diode; the ports of each power dissipation sub-module are the two ends of the second switching transistor; the DC capacitor in each power dissipation sub-module is connected in parallel with the static voltage equalization resistor. The method includes: Obtain time parameters, resistance parameters, safety factor, and energy consumption factor. The time parameter is the minimum allowable activation time of a single energy consumption switching cycle submodule of the DC energy consumption device. The steps for determining the time parameter include: Obtain the structural parameters and power consumption of the DC power consumption device; Based on the structural parameters, a power transfer coefficient is determined; The target surplus power is calculated when the ratio of surplus power to energy consumption power matches the power transfer coefficient. The target surplus power is obtained using the following formula: in, The surplus power, The energy consumption power is n, and the structural parameters of the DC energy consumption device are n and N. Specifically, n is the number of redundant energy consumption sub-modules, and N is the number of rated energy consumption sub-modules. The allowable operating time for a single energy consumption switching cycle submodule corresponding to the target surplus power is determined as the time parameter, which is calculated using the following formula: in, The allowed deployment time for the single energy consumption switching cycle submodule. The total capacitance of the DC power consumption device. The capacitor of the energy-consuming submodule of the DC energy-consuming device. The DC bus voltage when the DC energy-consuming device is put into operation. This refers to the DC bus voltage when the DC power-consuming device is disconnected. The surplus power, The power consumption is defined as n, and the structural parameters of the DC power consumption device are n and N. Specifically, n is the number of redundant power consumption submodules, and N is the number of rated power consumption submodules; R s It is a centralized energy-consuming resistor. This represents the peak voltage of the submodule capacitor. The rated operating voltage of the submodule; Based on the time parameter and the energy consumption coefficient, the upper limit of the range of values ​​for the voltage equalization resistor of the energy consumption submodule is determined. The upper limit of the range of values ​​for the voltage equalization resistor of the energy consumption submodule is calculated using the following formula: in, This is the upper limit of the range of values. For the time parameter, Let be the energy consumption coefficient, where This refers to the peak value of the capacitor voltage of the energy-consuming submodule. The rated operating voltage of the energy-consuming submodule is... This represents the number of rated energy-consuming submodules. The capacitor of the energy-consuming submodule of the DC energy-consuming device; Based on the safety factor and the resistance parameters, the lower limit of the voltage equalization resistor value range for the energy-consuming submodule is determined.

2. The method according to claim 1, characterized in that, The step of determining the lower limit of the voltage equalization resistor range for the energy-consuming submodule based on the safety factor and the resistance parameters includes: in, This is the lower limit of the range of values. The safety factor is... The resistance parameter is... This refers to the peak value of the capacitor voltage of the energy-consuming submodule. This refers to the peak allowable turn-off current of the switching transistor connected in parallel with the energy-consuming resistor in the energy-consuming submodule.

3. A device for determining the range of values ​​for the voltage equalizing resistor in an energy-consuming submodule of a DC energy-consuming device, characterized in that, The device includes: The acquisition module is used to acquire time parameters, resistance parameters, safety factor, and energy consumption factor. The time parameter is the minimum allowable operation time of the sub-module in a single energy consumption switching cycle of the DC energy consumption device. The steps for determining the time parameter include: Obtain the structural parameters and power consumption of the DC power consumption device; Based on the structural parameters, a power transfer coefficient is determined; The target surplus power is calculated when the ratio of surplus power to energy consumption power matches the power transfer coefficient. The target surplus power is obtained using the following formula: in, The surplus power, The energy consumption power is n, and the structural parameters of the DC energy consumption device are n and N. Specifically, n is the number of redundant energy consumption sub-modules, and N is the number of rated energy consumption sub-modules. The allowable operating time for a single energy consumption switching cycle submodule corresponding to the target surplus power is determined as the time parameter, which is calculated using the following formula: in, The allowed deployment time for the single energy consumption switching cycle submodule. The total capacitance of the DC power consumption device. The capacitor of the energy-consuming submodule of the DC energy-consuming device. The DC bus voltage when the DC energy-consuming device is put into operation. This refers to the DC bus voltage when the DC power-consuming device is disconnected. The surplus power, The power consumption is defined as n, and the structural parameters of the DC power consumption device are n and N. Specifically, n is the number of redundant power consumption submodules, and N is the number of rated power consumption submodules; R s It is a centralized energy-consuming resistor. This represents the peak voltage of the submodule capacitor. The rated operating voltage of the submodule; The upper limit determination module is used to determine the upper limit of the range of values ​​for the voltage equalization resistor of the energy-consuming submodule based on the time parameter and the energy consumption coefficient. The upper limit of the range of values ​​for the voltage equalization resistor of the energy-consuming submodule is calculated using the following formula: in, This is the upper limit of the range of values. For the time parameter, Let be the energy consumption coefficient, where This refers to the peak value of the capacitor voltage of the energy-consuming submodule. The rated operating voltage of the energy-consuming submodule is... This represents the number of rated energy-consuming submodules. The capacitor of the energy-consuming submodule of the DC energy-consuming device; The lower limit determination module is used to determine the lower limit value of the voltage equalization resistor range of the energy-consuming submodule based on the safety factor and the resistance parameters.

4. A controller comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 2.

5. A DC energy dissipation device, characterized in that, include: Multiple energy-consuming sub-modules are connected in series between the positive and negative terminals of the DC bus; The controller as described in claim 4 is connected to the switching switch and the switching transistor in the energy-consuming submodule, and the controller is used to control the on / off state of the switching switch and the switching transistor according to the value range of the voltage equalization resistor of the energy-consuming submodule, so as to consume the surplus power of the DC bus.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 2.

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