DC system equipment selection tools and their usage methods
By using automated and intelligent selection methods for DC system equipment selection tools, the problems of battery capacity selection and feeder switch range mismatch were solved, enabling accurate calculation and rational configuration of equipment parameters, and improving the reliability and safety of the power system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 天津华冶工程设计有限公司
- Filing Date
- 2025-12-30
- Publication Date
- 2026-06-02
AI Technical Summary
In the process of selecting equipment for DC systems, the selection of battery capacity relies on empirical estimation and fails to fully consider environmental and load characteristics, resulting in wasted resources or insufficient capacity; the range coordination of feeder switches lacks a systematic approach, which can easily lead to cascading trips and affect the reliable operation of the power system.
A DC system equipment selection tool is provided, including a data input module, an equipment parameter initial selection module, a range matching analysis module, and an equipment parameter adjustment module. By calculating battery parameters and switch range matching, it achieves automated and intelligent equipment selection.
This improves the accuracy of battery capacity selection, ensures reasonable polarity matching of switches, avoids cascading tripping, and enhances the reliability and safety of DC systems.
Smart Images
Figure CN122136779A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power system design technology, and more specifically, to a DC system equipment selection tool and its usage method. Background Technology
[0002] In power systems, DC systems serve as the operating power source for crucial equipment such as control, protection, and signaling devices, and their reliability directly impacts the safe and stable operation of the entire power system. Currently, numerous issues exist in the equipment selection process for DC systems, such as battery capacity selection and range mismatch issues with feeder switches (switching devices located at the beginning of the main or branch lines of a distribution line, responsible for controlling the on / off state of the line and protecting it). These issues refer to the situation in a multi-level distribution network where, when a fault occurs at the end of a line, only the upstream switch closest to the fault point trips, while switches at higher levels remain inactive.
[0003] Specifically, in existing technologies, the selection of battery capacity often relies on empirical estimation, failing to fully consider the impact of different operating environments, load characteristics, and discharge times. This often results in excessively large battery capacity leading to resource waste, or insufficient battery capacity affecting the reliable power supply of the system. As for feeder switches, existing technologies lack systematic and scientific methods for differential coordination of feeder switches, frequently leading to situations such as switch over-tripping and protection failure. In severe cases, this may even cause DC system faults, thereby affecting the normal operation of the entire power system.
[0004] Based on the aforementioned technical issues, there is an urgent need for a solution that can effectively improve the accuracy and rationality of equipment selection for DC systems, so as to ensure the reliable operation of the entire power system. Summary of the Invention
[0005] In view of the above problems, the purpose of this invention is to provide a DC system equipment selection tool and its usage method to solve the problems of resource waste and easy over-level tripping in existing DC system equipment selection methods.
[0006] The DC system equipment selection tool provided by this invention includes a data input module, an equipment parameter initial selection module, a range matching analysis module, and an equipment parameter adjustment module; wherein, The data input module is used to acquire the initial parameters of the DC system to be configured. The device parameter initial selection module is used to initially select the initial parameters for each device based on the initial parameters. The range matching analysis module is used to perform range matching analysis on each switch of the DC system to be configured based on the corresponding initial equipment selection parameters, so as to determine the rationality of the range matching of each switch. The device parameter adjustment module is used to adjust the corresponding initial device parameters so that the compatibility of each switch meets the preset requirements.
[0007] Alternatively, the device parameter initial selection module may include a battery parameter initial selection unit and a charging device parameter initial selection unit; wherein, The battery parameter initial selection unit is used to calculate the required battery parameters based on the corresponding initial parameters, and use them as the initial battery selection parameters. The charging device parameter initial selection unit is used to calculate the required charging device parameters based on the battery initial selection parameters, and use them as the initial selection parameters for the charging device.
[0008] Alternatively, the device parameter initial selection module may further include the cable parameter initial selection unit, which includes a feeder cable parameter initial selection subunit, a battery cable parameter initial selection subunit, and a charging device cable parameter initial selection subunit; wherein, The feeder cable parameter initial selection subunit is used to calculate the initial cable selection parameters required for the feeder of the DC system to be configured based on the corresponding initial parameters. The battery cable parameter initial selection subunit is used to calculate the required cable initial selection parameters for the battery based on the battery initial selection parameters. The charging device cable parameter initial selection subunit is used to calculate the required cable initial selection parameters for the charging device based on the charging device initial selection parameters.
[0009] Alternatively, the device parameter initial selection module may further include a switch parameter initial selection unit, which comprises a feeder switch parameter initial selection subunit, a battery switch parameter initial selection subunit, and a charging device switch parameter initial selection subunit; wherein, The feeder switch parameter initial selection subunit is used to calculate the required switch initial selection parameters for the feeder of the DC system to be configured based on the corresponding initial parameters. The battery switch parameter initial selection subunit is used to calculate the required switch initial selection parameters for the battery based on the battery initial selection parameters. The charging device switch parameter initial selection subunit is used to calculate the required initial switch parameters of the charging device based on the initial selection parameters of the charging device.
[0010] Alternatively, the range matching analysis module may be configured with a switch parameter library, which stores usage parameters for various types of switches; and... The range matching analysis module is used to call the usage parameters of each switch from the switch parameter library based on the initial selection parameters of each switch.
[0011] Alternatively, the range coordination analysis module is configured with a range coordination quantitative analysis model. The range coordination quantitative analysis model is used to calculate the rated current and operating time between the upper and lower levels of each switch based on the operating parameters and corresponding initial parameters of each switch, and to determine the range coordination rationality of each switch based on the rated current calculation results and operating time calculation results between the upper and lower levels of each switch.
[0012] In addition, an optional solution is to include an output display module; among which, The output display module is used to display the final selected parameters for each device.
[0013] On the other hand, the present invention also provides a method for using the aforementioned DC system equipment selection tool, comprising: Obtain the initial parameters within the DC system to be configured; Based on the initial parameters, preliminary parameters for each device are initially selected; Based on the corresponding initial equipment selection parameters, a range coordination analysis is performed on each switch of the DC system to be configured to determine the rationality of the range coordination of each switch. The initial parameters of the corresponding equipment are adjusted to ensure that the compatibility of each switch meets the preset requirements.
[0014] Alternatively, the initial selection parameters for the equipment may include initial selection parameters for the battery and initial selection parameters for the charging device; and the preliminary selection of initial selection parameters for each device based on the initial parameters may include: The required battery parameters are calculated based on the corresponding initial parameters and used as the initial selection parameters for the battery. The parameters of the required charging device are calculated based on the initial parameters of the battery and used as the initial parameters of the charging device.
[0015] Alternatively, the step of performing a range coordination analysis on each switch of the DC system to be configured based on the corresponding initial equipment selection parameters to determine the rationality of the range coordination of each switch includes: The system retrieves the usage parameters of each switch from the switch parameter library based on the initial selection parameters of each switch. Based on the operating parameters and corresponding initial parameters of each switch, the rated current and operating time between the upper and lower levels of each switch are calculated, and the range coordination rationality of each switch is determined according to the results of the rated current calculation and operating time calculation between the upper and lower levels of each switch.
[0016] Compared with the prior art, the DC system equipment selection tool and its usage method provided by the present invention have the following advantages: By introducing initial parameters to calculate the required battery parameters, the accuracy of battery capacity (and power, etc.) selection can be effectively improved. By constructing a range coordination quantitative analysis model, appropriate switch models and their operating parameters can be automatically matched according to system parameters, thereby determining the rationality of the range coordination of each switch. Based on this rationality of range coordination, the coordination of upper and lower level switch actions can be ensured, avoiding cascading tripping. Integrating battery parameter calculation with switch range coordination analysis into one system can automate and intelligentize the DC system equipment selection process, simplifying the operation process.
[0017] To achieve the foregoing and related objectives, one or more aspects of the invention include the features which will be described in detail below and specifically pointed out in the claims. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to include all such aspects and their equivalents. Attached Figure Description
[0018] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings and the contents of the claims, and with a more complete understanding of the invention. In the drawings: Figure 1 A circuit structure diagram of a DC system provided according to an embodiment of the present invention; Figure 2 This is an internal module framework diagram of a DC system equipment selection tool provided according to an embodiment of the present invention; Figure 3 This is an internal unit framework diagram of the device parameter initial selection module provided according to an embodiment of the present invention; Reference numerals in the attached diagram: 1. Feeder switch; 2. Charging device switch; 3. Battery switch; 4. Battery cable; 5. Battery; 6. Charging device. Detailed Implementation
[0019] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.
[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate structural component; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0021] Before detailing the specific structure and working principle of the DC system equipment selection tool provided by this invention, it is necessary to briefly explain the circuit structure of the DC system to which the DC system equipment selection tool provided by this invention is applicable. Figure 1 The circuit structure of a DC system provided according to an embodiment of the present invention is shown, such as... Figure 1 As shown, the DC system applicable to this embodiment of the invention includes a DC power line (i.e., a feeder line, divided into positive and negative power lines), a charging system connected to the DC power line, and an energy storage system connected to the DC power line. The charging system includes a charging device 6, an energy storage system, and a charging device switch 2. The energy storage system connects the charging device to the DC power line, and the charging device switch is connected between the energy storage system and the DC power line. The energy storage system includes a battery 5, a battery cable 4, and a battery switch 3. The battery cable 4 connects the battery 5 to the DC power line, and the battery switch 3 is connected between the battery 5 and the DC power line. Furthermore, the DC power line is also connected to various load devices, and a feeder switch 1 is provided between each load device and the DC power line.
[0022] The structure of the DC system equipment selection tool provided by this invention is described in detail below. Figure 2 The internal module framework structure of the DC system equipment selection tool provided according to an embodiment of the present invention is shown. Figure 3 The internal unit framework structure of the device parameter initial selection module provided according to an embodiment of the present invention is shown, in conjunction with... Figure 2 and Figure 3 As shown in the embodiments of the present invention, the DC system equipment selection tool includes a data input module, an equipment parameter initial selection module, a range matching analysis module, and an equipment parameter adjustment module.
[0023] Specifically, the data input module is used to acquire the initial parameters of the DC system to be configured. The initial parameters include environmental data (such as ambient temperature and humidity), load data (including normal load capacity and emergency load capacity), required voltage level, expected discharge time, required battery type, and other parameters.
[0024] Furthermore, the equipment parameter preliminary selection module is used to initially select parameters for each device based on initial parameters. Specifically, the equipment parameter preliminary selection module includes a battery parameter preliminary selection unit and a charging device parameter preliminary selection unit. The battery parameter preliminary selection unit is used to calculate the required battery parameters (including battery capacity and storage power, etc.) based on the corresponding initial parameters, and uses these as the battery preliminary selection parameters. The charging device parameter preliminary selection unit is used to calculate the required charging device parameters (including charging device capacity and charging power, etc.) based on the battery preliminary selection parameters, and uses these as the charging device preliminary selection parameters. The equipment parameter preliminary selection module also includes... The system includes a cable parameter initial selection unit, which comprises a feeder cable parameter initial selection subunit, a battery cable parameter initial selection subunit, and a charging device cable parameter initial selection subunit (cable parameters include wire type and wire width, etc.). The feeder cable parameter initial selection subunit calculates the required cable initial selection parameters for the feeder of the DC system to be configured based on the corresponding initial parameters. The battery cable parameter initial selection subunit calculates the required cable initial selection parameters for the battery based on the battery initial selection parameters. The charging device cable parameter initial selection subunit calculates the required cable initial selection parameters for the charging device based on the charging device initial selection parameters.
[0025] In addition, the equipment parameter initial selection module also includes a switch parameter initial selection unit (equipment parameters include switch model). The switch parameter initial selection unit includes a feeder switch parameter initial selection subunit, a battery switch parameter initial selection subunit, and a charging device switch parameter initial selection subunit. Among them, the feeder switch parameter initial selection subunit is used to calculate the switch initial selection parameters required for the feeder of the DC system to be configured based on the corresponding initial parameters; the battery switch parameter initial selection subunit is used to calculate the switch initial selection parameters required for the battery based on the battery initial selection parameters; and the charging device switch parameter initial selection subunit is used to calculate the switch initial selection parameters required for the charging device based on the charging device initial selection parameters.
[0026] The range matching analysis module is used to perform range matching analysis on each switch of the DC system to be configured based on the corresponding initial equipment selection parameters, so as to determine the rationality of the range matching of each switch. The equipment parameter adjustment module is used to adjust the corresponding initial equipment parameters so that the compatibility of each switch meets the preset requirements.
[0027] Furthermore, the range coordination analysis module is equipped with a range coordination quantitative analysis model. The range coordination quantitative analysis model is used to calculate the rated current and operating time between the upper and lower levels of each switch based on the operating parameters and corresponding initial parameters of each switch, and to determine the rationality of the range coordination of each switch based on the rated current calculation results and operating time calculation results between the upper and lower levels of each switch.
[0028] In addition, the DC system equipment selection tool provided by the present invention also includes an output display module; wherein, the output display module is used to display the final selected parameters of each device, providing a basis for the subsequent selection of other DC system equipment.
[0029] On the other hand, the present invention also provides a method for using the aforementioned DC system equipment selection tool, comprising: Obtain the initial parameters within the DC system to be configured; Initial parameters for each device are selected based on the initial parameters. Based on the corresponding initial equipment parameters, range coordination analysis is performed on each switch of the DC system to be configured to determine the rationality of range coordination of each switch. The initial parameters of the corresponding equipment are adjusted to ensure that the compatibility of each switch meets the preset requirements.
[0030] Specifically, the initial selection parameters for the equipment include initial selection parameters for the battery and initial selection parameters for the charging device; and, based on the initial parameters, the initial selection parameters for each piece of equipment are initially selected, including: The required battery parameters are calculated based on the corresponding initial parameters and used as the initial selection parameters for the battery. The parameters of the required charging device are calculated based on the initial parameters of the battery and used as the initial parameters of the charging device.
[0031] Furthermore, based on the corresponding initial equipment selection parameters, a range coordination analysis is performed on each switch of the DC system to be configured to determine the rationality of the range coordination of each switch, including: The system retrieves the usage parameters of each switch from the switch parameter library based on the initial selection parameters of each switch. Based on the operating parameters and corresponding initial parameters of each switch, the rated current and operating time between the upper and lower levels of each switch are calculated, and the range coordination rationality of each switch is determined according to the results of the rated current calculation and operating time calculation between the upper and lower levels of each switch.
[0032] The working principle of the DC system equipment selection tool and its usage method provided by the present invention will be further illustrated below by way of examples.
[0033] Example 1: Step 1: Obtain all initial parameters of a DC system to be configured using the data input module. Some of these initial parameters are shown in the table below: Step 2: Initial Selection of Battery Parameters Specifically, the battery selection results are shown in the table below: The selection of the storage battery is based on DL / T 5044-2014 "Technical Specification for Design of DC System of Power Engineering" 3.3.1 and 3.3.3, and GB50049-2011 "Design Specification for Small Thermal Power Plant" 17.5.2. After selection, the storage battery adopts valve-regulated sealed lead-acid battery, and one set of storage batteries is provided.
[0034] Calculation of the number of batteries: Float charge voltage of a single battery DC bus voltage During float charging operation, the DC bus voltage meets the requirements. Therefore, the number of batteries can be calculated as follows: Take 104.
[0035] Battery equalization charging voltage calculation: For combined power supply to control and power loads, the equalization charging voltage of individual batteries must meet the following formula: The formula for calculating the battery discharge termination voltage is as follows: 1.87V is preferred.
[0036] Battery capacity calculation: The battery capacity is calculated using a stepped method, based on Appendix C.2.3-2 and Table C.3-3 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering". The calculated capacities for each stage are as follows: During the random load phase: Fault discharge current: Discharge time 5s, conversion factor obtained from table: In the first stage: Discharge time 1 minute, refer to table In the second stage: Discharge time (min), refer to table Discharge time (min), refer to the table. In Phase 3: Discharge time (min), refer to table Discharge time (min), refer to table Discharge time (min), refer to table It should be noted that, except for Phase 1, The maximum value appears in stage 3, and... After superposition, we get In the first stage, ,and After comparison, the larger value is taken. The minimum required capacity of the battery is 562.2Ah, and 600Ah is selected for this phase of the project.
[0037] Step 3: Initial selection of charging device parameters The selection of charging devices is shown in the table below: According to DL / T 5044-2014 "Technical Specification for Design of DC System of Power Engineering" 3.4.2-2, when using high-frequency switching type charging device, it is advisable to configure 2 sets of charging devices for 1 group of batteries.
[0038] Calculation of rated current for charging device: The battery is a valve-regulated sealed lead-acid battery with a capacity of 600Ah, and the discharge rate current is calculated over 10 hours. According to Appendix D.1.1 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", the calculation is based on meeting the requirements of float charging: Regular load ; Calculation based on the required charging output current when disconnected from the battery: Calculated based on meeting equalization charging requirements: Based on the maximum current operating condition, the rated current of the charging device is required. or .
[0039] Calculation of rated output voltage of charging device: The battery pack is a valve-regulated sealed lead-acid battery, and the voltage at the end of charging is: The number of battery cells n = 104. According to Appendix D.1.2 of DL / T 5044-2014 "Technical Specification for Design of DC Systems for Power Engineering", the minimum output voltage of the charging device is... According to DL / T 781-2021 "High-Frequency Switching Rectifier Modules for Power Applications" 4.2.3 / 4 and 5.6-a 1, the nominal output voltage... V, rated output voltage V, the output voltage adjustment range should not be lower than 90% to 130% of the nominal output voltage.
[0040] Calculation of high-frequency switching power supply rectifier module in charging device: Selection of rated current for a single module According to Appendix D.2 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", the basic modules Six modules were selected, and the number and specifications of the modules met the requirements.
[0041] According to DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering" 6.2.3-2, when one battery group should preferably be equipped with two sets of charging devices: spare module Total number of modules The rated current of the device is (Excluding spare modules).
[0042] In summary, the battery pack is equipped with two sets of high-frequency switching charging devices. Each charging device has a total of 6 individual modules, including 6 basic modules and 0 spare modules. Each module has a rated current of 20 A and a rated output voltage of 230 A. The device's rated current is 120 A (excluding spare modules).
[0043] Step 4: Initial selection of cable parameters The selection of battery circuit cables shall be based on Appendices E.1 and E.2 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering". The allowable current carrying capacity of the cables shall be calculated based on the 10-hour discharge rate current of a valve-regulated sealed lead-acid battery. 1-hour discharge rate current: Long-term operating current calculation The battery outlet uses one wire for both the positive and negative terminals. Fire-resistant cable; current carrying capacity correction factor The cable's allowable current carrying capacity The cable current carrying capacity can be found in the table. The requirements are met.
[0044] Calculated based on allowable voltage drop: DC voltage Cable path length The allowable voltage drop range is Long-term operating current calculation Initial impulse discharge current of the accident A; Total cross-section of the circuit cable The requirements are met.
[0045] .
[0046] For the initial selection of cables for the DC cabinet to the distribution cabinet circuit, according to Appendices E.1 and E.2 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", the allowable current carrying capacity of the cables is calculated as follows: the power supply current of the distribution cabinet is calculated as 64A, therefore, one cable is used for this circuit. Fire-resistant cables; Among them, the current carrying capacity correction factor The cable's allowable current carrying capacity The cable current carrying capacity can be found in the table. The requirements are met.
[0047] According to the allowable pressure drop: DC voltage Cable path length The allowable voltage drop range is The cross-section of the circuit cable The requirements are met. Preliminary selection of cable parameters from the distribution cabinet to the terminal: Based on Appendices E.1 and E.2 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", the current carrying capacity of the cable is calculated according to the allowable current carrying capacity: the current from the distribution cabinet to the terminal is considered to be 10A, and this circuit uses one cable. Fire-resistant cable, current carrying capacity correction factor The cable's allowable current carrying capacity The cable current carrying capacity can be found from the table: The requirements are met.
[0048] Based on the allowable voltage drop, DC voltage Cable path length According to DL / T5044-2014 "Technical Specification for Design of DC Systems in Power Engineering" 6.3.6, the allowable voltage drop range is... No greater than The cross-section of the circuit cable The requirements are met.
[0049] .
[0050] Step 5: Selective coordination of switches (range check) Resistance calculation is based on Appendix Table G.2-1 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", which specifies the internal resistance of the battery. Cable L1: Path length 20m, According to Appendix Table A.6-1 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", circuit breaker S4: Preliminary selection of circuit breaker MCB-DC-4A / 2P: Circuit breaker S3: Initial selection of circuit breaker MCB-DC-40A / 2P: Circuit breaker S2: Initial selection of circuit breaker MCCB-DC-125 / 100A / 2P: Fuse F1: Internal resistance is negligible.
[0051] Short-circuit current calculation at each point: Based on Appendix A.4.2-4 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering": Regarding the selection and selective coordination of protective electrical components, for the S4 circuit breaker, a type B trip unit miniature DC circuit breaker is adopted. Instantaneous trip value Tripping range According to Appendix A.4.1-1 and A.4.1-4 of DL / T5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", when S4 output is short-circuited, S4 must operate reliably with a sensitivity coefficient of not less than 1.2, i.e. ,therefore The S4 circuit breaker operates reliably and instantaneously, meeting the requirements.
[0052] Sensitivity coefficient The sensitivity meets the requirements.
[0053] The S3 circuit breaker selection adopts a C-type trip unit miniature DC circuit breaker with an instantaneous trip value of Tripping range .
[0054] According to Appendices A.4.1-1 and A.4.1-4 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering", to ensure the selectivity of circuit breakers S3 and S4, it is required that when a short circuit occurs at the output of S4, S3 should not operate. ,therefore ; To ensure the sensitivity of circuit breaker S3, it is required that S3 operates reliably and has a sensitivity coefficient of not less than 1.2 when a short circuit occurs at the S3 outlet; the formula for calculating the sensitivity coefficient is as follows: The sensitivity meets the requirements.
[0055] The S2 circuit breaker selection adopts a three-stage molded case DC circuit breaker with an instantaneous tripping value of [value missing]. Tripping range, According to Appendices A.4.1-1 and A.4.1-4 of DL / T 5044-2014 "Technical Specification for Design of DC Systems in Power Engineering"; to ensure the selectivity of circuit breakers S2 and S3, it is required that when a short circuit occurs at the output of S3, S2 should not operate, i.e. therefore .
[0056] To ensure the sensitivity of circuit breaker S2, it is required that S2 operates reliably and its sensitivity coefficient is not less than 1.2 when a short circuit occurs at the S2 output. The formula for calculating the sensitivity coefficient is as follows: The sensitivity meets the requirements.
[0057] Short-time trip value Tripping range When the end of the S2 feeder is short-circuited The S2 circuit breaker operates reliably and instantaneously, meeting the requirements.
[0058] F1 fuse selection is based on the battery discharge rate current, specifically the 1-hour discharge rate current of a valve-regulated sealed lead-acid battery. Circuit breaker rated current ; Based on the selectivity between upper and lower levels, the maximum circuit breaker current of the feeder is: In conclusion, S1 and F1 are selective.
[0059] As can be seen from the above specific embodiments, the DC system equipment selection tool provided by the present invention has at least the following advantages in its usage method: 1. In the past, the selection of battery capacity relied heavily on empirical formulas, ignoring key factors such as ambient temperature and load fluctuations, resulting in large errors in the calculation results. This invention significantly improves the accuracy of battery capacity selection through multi-parameter correction calculation, reducing the situation of insufficient or redundant capacity. 2. Traditional switch range matching mainly relies on manual experience for judgment, lacking systematic quantitative analysis, which easily leads to unreasonable matching problems; the quantitative analysis model established in this invention can quickly and accurately complete the analysis and selection of switch range matching, improving the safety of DC systems; 3. In the past, battery capacity selection and feeder switch selection were mostly independent processes with a lack of coordinated consideration; this invention integrates the two into a unified practical tool, which can realize data sharing and collaborative analysis, improve selection efficiency, and reduce the probability of human error.
[0060] As referred above Figures 1 to 3 The DC system equipment selection tool according to the present invention is described by way of example. However, those skilled in the art will understand that various modifications can be made to the DC system equipment selection tool proposed in the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.
Claims
1. A DC system equipment selection tool, characterized in that, It includes a data input module, a preliminary equipment parameter selection module, a range and fit analysis module, and an equipment parameter adjustment module; among which, The data input module is used to acquire the initial parameters of the DC system to be configured. The device parameter initial selection module is used to initially select the initial parameters for each device based on the initial parameters. The range matching analysis module is used to perform range matching analysis on each switch of the DC system to be configured based on the corresponding initial equipment selection parameters, so as to determine the rationality of the range matching of each switch. The device parameter adjustment module is used to adjust the corresponding initial device parameters so that the compatibility of each switch meets the preset requirements.
2. The DC system equipment selection tool as described in claim 1, characterized in that, The device parameter initial selection module includes a battery parameter initial selection unit and a charging device parameter initial selection unit; wherein... The battery parameter initial selection unit is used to calculate the required battery parameters based on the corresponding initial parameters, and use them as the initial battery selection parameters. The charging device parameter initial selection unit is used to calculate the required charging device parameters based on the battery initial selection parameters, and use them as the initial selection parameters for the charging device.
3. The DC system equipment selection tool as described in claim 2, characterized in that, The equipment parameter initial selection module further includes the cable parameter initial selection unit, which comprises a feeder cable parameter initial selection subunit, a battery cable parameter initial selection subunit, and a charging device cable parameter initial selection subunit; wherein... The feeder cable parameter initial selection subunit is used to calculate the initial cable selection parameters required for the feeder of the DC system to be configured based on the corresponding initial parameters. The battery cable parameter initial selection subunit is used to calculate the required cable initial selection parameters for the battery based on the battery initial selection parameters. The charging device cable parameter initial selection subunit is used to calculate the required cable initial selection parameters for the charging device based on the charging device initial selection parameters.
4. The DC system equipment selection tool as described in claim 3, characterized in that, The equipment parameter initial selection module further includes a switch parameter initial selection unit, which comprises a feeder switch parameter initial selection subunit, a battery switch parameter initial selection subunit, and a charging device switch parameter initial selection subunit; wherein... The feeder switch parameter initial selection subunit is used to calculate the required switch initial selection parameters for the feeder of the DC system to be configured based on the corresponding initial parameters. The battery switch parameter initial selection subunit is used to calculate the required switch initial selection parameters for the battery based on the battery initial selection parameters. The charging device switch parameter initial selection subunit is used to calculate the required initial switch parameters of the charging device based on the initial selection parameters of the charging device.
5. The DC system equipment selection tool as described in claim 4, characterized in that, The range matching analysis module is equipped with a switch parameter library, which stores the usage parameters of various switches; and... The range matching analysis module is used to call the usage parameters of each switch from the switch parameter library based on the initial selection parameters of each switch.
6. The DC system equipment selection tool as described in claim 5, characterized in that, The range coordination analysis module is equipped with a range coordination quantitative analysis model. The range coordination quantitative analysis model is used to calculate the rated current and operating time between the upper and lower levels of each switch based on the operating parameters and corresponding initial parameters of each switch, and to determine the rationality of the range coordination of each switch based on the rated current calculation results and operating time calculation results between the upper and lower levels of each switch.
7. The DC system equipment selection tool as described in claim 6, characterized in that, It also includes an output display module; among which, The output display module is used to display the final selected parameters for each device.
8. A method of using the DC system equipment selection tool as described in any one of claims 1 to 7, characterized in that, include: Obtain the initial parameters within the DC system to be configured; Based on the initial parameters, preliminary parameters for each device are initially selected; Based on the corresponding initial equipment selection parameters, a range coordination analysis is performed on each switch of the DC system to be configured to determine the rationality of the range coordination of each switch. The initial parameters of the corresponding equipment are adjusted to ensure that the compatibility of each switch meets the preset requirements.
9. The method of using the DC system equipment selection tool as described in claim 8, characterized in that, The initial selection parameters for the equipment include initial selection parameters for the battery and initial selection parameters for the charging device; and the preliminary selection of initial selection parameters for each device based on the initial parameters includes: The required battery parameters are calculated based on the corresponding initial parameters and used as the initial selection parameters for the battery. The parameters of the required charging device are calculated based on the initial parameters of the battery and used as the initial parameters of the charging device.
10. The method of using the DC system equipment selection tool as described in claim 9, characterized in that, The step of performing range coordination analysis on each switch of the DC system to be configured based on the corresponding initial equipment selection parameters to determine the rationality of the range coordination of each switch includes: The system retrieves the usage parameters of each switch from the switch parameter library based on the initial selection parameters of each switch. Based on the operating parameters and corresponding initial parameters of each switch, the rated current and operating time between the upper and lower levels of each switch are calculated, and the range coordination rationality of each switch is determined according to the results of the rated current calculation and operating time calculation between the upper and lower levels of each switch.