A remote power supply voltage drop compensation system

Abstract

The utility model provides a kind of remote power supply voltage drop compensation system, it includes: main cable circuit and branch cable circuit, the voltage drop calculation module and voltage drop compensation control module of connecting main cable circuit and branch cable circuit;The utility model obtains the voltage drop of corresponding cable circuit by voltage drop calculation module, voltage drop compensation control module is based on the voltage drop signal output by voltage drop calculation module, and the output voltage of adjustable voltage power supply is regulated and controlled, to compensate corresponding cable circuit, avoid the problem such as poor equipment stability between main cable circuit and branch cable circuit due to voltage drop.

Description

Technical Field

[0001] This utility model relates to the field of voltage regulation technology, specifically to a long-distance voltage drop compensation system. Background Technology

[0002] In applications requiring long-distance power supply, cable selection must not only meet current-carrying capacity requirements but also fully consider the impact of line voltage drop. When current flows through a cable conductor, the conductor's resistance causes potential loss, leading to a voltage drop—a phenomenon commonly known as "voltage drop." The actual selection of a cable requires a comprehensive evaluation of key parameters such as its resistance, laying length, and transmission power. Especially under long-distance power transmission conditions, line resistance increases significantly, current transmission is severely hampered, and the load-side voltage falls below the range required for normal equipment operation, seriously affecting equipment stability and even causing equipment damage.

[0003] To address the voltage drop issue in long-distance power supply, existing voltage drop compensation technologies and their corresponding drawbacks include:

[0004] 1. It often adopts a closed-loop feedback control mechanism, which requires continuous acquisition of load-side voltage, current and other signals for dynamic compensation, making system stability control more difficult;

[0005] 2. Voltage regulation is achieved through distribution transformers, but the range is limited, the adjustment method is crude, and the operation requires a power outage, making it impossible to achieve rapid and precise adjustment based on line voltage drop;

[0006] 3. The addition of voltage stabilizing devices can only cope with grid fluctuations and maintain the standard voltage at the substation outlet, without considering the voltage drop compensation of the power supply line itself.

[0007] 4. To meet the requirements for voltage deviation at the end, the cross-section of the cable is usually increased, which leads to an increase in material and engineering costs. Utility Model Content

[0008] In order to overcome the shortcomings of the prior art, this utility model provides a long-distance power supply voltage drop compensation system.

[0009] To achieve the above objectives, this utility model provides a long-distance power supply voltage drop compensation system, which includes:

[0010] The main cable circuit and the branch cable circuit are connected to an adjustable voltage power supply at one end of the main cable circuit and multiple loads are connected to the branch cable circuit.

[0011] The voltage drop calculation module is connected to the main cable circuit and the branch cable circuit to obtain the voltage drop of the corresponding cable circuit.

[0012] The voltage drop compensation control module is connected to the adjustable voltage power supply and the voltage drop calculation module. Based on the voltage drop signal output by the voltage drop calculation module, it adjusts the output voltage of the adjustable voltage power supply to compensate the corresponding cable circuit.

[0013] Preferably, an intermediate switch is provided between the main cable circuit and the branch cable circuit to control the status of all load switches.

[0014] Preferably, the voltage drop calculation module includes a first calculation module and a second calculation module, wherein the first calculation module is connected to any position on the main cable circuit and the second calculation module is connected to any position on the branch cable circuit.

[0015] Preferably, when the cable power remains unchanged, the compensation voltage output by the adjustable voltage power supply is the sum of the voltage drops of the main cable circuit and the branch cable circuit.

[0016] Preferably, when the cable power changes, the compensation voltage output by the voltage regulating power supply is the sum of the voltage drops of the main cable circuit and the branch cable circuit after the change.

[0017] Preferably, when the voltage connected to the end load after compensation is greater than the preset voltage, the voltage drop compensation control module outputs a control signal to control the adjustable voltage power supply to output the compensation voltage between the voltage drop of the main cable circuit and the branch cable circuit under normal state or power change.

[0018] Preferably, when only the power of the main cable circuit or only the power of the branch cable circuit changes, the voltage drop compensation control module outputs a control signal to control the adjustable voltage power supply to output a compensation voltage corresponding to the change in voltage drop.

[0019] The long-distance power supply voltage drop compensation system provided by this utility model has the following advantages:

[0020] By connecting voltage drop calculation modules to the main cable circuit and branch cable circuits, these modules can perform real-time calculations based on the parameters and load changes of the corresponding cable circuits, obtaining the corresponding dynamic voltage drops. Based on the obtained cable circuit voltage drops, the voltage drop compensation control module, combined with the parameters and load changes of the corresponding cable circuits, calculates the required compensation voltage for each cable circuit to ensure voltage drop balance between the main cable circuit and branch cable circuits. Based on the compensation voltage calculated by the voltage drop compensation control module, a corresponding control signal is output to an adjustable voltage power supply, allowing the controller to output the corresponding voltage compensation to the main cable circuit and / or branch cable circuits, thus avoiding problems such as poor equipment stability caused by voltage drops between the main cable circuit and branch cable circuits. Attached Figure Description

[0021] Figure 1This is an architecture diagram of a long-distance power supply drop compensation system provided by this utility model;

[0022] Figure 2 This is a flowchart illustrating how the voltage drop compensation control module provided by this utility model regulates the output of the adjustable voltage power supply.

[0023] Figure label:

[0024] 1. Adjustable voltage power supply; 101. Initial voltage of main cable U11 (i.e., output voltage of adjustable voltage power supply); 102. Voltage drop of main cable ΔU_main; 103. Voltage at the end of main cable U12; 11. Main cable; 111. Resistivity of main cable ρ; 112. Cross-sectional area of ​​main cable S; 113. Length of main cable L; 2. Intermediate switch; 201. Initial voltage of branch cable U21 (consistent with the value of 103. Voltage at the end of main cable U12); 202. Voltage drop of branch cable ΔU_branch; 203. Voltage at the end of branch cable U22; 21. Branch cable; 211. Resistivity of branch cable ρ'; 212. Cross-sectional area of ​​branch cable S'; 213. Length of each branch segment (distance between two loads) L'; 3. Electrical load; 31. Power of a single load p; 32. Total number of loads l; 4. Total power of load P. Detailed Implementation

[0025] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0026] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0027] In this embodiment of the invention, all directional indicators (such as up, down, left, right, front, back, horizontal, vertical, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0028] Due to installation errors and other reasons, the parallel relationship referred to in the embodiments of this utility model may actually be an approximate parallel relationship, and the perpendicular relationship may actually be an approximate perpendicular relationship.

[0029] like Figure 1 As shown, this utility model provides a long-distance power supply voltage drop compensation system, which includes: a main cable circuit and branch cable circuits, a voltage drop calculation module, and a voltage drop compensation control module. One end of the main cable circuit is connected to an adjustable voltage power supply, and multiple loads are connected to the branch cable circuits. The voltage drop calculation module is connected to the main cable circuit and the branch cable circuits to obtain the voltage drop of the corresponding cable circuits. The voltage drop compensation control module is connected to the adjustable voltage power supply and the voltage drop calculation module. Based on the voltage drop signal output by the voltage drop calculation module, it adjusts the output voltage of the adjustable voltage power supply to compensate the corresponding cable circuits.

[0030] Specifically, this invention connects voltage drop calculation modules to the main cable circuit and branch cable circuits. These modules perform real-time calculations based on the parameters and load changes of the corresponding cable circuits, obtaining the corresponding dynamic voltage drops. Based on the obtained cable circuit voltage drops, the voltage drop compensation control module, combined with the parameters and load changes of the corresponding cable circuits, calculates the required compensation voltage for each cable circuit to ensure voltage drop balance between the main cable circuit and the branch cable circuits. Based on the compensation voltage calculated by the voltage drop compensation control module, a corresponding control signal is output to an adjustable voltage power supply, so that the controller outputs the corresponding voltage compensation to the main cable circuit and / or branch cable circuit.

[0031] It is important to note that the "real-time calculation" mentioned in this invention refers to the immediate calculation of voltage drop based on existing cable and load parameters after each load change demand is issued. Specifically, the "real-time calculation" in this invention involves proactive compensation calculation under fixed parameters such as existing cables and loads. For example, when a 100% power command is issued, this invention calculates the compensation voltage under the 100% power target based on fixed cable and load parameters and a predetermined compensation strategy formula, and then superimposes the compensation voltage on the power supply output. Similarly, when a 50% power command is issued, this invention calculates the compensation voltage under the 50% power target based on fixed cable and load parameters and a predetermined compensation strategy formula, and then superimposes the compensation voltage on the adjustable voltage power supply output. The compensation calculation and implementation actions in this invention are triggered by the command; the calculation is a one-time event. There is no "adaptive control system that collects, feeds back, and adjusts closed-loop voltage through information acquisition and feedback from multiple components in the system loop," and no other information is collected. This invention lacks a control link for comparing, correcting, and adjusting the implementation results. Although it calculates and implements power commands in real time, it operates in a "post-command, forget about" mode.

[0032] In this embodiment, an intermediate switch is also provided between the main cable circuit and the branch cable circuit to control the state of all load switches.

[0033] Specifically, in this embodiment, all loads are integrated into one unit and connected sequentially to the branch cable circuit. The switching state of all loads is uniformly controlled by the intermediate switch. When the voltage drop of the branch cable circuit changes, the voltage drop calculation module can immediately calculate the change in voltage drop, so that the voltage drop of the branch cable circuit can be quickly compensated.

[0034] In this embodiment, the voltage drop calculation module includes a first calculation module and a second calculation module. The first calculation module is connected to any position on the main cable circuit, and the second calculation module is connected to any position on the branch cable circuit.

[0035] Specifically, the first calculation module performs real-time calculations on parameters and load changes in the main cable circuit, obtaining dynamic voltage drop calculation results. The second calculation module performs real-time calculations on parameters and load changes in the branch cable circuits, obtaining dynamic voltage drop calculation results. The first calculation module calculates the voltage drop of the main cable based on its rated power. If the load power of the main cable changes during power supply, the first calculation module recalculates based on the changed load power and transmits the results to the voltage drop compensation calculation control module for aggregation. Similarly, the second calculation module calculates the voltage drop of the branch cables based on their rated power. If the load power of the branch cables changes during power supply, the second calculation module recalculates based on the changed load power and transmits the results to the voltage drop compensation calculation control module for aggregation.

[0036] In this embodiment, when the cable power remains unchanged, the compensation voltage output by the adjustable voltage power supply is the sum of the voltage drops of the main cable circuit and the branch cable circuit.

[0037] Specifically, during normal operation, the first calculation module calculates the voltage drop of the main cable as ΔU. 主 The second calculation module calculates the voltage drop of the branch cable as ΔU. 分 Then the compensation voltage that the adjustable voltage power supply needs to boost is ΔU. 主 +ΔU 分 This is called full compensation.

[0038] If the power supply process controls the power variation of individual loads according to demand, meaning the load power of both the main cable circuit and branch cable circuits varies, the first calculation module calculates the voltage drop of the main cable as ΔU. 主 The second calculation module calculates the voltage drop of the branch cable as ΔU. 分'Then the compensation voltage that the adjustable voltage power supply needs to boost is: ΔU 主 '+ΔU 分 This is called full compensation.

[0039] If the voltage connected to the end load needs to be greater than 0.95U after compensation. 工作 The compensation voltage output of the adjustable voltage power supply is then set to ΔU. 欠补偿 Or ΔU 欠补偿 This is called undercompensation, and its voltage range is: ΔU 主 <ΔU 欠补偿 <ΔU 主 +ΔU 分 Alternatively, in the case of power adjustment, the compensation voltage is set to ΔU. 主 '<ΔU 欠补偿 '<ΔU 主 '+ΔU 分 The minimum compensation principle for undercompensation is that the voltage connected to the end load after compensation is greater than 0.95U. 工作 U 工作 It is the operating voltage corresponding to the required operating state of the load.

[0040] Full compensation means that the current at the end of each branch reaches U. 工作 However, the voltage at the branch cable head is higher than the operating voltage, which may cause the load power at the head to exceed the limit by too much; only compensating for the voltage drop of the main cable, the voltage at the branch cable head reaches U 工作 However, if the voltage at the branch current's end is lower than the operating voltage, the load power at the end may not reach the expected level. In this case, undercompensation falls within this range and includes the optimal solution. Furthermore, since general design specifications consider the voltage drop at the end to be ≤5%, the minimum compensation principle for undercompensation is that the voltage connected to the load at the end after compensation should be greater than 0.95U. 工作 That is, the preset value.

[0041] Furthermore, if only the load power of the main cable changes during the power supply process, the first calculation module calculates the voltage drop of the main cable as ΔU. 主 'Then the adjustable voltage power supply needs to increase the compensation voltage by ΔU'. 主 If, during the power supply process, only the load power of the branch cable changes, the second calculation module calculates the voltage drop of the branch cable as ΔU. 分 'Then the adjustable voltage power supply needs to increase the compensation voltage by ΔU'. 分 '.

[0042] The formula for calculating the voltage drop of the main cable is as follows:

[0043] , , ,

[0044] The resistance of the main cable is:

[0045] ,

[0046] One circuit requires a 2-core cable, so the resistance is calculated as twice the cable length.

[0047] The voltage drop of the main cable is:

[0048]

[0049] Among them, U 工作 The operating voltage is the voltage required by the load under the specified operating conditions. P is the total load power, I is the main cable current, R is the main cable resistance, ρ is the resistivity of the main cable material, L is the main cable length, S is the main cable cross-sectional area, and U... 工作 This refers to the operating voltage required by the load under its operating conditions.

[0050] The formula for calculating the voltage drop of a branch cable is:

[0051] p=U 工作 I', I'=p / U 工作 U 工作= I'*R',

[0052] The resistance of each section of the branch cable is:

[0053] ,

[0054] One circuit requires a 2-core cable, so the resistance is calculated as twice the cable length.

[0055] The current for each load is: I' = p / U 工作 The voltage drop of the branch cable is: ΔU 分 =I'*R'* n*(n+1) / 2. Therefore:

[0056]

[0057] Where p is the power of a single load, I' is the current of a single load, and R' is the resistance of each segment of the branch cable (between two loads). L' is the resistivity of the branch cable material, L' is the length of each segment of the branch cable (between two loads), S' is the cross-sectional area of ​​the branch cable, and n is the number of loads distributed on the branch cable.

[0058] If the load adjusts its power according to the working requirements during the power supply application, then the voltage drop ΔU needs to be recalculated based on the total load power P and the individual load power p under the new state. 主 'and ΔU 分 '.

[0059] Ultimately, under the full compensation strategy, the voltage drop compensation calculation and control module outputs a command to the adjustable voltage power supply to increase the compensated output voltage U11 to the operating voltage plus the full compensation voltage = U 工作 +ΔU 主 +ΔU 分 .

[0060] Under the undercompensation strategy, the voltage drop compensation calculation and control module commands the adjustable voltage power supply to increase the compensation output voltage U11, which is the operating voltage plus the undercompensation voltage = U. 工作 +ΔU 欠补偿 The minimum compensation principle is that the voltage connected to the end load after compensation is greater than 0.95U. 工作 .

[0061] like Figure 2 As shown, the entire compensation process of this system is as follows:

[0062] (1) The upper-level system issues control information;

[0063] (2) After receiving the control information, the voltage drop compensation calculation control module calculates the total load power P and the load operating voltage U after the control is executed. 工作 Single load power p;

[0064] (3) ΔU of the first calculation module 主 The calculation section calculates ΔU based on the total load P and the main cable parameters. 主 Numerical value;

[0065] (4) ΔU of the second calculation module 分 The calculation section calculates ΔU based on the single load p, branch cable parameters, and load distribution. 分 Numerical value;

[0066] (5) The summary calculation section, based on the set compensation strategy requirements and combined with U 工作 , ΔU 主 , ΔU 分 The numerical values ​​are summarized and calculated to obtain the compensated output voltage value, which is then translated into the corresponding voltage command to control the output of the adjustable voltage power supply.

[0067] (6) The voltage drop compensation calculation and control module sends the generated corresponding voltage command to the adjustable voltage power supply;

[0068] (7) The adjustable voltage power supply executes the corresponding voltage command, outputs the executed feedback information, and sends the executed feedback information to the voltage drop compensation calculation and control module;

[0069] (8) The voltage drop compensation calculation and control module verifies the feedback information. If it does not conform to the voltage command information of the adjustable voltage power supply, the voltage drop compensation calculation and control module resends the corresponding voltage command to the adjustable voltage power supply. If it conforms, the voltage drop compensation calculation and control module sends the feedback information that the adjustable voltage power supply has executed to the host system.

[0070] Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort should fall within the protection scope of this utility model.

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