A line loss management system for seasonal power consumption of a transformer area

Abstract

This invention discloses a line loss management system for seasonal power consumption in distribution transformer areas, comprising a seasonal load distribution transformer area line loss management device (LN1001), a seasonal load distribution transformer area line loss management device (LN1002), and a seasonal load distribution transformer area line loss management device (LN1003). These three devices together form a three-level management system, respectively addressing the standby losses of intelligent equipment, the no-load losses of transmission lines, and the no-load losses of transformers. The seasonal load distribution transformer area line loss management device (LN1001) is deployed on the user side, the seasonal load distribution transformer area line loss management device (LN1002) is deployed on the distribution transformer area side, and the seasonal load distribution transformer area line loss management device (LN1003) is deployed on the high-voltage side of the transformer. This line loss management system for seasonal power consumption in distribution transformer areas, through the adoption of an "integrated design of line loss management module and switch body," adheres to higher standards of circuit breaker specifications in terms of fault current breaking capacity, mechanical and electrical life, and material flame retardancy compared to external magnetic latching relay solutions, resulting in a higher system safety factor.

Description

Technical Field

[0001] This invention relates to the field of power system transformer substation line loss management technology, specifically a line loss management system for seasonal power consumption in transformer substations. Background Technology

[0002] In a power distribution network, the line loss rate of a distribution transformer area is a key indicator for measuring power supply efficiency and management level. For distribution transformer areas with obvious cyclical power consumption characteristics, such as agricultural irrigation and seasonal tourism loads, the overall load rate of the distribution transformer area is extremely low during off-seasons or low-load periods. However, transformers, transmission lines, and user-side smart devices will still continuously generate no-load losses. These losses mainly include: transformer no-load losses; no-load losses caused by the ground capacitance current of long-distance transmission lines; and standby power consumption of user smart devices, which cannot be measured if it is lower than the starting current of the electricity meter.

[0003] Currently, line loss management is a key aspect of improving power grid efficiency during the operation of low-voltage distribution transformer areas. Among existing technologies, the patent with authorization announcement number CN 218124396 U discloses a line loss management device for low-capacity, high-loss distribution transformer areas based on magnetic latching relays. This device sets up a distribution transformer area line loss detection unit at the lower end of each energy meter in the user-side meter box. When the user load is unloaded, it automatically trips and cuts off the power supply and enters a sleep state. When the user load is connected, it wakes up the CPU to perform the closing operation. The power restoration process is controlled within 1 second. It mainly manages the line loss behind the energy meter in the low-voltage distribution transformer area and the standby loss of user equipment.

[0004] However, this solution has significant drawbacks. It cannot address transformer no-load losses or transmission line no-load losses. Transformer no-load losses are iron losses generated when the transformer establishes an alternating magnetic field, including hysteresis losses and eddy current losses. Transmission line no-load losses are heat losses generated by the ground capacitance current flowing through the line in long-distance transmission lines. Furthermore, this solution has limited effectiveness in addressing standby losses of smart devices below the starting current of the electricity meter, and cannot meet the comprehensive line loss management needs under seasonal and periodic power consumption conditions in distribution areas.

[0005] Therefore, there is an urgent need for a comprehensive line loss management solution that can systematically cover the no-load losses of transformers, transmission lines and user smart equipment across the entire chain, without affecting the normal monitoring and data collection of the power grid. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention discloses a line loss management system for seasonal power consumption in transformer substations. The technical solution adopted includes a seasonal load transformer substation line loss management device (LN1001), a seasonal load transformer substation line loss management device (LN1002), and a seasonal load transformer substation line loss management device (LN1003), which together form a three-level management system, corresponding to the management of standby loss of intelligent equipment, no-load loss of transmission lines, and no-load loss of transformers, respectively. The seasonal load distribution area line loss management device (LN1001) is deployed on the user side and adopts a magnetic control closing mechanism. When the user load is detected to be less than 5W, the user's power load is cut off and the device enters a sleep state, while the user load monitoring circuit is activated. When the user load monitoring circuit detects that the user load is greater than 3W, a pulse wake-up signal is generated to wake up the seasonal load distribution area line loss management device (LN1001) and control its built-in switch to close to restore power supply. The seasonal load distribution area line loss management device (LN1002) is deployed on the distribution area side to collect the power load of the distribution area in real time. When it is determined that the user's load power is lower than the set limit and continues for a corresponding period, the power is cut off on the low voltage side of the transformer after manual review and confirmation. The seasonal load distribution area line loss management device (LN1003) is deployed on the high-voltage side of the transformer. It is used to receive commands from the distribution automation system through the FTU and control the closing or opening of the built-in switch to realize the power supply or power cut-off of the transformer. When the transformer is de-energized, the intelligent equipment in the distribution area is switched to the power supply of the voltage transformer on the high-voltage side of the distribution area.

[0007] As a preferred technical solution of the present invention, the seasonal load distribution area line loss management device (LN1001) is based on the smart meter switch, with the addition of a line loss management software module in the software and a load detection circuit, a CPU wake-up circuit and a metering unit in the hardware; the metering unit includes a voltage transformer, a current transformer, a voltage and current sampling circuit and a metering chip; the magnetic control closing mechanism of the seasonal load distribution area line loss management device (LN1001) has a power restoration response time ≤100ms.

[0008] As a preferred embodiment of the present invention, the load detection circuit includes a resistor voltage divider circuit, a differential amplifier circuit, and a voltage comparison circuit; when the user applies a load, a voltage divider signal is generated on the sampling resistor, which is then differentially amplified and compared with a reference voltage to generate a pulse signal for waking up the main control unit of the seasonal load distribution area line loss management device (LN1001).

[0009] As a preferred technical solution of the present invention, the seasonal load distribution area line loss management device (LN1002) adds a line loss management software module to the residual current protection circuit breaker.

[0010] As a preferred technical solution of the present invention, the seasonal load transformer area line loss management device (LN1002) is connected to the distribution transformer terminal (TTU), concentrator or fusion terminal through the NB-IOT communication module, and then sends the judgment result to the distribution automation master station system; after power failure, the seasonal load transformer area line loss management device (LN1002) is closed according to a predetermined cycle through the line loss management APP.

[0011] As a preferred embodiment of the present invention, the seasonal load distribution area line loss mitigation device (LN1003) includes a power supply module, a drive module, and a main control unit; the power supply module is used to provide a stable low-voltage power supply and isolate high-voltage and low-voltage circuits; the drive module is used to perform opening and closing operations and provide feedback on the switch status; the main control unit has logic judgment, protection interlocking, and telemetry, remote signaling, and remote control functions.

[0012] As a preferred technical solution of the present invention, the seasonal load distribution area line loss management device (LN1003) communicates with the distribution automation master station system through FTU and receives closing or opening commands from the master station system; the manual review is a multi-department hierarchical review process, including on-site verification and review by the operation and maintenance team and final review by the dispatch center.

[0013] As a preferred embodiment of the present invention, the seasonal load distribution area line loss management device (LN1001) communicates with the meter box switch via RS485, and the meter box switch communicates with the line loss management APP via NB-IoT; the seasonal load distribution area line loss management device (LN1002) and the seasonal load distribution area line loss management device (LN1003) communicate with the line loss management APP via NB-IoT respectively; the seasonal load distribution area line loss management device (LN1003) also communicates with the concentrator, fusion terminal or TTU terminal via RS485.

[0014] As a preferred technical solution of the present invention, in the voltage transformer power supply mode, the seasonal load distribution area line loss management device (LN1001) is set to the distribution area transformer no-load management mode through the line loss management APP, and the circuit breaker is not closed when the user uses electricity.

[0015] As a preferred embodiment of the present invention, the seasonal load distribution area line loss management device (LN1001) is suitable for managing the line loss after the user's meter and the standby loss of the user's load; the seasonal load distribution area line loss management device (LN1002) is suitable for managing the no-load loss of the transmission line; and the seasonal load distribution area line loss management device (LN1003) is suitable for managing the no-load loss of the transformer and the line loss between the low-voltage side of the transformer and the user's meter.

[0016] The beneficial effects of this invention are: 1. The seasonal load distribution area line loss mitigation device (LN1001) adopts a magnetic control closing mechanism, with a power restoration response time of less than 100ms, ensuring seamless power restoration for users during peak electricity consumption seasons. Compared to the motor closing mechanism of the smart meter's downstream switch, the power restoration response time is approximately 10s, offering a significant advantage. 2. When the seasonal load distribution area line loss management device (LN1003) is put into operation, after the transformer is de-energized, LN1003 will switch the intelligent equipment in the distribution area to the voltage transformer on the high voltage side of the distribution area to meet the power supply of the main meter, concentrator and household meter in the distribution area, and meet the normal collection of marketing data. 3. LN1001 adds a line loss management software module to the existing smart meter switch, and adds a load detection circuit and a CPU wake-up circuit to the hardware. LN1002 adds a line loss management software module to the existing residual current protection circuit breaker. LN1003 optimizes the structure of the voltage transformer on the high-voltage side of the distribution area and adds secondary taps to the voltage transformer. Overall, no new equipment is required, and no modification to the existing JP cabinet and meter box space is needed. 4. Compared with the current solution using magnetic latching relays, by adopting the "integrated design of line loss management module and switch body", it follows higher standards of circuit breaker specifications in terms of fault current breaking capacity, mechanical and electrical life, and material flame retardancy, and the system safety factor is higher. Attached Figure Description

[0017] Figure 1 This is a system architecture block diagram of the present invention;

[0018] Figure 2 This is a system flowchart of the present invention;

[0019] Figure 3 This invention includes a resistor voltage divider circuit, a differential amplifier circuit, and a voltage comparator circuit diagram.

[0020] Figure 4 This is a schematic diagram (red area) of the line loss mitigation range of the seasonal load distribution area line loss mitigation device (LN1001) of the present invention.

[0021] Figure 5 This is a schematic diagram (red area) showing the line loss mitigation range when the seasonal load distribution line loss mitigation device (LN1003) of the present invention is put into operation.

[0022] Figure 6 This is a hardware block diagram of the seasonal load distribution area line loss mitigation device (LN1001) of the present invention;

[0023] Figure 7 This is a circuit diagram of the load monitoring circuit in the seasonal load distribution area line loss mitigation device (LN1001) of the present invention;

[0024] Figure 8 This is a simulation waveform of the wake-up pulse of the load monitoring circuit of the present invention when the load is 3W;

[0025] Figure 9 The simulation waveform diagram of the load monitoring circuit of the present invention at a load of 2.84W is shown.

[0026] Figure 10 This is a simulation waveform of the wake-up pulse of the load monitoring circuit of the present invention when the load is short-circuited (0Ω);

[0027] Figure 11 This invention includes a user load monitoring loop diagram;

[0028] Figure 12 This invention provides a circuit diagram for user load connection without user load monitoring.

[0029] Figure 13 This is a schematic diagram of the impedance parameters of the power cable of the present invention;

[0030] Figure 14 This is a hardware block diagram of the seasonal load distribution area line loss mitigation device (LN1002) of the present invention;

[0031] Figure 15 This is a hardware block diagram of the seasonal load distribution area line loss mitigation device (LN1003) of the present invention;

[0032] Figure 16 This is the user load monitoring loop diagram of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments; the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0034] Example 1 like Figures 1 to 16 As shown, this invention discloses a line loss management system for seasonal power consumption in transformer substations. The technical solution adopted includes a seasonal load transformer substation line loss management device (LN1001), a seasonal load transformer substation line loss management device (LN1002), and a seasonal load transformer substation line loss management device (LN1003), which together form a three-level management system, corresponding to the management of standby losses of intelligent equipment, no-load losses of transmission lines, and no-load losses of transformers, respectively.

[0035] The seasonal load distribution area line loss management device (LN1001) is deployed on the user side and adopts a magnetic control closing mechanism. When the user load is detected to be less than 5W, the user's power load is cut off and the device enters a sleep state, activating the user load monitoring circuit. When the user load monitoring circuit detects that the user load is greater than 3W, a pulse wake-up signal is generated to wake up the seasonal load distribution area line loss management device (LN1001), controlling its built-in switch to close and restore power supply. The seasonal load distribution area line loss management device (LN1001) is based on the smart meter switch, with the addition of a line loss management software module in the software and a load detection circuit and CPU wake-up function in the hardware. The device includes a wake-up circuit and a metering unit; the metering unit comprises a voltage transformer, a current transformer, a voltage and current sampling circuit, and a metering chip; the magnetic control closing mechanism of the seasonal load distribution area line loss management device (LN1001) has a power-on response time ≤100ms; the load detection circuit includes a resistor voltage divider circuit, a differential amplifier circuit, and a voltage comparison circuit; when a user applies a load, a voltage divider signal is generated across the sampling resistor, which is differentially amplified and compared with a reference voltage to generate a pulse signal used to wake up the main control unit of the seasonal load distribution area line loss management device (LN1001); the parameters of the pulse signal are 2.31V~3.3V / 5.8μs;

[0036] The seasonal load distribution area line loss management device (LN1002) is deployed on the distribution area side to collect the power load of the distribution area in real time. When it is determined that the user's load power is lower than the set limit and continues for a corresponding period, the low-voltage side of the transformer is de-energized after manual review and confirmation. The seasonal load distribution area line loss management device (LN1002) is based on the residual current protection circuit breaker, with the addition of a line loss management software module. The hardware adopts a 400A / 630A frame structure and includes a 128×64 dot matrix COG monochrome LCD display module. The seasonal load distribution area line loss management device (LN1002) is connected to the distribution transformer terminal (TTU), concentrator, or fusion terminal through an NB-IoT communication module, and then sends the judgment result to the distribution automation master station system. After the power is de-energized, the seasonal load distribution area line loss management device (LN1002) is closed according to a predetermined period through the line loss management APP.

[0037] The seasonal load distribution area line loss management device (LN1003) is deployed on the high-voltage side of the transformer. It receives commands from the distribution automation system via the FTU and controls the closing or opening of the built-in switch to supply or disconnect power to the transformer. When the transformer is de-energized, the intelligent equipment in the distribution area is switched to be powered by the voltage transformer on the high-voltage side. The seasonal load distribution area line loss management device (LN1003) includes a power supply module, a drive module, and a main control unit. The power supply module provides a stable low-voltage power supply and isolates the high-voltage and low-voltage circuits. The drive module performs opening and closing operations and provides feedback on the switch status. The main control unit has logic judgment, protection interlocking, and telemetry, remote signaling, and remote control functions. The seasonal load distribution area line loss management device (LN1003) communicates with the distribution automation master station system via the FTU and receives closing or opening commands from the master station system. The manual review is a multi-department, tiered review process, including on-site verification and review by the maintenance team and final review by the dispatch center.

[0038] The seasonal load distribution area line loss management device (LN1001) communicates with the meter box switch via RS485, and the meter box switch communicates with the line loss management APP via NB-IoT; the seasonal load distribution area line loss management devices (LN1002) and (LN1003) communicate with the line loss management APP via NB-IoT respectively; the seasonal load distribution area line loss management device (LN1003) also communicates with the concentrator, converged terminal, or TTU terminal via RS485.

[0039] In voltage transformer power supply mode, the seasonal load distribution area line loss management device (LN1001) is set to the distribution area transformer no-load management mode via the line loss management APP, and the circuit breaker is not closed when users consume electricity.

[0040] The seasonal load distribution area line loss management device (LN1001) is suitable for managing line losses after the user's meter and standby losses of the user's load; the seasonal load distribution area line loss management device (LN1002) is suitable for managing no-load losses of transmission lines; the seasonal load distribution area line loss management device (LN1003) is suitable for managing transformer no-load losses and line losses between the transformer's low-voltage side and the user's meter.

[0041] The communication methods between devices are shown in the table below:

[0042] Example 2

[0043] like Figure 4As shown, the seasonal load distribution area line loss mitigation device (LN1001) is an improvement on the commonly used 80A or 125A frame. The software adds a line loss mitigation software module, and the hardware adds a load detection circuit, a CPU wake-up circuit, and a metering unit. The metering unit is similar to the analog quantity acquisition unit of an electricity meter, mainly including voltage and current transformers, voltage and current sampling circuits, and metering chips. Due to the added metering function, the length from the inlet to the outlet is increased by 39mm compared to the external circuit breaker of the electricity meter; this space must be reserved in the meter box design. The business logic of the seasonal load distribution area line loss mitigation device (LN1001) is as follows: 1) When the user load is less than 5W, the seasonal load distribution area line loss management device (LN1001) cuts off the user's power load. At the same time, the seasonal load distribution area line loss management device (LN1001) enters the sleep state and the user load monitoring circuit is activated. Through on-site survey of the seasonal load distribution area, the minimum load of the user's electrical equipment is 5W. This power can be automatically metered and monitored by the seasonal load distribution area line loss management device (LN1001). 2) When the user's load exceeds 3W, a pulse wake-up signal is generated through the user load monitoring circuit to wake up the seasonal load distribution area line loss management device (LN1001). Then, the seasonal load distribution area line loss management device (LN1001) switches off and restores normal power supply to the user load. When the user load is detected to be less than 5W again, the process continues to step 1). The minimum starting metering power of the electricity meter is 4.4W. The main target of the seasonal load distribution area line loss management device (LN1001) is the line loss of small-scale power consumption in the distribution area, such as the standby power consumption of equipment less than 4.4W. Here, the monitoring is set to monitor a 3W user load, which is close to 4.4W and also close to the user's minimum power load. The value is adjustable. 3): When using voltage transformer power supply mode, the seasonal load distribution area line loss management device (LN1003) operates in the distribution area transformer no-load management mode, and does not close when users use electricity to protect the voltage transformer. When using voltage transformer power supply (mode), the line loss management system APP sets the seasonal load distribution area line loss management device (LN1001) to the distribution area transformer no-load management mode through command (via NB-IOT). The scope of the seasonal load transformer area line loss mitigation device (LN1001) is to reduce losses after the user's meter, including the loss of the incoming line and the user's standby load loss. The applicable scenarios for the seasonal load transformer area line loss mitigation device (LN1001) are: scenarios where the transformer area load is small and the user's standby loss is large. Compared to the external circuit breaker of the electricity meter, the seasonal load distribution area line loss management device (LN1001) adds a metering unit, and the length from the incoming end to the outgoing end is increased by 39mm. The 39mm is the length increase from the incoming end to the outgoing end of the seasonal load distribution area line loss management device (LN1001) due to the addition of the metering function.

[0044] like Figure 12 As shown, the seasonal load distribution area line loss management device (LN1002) is an improvement on the existing residual current protection circuit breaker. The software adds a line loss management software module, and the hardware adopts a 400A / 630A frame structure, which is generally placed in the meter box. Compared with the 80A / 125A frame of the seasonal load distribution area line loss management device (LN1001), it has a larger overcurrent capacity. The seasonal load distribution area line loss management device (LN1002) adds a 128×64 dot matrix COG monochrome LCD display module for local information display. The business logic of the seasonal load distribution area line loss mitigation device (LN1002) is as follows: The seasonal load distribution area line loss management device (LN1002) collects the power load of the distribution area in real time. When it is in the off-season setting range, if it is determined that the user's load power is lower than the setting limit, it sends the judgment result that the transformer high-voltage side switch can be cut off to the distribution automation master station system through the distribution transformer terminal TTU, concentrator or fusion terminal. The user load power is monitored by the metering function built into the seasonal load distribution area line loss management device (LN1002); when the user load power is detected to be lower than the set value, the high-voltage side switch of the transformer is cut off through the link of NB-IOT, distribution transformer terminal TTU, distribution automation master station system, and seasonal load distribution area line loss management device (LN1003). The distribution automation master station system is the core command and decision-making center of the entire distribution automation system. It undertakes the functions of monitoring, controlling, analyzing and managing the operation status of the distribution network, and is a key platform for realizing the "observable, measurable and controllable" distribution network.

[0045] like Figure 13 As shown, the seasonal load distribution area line loss mitigation device (LN1003) is deployed on the high-voltage side of the transformer. It optimizes the structure of the voltage transformer on the high-voltage side of the distribution area and adds taps on the secondary side of the voltage transformer to provide backup power. LN1003 includes a power supply module that provides a stable low-voltage power supply, isolates high and low voltage circuits, and has surge protection, undervoltage / overvoltage protection, a drive module that performs opening and closing and provides status feedback, and a main control unit (with logic judgment, protection interlocking, telemetry / telecommunication / remote control functions). The business logic of the seasonal load distribution area line loss mitigation device (LN1003) is as follows: 1) After a user's electricity application is manually reviewed and approved, the distribution automation master station system sends a command through the FTU to the seasonal load distribution area line loss management device (LN1003) to supply power to the transformer; 2): When the seasonal load distribution area line loss management device (LN1002) determines that the user's load power is lower than the limit and passes manual review, the system sends a command to the FTU to the seasonal load distribution area line loss management device (LN1003) to cut off the power to the transformer; 3): When the transformer is de-energized, the seasonal load distribution area line loss management device (LN1003) will switch the intelligent equipment in the distribution area to the voltage transformer on the high-voltage side of the distribution area for power supply. Combined with the seasonal load distribution area line loss management device (LN1002), it supports closing the circuit according to the predetermined cycle, ensuring the normal operation of the concentrator, main meter, and household meter, and supporting the normal collection of marketing data. After a user applies for electricity and it is approved by manual review, the distribution automation system uses the FTU to close the high-voltage side switch of the transformer in the distribution area. This is a closed-loop operation involving multiple terminals, including the marketing business system, the distribution automation master station, the field FTU, and the high-voltage switch. It ensures both power supply safety and process compliance. Specifically, after the electricity application is submitted and the basic information is verified, it undergoes multi-departmental manual review, such as on-site verification and review by the maintenance team and final review by the dispatch center. Then, the distribution automation master station preprocesses and issues instructions, such as parameter verification, generation of standardized instructions, and instruction issuance. Next, the instructions are verified and prepared for execution by the FTU, such as legality verification, pre-judgment of operating conditions, and feedback. The FTU drives the high-voltage switch to close, and the status feedback and process closure include on-site status upload, master station confirmation and archiving, and on-site verification by the maintenance team. The scope of the seasonal load transformer area line loss mitigation device (LN1003) is to reduce the overall loss of the distribution transformer area, including: power distribution, transformer no-load loss, low-voltage side power distribution, transformer, line loss between the transformer and the meter, and loss after the meter. The applicable scenarios for the seasonal load transformer area line loss mitigation device (LN1003) are: suitable for transformer areas that have no electricity demand for a long period of time due to seasonality, and for scenarios where the transformer can be shut down.

[0046] Simulation Experiment 1

[0047] Hardware solution for seasonal load distribution area line loss mitigation device (LN1001), such as Figure 6 As shown, the main functional circuits in the circuit module are the load monitoring circuit, the metering circuit, and the electromagnet opening and closing drive circuit; the other circuit modules are commonly used circuit modules.

[0048] The newly added circuit in this design is the user load monitoring circuit. When the user load is detected to be ≥3W, a pulse wake-up signal is generated to wake up the CPU. The seasonal load line loss mitigation device (LN1001) switch circuit closes, restoring power supply to the user load. The electromagnet opening and closing drive circuit mainly consists of a relay drive circuit and an AC220V rectifier circuit. The relay drive circuit controls the opening and closing of AC220V, and the rectifier circuit converts AC220V to DC. The metering circuit mainly consists of a current CT transformer, voltage and current sampling circuits, and peripheral circuits of the metering chip HT7132, used to collect voltage, current, and power data.

[0049] Simulation of the load monitoring loop wake-up signal, see attached. Figure 7 As shown;

[0050] When the equivalent load is 16.2KΩ / 3W, the comparison voltage is set to 4.6V. The sampling voltage obtained through sampling circuit R1 is compared with the set voltage input, generating a pulse signal of 2.57V / 1ms. (See attached diagram) Figure 8 As shown;

[0051] When the equivalent load is 17KΩ / 2.84W, and the comparison voltage is set to 4.6V, the sampling voltage obtained through sampling circuit R1 is compared with the set voltage input, generating a pulse signal of -10.49mV / 1ms; it cannot be woken up, see appendix. Figure 9 As shown;

[0052] When the equivalent load is 0Ω / infinite power, the sampling resistor signal is 6V, the set comparison voltage is 4.6V, and the sampling voltage obtained through sampling resistor R1 is compared with the set voltage input, generating a pulse signal of 4.02V / 2ms; it can be woken up, see appendix. Figure 10 As shown;

[0053] The simulation table of wake-up power for the load monitoring loop is as follows:

[0054] As shown in the table above, when the user load input is ≥3W, the user load monitoring circuit can generate a pulse wake-up signal to wake up the CPU, and the seasonal load distribution area line loss management device (LN1001) will perform a closing operation to restore power supply to the user load.

[0055] Simulation comparison of user standby load power consumption with and without user load monitoring loop:

[0056] Simulations were performed on the standby load of users downstream of the meter, assuming the user load monitoring circuit is activated, the user load standby power consumption is 2.9W / 3W, and the distance from the meter to the user load switch is 500 meters. Cable electrical parameters are attached. Figure 11 As shown, simulations are performed for six different scenarios. The simulation principles and structures are detailed in the appendix. Figure 12, 13 As shown;

[0057] Traditional power supply mode, no-load LN001 line loss management device

[0058] Install LN001 line loss mitigation device

[0059] Based on the comparison of the above simulation data:

[0060] When the user load is ≥3W, the user load monitoring circuit can wake up the seasonal load distribution area line loss management device (LN1001) and perform a closing operation. At this time, the user load monitoring circuit is disconnected. The seasonal load distribution area line loss management device (LN1001) measures that the user's actual power is 4.48W, which is greater than the starting metering power of the electricity meter of 4.4W. At this time, the user load can be metered by the electricity meter.

[0061] When the user standby load is less than 3W, such as 2.9W, the standby power consumption of the entire circuit with the user load monitoring loop is 1.35W, and the user standby power consumption of the entire circuit without the user load monitoring loop is 4.35W. The user load monitoring loop cannot wake up the seasonal load distribution area line loss management device (LN1001) and is still in a dormant state. At this time, the user load standby power consumption is reduced by 4.35W-1.35W=3W. The maximum loss that the seasonal load distribution area line loss management device (LN1001) can manage is approximately 4.35W-1.35W=3W.

[0062] See attached Figure 16 As shown in the figure, the circuit is a newly added user load monitoring circuit. In the AC 220V circuit, the circuit mainly includes a resistor voltage divider circuit and a comparator circuit. On the AC 220V circuit, a voltage signal is generated by sampling the resistor, and then compared with the negative terminal of the comparator to generate a pulse signal. Through calculation and simulation, the adjustment resistor R20 is 36.7kΩ and the sampling resistor R22 is 560Ω. When the user load is ≥16.2kΩ (3W), it just generates the CPU wake-up pulse signal.

[0063] Simulation treatment results

[0064] When the user load is disconnected, the user line loss is 72.6uW regardless of whether there is a user load monitoring loop;

[0065] When the user load is 2.9W, the maximum standby power consumption that the entire circuit can manage is 4.35W - 1.35W - 72.6uW ≈ 3W (2.9W standby user load).

[0066] Simulation Experiment 2

[0067] Taking the power supply area for agricultural irrigation as an example, its power parameters and power load characteristics are as follows:

[0068] 1. The typical capacity of a distribution transformer is 200KVA;

[0069] 2. The typical length of the transmission line is 500m;

[0070] 3. The typical number of users is 20.

[0071] 4. The maximum current of the user's electricity meter is 60A, the Class B starting current is 0.02A, and billing is only possible for a minimum power of 4.4W. Under the above typical circuit, when the user's standby load is 2.9W, the standby loss of the smart device + the no-load loss of the transmission line = 4.35W, and the electricity meter cannot bill normally; when the user's standby load is 3W, the standby loss of the smart device and the no-load loss of the transmission line = 4.48W, and the electricity meter bills normally. Set the wake-up power threshold of LN1001 to 3W; see the results of simulation experiment 1.

[0072] 5. According to GB 20052-2024 "Minimum Allowable Values ​​of Energy Efficiency and Energy Efficiency Grades for Power Transformers", the no-load line loss limit for a 10kV / 200KVA oil-immersed distribution transformer is 190W.

[0073] 6. When the user switch is off, the no-load loss of the transmission line is 72.6uW per household; see the results of simulation experiment 1;

[0074] 7. Without the seasonal load distribution area line loss mitigation device (LN1001), when the standby load of the user's smart device is 2.9W, the no-load loss of the transmission line + the standby loss of the smart device = 4.35W, which is less than the minimum starting power of the electricity meter of 4.4W and cannot be measured. With the seasonal load distribution area line loss mitigation device (LN1001) configured, the load detection circuit is activated, and when the standby load of the user's smart device is 2.9W, the no-load loss of the transmission line + the standby loss of the smart device = 1.35W, which is equivalent to achieving 3W of no-load mitigation per household; see the results of simulation experiment 1.

[0075] 8. The seasonal load distribution area line loss management device (LN1003) was put into operation. According to statistics, the annual time for transformer no-load loss management, transmission line no-load loss, and intelligent equipment standby loss is 120 days; 120*(190+20*0.6(electricity meter loss)+20*4.35(standby loss of 2.9W user load and line)) = 832.32kWh;

[0076] 9. The seasonal load distribution area line loss management device (LN1003) was put into operation. According to statistics, the standby loss management time for each household's smart devices is 90 days per year; 90*(20*(4.35-1.35)(difference between the normal load return line loss and the return line loss detected by LN1003 when the 2.9W user load is on standby)) = 129.6kWh;

[0077] The annual no-load line loss management system for seasonal electricity consumption in the distribution area manages 974.88 kWh of line loss annually, with the line loss rate in the distribution area below 5%, ensuring that the line loss data in the distribution area meets the requirements of the power grid.

[0078] The circuit connection involved in this invention is a conventional method used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments. It belongs to the widely used prior art.

[0079] Components not described in detail in this article are existing technologies.

[0080] While the specific embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and modifications or variations without creative effort are still within the protection scope of the present invention.

Claims

1. A line loss management system for seasonal power consumption in transformer substations, characterized in that, The system includes three devices: seasonal load transformer area line loss management device (LN1001), seasonal load transformer area line loss management device (LN1002), and seasonal load transformer area line loss management device (LN1003). Together, they form a three-level management system, which respectively manages the standby loss of intelligent equipment, the no-load loss of transmission lines, and the no-load loss of transformers. The seasonal load distribution area line loss management device (LN1001) is deployed on the user side and adopts a magnetic control closing mechanism. When the user load is detected to be less than 5W, the user's power load is cut off and the device enters a sleep state, while the user load monitoring circuit is activated. When the user load monitoring circuit detects that the user load is greater than 3W, a pulse wake-up signal is generated to wake up the seasonal load distribution area line loss management device (LN1001) and control its built-in switch to close to restore power supply. The seasonal load distribution area line loss management device (LN1002) is deployed on the distribution area side to collect the power load of the distribution area in real time. When it is determined that the user's load power is lower than the set limit and continues for a corresponding period, the power is cut off on the low voltage side of the transformer after manual review and confirmation. The seasonal load distribution area line loss management device (LN1003) is deployed on the high-voltage side of the transformer. It is used to receive commands from the distribution automation system through the FTU and control the closing or opening of the built-in switch to realize the power supply or power cut-off of the transformer. When the transformer is de-energized, the intelligent equipment in the distribution area is switched to the power supply of the voltage transformer on the high-voltage side of the distribution area.

2. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: The seasonal load distribution area line loss management device (LN1001) is based on the smart meter switch, with the addition of a line loss management software module in the software and a load detection circuit, a CPU wake-up circuit, and a metering unit in the hardware. The metering unit includes a voltage transformer, a current transformer, a voltage and current sampling circuit, and a metering chip. The magnetic control closing mechanism of the seasonal load distribution area line loss management device (LN1001) has a power restoration response time of ≤100ms.

3. A line loss management system for seasonal power consumption in transformer substations according to claim 2, characterized in that: The load detection circuit includes a resistor voltage divider circuit, a differential amplifier circuit, and a voltage comparison circuit. When the user applies a load, a voltage divider signal is generated on the sampling resistor. After differential amplification, the signal is compared with the reference voltage to generate a pulse signal used to wake up the main control unit of the seasonal load distribution area line loss management device (LN1001).

4. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: The seasonal load distribution area line loss management device (LN1002) is based on the residual current protection circuit breaker, with the addition of a line loss management software module.

5. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: The seasonal load distribution area line loss management device (LN1002) is connected to the distribution transformer terminal (TTU), concentrator, or fusion terminal via an NB-IoT communication module, and then sends the judgment results to the distribution automation master station system; after power failure, the seasonal load distribution area line loss management device (LN1002) is closed according to a predetermined cycle through the line loss management APP.

6. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: The seasonal load distribution area line loss mitigation device (LN1003) includes a power supply module, a drive module, and a main control unit. The power supply module is used to provide a stable low-voltage power supply and isolate high-voltage and low-voltage circuits. The drive module is used to perform opening and closing operations and provide feedback on the switch status. The main control unit has logic judgment, protection interlocking, and telemetry, remote signaling, and remote control functions.

7. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: The seasonal load distribution area line loss management device (LN1003) communicates with the distribution automation master station system via FTU and receives closing or opening commands from the master station system; the manual review is a multi-department hierarchical review process, including on-site verification and review by the operation and maintenance team and final review by the dispatch center.

8. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: The seasonal load distribution area line loss management device (LN1001) communicates with the meter box switch via RS485, and the meter box switch communicates with the line loss management APP via NB-IoT; the seasonal load distribution area line loss management devices (LN1002) and (LN1003) communicate with the line loss management APP via NB-IoT respectively; the seasonal load distribution area line loss management device (LN1003) also communicates with the concentrator, converged terminal or TTU terminal via RS485.

9. A line loss management system for seasonal power consumption in transformer substations according to claim 1, characterized in that: In the voltage transformer power supply mode, the seasonal load distribution area line loss management device (LN1001) is set to the distribution area transformer no-load management mode through the line loss management APP, and the circuit breaker is not closed when the user uses electricity.

10. A line loss management system for seasonal power consumption in transformer substations according to any one of claims 1-9, characterized in that: The seasonal load distribution area line loss management device (LN1001) is suitable for managing line losses after the user's meter and standby losses of the user's load; the seasonal load distribution area line loss management device (LN1002) is suitable for managing no-load losses of transmission lines; the seasonal load distribution area line loss management device (LN1003) is suitable for managing transformer no-load losses and line losses between the transformer's low-voltage side and the user's meter.

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