Mine belt conveyor load side light storage load dynamic electric energy distribution scheduling method and system

Abstract

The application discloses a kind of mine belt conveyor load side's light storage load dynamic electric energy distribution scheduling method and system, it is related to the electric energy scheduling and control field of mine belt conveyor power supply system, the method includes: obtaining mine belt conveyor scheduling parameter;And according to the comparison relationship of motor real-time electric power demand and rated power or according to motor speed state, determine motor operating state;According to the remaining time length of current time distance daily electricity price peak section end and battery temperature, calculate the dynamic threshold of discharge minimum allowable state of charge and charge upper limit state of charge;According to current electricity price period and motor operating state, according to the preset priority logic decision storage battery charge-discharge power instruction, and determine grid difference power based on power balance relationship;The charge-discharge power instruction is issued to energy storage converter, and before issuing, according to the safety clamping check of equipment hard limit value and motor operating state to charge-discharge power instruction execution, improve photovoltaic consumption rate, reduce electricity cost.

Description

Technical Field

[0001] This application relates to the field of power dispatching and control of power supply systems for mine belt conveyors, and in particular to a method and system for dynamic power distribution and dispatching of photovoltaic power storage on the load side of a mine belt conveyor. Background Technology

[0002] Conveyor belt conveyors in mining areas mostly operate in open-air and semi-open-air environments, and rooftops, parking sheds, and slopes can be used to deploy photovoltaic arrays. Theoretically, electricity costs can be reduced through a model of "photovoltaic priority for self-consumption + surplus electricity for battery storage + off-peak electricity for charging". However, in actual engineering, the application of photovoltaic + energy storage for belt conveyor power supply has long remained at two levels: 1) Coarse power supply level: solar panel → battery → inverter → belt conveyor, only performing on-off switching of "use when there is sunshine, disconnect from the grid when there is no sunshine", without continuous power distribution, low photovoltaic absorption rate (20%~50%), and batteries often miss peak arbitrage windows or have their lifespan shortened due to rigid thresholds of fixed 30% lower limit / 80% upper limit; 2) Pure scheduling calculation level: establish a day-ahead optimization model of belt conveyor + photovoltaic + battery (such as mixed integer programming) to calculate "what belt speed to set for the conveyor and how much to charge and discharge the battery" for each period of 24 hours. However, this type of solution treats the belt conveyor load as a preset curve or a freely adjustable variable, ignoring a hard fact - the belt speed of the belt conveyor in mining production cannot be arbitrarily increased or decreased significantly (material accumulation, risk of blockage), and its actual instantaneous power of the motor fluctuates in real time, which cannot be accurately locked by the day-ahead plan.

[0003] One related technology proposes using changes in coal bunker level as "virtual energy storage" capacity, establishing a joint economic dispatch model for belt conveyors, fans, photovoltaics, and virtual energy storage, and solving day-ahead optimization schemes through nonlinear programming. However, it suffers from the following drawbacks: limited power regulation capability of "virtual energy storage"; reliance on day-ahead forecasting without real-time power closed-loop feedback; and reliance on belt speed regulation, conflicting with the rigid constraints of mine production. Another related technology proposes integrating photovoltaic modules and batteries onto the belt conveyor, using a control module to achieve power supply management of "direct photovoltaic supply when photovoltaics are sufficient, switching to batteries or the grid when photovoltaics are insufficient," but it lacks a continuous power allocation model. Yet another related technology proposes real-time collection of sunlight, temperature, and load data, simulating photovoltaic output through probability distribution, and then comparing photovoltaic output with load demand to determine the charging and discharging state of energy storage; however, its load model lacks the specific characteristics of belt conveyors. Summary of the Invention

[0004] The purpose of this application is to provide a method and system for dynamic power distribution and scheduling of photovoltaic power storage on the load side of a mine belt conveyor, which can improve the photovoltaic absorption rate and reduce electricity costs.

[0005] To achieve the above objectives, this application provides the following solution.

[0006] In a first aspect, this application provides a method for dynamic power distribution and scheduling of photovoltaic power storage on the load side of a mine conveyor belt, including: The system obtains real-time available active power output of photovoltaic power, real-time power demand of belt conveyor motor, state of charge and battery temperature of energy storage battery, and current electricity price period by means of preset scheduling cycle or event triggering method; and determines whether the motor is in start-up state or steady-state operation state based on the comparison between the real-time power demand of motor and rated power, or based on the motor speed state. Based on the remaining time before the end of the peak electricity price period, a first dynamic threshold for the minimum permissible state of charge during discharge is calculated; the first dynamic threshold increases monotonically with the remaining time and is corrected for by the battery temperature; a second dynamic threshold for the upper limit of the state of charge during charging is calculated based on the battery temperature. Based on the current electricity price period and motor operating status, the system determines the charging and discharging power commands for the energy storage battery according to a preset priority logic, and determines the grid compensation power based on the power balance relationship. Specifically, during peak electricity price periods and when the motor is in steady-state operation, the preset priority logic prioritizes photovoltaic power output to meet the load, with the shortfall being compensated by the energy storage battery discharge, and discharge is only allowed when the current state of charge of the energy storage battery is higher than a first dynamic threshold. During peak electricity price periods and when the motor is running, the energy storage battery discharge is forcibly prohibited. During off-peak electricity price periods, the grid is allowed to simultaneously supply power to the load and charge the energy storage battery. During flat electricity price periods, the system performs gentle charging and discharging or puts the energy storage battery into standby mode based on the current state of charge of the energy storage battery. The charging and discharging power command is sent to the energy storage converter, and a safety clamping verification is performed on the charging and discharging power command based on the equipment hard limit and the motor operating status before the command is sent.

[0007] Secondly, this application provides a dynamic power distribution and scheduling system for photovoltaic power storage on the load side of a mine conveyor belt, used to implement the aforementioned dynamic power distribution and scheduling method for photovoltaic power storage on the load side of a mine conveyor belt, including: Photovoltaic power generation modules are used to convert solar energy into electrical energy and output real-time usable photovoltaic active power. The energy storage module includes an electrochemical energy storage battery pack, a battery management system, and a bidirectional energy storage converter. The battery management system outputs the state of charge, battery temperature, and health status of the energy storage battery. The bidirectional energy storage converter is used to switch between charging and discharging modes in a controlled manner. The belt conveyor load module includes a three-phase asynchronous motor driven by a frequency converter and a belt conveyor. The frequency converter side is equipped with a power detection unit for real-time acquisition of the real-time power demand of the belt conveyor motor. The main control and scheduling controller reads the real-time available active power output of photovoltaics, the real-time power demand of motors, the state of charge of energy storage batteries, battery temperature and current electricity price period according to the preset scheduling cycle or event triggering method, performs dynamic threshold calculation and power supply priority decision, and sends charging and discharging power commands to the bidirectional energy storage converter. The main control scheduling controller is programmed to forcibly prevent the energy storage battery from discharging when the motor is running.

[0008] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a dynamic power allocation and scheduling method and system for photovoltaic-storage load on the load side of a mining conveyor belt. By clearly distinguishing the motor into "start-up state" and "steady-state operation state", and forcibly executing the "start-up period no-discharge" logic in the decision-making steps of the energy storage battery's charging and discharging power command and safety clamping verification steps, the algorithm avoids the risk of bus voltage collapse and inverter tripping caused by mis-discharge during the high current impact period of motor start-up in traditional photovoltaic-storage systems. This hard constraint based on real-time physical state (rather than simple time planning) improves the power supply reliability of the special high-inertia load of the mining conveyor belt from "experience guarantee" to "logic-forced guarantee" when connected to the photovoltaic-storage system, completely eliminating the risk of power outage during grid connection switching. The first dynamic threshold (discharge lower limit) is not a fixed value, but increases monotonically with the "remaining peak time length of the day". This gives the energy storage system "forward-looking" intelligence: when there is still a long time before the end of the peak period, it automatically raises the discharge threshold, forcibly reserving power to cope with the arbitrage of the subsequent longer peak periods; when the peak period is about to end, it automatically lowers the threshold to fully release the remaining power. Compared with the "one-size-fits-all" approach of a fixed threshold, this mechanism can adaptively adjust the power consumption strategy to ensure that the limited battery capacity always serves the period with the highest electricity price, thereby significantly reducing the overall electricity cost over the entire day and solving the pain point of "over-discharging in the early stage of the peak period and having no power to discharge in the later stage of the peak period" in traditional solutions; it decides the charging and discharging power commands of the energy storage battery according to a preset priority logic, and based on the power... The power balance relationship determines the grid compensation power, abandoning the traditional "day-ahead forecasting plan" or "binary on / off logic". During steady-state peak periods, a rigid priority of "direct photovoltaic supply → energy storage compensation → grid backup" is enforced, and the instantaneous power balance equation is strictly followed. This mechanism ensures that photovoltaic output can be preferentially consumed locally (directly supplied to load) under any instantaneous fluctuations. Excess electricity is stored through charging instructions during valley and flat periods, avoiding curtailment. At the same time, the grid always acts as the final backup, which not only ensures the continuity of power supply, but also improves the local photovoltaic consumption rate to the optimal level in engineering, significantly reducing the proportion of purchased thermal power and directly bringing about a substantial reduction in carbon emissions. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 A flowchart illustrating a dynamic power distribution and scheduling method for photovoltaic power storage on the load side of a mine conveyor belt, provided as an embodiment of this application; Figure 2 This is a schematic diagram of a dynamic power distribution and scheduling system for the load side of a mine conveyor belt, provided as an embodiment of this application. Detailed Implementation

[0010] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0011] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0012] In one exemplary embodiment, such as Figure 1 As shown, a dynamic power distribution and scheduling method for photovoltaic power storage on the load side of a mine belt conveyor is provided, which includes the following steps 201 to 204.

[0013] Step 201: Obtain the real-time available active power output of photovoltaic power, the real-time power demand of the belt conveyor motor, the state of charge and battery temperature of the energy storage battery, and the current electricity price period by means of a preset scheduling cycle or event triggering method; and determine whether the motor is in the starting state or the steady-state operation state based on the comparison between the real-time power demand of the motor and the rated power, or based on the motor speed state.

[0014] Step 202: Calculate the first dynamic threshold for the minimum allowable state of charge of discharge based on the remaining time before the end of the peak electricity price period of the day; the first dynamic threshold increases monotonically with the increase of the remaining time and is corrected by the battery temperature; calculate the second dynamic threshold for the upper limit of the state of charge of charging based on the battery temperature.

[0015] Step 203: Based on the current electricity price period and motor operating status, determine the charging and discharging power command of the energy storage battery according to the preset priority logic, and determine the grid compensation power based on the power balance relationship. The preset priority logic is as follows: During peak electricity price periods and when the motor is in steady-state operation, photovoltaic power output is prioritized to meet the load, and the insufficient part is prioritized to be supplemented by the discharge of the energy storage battery, and discharge is only allowed when the current state of charge of the energy storage battery is higher than the first dynamic threshold; During peak electricity price periods and when the motor is in the starting state, the discharge of the energy storage battery is forcibly prohibited; During off-peak electricity price periods, the grid is allowed to supply power to the load and charge the energy storage battery at the same time; During flat electricity price periods, perform gentle charging and discharging or put the energy storage battery into standby mode according to the current state of charge of the energy storage battery.

[0016] Step 204: Send the charging and discharging power command to the energy storage converter, and perform a safety clamping verification on the charging and discharging power command according to the equipment hard limit and the motor operating status before sending it.

[0017] By implementing steps 201 to 204 above, the motor is clearly distinguished into "start-up state" and "steady-state operation state," and the "start-up period no-discharge" logic is enforced in the decision-making steps for the charging and discharging power of the energy storage battery and the safety clamping verification steps. This avoids the risk of bus voltage collapse and inverter tripping caused by mis-discharge during the high current surge period of motor startup in traditional photovoltaic energy storage systems from the source of the algorithm. This hard constraint based on real-time physical state (rather than simple time planning) improves the power supply reliability of the special large inertia load of the mine belt conveyor from "experience-based guarantee" to "logic-forced guarantee" when connected to the photovoltaic energy storage system, completely eliminating the risk of power outage during grid connection switching. The first dynamic threshold (discharge lower limit) is not a fixed value, but increases monotonically with the "remaining peak time length of the day." This gives the energy storage system "forward-looking" intelligence: when there is still a long time before the end of the peak period, it automatically raises the discharge threshold, forcibly reserving power to cope with the arbitrage of the subsequent longer peak periods; when the peak period is about to end, it automatically lowers the threshold to fully release the remaining power. Compared with the "one-size-fits-all" approach of a fixed threshold, this mechanism can adaptively adjust the power consumption strategy to ensure that the limited battery capacity always serves the period with the highest electricity price, thereby significantly reducing the overall electricity cost over the entire day and solving the pain point of "over-discharging in the early stage of the peak period and having no power to discharge in the later stage of the peak period" in traditional solutions; it decides the charging and discharging power commands of the energy storage battery according to a preset priority logic, and based on the power... The power balance relationship determines the grid compensation power, abandoning the traditional "day-ahead forecasting plan" or "binary on / off logic". During steady-state peak periods, a rigid priority of "direct photovoltaic supply → energy storage compensation → grid backup" is enforced, and the instantaneous power balance equation is strictly followed. This mechanism ensures that photovoltaic output can be preferentially consumed locally (directly supplied to load) under any instantaneous fluctuations. Excess electricity is stored through charging instructions during valley and flat periods, avoiding curtailment. At the same time, the grid always acts as the final backup, which not only ensures the continuity of power supply, but also improves the local photovoltaic consumption rate to the optimal level in engineering, significantly reducing the proportion of purchased thermal power and directly bringing about a substantial reduction in carbon emissions.

[0018] Each scheduling step in the dynamic power allocation and scheduling process of photovoltaic storage and load follows the basic power balance equation: ;in, for The real-time available active power output of the photovoltaic array after passing through the MPPT controller at any given moment is expressed in kW. This refers to the actual charge and discharge power of the energy storage battery. for The grid compensation power at any given time, i.e., the grid-side output power; for The actual power demand of the belt conveyor motor at any given time is calculated from the three-phase voltage and current sampling. Alternatively, it can be calculated from the DC bus power of the frequency converter. The calculation formula is used in a three-phase balanced power frequency AC system to calculate the active power of the three-phase asynchronous motor on the input side of the belt conveyor frequency converter in real time. The three-phase line voltage (in V) is the effective value of the voltage between any two live wires at the input of the frequency converter. The standard for mining industrial sites is 380V / 400V, which is obtained by real-time sampling from a three-phase voltage transformer. The three-phase line current (unit: A) is the effective value of the current of a single live wire input to the frequency converter. It is obtained in real time by sampling through a three-phase current transformer (CT) installed on the input side of the frequency converter. It is the core data acquisition quantity for determining load change. For motor power factor, The phase difference between line voltage and line current represents the ratio of active power to apparent power of the motor. The phase difference is typically 0.80 to 0.88 for asynchronous motors operating in steady state. The power factor will decrease significantly during the startup phase. It can be read from the internal register of the frequency converter or calculated in real time using voltage, current, and reactive power.

[0019] Without relying on current transformers, the actual power demand of the belt conveyor motor can be calculated using the DC bus parameters of the frequency converter: in, This refers to the inverter power. This refers to the DC bus voltage of the frequency converter. This refers to the DC bus output current of the frequency converter; applicable scenarios: when it is not possible to install voltage or current transformers on the AC incoming line, it allows direct reading of the DC bus power register inside the frequency converter, simplifying on-site sampling and wiring. Agreement: Discharge (supply to the busbar) when the value is >0. Charging when the voltage is below 0 (drawn from the busbar). It can operate with either positive (purchased electricity) or zero (islanded / prohibited from purchasing). When the output of photovoltaic + energy storage is insufficient to cover the load of the conveyor belt, the grid will supplement the remaining power gap. Representing the power grid in purchasing and supplying electricity to the plant's load; This indicates that there is no power grid supply.

[0020] Preset scheduling cycle mode: The timed periodic trigger is the system's normal steady-state scheduling mechanism. The system completes a full round of data acquisition and power distribution calculation at fixed times according to a preset fixed cycle of 1 minute to 10 minutes. It is suitable for normal operating conditions where the belt conveyor load is stable and there is no obvious power fluctuation, ensuring the continuous and regular optimized operation of the system.

[0021] Event-triggered mode is a dynamic refresh mechanism relative to fixed-cycle scheduling. It specifically refers to the system monitoring abnormal operating conditions such as sudden load changes in the belt conveyor outside of the regular timed scheduling cycle. Once a sudden load change event is determined to have occurred, the scheduling strategy is refreshed and the power allocation instructions are recalculated immediately without waiting for the original scheduling cycle to expire.

[0022] The specific determination and triggering rules for the event triggering method are as follows: The system continuously collects the real-time power of the conveyor belt motor and calculates the fluctuation deviation of the real-time power relative to its moving average. When the jump amplitude of the real-time power of the motor relative to its moving average exceeds ±30% within at least three consecutive sampling periods, it is determined that a load change event has occurred on the conveyor belt. This immediately triggers a new three-port power allocation and scheduling calculation, and updates the energy storage charging and discharging power commands and grid replenishment strategies in real time. This event triggering mechanism is designed specifically for the characteristics of large fluctuations in the operating conditions of mine conveyor belts and frequent material step disturbances. It can solve the problems of fixed-period scheduling being unable to respond to instantaneous load changes and scheduling lag, realize dynamic following and matching of the power of the photovoltaic, energy storage, and load three ports, and improve the system's power supply stability and real-time photovoltaic absorption capacity.

[0023] The two triggering methods mentioned above (preset scheduling cycle or event triggering method) take into account the economic scheduling of the smooth operation of the mine belt conveyor and the dynamic adaptability under sudden working conditions through the dual-layer triggering logic of "steady-state timed update and sudden change instant update", and completely avoid the lag defects of fixed cycle scheduling.

[0024] Step 201 above is the real-time sensing step. The real-time available active power output is read from the photovoltaic inverter communication port via the RS485 / Modbus RTU protocol, with an update cycle of 1 second. The real-time power demand of the belt conveyor motor is obtained through real-time sampling and calculation using a three-phase current transformer mounted on the inverter side, or through the DC bus voltage V inside the inverter. dc With bus current I dc The product P dc =V dc ·I dc Equivalent calculations are used, independent of the load curve setpoints of the current day plan. When the real-time power demand of the motor relative to its sliding average changes by more than a preset abrupt change threshold (which can be ±30%) over multiple consecutive sampling periods (N consecutive sampling periods, N≥3), a load abrupt change event is determined to have occurred, triggering an early refresh of the event in the scheduling cycle (skipping the remaining timed wait). The actual power demand of the belt conveyor motor is calculated in real time by sampling the three-phase current and line voltage using three-phase current transformers mounted on the input or output wires of the frequency converter. Specifically, this can be calculated from the three-phase power sampled by the CT (or by reading the DC bus power or active power reading from the active power register inside the frequency converter). When N consecutive sampling periods (N≥3) occur... When the change in the relative sliding mean exceeds ±30%, a load surge is identified, triggering an event to refresh the scheduling cycle. The state of charge (SOC(t)) and battery temperature of the energy storage battery are read via the Battery Management System (BMS) and the CANopen protocol. State of Health (SOH) is updated every 100ms. The local peak-valley electricity price table is checked via the Real-Time Clock (RTC) to determine the current electricity price period. {VALLEY, FLAT, PEAK}, supporting dynamic adjustment of time periods by week and holiday. The energy storage batteries are lithium iron phosphate (LiFePO4), lithium titanate, or sodium-ion batteries, with a nominal single-cell voltage of 3.2V and a nominal system voltage of 48V~240V after series and parallel connection, and a cycle life ≥4000 cycles; the BMS publishes SOC(t) and maximum single-cell voltage V to the main control and scheduling controller via CAN2.0 or RS485 / Modbus. cell_max Battery temperature T bat .

[0025] The motor operating status is distinguished based on the collected real-time electrical power and speed signals: if the real-time electrical power of the motor exceeds 1.3 times the rated power, or if the motor speed is in the starting phase of gradually increasing from zero, the motor operating status is marked as the starting state, i.e., the motor is set to start. state =STARTING (starting state); if the above conditions are not met, the motor's operating state will be uniformly marked as a stable operating state, i.e., the motor will be set to STARTING. state =STEADY (Stable operating state).

[0026] Two types of motor operating status flags are set up, corresponding to different operating conditions of the belt conveyor, for use in executing differentiated control logic in subsequent power allocation scheduling. This application achieves a hierarchical scheduling logic of "ensuring safety during startup and ensuring economy during steady state" by distinguishing between startup and steady state. This not only avoids the power instability problem that is prone to occur in traditional photovoltaic-storage systems under the impact of motor startup, but also ensures energy saving and cost reduction during normal operation of the equipment.

[0027] The startup state signifies that the belt conveyor motor is in the startup impact phase. During this phase, the motor speed climbs from zero, there is a large instantaneous power surge, and the bus voltage stability is poor, representing a short-term unstable operating condition. Upon entering this startup state, the system forcibly prohibits the energy storage battery from discharging during peak electricity price periods. The energy storage discharge power command is set to zero, allowing only direct photovoltaic power supply, with the entire power gap being filled by the grid. This logic avoids the risks of bus voltage collapse, inverter tripping, and equipment shutdown caused by the sudden surge in power during startup, ensuring safe and reliable startup operation.

[0028] Steady-state operation means that the conveyor belt motor has started up, its speed is stable, the load is not impacted, and the whole machine is in a normal working condition of smooth and continuous operation. After entering this steady-state operation, the system removes the restriction on energy storage discharge, and the economic dispatch strategy of "photovoltaic priority, energy storage peak supplementation, and grid backup" can be implemented normally during peak periods. The battery is allowed to discharge normally for arbitrage based on the dynamic SOC threshold and electricity price strategy, maximizing the reduction of electricity costs for mine conveyor belts, while improving the local photovoltaic consumption rate.

[0029] The first and second dynamic thresholds mentioned above are updated based on electricity price forecasts, photovoltaic forecasts, battery temperature, and SOH.

[0030] Calculate the remaining peak hours for the day (The time from the current moment to the end of the last peak period of the day, in hours), and calculate the first dynamic threshold (the dynamic lower limit of the minimum allowable state of charge) for discharge using the following formula: (1); in, The first dynamic threshold; This indicates taking the maximum value; As a safety baseline value, it can be set between 0.18 and 0.22 to prevent over-discharge of the battery; The peak SOC retention coefficient can be taken as 0.08~0.15 / h; For the current moment The longer the remaining time before the end of the peak electricity price period, the more worthwhile it is to maintain the State of Charge (SOC). This is a low-temperature thickening compensation term. It raises the lower discharge limit when the battery temperature is below a preset low-temperature threshold, correcting the energy storage discharge threshold under low-temperature conditions and mitigating the risk of over-discharge at low temperatures. When the battery temperature is below 10°C... The compensation value ranges from 0.02 to 0.05, with a larger compensation value at lower temperatures. An additional +0.03 to +0.05 value is also added to prevent lithium deposition. No low-temperature compensation is needed when the battery temperature is greater than or equal to 10°C. The value is 0.

[0031] Remaining peak hours for the day Weather forecast parameters can also be input into the photovoltaic prediction model for prediction. The photovoltaic prediction model can use LSTM-BiGRU or CNN-BiGRU models.

[0032] The calculation of the remaining time until the end of the peak electricity price period for the current day also incorporates corrections based on the forecast of the next day's peak and valley periods or weather and sunshine forecasts: When the system is configured with weather and sunshine forecast interfaces, if the forecast indicates sufficient photovoltaic output for the next day, the current day's output will be adjusted accordingly. Peak retention factor multiplied by preset attenuation factor This allows for a moderate relaxation of the daily discharge retention requirement, thereby increasing the daily photovoltaic power consumption capacity.

[0033] Unlike all fixed threshold schemes: First dynamic threshold The values ​​calculated at 14:00 today (4 hours before the end of the peak period) and 10:00 today (8 hours before the end of the peak period) are different, so that the battery "knows" how much peak period is left to discharge today.

[0034] In a specific example The value is 0.20±0.03. The value is set to 0.10 ± 0.04 / h, ensuring that the peak period of the day has ended ( When →0), Automatically fall back to ≈ This allows for deeper battery utilization; when the current period is still far from the end of the peak ( When it is relatively large, Automatically raised to retain battery power for subsequent peak discharge arbitrage.

[0035] In this scenario, after the peak period ends and there is no subsequent demand for arbitrage using high-priced electricity, the system automatically lowers the battery discharge protection limit, and the battery no longer retains additional reserve capacity. Compared to the conservative strategy of actively raising the first dynamic threshold (SOC lower limit) and reserving energy storage capacity during peak periods, the available battery capacity range and depth of discharge are larger after the peak period ends. This fully releases the remaining battery capacity to participate in the power supply of the conveyor belt load, reducing the purchase of electricity from the grid. This state allows for deeper battery utilization. Essentially, when there is no subsequent demand for peak period revenue, redundant power reservations are cancelled, maximizing the utilization of battery capacity and improving energy storage efficiency.

[0036] The formula for calculating the second dynamic threshold is as follows: (2); in, This is the second dynamic threshold; This is a high-temperature derating correction item.

[0037] The high-temperature derating correction term is assigned a gradient value based on the real-time battery temperature. It is used to constrain the upper limit of the energy storage battery's charging capacity under high-temperature conditions, preventing damage from overheating. The value selection rule for the high-temperature derating correction term is as follows: when the battery temperature is less than or equal to the first preset high-temperature threshold, there is no high-temperature derating constraint, and the high-temperature derating correction term is 0; when the battery temperature is greater than the first preset high-temperature threshold but less than or equal to the second preset high-temperature threshold, it is assigned a value according to a linear derating rule. The calculation formula for the high-temperature derating correction term is as follows: When the battery temperature exceeds the second preset high-temperature threshold, the battery enters a high-temperature derating range with a high-temperature derating correction term of 0.05, forcibly reducing the battery's charging and discharging power to ensure the safe operation of the energy storage system. The second preset high-temperature threshold is greater than the first preset high-temperature threshold. The first preset high-temperature threshold can be 45℃, and the second preset high-temperature threshold can be 55℃.

[0038] The aforementioned preset priority logic is based on electricity price time periods. Execute a mutually exclusive power allocation branch: (a) During peak electricity prices and when the motor is in steady-state operation, i.e. = Peak segment PEAK and motor state ≠STARTING: Let And impose constraints Otherwise, set the discharge power setting or charging current limit of the bidirectional AC / DC converter. =0; where, To perform the minimum positive operation, only the effective discharge power greater than or equal to zero is output. The conditions where the photovoltaic output exceeds the load demand are automatically shielded to avoid false charging logic and ensure that the peak control logic is unique, rigorous and unambiguous. The remaining power gap that still exists after the photovoltaic output offsets the load of the belt conveyor is the theoretically required power shortfall that the system needs to make up. This represents the maximum allowable discharge power of the energy storage system after considering the inverter's conversion efficiency, signifying the hardware's ultimate output capability. Under peak-hour steady-state conditions, the energy storage discharge power must not exceed the actual load shortfall, nor exceed the equipment's maximum discharge capacity. This avoids over-discharge of the energy storage system, preventing reactive power backflow and excessive bus power; it also strictly constrains the equipment's output limit, protecting the bidirectional converter and battery system from over-power operation and ensuring equipment safety.

[0039] Grid compensation power In other words, photovoltaic power is prioritized for direct supply to the conveyor belt, and any shortfall is made up by the discharge of energy storage batteries. Only the final shortfall is covered by purchasing electricity.

[0040] During peak electricity price periods and when the motor is in steady-state operation, an upper limit is also set for the maximum discharge replacement ratio of the energy storage battery. This ensures that the grid side still provides at least a preset ratio (1-) during peak hours. )· The power frame is designed to prevent the load (belt conveyor) from completely losing power in the event of a battery failure. This is the discharge substitution coefficient.

[0041] (b) During peak electricity price periods and when the motor is running, i.e. when = Peak segment PEAK and motor state=When starting, the energy storage battery is forcibly prevented from discharging. =0, during the initial impact period, energy storage discharge is prohibited to prevent busbar collapse. The grid is then required to compensate for the power shortage. Direct photovoltaic power supply is allowed, but the batteries do not discharge.

[0042] (c) During off-peak electricity prices =During valley periods, the grid is allowed to simultaneously supply power to the load and charge the energy storage batteries. This allows motors to operate at full load as needed. Calculate the rechargeable capacity of the battery. Set the discharge power setting or charging current limit of the bidirectional AC / DC converter. (Negative values ​​represent charging), and the grid compensates for the power difference. (Allowing off-peak electricity to simultaneously power generators and recharge batteries); among which, Motor operating power; The rated available capacity of the energy storage battery is the rated available capacity of the energy storage battery pack that is matched with the mine belt conveyor, and the unit is kWh (kilowatt-hour). The time step is used for scheduling calculation.

[0043] (d) During the electricity price flat period = During the flat-segment FLAT, perform gentle charging and discharging or put the energy storage battery into standby mode based on the current state of charge of the energy storage battery. If State of charge of the energy storage battery at any time Then, gentle charging ( (for smaller negative values), if Then, gentle discharge ( (for smaller positive values), otherwise =0; final grid compensation power All of these powers satisfy the fundamental power balance equation. .

[0044] The rule-based state machine can be replaced by a Mixed Integer Linear Program (MILP) that rolls every 15 minutes.

[0045] The specific process of step 204 above is as follows: ... Translate these values ​​into the discharge power setpoint or charging current limit of the bidirectional AC / DC converter, and enforce a hard constraint for safety clamping verification before issuance. , As a hard limit for the device, the SOC(t) hard boundary clamp is located in [0.10, 0.90], discharging is prohibited in the startup state, that is, when the motor... state =Overwrite during STARTING To prevent voltage dips.

[0046] The dynamic power allocation and scheduling method for photovoltaic and energy storage load on the load side of the mine conveyor belt also includes: recording the scheduling results of this round into a historical buffer for prediction and correction the next day (reinforcement learning or recursive averaging methods can be selected), and calculating the rolling average cost-saving rate based on the historical buffer. When the rolling average cost-saving rate continuously decreases beyond a preset threshold, a prompt signal is triggered, indicating that the scheduling parameters need to be reviewed. The scheduling results of this round include the real-time available active power output of photovoltaic, the real-time power demand of the conveyor belt motor, the actual charging and discharging power of the energy storage battery, the state of charge of the energy storage battery, the electricity price period, and the cost-saving rate.

[0047] Rolling average savings rate The calculation formula is as follows: (3); in, For the first Rolling average cost-saving rate of round-robin scheduling; for The time-based cost-saving rate is the difference in energy-saving costs after the optimization of photovoltaic and energy storage scheduling; for Real-time power consumption of the belt conveyor motor; The benchmark electricity price, i.e., the grid benchmark settlement price corresponding to the load of the conveyor belt in the mining plant area, can be matched with the official industrial and commercial electricity price standard value for the corresponding time period according to the different electricity price periods of peak, valley and flat periods of the day, providing a unified pricing benchmark for energy saving calculation. If the continuous decline exceeds the preset threshold, an HMI alarm is triggered, indicating scheduling parameter drift, and a review is recommended. Formula coefficients.

[0048] This application has the following beneficial effects: 1) The photovoltaic absorption rate is increased to ≥85% (compared to 20%~50% for the coarse-through-interruption scheme). Because the basic equation of power balance allows "photovoltaics → direct power supply to motors + surplus power → batteries instead of curtailed photovoltaic power", it solves the problem that the photovoltaic output cannot be absorbed when there is excess power in the traditional scheme.

[0049] 2) Daily electricity costs are reduced by 15%~25%, and peak SOC is reduced. low (t) Dynamic retention ensures that the battery is actually charged and is not wasted when it should be discharged; pilot data from Nanlin Industrial Park in X City shows that under normal weather conditions, the average electricity cost is reduced by 20.3%.

[0050] 3) Carbon emissions are reduced by more than 25%. Pilot data show that the system reduces carbon emissions by 25.7% by increasing the proportion of photovoltaic power consumption and replacing grid-connected thermal power, thus contributing to the construction of green mines.

[0051] 4) Fewer deep discharge cycles, resulting in a lifespan that is more than 20% longer and a lower SOC. low(t) not lower than SOC reserve The hard constraint (≈20%) and temperature derating to prevent over-stress reduce battery damage from overcharging and over-discharging, and extend cycle life.

[0052] 5) The risk of no power outage during startup is reduced to zero. The startup status indicator prohibits discharge, preventing busbar collapse and avoiding the risk of busbar voltage drop and equipment shutdown caused by startup impact in traditional solutions.

[0053] 6) Equipment failure rate reduced by 15.2%. Pilot operation data shows that the system reduces the failure rate of equipment such as frequency converters and motors by smoothing power fluctuations and reducing grid impact.

[0054] 7) The project can achieve: all physical quantities (P) pv P m SOC All of them have sensors / communication sources that can be obtained from the mine site, and the controller is a conventional PLC / industrial computer, which can be deployed without additional modifications.

[0055] This application also provides an application scenario in which the above-mentioned dynamic power allocation and scheduling method for photovoltaic storage and load on the load side of a mining conveyor belt is applied. Specifically, the dynamic power allocation and scheduling method for photovoltaic storage and load on the load side of a mining conveyor belt provided in this embodiment can be applied to a power allocation and scheduling scenario for mining conveyor belts. The power allocation and scheduling scenario for mining conveyor belts includes a content production stage, a content processing link, and a content distribution stage; requests to be processed enter the content processing link from the content production stage, obtain corresponding charging and discharging power instructions through human-machine collaboration, and then enter the downstream content distribution stage. The dynamic power allocation and scheduling method for photovoltaic storage and load on the load side of a mining conveyor belt provided in this embodiment belongs to the content processing link. Specifically, in the content processing chain for pending requests, the scheduling parameters of the mine conveyor belt can be obtained. Based on the comparison between the real-time power demand of the motor and the rated power, or based on the motor speed status, the motor operating status can be determined. Based on the remaining time before the end of the peak electricity price period and the battery temperature, the dynamic thresholds of the minimum allowable state of charge for discharge and the upper limit of the state of charge for charging can be calculated. Based on the current electricity price period and the motor operating status, the charging and discharging power commands of the energy storage battery are decided according to the preset priority logic. Based on the power balance relationship, the grid compensation power is determined, and the charging and discharging power commands are sent to the energy storage converter. Before sending, the charging and discharging power commands are checked for safety clamping based on the equipment hard limit and the motor operating status.

[0056] Based on the same inventive concept, this application also provides a dynamic power allocation and scheduling system for the load side of a mine conveyor belt, used to implement the aforementioned dynamic power allocation and scheduling method for the load side of a mine conveyor belt. The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the dynamic power allocation and scheduling system for the load side of a mine conveyor belt provided below can be found in the limitations of the dynamic power allocation and scheduling method for the load side of a mine conveyor belt described above, and will not be repeated here.

[0057] In one exemplary embodiment, such as Figure 2 As shown, a dynamic power distribution and scheduling system for photovoltaic power generation and energy storage on the load side of a mine conveyor belt is provided, including a photovoltaic power generation module, an energy storage module, a conveyor belt load module, and a main control and scheduling controller.

[0058] A photovoltaic (PV) power generation module is used to convert solar energy into electrical energy and output real-time available active power from the photovoltaic system. It connects to a PV array, combiner box, MPPT (Maximum Power Point Tracking) controller, or grid-connected inverter to output real-time available active power from the photovoltaic system. The power of a single component is 300W~550W, and the total power of the array is 50kW~500kW, suitable for installation on mining slopes / roofs.

[0059] The energy storage module includes an electrochemical energy storage battery pack, a battery management system, and a bidirectional energy storage converter. The battery management system outputs the state of charge, battery temperature, and health status of the energy storage battery. The bidirectional energy storage converter is used to switch between charging and discharging modes in a controlled manner.

[0060] The 380V distribution network is connected to the power supply bus via a bidirectional energy meter, which can measure P. grid (t) is equipped with a switchable contactor / static switch and supports grid-connected / off-grid mode switching.

[0061] The belt conveyor load module includes a three-phase asynchronous motor (110kW~315kW) driven by a frequency converter and a belt conveyor. The frequency converter side is equipped with a power detection unit for real-time acquisition of the real-time power demand of the belt conveyor motor, with a sampling accuracy of 0.5 class.

[0062] The main control dispatch controller reads the real-time available active power output of the photovoltaic system, the real-time power demand of the motor, the state of charge of the energy storage battery, the battery temperature, and the current electricity price period according to the preset dispatch cycle or event triggering method. It performs dynamic threshold calculation and power supply priority decision, and issues charging and discharging power commands to the bidirectional energy storage converter. The main control dispatch controller uses a Siemens S7-1215C / S7-1500 series industrial PLC (Programmable Logic Controller), and performs the following allocation decision in a cycle Ts (1~10min, or event triggering), with a power setpoint P. bat_cmd The mode command is issued to the bidirectional converter to support 7 modes in harsh industrial environments. It operates stably 24 hours a day and can read and write the operation / disable interlock of the inverter.

[0063] The main control scheduling controller is programmed to: when the motor is in the starting state, when the motor... state =When starting, overwrite P bat_cmd Set its value to ≤0 to forcibly prevent the energy storage battery from discharging.

[0064] In a specific example, the main control scheduling controller is an industrial programmable logic controller or an industrial control computer; the real-time available active power output of the photovoltaic system is read from the photovoltaic inverter or MPPT controller via an industrial fieldbus RS485 / Modbus RTU; the state of charge and battery temperature of the energy storage battery are read from the battery management system via an industrial fieldbus (CANopen or RS485 / Modbus); the signal output by the power detection unit is connected to the main control scheduling controller via a CT and an analog input module (±10V / ±20mA) and stored in the PLC data block (DB); the current electricity price period is obtained by the internal clock of the main control scheduling controller combined with a pre-entered peak and valley time lookup table (indexed by day of the week × minute).

[0065] In a specific example, the dynamic power distribution and scheduling system for photovoltaic storage on the load side of the mine conveyor belt also includes a human-machine interface; the human-machine interface displays at least a dynamic diagram of real-time power flow (in bar / arrow format, P). pv (t)→P m (t) (direct supply), P bat (t)→P m (t) (discharge peak compensation), P grid (t)→P m(t) (electricity purchase), and a progress bar for the state of charge of the energy storage battery, and overlay the first dynamic threshold as a dynamic warning line that changes with the parameters on the progress bar to show the changing trend of the allowable boundary of energy storage discharge, so that operation and maintenance personnel can intuitively see "why the system does not allow the system to discharge to the end today".

[0066] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with relevant regulations and be authorized by the owner of the corresponding device.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for dynamic power distribution and scheduling of photovoltaic power storage on the load side of a mine belt conveyor, characterized in that, The dynamic power distribution and scheduling method for photovoltaic storage load on the load side of the mine belt conveyor includes: The system obtains real-time available active power output of photovoltaic power, real-time power demand of belt conveyor motor, state of charge and battery temperature of energy storage battery, and current electricity price period by means of preset scheduling cycle or event triggering method; and determines whether the motor is in start-up state or steady-state operation state based on the comparison between the real-time power demand of motor and rated power, or based on the motor speed state. Based on the remaining time before the end of the peak electricity price period, a first dynamic threshold for the minimum permissible state of charge during discharge is calculated; the first dynamic threshold increases monotonically with the remaining time and is corrected for by the battery temperature; a second dynamic threshold for the upper limit of the state of charge during charging is calculated based on the battery temperature. Based on the current electricity price period and motor operating status, the system determines the charging and discharging power commands for the energy storage battery according to a preset priority logic, and determines the grid compensation power based on the power balance relationship. Specifically, during peak electricity price periods and when the motor is in steady-state operation, the preset priority logic prioritizes photovoltaic power output to meet the load, with the shortfall being compensated by the energy storage battery discharge, and discharge is only allowed when the current state of charge of the energy storage battery is higher than a first dynamic threshold. During peak electricity price periods and when the motor is running, the energy storage battery discharge is forcibly prohibited. During off-peak electricity price periods, the grid is allowed to simultaneously supply power to the load and charge the energy storage battery. During flat electricity price periods, the system performs gentle charging and discharging or puts the energy storage battery into standby mode based on the current state of charge of the energy storage battery. The charging and discharging power command is sent to the energy storage converter, and a safety clamping verification is performed on the charging and discharging power command based on the equipment hard limit and the motor operating status before the command is sent.

2. The dynamic power distribution and scheduling method for photovoltaic storage on the load side of a mine belt conveyor according to claim 1, characterized in that, The formula for calculating the first dynamic threshold is as follows: ； in, The first dynamic threshold; This indicates taking the maximum value; This is the minimum safety threshold. The peak SOC retention coefficient; For the current moment The remaining time until the end of the peak electricity price period for the day; This is a low-temperature thickening compensation term, which is used to raise the lower discharge limit when the battery temperature is below a preset low-temperature threshold. The formula for calculating the second dynamic threshold is as follows: ； in, This is the second dynamic threshold; This is a high-temperature derating correction item.

3. The dynamic power distribution and scheduling method for photovoltaic storage on the load side of a mine belt conveyor according to claim 2, characterized in that, The calculation of the remaining time from the end of the peak electricity price period of the current day also incorporates the prediction of the peak and valley periods of the next day or the prediction of weather and sunshine: when it is predicted that the photovoltaic output will be sufficient the next day, the peak retention coefficient is multiplied by a preset attenuation coefficient to appropriately relax the discharge retention requirements of the day.

4. The dynamic power distribution and scheduling method for photovoltaic storage on the load side of a mine belt conveyor according to claim 1, characterized in that, The real-time power demand of the belt conveyor motor is obtained by real-time sampling and calculation through the three-phase current transformer installed on the inverter side, or by equivalent calculation through the product of DC bus voltage and current inside the inverter, without depending on the load curve setting value of the day-ahead plan. When the change in the real-time power demand of the motor relative to its moving average exceeds a preset change threshold for multiple consecutive sampling periods, a load change event is determined to have occurred, triggering an early refresh of the event in the scheduling period.

5. The dynamic power distribution and scheduling method for photovoltaic storage on the load side of a mine belt conveyor according to claim 1, characterized in that, During peak electricity price periods and when the motor is in steady-state operation, an upper limit for the maximum discharge replacement ratio of the energy storage battery is also set, so that the grid side still provides a power backbone of no less than the preset ratio during peak periods, in order to avoid a complete power outage of the load when the energy storage battery fails.

6. The dynamic power distribution and scheduling method for photovoltaic storage on the load side of a mine belt conveyor according to claim 1, characterized in that, The dynamic power distribution and scheduling method for photovoltaic storage load on the load side of the mine belt conveyor also includes: The scheduling results of this round are recorded in the historical buffer, and the rolling average cost-saving rate is calculated based on the historical buffer. When the rolling average cost-saving rate continuously decreases beyond a preset threshold, a prompt signal is triggered, indicating that the scheduling parameters need to be reviewed. The scheduling results of this round include the real-time available active power output of photovoltaic power, the real-time power demand of the belt conveyor motor, the actual charging and discharging power of the energy storage battery, the state of charge of the energy storage battery, the electricity price period, and the cost-saving rate.

7. The dynamic power distribution and scheduling method for photovoltaic storage on the load side of a mine belt conveyor according to claim 2, characterized in that, The rules for determining the value of the high-temperature derating correction term are as follows: When the battery temperature is less than or equal to the first preset high temperature threshold, the high temperature derating correction term is 0; when the battery temperature is greater than the first preset high temperature threshold and less than or equal to the second preset high temperature threshold, the calculation formula for the high temperature derating correction term is as follows: When the battery temperature exceeds the second preset high temperature threshold, the high temperature derating correction term is 0.05; the second preset high temperature threshold is greater than the first preset high temperature threshold.

8. A dynamic power distribution and scheduling system for photovoltaic power storage on the load side of a mine belt conveyor, characterized in that, The method for implementing the dynamic power distribution and scheduling of photovoltaic storage on the load side of a mine conveyor belt according to any one of claims 1 to 7 is characterized in that the dynamic power distribution and scheduling system for photovoltaic storage on the load side of the mine conveyor belt includes: Photovoltaic power generation modules are used to convert solar energy into electrical energy and output real-time usable photovoltaic active power. The energy storage module includes an electrochemical energy storage battery pack, a battery management system, and a bidirectional energy storage converter. The battery management system outputs the state of charge, battery temperature, and health status of the energy storage battery. The bidirectional energy storage converter is used to switch between charging and discharging modes in a controlled manner. The belt conveyor load module includes a three-phase asynchronous motor driven by a frequency converter and a belt conveyor. The frequency converter side is equipped with a power detection unit for real-time acquisition of the real-time power demand of the belt conveyor motor. The main control and scheduling controller reads the real-time available active power output of photovoltaics, the real-time power demand of motors, the state of charge of energy storage batteries, battery temperature and current electricity price period according to the preset scheduling cycle or event triggering method, performs dynamic threshold calculation and power supply priority decision, and sends charging and discharging power commands to the bidirectional energy storage converter. The main control scheduling controller is programmed to forcibly prevent the energy storage battery from discharging when the motor is running.

9. The dynamic power distribution and scheduling system for photovoltaic storage on the load side of a mine belt conveyor according to claim 8, characterized in that, The main control scheduling controller is an industrial programmable logic controller or an industrial control computer; the real-time available active power output of the photovoltaic system is read from the photovoltaic inverter or MPPT controller via an industrial fieldbus; the state of charge and battery temperature of the energy storage battery are read from the battery management system via an industrial fieldbus; the signal output by the power detection unit is connected to the main control scheduling controller via an analog input module. The current electricity price period is obtained by looking up the internal clock of the main control dispatch controller in conjunction with a pre-recorded peak-valley time lookup table.

10. The dynamic power distribution and scheduling system for photovoltaic storage on the load side of a mine belt conveyor according to claim 8, characterized in that, The dynamic power distribution and scheduling system for photovoltaic storage and energy storage on the load side of the mine conveyor belt also includes a human-machine interface; the human-machine interface displays at least a dynamic diagram of real-time power flow and a progress bar of the energy storage battery charge status, and overlays the first dynamic threshold as a dynamic warning line that changes with parameters on the progress bar to show the changing trend of the allowable boundary of energy storage discharge.

Images