Multi-energy complementary uninterruptible power supply system

Abstract

The invention discloses a multi-energy complementary type uninterruptible power supply system, which realizes efficient and stable power supply by integrating a photovoltaic power generation system, a wind power generation system, a fuel cell power generation system and an energy storage system. The system comprises a photovoltaic module, a wind driven generator, a fuel cell, an energy storage device, an inverter and an intelligent energy scheduling system. By introducing an advanced intelligent scheduling algorithm, the system can dynamically adjust energy acquisition, conversion and distribution strategies according to real-time weather, electricity price fluctuation, load requirements and energy states. When photovoltaic power generation and wind power generation cannot meet load requirements, the fuel cell system serves as a supplementary power supply to provide stable direct current and is matched with energy storage equipment to efficiently supply power. The system supports seamless switching of multiple energy modes, low-cost and environment-friendly renewable energy sources are preferentially used through intelligent scheduling, meanwhile, battery charging and discharging are optimized, and the service life of equipment is prolonged. In addition, the system has a power grid interaction function, can store energy when the commercial power is stable, or feeds back electric energy to a power grid during the peak period of electricity price.

Description

Technical Field

[0001] The present invention discloses a multi-energy complementary uninterruptible power supply system, which aims to achieve efficient, stable and reliable power supply by integrating multiple power generation and energy storage technologies, and is particularly suitable for scenarios with high requirements for power supply stability and energy utilization efficiency. Through the intelligent energy scheduling algorithm, the system can dynamically adjust the operating status of each energy module, achieve seamless switching of multiple energy modes, and give priority to load power supply in emergencies. Technical Background

[0002] Traditional uninterruptible power supply systems usually rely on a single power supply mode or a single energy storage system, which has the following problems:

[0003] 1. The utilization rate of environmental resources is low, and it is difficult to make full use of renewable energy such as wind and solar energy;

[0004] 2. The response speed is slow when the load demand fluctuates, and it is difficult to quickly and stably supply power;

[0005] 3. The utilization efficiency of energy storage equipment is low, the charging and discharging strategy is not optimized, and the equipment life is short;

[0006] 4. Lack of ability to interact with the power grid and unable to optimize overall economics through energy feedback.

[0007] To solve the above problems, the present invention provides a multi-energy complementary uninterruptible power supply system, which integrates photovoltaic power generation, wind power generation, fuel cell power generation and energy storage equipment, and combines with an intelligent scheduling system to ensure the stability and economy of load power supply while optimizing energy utilization.

[0008] Technical Solution

[0009] The multi-energy complementary uninterruptible power supply system of the present invention mainly includes the following modules:

[0010] Photovoltaic power generation module: includes photovoltaic modules and boost modules. The photovoltaic modules are responsible for converting solar energy into direct current, and the boost modules increase the output voltage of the photovoltaic modules to the DC bus voltage range. The maximum power point tracking (MPPT) algorithm is used to achieve real-time optimization of the power generation efficiency of the photovoltaic modules, giving priority to powering the load or charging the hybrid energy storage module.

[0011] Wind power generation module: including wind turbine and rectifier module. Wind turbine collects wind energy and converts it into

[0012] The rectifier module rectifies three-phase AC power into DC power and connects it to the DC bus; the module can dynamically adjust the output power according to changes in wind speed, and give priority to using wind energy to power the load or supplement energy storage.

[0013] Fuel cell power generation module: includes fuel cell and boost module. The fuel cell starts when the photovoltaic power generation module and wind power generation module cannot meet the load demand to provide stable DC power for the system. The boost module increases the low-voltage DC power output by the fuel cell to the DC bus voltage range to supplement the load or charge the hybrid energy storage module.

[0014] Hybrid energy storage module: includes lithium battery pack and supercapacitor pack. The lithium battery pack is used to provide long-term and stable power output, and the supercapacitor pack is used to quickly respond to the instantaneous power demand of the load. The two groups of energy storage devices are connected to the DC bus through bidirectional DC-DC converters, which support efficient charge and discharge management, and optimize the charge and discharge strategy according to the intelligent scheduling algorithm to extend the life of the equipment.

[0015] Inverter module: includes a first inverter and a second inverter. The first inverter inverts the electric energy in the hybrid energy storage module into AC power to supply power to the load, and the second inverter inverts the distributed power generation module into AC power to supply power to the load. The inverter module is responsible for converting the DC bus into AC power and supplying the converted electric energy to the load.

[0016] Intelligent energy dispatching system: equipped with voltage sensors and current sensors to monitor the operating status and DC bus voltage of photovoltaic, wind, fuel cell and hybrid energy storage modules in real time; based on weather conditions, electricity price fluctuations, load demand and energy storage status, it dynamically adjusts the operating mode and output power of each module to achieve seamless switching and coordinated optimization of multiple energy modules.

[0017] DC BUS: As the core channel for power transmission, it connects the power generation modules, hybrid energy storage modules and inverter modules; it is equipped with surge protection circuits and filter capacitors to smooth bus voltage fluctuations and absorb current shocks to ensure stable system operation.

[0018] How it works

[0019] 1) Under normal circumstances, the system uses photovoltaic power generation modules and wind power generation modules as its priority, and the excess electricity is stored in the lithium battery pack.

[0020] 2) When photovoltaic and wind power generation are insufficient to meet load demand, the fuel cell power generation module starts to provide supplementary power.

[0021] 3) When all power generation modules cannot meet the load demand or the grid is out of power, the energy storage module automatically switches to power supply mode to ensure power supply to critical loads.

[0022] 4) When the grid voltage is stable and the electricity price is low, the system charges the energy storage module through the grid-connected module; when the electricity price is high, the energy storage module feeds the electricity back to the grid through the inverter module, reducing the overall operating cost.

[0023] Technical Effects

[0024] The present invention achieves the following technical effects through modular design and intelligent energy scheduling:

[0025] 1. Multi-energy complementarity: Through the coordinated operation of photovoltaics, wind power, fuel cells and energy storage equipment, we can make full use of renewable energy and reduce dependence on a single power supply mode.

[0026] 2. Efficient energy utilization: Dynamically allocate energy through intelligent scheduling algorithms, give priority to the use of low-cost, environmentally friendly renewable energy, and optimize the energy structure.

[0027] 3. Fast response: The hybrid energy storage module combines supercapacitors and lithium batteries to achieve fast response to load power requirements and smooth power supply.

[0028] 4. Improved economic efficiency: With the function of grid interaction, the cost of electricity utilization can be optimized through energy storage equipment when electricity prices fluctuate.

[0029] 5. Extended equipment life: The intelligent scheduling algorithm optimizes the charging and discharging strategy of the energy storage module, effectively reducing the charging and discharging frequency of the battery pack and extending the service life of the equipment.

[0030] The multi-energy complementary uninterruptible power supply system of the present invention can be widely used in the following scenarios: industrial applications: industrial scenarios with high requirements for power supply stability, such as manufacturing plants and data centers; civil fields: homes or commercial places, reducing electricity costs by optimizing the energy structure; off-grid scenarios: remote areas or outdoor scenarios, using renewable energy and energy storage modules to achieve independent power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of a framework of a multi-energy complementary uninterruptible power supply system; DETAILED DESCRIPTION

[0032] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0033] The system consists of the modules shown in the figure. Each module is electrically connected through a DC bus (DC BUS) and is uniformly managed and controlled by the intelligent energy dispatching system:

[0034] The photovoltaic power generation module: The photovoltaic module uses polycrystalline silicon or monocrystalline silicon photovoltaic panels to directly convert solar energy into direct current, with a typical output voltage range of 30-50V; the boost module is based on a high-efficiency DC-DC boost circuit, integrated with a maximum power point tracking (MPPT) algorithm, and achieves maximum power generation efficiency by controlling the working voltage of the module; there is an isolation diode to prevent the energy of the DC bus from flowing back to the photovoltaic module; there is an electrical protection circuit, including overcurrent protection and overvoltage protection, to ensure that the photovoltaic module is not damaged under abnormal conditions; the output end of the photovoltaic module is connected to the input end of the boost module through a DC cable; the output end of the boost module is connected to the DC bus through an isolation diode. When the daytime lighting conditions are good, the DC power generated by the photovoltaic module is boosted to the bus voltage through the boost module, and the load is powered first; if the load demand is less than the photovoltaic power generation power, the system stores the excess power in the lithium battery pack through the energy storage module; when the light is insufficient, the output power of the photovoltaic power generation module is reduced, and the system automatically dispatches other modules to supplement the power supply for the load.

[0035] The wind power generation module: the wind turbine generally adopts a permanent magnet synchronous generator to convert wind energy into three-phase alternating current, with a typical output voltage of 60-120V; the rectifier module is composed of a three-phase full-bridge rectifier circuit to rectify the alternating current into direct current; the module has an anti-reverse diode to prevent the current of the DC bus from flowing back to the rectifier module; there is an electrical protection circuit including a voltage limiting and current limiting circuit to protect the wind turbine and the rectifier module; the wind turbine is connected to the rectifier module through a three-phase cable, and the output end of the rectifier module is connected to the DC bus through an anti-reverse diode. When the wind speed is sufficient, the wind power generation module gives priority to supplying power to the load; when the wind speed is insufficient, the power generation power decreases, and the intelligent scheduling system starts the fuel cell module or the energy storage module according to the load demand to supplement the power supply for the load; when the wind speed is too high, the voltage limiting circuit starts to protect the wind turbine from overvoltage damage.

[0036] The fuel cell power generation module: the fuel cell stack generally uses hydrogen fuel cells to output low-voltage direct current, with a typical output voltage of 10-30V; the boost module is based on a high-efficiency DC-DC boost circuit to boost the low-voltage direct current to the DC bus voltage range (300V-800V); there is a short-circuit protection circuit. When an abnormal current occurs at the output end of the fuel cell, the module is immediately disconnected from the DC bus; the output end of the fuel cell is connected to the boost module through a DC cable; the output end of the boost module is directly connected to the positive and negative poles of the DC bus. The fuel cell module starts when the photovoltaic power generation module and the wind power generation module are not enough to meet the load demand; the fuel cell module gives priority to powering the DC bus, and can also charge the energy storage module; when the load demand decreases or photovoltaic and wind power generation return to normal, the fuel cell module automatically enters standby mode to save fuel.

[0037] The hybrid energy storage module: the typical operating voltage range of the lithium battery pack is 300V-400V, which is used to provide long-term stable power. The supercapacitor group has a fast response time of less than 10 milliseconds to compensate for instantaneous power fluctuations; the bidirectional DC-DC converter supports bidirectional energy transmission of the energy storage module, and integrates constant voltage control and constant current control algorithms; the module has electrical protection circuits including overcurrent protection and short circuit protection to ensure the safe operation of the energy storage module; the lithium battery pack and the supercapacitor group are connected to the DC bus through independent bidirectional DC-DC converters. When the load power demand suddenly increases, the supercapacitor group quickly releases energy and smoothes the bus voltage; the lithium battery pack is used to provide continuous power output, especially when photovoltaic, wind and fuel cell power are insufficient; when the system load is small, the energy storage module stores excess power from photovoltaic and wind power generation modules.

[0038] The inverter module: the first inverter obtains direct current from the energy storage module and converts it into alternating current, and supplies power to the load first; the second inverter obtains direct current from the photovoltaic power generation module, the wind power generation module or the fuel cell module and converts it into alternating current; the input ends of the first inverter and the second inverter are respectively connected to the energy storage module and the power generation module; the output end of the inverter is connected to the load in parallel. The output power of the two inverters is dynamically adjusted according to the load demand; when the load demand fluctuates greatly, the first inverter is given priority to supply power to ensure stable power.

[0039] The intelligent energy dispatching system is the core control module of the entire uninterruptible power supply system, which is used to manage and optimize the operating status of each power generation module, energy storage module and load in real time. Its main hardware includes:

[0040] (1) Voltage sensor: It uses a high-precision voltage sampling circuit and an analog-to-digital conversion chip (ADC) to transmit the digital signal to the control unit to monitor the voltage changes of the DC bus in real time, ensure that the bus voltage is always within the safe operating range (for example, 300V-800V), detect the output voltage of each power generation module (photovoltaic, wind power, fuel cell) and energy storage module, and identify possible faults or voltage abnormalities.

[0041] (2) Current sensor: Use a Hall effect current sensor or a shunt resistor sensor in combination with an analog-to-digital conversion circuit to transmit the current signal to the control unit, monitor the current output of each power generation module, energy storage module, and load in real time, and evaluate whether the current exceeds the rated range of the module; monitor the real-time power demand of the load and dynamically adjust the output power of the module; the data of the current sensor is combined with the voltage sensor to calculate the real-time power of each module.

[0042] (3) Communication bus: An industrial communication method based on the CAN bus or RS485 protocol, which ensures high reliability and anti-interference of data transmission. The communication rate can reach hundreds of Kbps to meet real-time scheduling requirements; it connects photovoltaic power generation modules, wind power generation modules, fuel cell modules, energy storage modules and inverter modules; it transmits the operating status information and control signals of each module to achieve unified scheduling.

[0043] (4) Control unit: It uses a high-performance microprocessor (such as ARM Cortex series or DSP chip) to run the preset control logic and scheduling algorithm, and has a built-in non-volatile memory to store historical operation data and algorithm parameters. The core processor runs an intelligent scheduling algorithm to control the start and stop, power distribution, and energy mode switching of each module based on the real-time collected voltage and current data, so as to achieve rapid response to emergencies (such as power outages or sudden load increases).

[0044] The working mode of the multi-energy complementary uninterruptible power supply system is as follows:

[0045] 1. Normal power supply mode

[0046] The normal power supply mode is the operating state of the system under the conditions of stable resources and normal load. It gives priority to the use of photovoltaic power generation and wind power generation, mainly based on renewable energy, and minimizes dependence on energy storage modules and fuel cell modules.

[0047] Photovoltaic power generation modules and wind power generation modules are operated first: the intelligent energy dispatching system collects the output power signals of photovoltaic modules and wind turbines in real time to monitor the power generation in real time; if the power of the photovoltaic power generation module is higher than the load demand, the system stores the excess power into the lithium battery pack through a bidirectional DC-DC converter;

[0048] P PV =V PV ×I PV

[0049] Among them, P PV is the output power of the photovoltaic power generation module, V PV is the output voltage of the photovoltaic module, I PV is the output current of the PV module.

[0050] If the load demand is greater than the output of the photovoltaic module, the wind power generation module will cooperate to supplement the power supply; the dispatching system calculates the difference between the current load demand and the generated power, dynamically adjusts the power distribution, and adjusts the working status of the boost module and the rectifier module to avoid excessive idle power or voltage fluctuations.

[0051]

[0052] Where ρ is the air density, A is the swept area of ​​the wind wheel, v is the wind speed, Cp is the power factor of the wind turbine.

[0053] Dynamic management of energy storage modules: When the load power demand changes, the energy storage module is used to balance the power fluctuations; supercapacitors are used for rapid compensation. If the load increases instantaneously, such as when high-power equipment starts, the supercapacitor group responds in milliseconds to smooth the DC bus voltage; the lithium battery group stores excess electrical energy. When the photovoltaic and wind power generation power is higher than the load demand, the lithium battery group is charged through a bidirectional DC-DC converter, while monitoring the battery health status to avoid overcharging.

[0054] P available =P PV +P wind

[0055] Among them, P available is the total available electricity from photovoltaic and wind power.

[0056]

[0057] If the available power is greater than the load demand, the remaining power will be stored in a lithium battery pack or supercapacitor bank through a bidirectional DC-DC converter:

[0058] P charge_battery =V battery ×I battery

[0059] Among them, P charge_battery is the charging power, V battery is the lithium battery pack voltage, I battery The battery charging current.

[0060]

[0061] Among them, P charge_cap is the charging power, C cap is the capacitance value of the supercapacitor, V cap_max and V cap_min are the maximum and minimum voltages of the capacitor respectively.

[0062]

[0063] If the available power is not enough to meet the load demand, the energy storage module will provide additional power. The supercapacitor bank is used to respond to instantaneous power needs, while the lithium battery bank provides continuous power support.

[0064] If the energy storage module is insufficient and the grid is available, the system will supplement power from the grid:

[0065] P grid =P load -(Pavailable +P storage )

[0066] Among them, P grid is the power obtained from the grid.

[0067] Coordinated operation of photovoltaic and wind power: Photovoltaic power generation modules have stable output during the day, while wind power generation modules rely on large fluctuations in wind speed. The intelligent scheduling system plans the start and stop sequence of modules in advance based on weather forecast data (such as light intensity and wind speed forecast) to ensure the priority use of renewable energy. If photovoltaic power generation is sufficient but wind speed is weak during the day, the system automatically reduces the power of the wind power generation module to reduce component losses.

[0068] 2. Burst power supply mode

[0069] The burst power supply mode is used to respond to abnormal situations such as insufficient photovoltaic or wind power generation or city power outages to ensure the continuity of load power supply.

[0070] Detection of insufficient photovoltaic and wind power generation: The intelligent energy dispatching system detects the input power of the DC bus in real time through a current sensor; when the input power is lower than the load demand, the system determines that photovoltaic and wind power generation is insufficient, and immediately starts the fuel cell module through the module start and stop priority.

[0071] P load =P critical +P non_critical

[0072]

[0073] Among them, P load is the total system load demand, P critical For critical load requirements (such as data centers, emergency equipment, etc.), P non_critical For non-critical load demand, when photovoltaic and wind power generation is insufficient or the city power is cut off, the system backup power supply starts, the fuel cell module is started first, and priority scheduling is performed.

[0074] Fuel cell module startup: The fuel cell module enters operation as a backup power source, and the boost module boosts the low-voltage DC power of the fuel cell to the standard voltage of the DC bus (300V-800V); the fuel cell module prioritizes powering critical loads, such as data center servers or emergency equipment, while charging the energy storage module.

[0075] P fc =V fc ×I fc

[0076] Among them, P fc is the output power of the fuel cell module, V fcis the fuel cell output voltage, I fc Outputting current to the fuel cell;

[0077]

[0078] Among them, V out is the output voltage after boost, V fc is the output voltage of the fuel cell module, and D is the duty cycle of the boost module.

[0079] Energy storage module supplements power supply: If the output power of the fuel cell module is insufficient to meet the load demand, the energy storage module provides continuous power supply through the lithium battery pack; when the load demand suddenly increases, the supercapacitor pack quickly releases power to avoid power interruption due to the long startup response time of the fuel cell module.

[0080] P storage =P load -P available -P fc

[0081] Among them, P storage is the discharge power of the energy storage module, P load is the load demand, P available is the available photovoltaic and wind power, P fc is the output power of the fuel cell module.

[0082] Intelligent switching of load priorities: The dispatching system prioritizes power supply to critical loads based on the importance of the loads, temporarily powering off non-critical loads to ensure the overall stable operation of the system.

[0083]

[0084] 3. Grid interaction mode

[0085] The grid interaction mode is one of the core functions of the present invention, which is used to realize the two-way energy interaction between the multi-energy complementary uninterruptible power supply system and the grid to optimize energy utilization efficiency and economy. In the scenario of connecting to the mains, this mode dynamically adjusts the charging and discharging strategy according to the fluctuation of electricity price, load demand and energy storage status. The specific implementation process is as follows:

[0086] (1) Charging the energy storage module when electricity prices are low

[0087] Real-time monitoring of online power grid status: voltage, current and frequency information of online power grid is collected in real time through voltage sensors and current sensors; the intelligent energy dispatching system uses built-in algorithms to determine whether the current power grid electricity price is at a low point (for example, during the night when electricity prices are lower);

[0088] P grid_price (t) = α·sin(ωt) + b

[0089] Among them, P grid_price (t) is the power price of the power grid, α is the fluctuation amplitude of the power price, ω is the frequency of the power price fluctuation, and b is the base value of the power price, which represents the basic level of the power price.

[0090] Energy storage module charging demand judgment: The dispatch system reads the real-time status of the energy storage module, including the remaining capacity (SoC) and health state (SoH) of the lithium battery pack. When the SoC of the lithium battery pack is lower than the preset threshold and the power grid price is at a low point, a charging command is triggered;

[0091] When the electricity price is lower than the set threshold, P grid_price (t)≤P grid_lowprice (t), and the SoC of the lithium battery pack is lower than the preset threshold, that is, SoC battery (t)<SoC min , the energy storage module will start charging from the grid.

[0092] The online grid module inputs AC power from the mains into the bidirectional DC-DC converter. The bidirectional DC-DC converter converts AC power into DC power through a rectifier and adjusts the output voltage and current to charge the lithium battery pack and supercapacitor pack. The battery management system (BMS) monitors the charging process of the lithium battery pack in real time: monitors the battery voltage to avoid overcharging; monitors the battery temperature to prevent damage caused by excessive temperature rise; balances the voltage of the battery cells to ensure balanced charging of the battery pack; when the SoC of the lithium battery pack reaches the set upper limit or the off-peak electricity price period ends, the dispatch system issues a stop charging command; the grid-connected module cuts off the charging circuit, and the lithium battery pack enters standby mode;

[0093]

[0094] Among them, V battery is the battery voltage, V battery_max The upper limit of the voltage of the lithium battery, T battery is the current temperature of the battery, T battery_max The maximum temperature threshold is set for the SoC max Setting an upper limit for lithium battery SoC, P grid_lowprice is the low price threshold of electricity price.

[0095] Dynamically adjust charging power: According to the real-time power demand of the load, the dispatching system dynamically adjusts the charging power of the bidirectional DC-DC converter to ensure that the load is powered first; if the load demand suddenly increases, the system will prioritize reducing the charging power of the lithium battery pack to release more AC power to power the load.

[0096] (2) Discharging of energy storage modules when electricity prices are high

[0097] Determine the peak period of the power grid: The dispatching system monitors the power price information of the power grid in real time. When the power price is at the peak period (such as daytime or peak power consumption period), that is, P grid_price (t)≥P grid_highprice (t), triggering the energy storage module discharge mode; the system predicts future power demand based on historical load data and current load demand, ensuring that excess power is fed back to the grid under the premise of load priority: The output P of the LSTM network load (t+k) is the prediction of future load demand based on the load data and hidden state at the previous moment. The load demand prediction at time t+k is

[0098] P load (t+k)=f({P load (t),P load (t-1),…})

[0099] Among them, P load (t+k) is the load forecast at time t+k, {P load (t),P load (t-1),…} is the input historical load data.

[0100] Discharge process: The energy storage module releases energy to the DC bus through a bidirectional DC-DC converter; the inverter module converts the voltage of the DC bus into AC power and outputs it to the grid through the grid-connected module; the system adjusts the output parameters of the inverter module according to the frequency and voltage of the grid to ensure that the grid-connected current is synchronized with the grid;

[0101]

[0102] Among them, V inverter (t) is the instantaneous value of the inverter output voltage, V grid (t) is the instantaneous value of the grid voltage, K i and K p All are voltage control gains;

[0103]

[0104] Among them, f inverter is the inverter output frequency, f grid is the grid frequency, K f Controls the gain for frequency.

[0105] Dynamic power adjustment: The dispatching system monitors the load power demand in real time. When the load power demand increases, it will give priority to reducing the power fed back to the grid by the energy storage module to ensure the load power supply. If the load demand decreases, the excess power will continue to be fed back to the grid.

[0106] P grid_feedback (t)=max(0,Pstorage (t)-P load (t))

[0107] Among them, P grid_feedback (t) is the electric energy fed back to the grid, P storage (t) is the discharge power of the energy storage module, P load (t) is the power demand of the current load.

[0108] Maximizing benefits: The system adjusts the discharge power according to the real-time electricity price, giving priority to feeding back electricity during high-price periods to maximize economic benefits; the system stops discharging when the peak electricity price ends or the SoC of the energy storage module falls below the set threshold;

[0109]

[0110] Among them, EG is the economic benefit, which means the benefit obtained from the power grid feedback, P grid_feedback (t) is the power fed back to the grid, P grid_price (t) is the grid electricity price.

[0111] 3. Rapid response to power grid fluctuations

[0112] Grid anomaly detection: The grid-connected module monitors the voltage fluctuation range and frequency stability of the grid in real time; when it detects that the grid voltage is out of the normal range (more than ±10%) or the frequency deviation is too large (lower than 48Hz or higher than 52Hz), the system determines that the grid is unstable;

[0113]

[0114] Where, ΔV grid is the grid voltage fluctuation percentage, V grid is the grid voltage, V n is the rated voltage of the power grid;

[0115] Δf grid =f grid -f n

[0116]

[0117] enter islanding mode

[0118] Where Δf grid is the grid frequency deviation, f grid is the grid frequency, f n is the rated frequency of the power grid.

[0119] Switch to off-grid mode: The dispatching system immediately cuts off the connection between the grid-connected module and the grid and switches to off-grid power supply mode; the photovoltaic and wind power generation modules operate as the main power sources, and the energy storage modules supplement the power shortage.

[0120] Fast response of energy storage module: The supercapacitor group releases electric energy within millisecond response time to stabilize the DC bus voltage; the lithium battery group provides continuous power support according to load demand to ensure uninterrupted power supply to the load.

[0121] Synergy between photovoltaic and wind power modules: If the output power of photovoltaic and wind power modules is insufficient, the fuel cell module starts to provide supplementary power on demand;

[0122] P fuel (t) = P demand (t)-(P PV (t)+P wind (t))

[0123] Among them, P fuel (t) is the output power of the fuel cell module, P demand (t) is the load power demand at the current moment, P PV (t) and P wind (t) are the output powers of photovoltaic and wind power generation modules respectively.

[0124] Grid restoration: After the grid is restored to stability, the dispatching system detects grid parameters and gradually restores the grid connection status; the energy storage module supplies power to the load through the grid connection module and recharges to replenish energy reserves.

[0125] Although the above describes the specific implementation methods of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention; the description of the embodiments disclosed in the present invention enables professional and technical personnel in the field to use or implement the present invention, and they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these replacements or modifications do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present application.

Claims

1. A multi-energy complementary uninterruptible power supply system, characterized in that: include: DC bus (DCBUS): It has a positive bus and a negative bus, which is used to collect DC power from multiple power modules and distribute the power to the load side; The online power grid module includes an input AC power terminal, a filter inductor L f And filter capacitor C f , a three-phase fully controlled bridge and a filter capacitor C, the output DC terminal of the online power grid module is connected to the DC bus, so that the mains power is rectified and filtered to supply power to the DC bus under normal working conditions; The wind power generation module comprises a wind generator and a rectifier module. The three-phase alternating current output by the wind generator is connected to the input end of the rectifier module, and direct current is generated at the output end after rectification; the output end is electrically connected to the direct current busbar via a cable conductor; The photovoltaic power generation module includes a photovoltaic module and a boost conversion module. After the direct current output by the photovoltaic module is boosted by the boost conversion module (DC-DC booster), it is electrically connected to the DC bus through a cable conductor; The fuel cell power generation module includes a fuel cell stack and a supporting boost conversion module. The low-voltage direct current output by the fuel cell stack is boosted to a voltage level suitable for the direct current bus by the boost conversion module and then electrically connected to the direct current bus through a cable conductor; The hybrid energy storage module includes a lithium battery pack and a supercapacitor pack, which are connected to a DC bus through a bidirectional DC-DC converter. When there is sufficient electric energy, the excess electric energy is stored in the lithium battery pack and the supercapacitor, and when the load demand increases or the mains is interrupted, the load is supplied with power through an inverter; The inverter module includes a first inverter and a second inverter. The input end of the first inverter is connected to the DC bus through a cable conductor to convert DC power into AC power and supply it to the critical load; the second inverter can convert the DC power of the hybrid energy storage module into AC power according to the UPS intelligent control instructions, and provide a stable backup power supply for the load when the mains power is abnormal; The UPS intelligent energy dispatching system communicates with the power generation module, hybrid energy storage module, and inverter module through data lines, receives and transmits signals, monitors the operating status of each module in real time, dynamically adjusts energy collection, conversion, and distribution strategies according to weather conditions, electricity price fluctuations, load demand, and energy storage device status, and sends control instructions to the bidirectional DC-DC converter, boost module, rectifier module, and inverter through control signal lines to achieve multi-energy complementarity and output stabilization.

2. A multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The photovoltaic power generation module adopts a maximum power point tracking (MPPT) algorithm to optimize power generation efficiency by adjusting the working voltage of the photovoltaic module.

3. A multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The wind power generation module converts three-phase alternating current into direct current through a rectifier module, and is connected to a direct current bus through an anti-reverse diode to avoid reverse flow.

4. A multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The fuel cell power generation module increases the low voltage direct current output by the fuel cell to the direct current bus voltage range through the boost module, and controls the start and stop of the fuel cell through the intelligent energy dispatching system.

5. The multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The inverter module includes: a first inverter, used to convert the direct current of the hybrid energy storage module into alternating current; a second inverter, used to convert the direct current of the photovoltaic power generation module, the wind power generation module or the fuel cell power generation module into alternating current; the output ends of the two inverters are connected in parallel to the load, and coordinated control is achieved through the intelligent energy scheduling system.

6. The multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The intelligent energy dispatching system includes: voltage sensors and current sensors for monitoring the electrical parameters of the DC bus and each module; a communication bus for real-time interaction with the control unit of each module; a dispatching algorithm module for optimizing energy distribution based on weather conditions, electricity price fluctuations, load demand and energy storage status; the system supports seamless switching of multiple energy modes, including: (1) under normal power supply conditions, photovoltaic power generation modules and wind power generation modules are used for power supply; (2) when photovoltaic power generation and wind power generation cannot meet the load demand, the fuel cell module is automatically started; (3) when all power generation modules cannot meet the load demand, the hybrid energy storage module is used as an emergency power supply to ensure load power supply.

7. The multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The hybrid energy storage module includes: (1) a lithium battery pack for providing long-term stable power output; (2) a supercapacitor pack for quickly responding to the instantaneous power demand of the load; and (3) a bidirectional DC-DC converter for controlling the charging and discharging process of the lithium battery pack and the supercapacitor pack. The hybrid energy storage module uses the supercapacitor pack to handle instantaneous power fluctuations through an intelligent scheduling system, and provides continuous power support through the lithium battery pack, thereby optimizing the charging and discharging cycle of the energy storage device to extend the life of the device.

8. The multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The system has grid interaction functions, including: (1) when the grid voltage is stable and the electricity price is low, the grid electricity is preferentially used to charge the hybrid energy storage module; (2) during the peak electricity price period, the electricity of the hybrid energy storage module is fed back to the grid to achieve economic optimization.

9. The multi-energy complementary uninterruptible power supply system according to claim 1, characterized in that: The intelligent energy dispatching system can estimate future load demand based on historical operation data, prediction models and real-time load data, and optimize energy collection and distribution strategies in advance.

Images