Thermal power auxiliary engine system based on wind-solar direct drive and energy efficiency improving method thereof

Abstract

The invention belongs to the technical field of energy optimization of a traditional thermal power plant, and discloses a thermal power auxiliary engine system based on wind and light direct drive and an energy efficiency improving method thereof. The wind-solar direct-drive auxiliary engine is preferentially adopted to operate in the daytime, redundant power is used for energy storage, the compressed air energy storage system supplies power at night or in cloudy days, and peak load shifting of energy is achieved; the central control system dynamically adjusts an energy supply structure and a power distribution strategy based on a meteorological prediction model, historical load data of the auxiliary machine and a real-time state, so that new energy resources are utilized to the greatest extent while stable operation of the auxiliary machine is ensured, and coal consumption reduction and power plant energy efficiency improvement are realized. According to the invention, the ratio of coal consumption to station service power of the auxiliary machine is obviously reduced, the utilization rate of wind power and photovoltaic power generation is improved, and flexible scheduling and high frequency response of operation of the auxiliary machine are realized.

Description

Technical Field

[0001] This invention belongs to the field of energy optimization technology in traditional thermal power plants, specifically relating to a thermal power auxiliary equipment system based on wind and solar direct drive and its energy efficiency improvement method. Background Technology

[0002] Traditional thermal power plants, as an important part of the energy system, face problems such as high energy consumption, low efficiency, and significant environmental pressure. Current technologies mainly focus on improving the thermal efficiency of the main boiler, optimizing boiler combustion, and treating flue gas, but insufficient attention is paid to optimizing the energy consumption of numerous auxiliary systems in thermal power plants (including boiler feedwater pumps, coal mills, induced draft fans, desulfurization pumps, etc.).

[0003] Auxiliary systems consume over 30% of the total electricity used in a power plant, making them a significant factor affecting the operational efficiency of thermal power plants. Currently, the mainstream method still relies on AC power to drive auxiliary motors, and a highly efficient power supply mechanism that fully integrates new energy resources has not yet been established. However, renewable energy sources such as wind and solar power have abundant daytime generating capacity. If these resources could be directly used to drive auxiliary systems, coupled with intelligent control systems for load forecasting and regulation, it would significantly improve overall energy utilization efficiency and reduce coal consumption and emissions. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem that the current auxiliary motors driven by AC power have not yet formed an efficient power supply mechanism that fully integrates new energy resources, and to provide a thermal power auxiliary motor system based on wind and solar direct drive and its energy efficiency improvement method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a thermal power auxiliary equipment system based on wind and solar direct drive, comprising: A photovoltaic power generation system is used to generate electricity through photovoltaics and send it to a power regulation module; A wind power generation system is used to generate electricity using wind power and send it to a power regulation module; The power regulation module is used to stabilize the fluctuating new energy voltage to the target voltage and send it to the compressed air energy storage system; Compressed air energy storage system is used to store regulated electrical energy and transmit current to the DC busbar; The central control system is used to collect meteorological forecast data, historical output information and load demand, and adjust the allocation priority of the compressed air energy storage system's electrical energy among the auxiliary machines in combination with the system's operating status, and generate control commands to send to the frequency converter drive unit. The variable frequency drive unit is used to adjust the speed and operating mode of the motor according to the control command, and to drive the auxiliary machines under different load requirements.

[0006] A further improvement of the present invention is that the central control system includes a data acquisition module, a predictive analysis module, an energy scheduling module, and a multi-objective optimization module; The data acquisition module is used to collect real-time data on the current output of wind power generation systems and photovoltaic power generation systems, weather change trends, voltage and current data, auxiliary power requirements, and the state of charge of compressed air energy storage systems. The predictive analysis module is used to build models of solar intensity, wind speed, and load change trends based on meteorological forecasts and historical operating data, predict changes in new energy power generation capacity and auxiliary power demand over a preset time, and generate predictive data. The energy dispatch module is used to execute an early power allocation strategy based on predicted data, determine the power supply ratio of each source in the DC bus, and determine whether to call the compressed air energy storage system or adjust the output power of the frequency converter drive unit. The multi-objective optimization module is used to generate control commands based on the judgment results and send them to the frequency converter drive unit.

[0007] A further improvement of the present invention is that the central control system also includes a redundancy safety mechanism, which is used to automatically switch to the compressed air energy storage system or grid-connected backup power supply when the wind and solar power output prediction deviation exceeds a set threshold.

[0008] A further improvement of the present invention is that the variable frequency drive unit is connected to the boiler feed water pump, coal mill, induced draft fan and desulfurization pump through independent drive channels, and each channel is equipped with a controller, which is used to adapt to the frequent start-stop and power changes when the wind and solar power output fluctuates.

[0009] A further improvement of the present invention is that, under typical operating mode, when the combined output of wind and solar power exceeds the real-time power demand of the auxiliary machine, the frequency converter drive unit prioritizes the operation strategy of the maximum efficiency section, so that the auxiliary machine motor is at a high energy efficiency operating point. When the output of new energy sources is insufficient and the state of charge of the compressed air energy storage system is lower than the preset threshold, the central control system controls the corresponding auxiliary machine load to be reduced or the power supply to be switched. When the output of photovoltaic power generation systems and wind power generation systems fluctuates frequently or changes abruptly, the central control system issues control strategies to the frequency converter drive unit.

[0010] A further improvement of the present invention is that the compressed air energy storage system includes a lithium-ion battery module, a supercapacitor module, a compressed air energy storage module, a flywheel energy storage module, or at least any combination of two of them. Lithium-ion batteries are used for frequent charging and discharging; Supercapacitors are used for second-level response; Compressed air energy storage modules are used to provide hourly power output; Flywheel energy storage modules are used for continuous energy supply during nighttime hours.

[0011] A further improvement of the present invention is that, after the compressed air energy storage system is connected to the DC bus, it is linked with the central control system through the converter to adjust its charging and discharging state according to the predicted data. During operation, when the sunshine and wind speed are higher than the preset threshold, the central control system controls the new energy to give priority to powering the corresponding auxiliary machine, and the redundant electrical energy is stored in the compressed air energy storage system. When the sunlight and wind speed are below the preset threshold or the auxiliary machine load suddenly increases, the central control system accurately calculates the required power release based on the current power gap and schedules the output of the compressed air energy storage system.

[0012] A further improvement of this invention is that the compressed air energy storage system supports switching between fixed-frequency and variable-frequency operation modes to adapt to different power supply requirements and the dynamic load characteristics of auxiliary equipment.

[0013] A method for improving the energy efficiency of a thermal power auxiliary equipment system based on wind and solar direct drive includes the following steps: The photovoltaic power generation system generates electricity through photovoltaics and sends it to the power regulation module; The wind power generation system generates electricity using wind power and sends it to the power regulation module; The power regulation module stabilizes the fluctuating new energy voltage to the target voltage and sends it to the compressed air energy storage system; The compressed air energy storage system stores and stabilizes electrical energy, and transmits current to the DC busbar. The central control system collects meteorological forecast data, historical output information and load demand, and adjusts the power allocation priority of the compressed air energy storage system among the auxiliary machines in combination with the system operating status, and generates control commands to send to the frequency converter drive unit. The variable frequency drive unit adjusts the speed and operating mode of the motor according to the control command to drive each auxiliary machine under different load requirements.

[0014] A further improvement of this invention lies in the following method for the central control system to collect meteorological forecast data, historical output information, and load demand, and adjust the allocation priority of the compressed air energy storage system's electrical energy among auxiliary machines in conjunction with the system's operating status, and generate control commands to send to the frequency converter drive unit: Real-time data collection includes the current output of wind power and photovoltaic power generation systems, weather change trends, voltage and current data, auxiliary equipment power requirements, and the state of charge of compressed air energy storage systems. Based on meteorological forecasts and historical operational data, a model for the changing trends of solar intensity, wind speed, and load is constructed to predict changes in the renewable energy generation capacity and auxiliary power demand over a preset time period, generating forecast data. Based on the predicted data, an early power allocation strategy is executed to determine the power supply ratio of each source in the DC bus and to determine whether to call the compressed air energy storage system or adjust the output power of the frequency converter drive unit. Based on the judgment result, a control command is generated and sent to the frequency converter drive unit.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention prioritizes the operation of wind-solar direct-drive auxiliary turbines during the day, with redundant power used for energy storage. At night or on cloudy days, a compressed air energy storage system provides power, achieving peak shaving and valley filling. The central control system dynamically adjusts the energy supply structure and power allocation strategy based on meteorological forecast models, historical load data of the auxiliary turbines, and real-time status. This ensures stable operation of the auxiliary turbines while maximizing the utilization of new energy resources, thereby reducing coal consumption and improving power plant energy efficiency. This invention significantly reduces the coal consumption of auxiliary turbines and the plant's power consumption ratio, improves the utilization rate of wind and solar power generation, and achieves flexible scheduling and high-frequency response of auxiliary turbine operation. It also reduces the overall energy consumption of thermal power plants and improves comprehensive energy utilization efficiency. This invention not only fills the gap in existing patents regarding the system structure and control methods of wind-solar direct-drive auxiliary turbines but also proposes a clear implementation path and control strategy, possessing significant promotional value and industrialization prospects. It is particularly suitable for the transformation needs of thermal power systems to improve flexibility and energy efficiency in future scenarios with high proportions of new energy access. Attached Figure Description Figure 1 This is a system diagram of the present invention. Detailed Implementation

[0016] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0017] See Figure 1 A thermal power auxiliary equipment system based on wind-solar direct drive includes: Photovoltaic power generation system 1 is used to generate electricity through photovoltaics and send it to power regulation module 4; Wind power generation system 2 is used to generate electricity using wind power and send it to power regulation module 4; The power regulation module 4 is used to stabilize the fluctuating new energy voltage to the target voltage and send it to the compressed air energy storage system 5; Compressed air energy storage system 5 is used to store regulated electrical energy and transmit current to DC bus 3; The central control system 6 is used to collect meteorological forecast data, historical output information and load demand, and adjust the power distribution priority of the compressed air energy storage system 5 among the auxiliary machines in combination with the system operating status, and generate control commands to send to the frequency converter drive unit 7. The variable frequency drive unit 7 is used to adjust the speed and operating mode of the motor according to the control command, and to drive each auxiliary machine under different load requirements.

[0018] A method for improving the energy efficiency of a thermal power auxiliary equipment system based on wind and solar direct drive includes the following steps: Step 1: The photovoltaic power generation system 1 generates electricity through photovoltaics and sends it to the power regulation module 4.

[0019] Step 2: The wind power generation system 2 generates electricity through wind power and sends it to the power regulation module 4.

[0020] Step 3: The power regulation module 4 stabilizes the fluctuating new energy voltage to the target voltage and sends it to the compressed air energy storage system 5.

[0021] Step four: The compressed air energy storage system 5 stores the stabilized electrical energy and transmits the current to the DC bus 3.

[0022] Step 5: The central control system 6 collects meteorological forecast data, historical output information and load demand, and adjusts the power allocation priority of the compressed air energy storage system 5 among the auxiliary machines in combination with the system operating status, and generates control commands to send to the frequency converter drive unit 7.

[0023] Step six: The variable frequency drive unit 7 adjusts the speed and operating mode of the motor according to the control command to drive each auxiliary machine under different load requirements.

[0024] Example 1: Photovoltaic power generation system 1 and wind power generation system 2 respectively output DC power, which is collected through DC combiner bus 3 and sent to power regulation module 4. Power regulation module 4 includes a multi-channel DC / DC converter, which is used to stabilize the fluctuating new energy voltage to the target voltage level. The compressed air energy storage system 5 is a lithium battery pack, supercapacitor or compressed air energy storage device, and its output end is also connected to the DC bus 3 to participate in power support or absorption. The central control system 6 is used to collect meteorological forecast data, historical output information and load demand, and intelligently allocate the allocation priority of new energy power among auxiliary machines in combination with the system operation status; the central control system 6 can also schedule the charging and discharging status of the compressed air energy storage system 5 in advance according to the output prediction model to match the upcoming new energy fluctuations, thereby ensuring the continuous operation and optimal energy efficiency of the auxiliary machine system.

[0025] The variable frequency drive unit 7 is connected to the boiler feed water pump 8, coal mill 9, induced draft fan 10, and desulfurization pump 11, respectively, and is used to adjust the speed and operating mode of the motor according to the control system instructions to achieve precise drive of each auxiliary machine under different load requirements. The photovoltaic power generation system 1, wind power generation system 2, and DC combiner bus 3 are flexibly mutually redundant through an automatic switching device to ensure power supply stability even when the output decreases. Example 2: The central control system 6 includes a data acquisition module, a predictive analysis module, an energy dispatch module, and a multi-objective optimization module. The data acquisition module collects real-time parameters such as the current output of the wind power system 2 and the photovoltaic power system 1, weather trends, voltage and current data, auxiliary equipment power demand, and the state of charge of the compressed air energy storage system 5. The predictive analysis module constructs models based on meteorological forecasts and historical operating data, including trends in sunlight intensity, wind speed, and load changes, to predict changes in the renewable energy generation capacity and auxiliary equipment power demand over the next 15 minutes to 2 hours. The energy dispatch module executes a preliminary power allocation strategy based on the predicted data, determines the power supply ratio of each source in the DC bus 3, and decides whether to call up the compressed air energy storage system 5 or adjust the output power of the frequency converter drive unit 7. The multi-objective optimization module uses linear programming, fuzzy control, or genetic algorithms to comprehensively consider factors such as minimum energy consumption, load stability, and reasonable auxiliary equipment speed, dynamically generating control commands and sending them to the frequency converter drive unit 7, thereby achieving optimal selection of the system's energy path when wind and solar power output fluctuates. The central control system 6 also includes a redundancy safety mechanism. When the wind and solar power output prediction deviation exceeds the set threshold, it automatically switches to the compressed air energy storage system for power supply or the grid-connected backup power supply to ensure the continuous operation of each auxiliary machine and the safety of the thermal power plant system.

[0026] Example 3: The variable frequency drive unit 7 is connected to the boiler feed pump 8, coal mill 9, induced draft fan 10, and desulfurization pump 11 through independent drive channels. Each channel includes an input current protection device, a voltage feedback unit, a speed detection unit, and a fault bypass controller to adapt to frequent start-stop and power changes during wind and solar power output fluctuations. In typical operating mode, when the combined output of wind and solar power exceeds the real-time power demand of auxiliary equipment, the variable frequency drive unit 7 prioritizes the maximum efficiency segment operation strategy, keeping the auxiliary motors at a high-efficiency operating point, saving power consumption and extending equipment life. When the output of new energy is insufficient and the state of charge of the compressed air energy storage system 5 is low, the system enters a derating operation mode, controlling the load of some auxiliary equipment to be reduced or rotating power supply, and realizing load sharing and peak-shifting operation among auxiliary equipment through variable frequency speed regulation. When wind and solar power output fluctuates frequently or abruptly, the central control system 6 quickly issues control strategies to the variable frequency drive unit 7 to achieve millisecond-level load adjustment response, avoiding power outages or motor damage to auxiliary equipment, and improving system stability and response flexibility.

[0027] Example 4: The compressed air energy storage system 5 includes at least one of the following devices: a lithium-ion battery module, a supercapacitor module, a compressed air energy storage module, a flywheel energy storage module, or a combination thereof; wherein, the lithium-ion battery is used for short-cycle frequent charge and discharge scenarios, the supercapacitor is used for second-level fast response, and the compressed air energy storage module can provide hour-level stable power output for continuous power supply at night or during low-output periods; after the compressed air energy storage system 5 is connected to the DC combiner bus 3, it is linked with the central control system 6 through an intelligent converter to adjust its charge and discharge state according to predicted data; during system operation, during periods of strong sunlight and wind speed, the central control system 6 controls the new energy source to prioritize power supply to the auxiliary machine, and the redundant electrical energy is stored in the compressed air energy storage system 5; when the output is insufficient or the load of the auxiliary machine suddenly increases, the central control system 6 accurately calculates the required power release based on the current power gap and schedules the output of the compressed air energy storage system 5 to maintain voltage stability and power balance; the compressed air energy storage system 5 supports switching between fixed-frequency and variable-frequency operation modes to adapt to different power supply needs and the dynamic load characteristics of the auxiliary machine.

[0028] Example 6: The photovoltaic (PV) power generation system 1 and the wind power generation system 2 have a complementary and coordinated mechanism. The PV modules are installed in a multi-array distributed manner and connected to micro-inverters and combiner controllers. The wind power generation uses fixed-pitch wind turbines or vertical-axis wind turbines to adapt to different wind resources and space conditions in the plant area. The central control system 6 dynamically adjusts the output ratio of PV and wind power based on real-time cloud cover and wind speed trends. When the sunlight is strong but the wind speed is low, the output ratio of PV is increased, and vice versa. At the same time, during periods of strong wind and strong sunlight, the excess power is sent to the compressed air energy storage system 5 or the auxiliary redundant load is increased through the dynamic shunt controller, realizing dynamic adjustment of wind, solar, energy storage, and load. The system supports a three-level energy supply mode of PV priority, wind power supplementation, and energy storage backup. It also supports the construction of output pre-adjustment curves based on prediction curves to buffer power surges in advance, achieving flexible scheduling of wind and solar output and maximizing energy utilization.

[0029] Example 7: The central control system 6 possesses an AI-based load optimization and forecasting algorithm platform. This platform employs algorithms such as Long Short-Term Memory (LSTM), Random Forest, or Support Vector Machine, using input variables like wind speed, irradiance, cloud cover, upper-level air pressure, historical load, and unit operating characteristics to predict output changes and auxiliary equipment loads at different time scales. The forecast results are fed into a multi-objective scheduling model to generate optimal load adjustment strategies and energy storage charging / discharging plans. The platform has self-learning capabilities, continuously refining parameters and optimizing its structure as system operating data accumulates, enhancing its ability to control the behavior of complex coupled systems. The forecast results not only guide current operations but also contribute to planned maintenance, strategic off-peak operations, and safety margin management, serving as the core decision-making tool for the efficient operation of the entire auxiliary equipment system. The forecasting module supports data interfaces with third-party meteorological platforms, integrating multi-source forecasts to improve accuracy. It can also generate pre-adjustment control commands minutes before drastic fluctuations in renewable energy output, proactively activating the compressed air energy storage system or adjusting the load to achieve flexible scheduling and load matching.

[0030] The system allows for the expansion or reduction of auxiliary equipment types and quantities based on actual needs in thermal power plants, supporting phased deployment during the retrofitting of existing thermal power plants. Auxiliary equipment such as boiler feed pumps (8), coal mills (9), induced draft fans (10), and desulfurization pumps (11) can be independently connected to the variable frequency drive unit (7) and the central control system (6). During system operation, auxiliary equipment operation is started or suspended as needed based on available renewable energy power and load prediction priorities. The system can also isolate and reconfigure power lines through intelligent circuit breaker modules to prevent system paralysis due to localized faults. The system supports remote monitoring and intelligent diagnostics; all core parameters are remotely uploaded to the main control platform via the central control system (6), enabling cloud data synchronization, anomaly identification, and strategy updates. This system possesses strong flexibility and robustness, is highly adaptable, and is suitable for auxiliary equipment energy efficiency improvement and retrofitting scenarios in thermal power plants of different sizes and operating modes.

[0031] Example 8: In this embodiment, the wind power units and photovoltaic arrays are installed on open land around the plant, on the roof of the plant, or in areas with abundant wind resources. They each output direct current, which is then fed into a unified DC bus via a DC / DC converter. Taking a 600 MW thermal power plant as an example, it is configured with a 20 MW photovoltaic system and a 10 MW wind power system.

[0032] The auxiliary equipment, such as feedwater pumps, coal mills, and induced draft fans, which were originally driven by steam extraction from steam turbines, have been replaced with high-efficiency permanent magnet synchronous motors and equipped with intelligent frequency converters that support DC input, real-time speed regulation, and have status feedback interfaces.

[0033] The central control system integrates meteorological forecast data such as wind speed, sunlight, and temperature to predict the power output curve of new energy sources for the next 1 to 24 hours. Combined with the load forecasting module, it estimates the power demand of auxiliary equipment systems in different time periods. It prioritizes direct drive of auxiliary equipment by wind and solar power to ensure maximum utilization of new energy output. When new energy fluctuates significantly or cannot fully meet the load, the controller issues a command to switch to the compressed air energy storage system for discharge or to supplement the plant's power supply. When there is a surplus of wind and solar power, the controller automatically coordinates to store some of the redundant power in the lithium battery system or use it for other auxiliary systems such as hydrogen production and compressed air energy storage. The system monitors the current, voltage, speed, and load of each auxiliary equipment in real time throughout the entire process to achieve closed-loop control.

[0034] During periods of high sunlight and high wind speeds during the day, all auxiliary equipment is directly powered by wind and solar power, and the compressed air energy storage system is charged. After sunset, as sunlight weakens and wind speeds decrease, the system determines that the output is insufficient and automatically activates the compressed air energy storage system to release electrical energy, ensuring stable operation of the auxiliary equipment. In special operating conditions, such as a sudden power outage from wind power, the control system allows the auxiliary equipment to switch to the grid power supply mode for a short period of time, and prioritizes the operation of low-priority auxiliary equipment at reduced frequency or temporary shutdown. Through direct wind and solar power supply to auxiliary equipment and supporting control strategies, this system can effectively reduce the main unit's steam extraction loss by about 3% to 6%, reduce the plant power consumption rate by 1.2% to 1.8%, and improve the overall coal consumption efficiency of power supply. The system has strong adaptability to new energy sources and supports integration with future virtual power plants and flexible load management platforms.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A thermal power auxiliary equipment system based on wind and solar direct drive, characterized in that, include: A photovoltaic power generation system (1) is used to generate electricity through photovoltaics and send it to a power regulation module (4). A wind power generation system (2) is used to generate electricity by wind power and send it to a power regulation module (4). The power regulation module (4) is used to stabilize the fluctuating new energy voltage to the target voltage and send it to the compressed air energy storage system (5). Compressed air energy storage system (5) is used to store the regulated electrical energy and transmit the current to the DC bus (3). The central control system (6) is used to collect meteorological forecast data, historical output information and load demand, and adjust the power distribution priority of the compressed air energy storage system (5) among the auxiliary machines in combination with the system operating status, and generate control commands to send to the frequency converter drive unit (7). The variable frequency drive unit (7) is used to adjust the speed and operating mode of the motor according to the control command, and to drive each auxiliary machine under different load requirements.

2. The auxiliary power plant system based on wind and solar direct drive according to claim 1, characterized in that, The central control system (6) includes a data acquisition module, a predictive analysis module, an energy scheduling module, and a multi-objective optimization module; The data acquisition module is used to collect the current output, weather change trend, voltage and current data, auxiliary power demand and the charge status of the compressed air energy storage system (5) in real time for the wind power generation system (2) and the photovoltaic power generation system (1); The predictive analysis module is used to build models of solar intensity, wind speed, and load change trends based on meteorological forecasts and historical operating data, predict changes in new energy power generation capacity and auxiliary power demand over a preset time, and generate predictive data. The energy dispatch module is used to execute the early power allocation strategy based on the predicted data, determine the power supply ratio of each source in the DC bus (3), and determine whether to call the compressed air energy storage system (5) or adjust the output power of the frequency converter drive unit (7). The multi-objective optimization module is used to generate control commands based on the judgment results and send them to the frequency converter drive unit (7).

3. A thermal power auxiliary equipment system based on wind and solar direct drive according to claim 1 or 2, characterized in that, The central control system (6) also includes a redundant safety mechanism, which is used to automatically switch to compressed air energy storage system or grid-connected backup power supply when the wind and solar power output prediction deviation exceeds the set threshold.

4. A thermal power auxiliary equipment system based on wind and solar direct drive according to claim 1, characterized in that, The variable frequency drive unit (7) is connected to the boiler feed water pump (8), coal mill (9), induced draft fan (10) and desulfurization pump (11) through independent drive channels, and each channel is equipped with a controller to adapt to the frequent start-stop and power changes when the wind and solar power output fluctuates.

5. A thermal power auxiliary equipment system based on wind and solar direct drive according to claim 1, characterized in that, In typical operating mode, when the combined output of wind and solar power exceeds the real-time power demand of the auxiliary machine, the frequency converter drive unit (7) prioritizes the maximum efficiency section operation strategy to keep the auxiliary machine motor at a high energy efficiency operating point. When the output of new energy is insufficient and the charge status of the compressed air energy storage system (5) is lower than the preset threshold, the central control system (6) controls the corresponding auxiliary machine load to be reduced or the power supply to be switched. When the output of the photovoltaic power generation system (1) and the wind power generation system (2) fluctuates frequently or changes abruptly, the central control system (6) issues control strategies to the frequency conversion drive unit (7).

6. A thermal power auxiliary equipment system based on wind and solar direct drive according to claim 1, characterized in that, The compressed air energy storage system (5) includes a lithium-ion battery module, a supercapacitor module, a compressed air energy storage module, a flywheel energy storage module, or at least any combination of two of them; Lithium-ion batteries are used for frequent charging and discharging; Supercapacitors are used for second-level response; Compressed air energy storage modules are used to provide hourly power output; Flywheel energy storage modules are used for continuous energy supply during nighttime hours.

7. A thermal power auxiliary equipment system based on wind and solar direct drive according to claim 1 or 6, characterized in that, After the compressed air energy storage system (5) is connected to the DC bus (3), it is linked with the central control system (6) through the converter and its charging and discharging state is adjusted according to the predicted data. During operation, when the sunshine and wind speed are higher than the preset threshold, the central control system (6) controls the new energy to give priority to the corresponding auxiliary machine, and the redundant electrical energy is stored in the compressed air energy storage system (5). When the sunshine and wind speed are below the preset threshold or the auxiliary machine load suddenly increases, the central control system (6) accurately calculates the required power release based on the current power gap and schedules the output of the compressed air energy storage system (5).

8. A thermal power auxiliary equipment system based on wind and solar direct drive according to claim 1, characterized in that, The compressed air energy storage system (5) supports switching between fixed frequency and variable frequency operation modes to adapt to different power supply requirements and auxiliary dynamic load characteristics.

9. A method for improving the energy efficiency of a thermal power auxiliary equipment system based on wind-solar direct drive as described in claim 1, characterized in that, Includes the following steps: The photovoltaic power generation system (1) generates electricity through photovoltaics and sends it to the power regulation module (4). The wind power generation system (2) generates electricity through wind power and sends it to the power regulation module (4); The power regulation module (4) stabilizes the fluctuating new energy voltage to the target voltage and sends it to the compressed air energy storage system (5). The compressed air energy storage system (5) stores the regulated electrical energy and transmits the current to the DC bus (3). The central control system (6) collects meteorological forecast data, historical output information and load demand, and adjusts the power allocation priority of the compressed air energy storage system (5) among the auxiliary machines in combination with the system operating status, and generates control commands to send to the frequency converter drive unit (7). The variable frequency drive unit (7) adjusts the speed and operating mode of the motor according to the control command, and drives each auxiliary machine under different load requirements.

10. The method for improving the energy efficiency of a thermal power auxiliary equipment system based on wind and solar direct drive according to claim 9, characterized in that, The central control system (6) collects meteorological forecast data, historical output information and load demand, and adjusts the power allocation priority of the compressed air energy storage system (5) among the auxiliary machines in combination with the system operating status, and generates control commands to send to the frequency converter drive unit (7). The specific method is as follows: Real-time acquisition of the current output, weather change trend, voltage and current data, auxiliary power demand and the charge status of the compressed air energy storage system (5) of the wind power generation system (2) and photovoltaic power generation system (1); Based on meteorological forecasts and historical operational data, a model for the changing trends of solar intensity, wind speed, and load is constructed to predict changes in the renewable energy generation capacity and auxiliary equipment power demand over a preset time period, generating forecast data. Based on the predicted data, an early power allocation strategy is executed to determine the power supply ratio of each source in the DC bus (3) and to determine whether to call the compressed air energy storage system (5) or adjust the output power of the frequency converter drive unit (7). Based on the judgment result, a control command is generated and sent to the frequency converter drive unit (7).

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