A combined power generation system and a power distribution method thereof

Abstract

The application provides a combined power generation system and a power distribution method thereof, the method comprising: collecting a voltage feedback signal of a load power supply bus, obtaining current power available values of a first power supply device and a second power supply device; generating a total power demand pre-command and a total power demand command; taking a low-frequency power command as a first power supply device power demand pre-command, and calculating a second power supply device power demand pre-command; outputting the first power supply device power demand command and the second power supply device power demand command according to the current power available value of the second power supply device; outputting the first power supply device power demand command to the first power supply device and outputting the second power supply device power demand command to the second power supply device; and repeating the above steps until the load stops consuming power. The power distribution system and method can correspond to the transient load of the load, absorb the feedback charge of the load, and ensure the stability of the power generation system and the normal operation of each load.

Description

Technical Field

[0001] This invention relates to the field of distributed generation technology, and more specifically to a combined generation system and its power distribution method. Background Technology

[0002] Power generation devices provide electrical energy to loads to ensure their normal operation. For example, gas turbines, as small and efficient power generation devices, provide electrical energy to loads. They have advantages such as diverse fuel forms, high power density, and low emissions, giving them unique advantages in distributed generation and distributed power systems. However, because gas turbine power generation systems convert chemical energy into electrical energy through combustion, their power changes relatively slowly and cannot respond to transient load changes, which can easily affect the normal operation of the load and shorten the lifespan of the micro gas turbine. At the same time, the power of a gas turbine flows in one direction only and cannot absorb energy fed back from the load, resulting in energy waste.

[0003] Currently, there are also hybrid power generation systems that combine supercapacitors with chemical energy storage. These systems are often used in new energy power generation such as photovoltaics and wind power to solve the problems of power quality and stability during load changes in intermittent energy generation. Power distribution is achieved through energy management and distribution strategies. For example, in the study "Research on Energy Management of Small Wind Power Generation System Based on Hybrid Energy Storage", an energy distribution strategy combining low-pass filters and fuzzy controllers is adopted. This requires the design of complex fuzzy control rules and faces the problem of high implementation difficulty. Another example is the "Control Strategy of Hybrid Energy Storage System of Battery and Supercapacitor", which designs four controllers. Two of them are used to smooth load fluctuations, and the other two are used for charging control based on the state of charge of the battery and capacitor. This requires the design of switching logic between different controllers, and the system is prone to fluctuations and instability during frequent switching of controllers. Summary of the Invention

[0004] To address the issues of slow transient power response and inability to recover regenerated power when using fuel to provide electricity, this invention provides a combined power generation system and its power allocation method. Based on the advantages of the different power supply devices described below, and according to the actual power demand of the load, this invention can rationally and quickly allocate the power between the two, enabling timely response to transient load changes. It can also avoid the problems of complex design, high implementation difficulty, and poor system stability in the energy allocation process of the aforementioned combined power generation system.

[0005] The technical solution to achieve the purpose of the invention is as follows:

[0006] In a first aspect, the present invention provides a power distribution method for a combined power generation system, comprising the following steps:

[0007] S1. Collect the voltage feedback signal of the load power supply bus, and obtain the current available power value of the first power supply device and the current available power value of the second power supply device;

[0008] S2. Compare the voltage feedback signal with the preset voltage command value to generate a total power demand pre-command;

[0009] S3. Generate a total power demand instruction based on the total power demand pre-instruction, the current available power value of the first power supply device, and the current available power value of the second power supply device;

[0010] S4. Separate the low-frequency power command within the total power demand command as the first power demand pre-command for the power supply device, and calculate the difference between the total power demand command and the low-frequency power command as the second power demand pre-command for the power supply device.

[0011] S5. Based on the current available power value of the second power supply device, generate the power demand command for the first power supply device and the power demand command for the second power supply device;

[0012] S6. Output the power demand command of the first power supply device to the first power supply device, and output the power demand command of the second power supply device to the second power supply device;

[0013] S7. Repeat steps S1 to S6 until the load stops receiving power.

[0014] The power allocation method of the combined power generation system designed in this invention manages the total power demand of the load and adopts a power allocation strategy in which the first power supply device undertakes the power generation command of slow-changing, low-frequency power and the second power supply device undertakes the power generation command of transient, high-frequency power. This fully leverages the advantages of the first power supply device having a large specific energy and the second power supply device having a large specific power, so that the two power supply devices complement each other to respond to the transient load, ensure the stability of the combined power generation system, and guarantee the normal operation of each load.

[0015] In one embodiment of the power allocation method of the present invention, in step S1 above, the sum of the current available power value of the first power supply device and the current available power value of the second power supply device is less than or equal to the sum of the maximum power of the first power supply device and the maximum power of the second power supply device.

[0016] In an improved embodiment of the power allocation method of the present invention, in step S1 above, the method for obtaining the current available power value of the second power supply device is as follows: based on the charge state of the second power supply device, when the current charge value of the second power supply device is less than the lower threshold, the current available power value of the second power supply device is zero; when the upper threshold ≥ the charge value of the second power supply device ≥ the lower threshold, the current available power value of the second power supply device is the maximum power value allowed by the second power supply device.

[0017] Furthermore, when the current charge of the second power supply device is less than the lower threshold, a charging signal for the second power supply device is generated and output. By charging the second power supply device, it is ensured that the second power supply device can meet the instantaneous high-frequency power requirements generated by the load during subsequent use.

[0018] In one embodiment of the power allocation method of the present invention, in step S3 above, the method for generating the total power demand instruction is as follows: the total power demand pre-instruction is compared with the current total available power value; if the total power demand pre-instruction is greater than the current total available power value, an alarm signal is generated and output; if the current total available power value is greater than or equal to the total power demand pre-instruction and greater than 0, then the total power demand pre-instruction is the total power demand instruction.

[0019] In one embodiment of the power allocation method of the present invention, the method for generating the power demand command of the first power supply device and the power demand command of the second power supply device in step S5 above is as follows:

[0020] S501. Compare the power demand pre-command of the second power supply device with the current available power value of the second power supply device. If the power demand pre-command of the second power supply device is less than or equal to the current available power value of the second power supply device, then proceed to step S502. If the power demand pre-command of the second power supply device is greater than or equal to the current available power value of the second power supply device, then proceed to step S503.

[0021] S502, the power demand pre-instruction of the first power supply device is the power demand instruction of the first power supply device, and the power demand pre-instruction of the second power supply device is the power demand instruction of the second power supply device.

[0022] S503. The current available power value of the second power supply device is the power demand of the second power supply device. The difference between the power demand pre-instruction of the second power supply device and the current available power value of the second power supply device is used as the power overflow compensation value. The sum of the power overflow compensation value and the power demand pre-instruction of the first power supply device is used as the power demand instruction of the first power supply device.

[0023] In another improved embodiment of the power distribution method of the present invention, the first power supply device is a micro gas turbine and the second power supply device is a battery.

[0024] Secondly, the present invention provides a combined power generation system, which includes a power distribution system. The input end of the power distribution system is electrically connected to the electrical equipment, and the output end is connected to a first power supply system and a second power supply system, respectively. The power distribution system is used to distribute the output power of the first power supply device in the first power supply system and the second power supply device in the second power supply system according to the total power demand of the electrical equipment. The power distribution system includes a power demand acquisition module, a total power limiting and alarm module, a power distribution module, and a second power supply device power limiting module.

[0025] The power demand acquisition module is used to acquire the voltage feedback signal of the power load bus in real time and generate a total power demand pre-instruction.

[0026] The total power limiting and alarm module is used to judge the total power demand pre-instruction and generate the total power demand instruction.

[0027] The power allocation module is used to separate the low-frequency power command from the total power demand command and form the first power demand pre-command for the power supply device. It is also used to calculate the difference between the total power demand command and the low-frequency power command as the second power demand pre-command for the power supply device.

[0028] The second power supply device power limiting module determines the current available power value of the second power supply device based on the state of charge of the second power supply device, controls the state of the second power supply device, and outputs the power demand command of the second power supply device.

[0029] In one embodiment of the combined power generation system of the present invention, the power distribution module includes a slope controller, the input terminal of which is electrically connected to the total power limiting and alarm module, the output terminal of which is electrically connected to a low-pass filter, and the output terminal of the low-pass filter is electrically connected to the first power supply device.

[0030] In one embodiment of the combined power generation system of the present invention, the power distribution system further includes a power overflow compensation module. The power overflow compensation module is used to calculate the difference between the power demand pre-instruction of the second power supply device and the current power available value of the second power supply device as a power overflow compensation value when the power demand pre-instruction of the second power supply device is greater than the current power available value of the second power supply device. The power overflow compensation value is output and superimposed with the power demand pre-instruction of the first power supply device as the power demand instruction of the first power supply device.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: The combined power generation system and its power distribution method designed in this invention manage the total power demand of multiple loads connected to the electrical equipment. By adopting a power distribution strategy in which the first power supply device undertakes slow-changing, low-frequency power commands and the second power supply device undertakes transient, high-frequency power commands, the advantages of the first power supply device having a large specific energy and the second power supply device having a large specific power are fully utilized. This allows the two energy advantages to complement each other to meet the transient loads that appear in the corresponding loads, ensuring the stability of the combined power generation system and guaranteeing the normal operation of each load. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are merely for the purpose of more clearly illustrating the technical solutions in the embodiments of the present invention or the prior art. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0033] Figure 1 This is a structural block diagram of the combined power generation system in a specific implementation embodiment;

[0034] Figure 2 This is a structural block diagram of the power distribution system in a specific implementation embodiment;

[0035] Figure 3 This is a schematic diagram of the power distribution system of the combined power generation system in a specific implementation.

[0036] Figure 4 This is a schematic diagram illustrating the state of charge and limiting of the battery in a specific implementation method;

[0037] Figure 5 This is a flowchart of the power distribution method for the combined power generation system in a specific implementation;

[0038] The system comprises: 1. Power distribution system; 2. Electrical equipment; 3. First power supply system; 31. First power supply device; 32. Motor; 33. Starter / generator controller; 4. Second power supply system; 41. Second power supply device; 42. Bidirectional DC / DC converter; 100. Power demand acquisition module; 101. Comparison module; 102. Bus voltage controller; 200. Total power limiting and alarm module; 300. Power distribution module; 301. Slope controller; 302. Low-pass filter; 303. First power supply device limiting module; 400. Second power supply device power limiting module; 500. Power overflow compensation module. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0040] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0041] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Example 1:

[0042] This embodiment provides a combined power generation system. In this embodiment, the reference... Figure 1 As shown, the combined power generation system includes a power distribution system 1. The input terminal of the power distribution system 1 is electrically connected to the electrical equipment 2, and the output terminals are respectively connected in parallel to a first power supply system 3 and a second power supply system 4. The power distribution system 1 is used to distribute the output power of the first power supply system 3 and the second power supply system 4 according to the total power demand of the electrical equipment 2.

[0043] like Figure 1 As shown, in this embodiment, the first power supply system 3 includes a first power supply device 31, a motor 32, and a starter / generator controller 33. The first power supply device 31 is coaxially connected to the motor 32 or connected via a gearbox. The motor 32 is connected to the electrical device 2 via a DC bus through the starter / generator controller 33. The motor 32 can be a permanent magnet motor or other types of motor. In this embodiment, the first power supply device 31 is selected from those capable of converting chemical energy into electrical energy and providing low-frequency power, such as a gas turbine / micro gas turbine.

[0044] like Figure 1As shown, in this embodiment, the second power supply system 4 includes a second power supply device 41 and a bidirectional DC / DC converter 42. The second power supply device 41 is connected to the electrical device 2 via the bidirectional DC / DC converter 42 through a DC bus. In this embodiment, the second power supply device 41 is a battery, which can preferably be either a chemical battery or a supercapacitor. Alternatively, a second power supply device group formed by parallel connection of a chemical battery and a supercapacitor can be used. The second power supply system 4 can be formed by at least one parallel second power supply device group consisting of the second power supply device 41 and the bidirectional DC / DC converter 42, and power can be supplied through the cooperation of at least one second power supply device group.

[0045] In this embodiment, the electrical device 2 can be one or more loads depending on the application scenario. When the electrical device 2 is connected to the power grid through a DC / AC converter, the combined power supply system is a grid-connected power generation system. When the electrical device 2 is connected to a three-phase load through a DC / AC converter or directly connected to a DC load, the combined power supply system is an independent power supply system. When the electrical device 2 is connected to a propeller through a motor, the combined power supply system is a power generation system for the aircraft.

[0046] like Figure 2 As shown, the power distribution system 1 includes a power demand acquisition module 100, a total power limiting and alarm module 200, a power distribution module 300, and a second power supply device power limiting module 400.

[0047] The power demand acquisition module 100 is connected to the busbar of the electrical equipment 2 and is used to acquire the voltage feedback signal of the power supply busbar of the electrical equipment 2 in real time and generate a total power demand pre-command. Specifically, the power demand acquisition module 100 includes a comparison module 101 and a busbar voltage controller 102. Figure 3 As shown, the comparison module 101 is used to compare the voltage feedback signal with the preset voltage command value, and then generate a total power demand pre-command through the bus voltage controller 102.

[0048] The total power limiting and alarm module 200 is used to determine the total power demand pre-command and generate the total power demand command. Specifically, for example... Figure 3 As shown, the total power limiting and alarm module 200 sets an upper limit and a lower limit for total power based on the sum of the current available power values ​​of the first power supply system 3 and the second power supply system 4. When the total power demand pre-instruction is within the upper limit and the lower limit, the total power limiting and alarm module 200 outputs a total power demand instruction. When the total power demand pre-instruction is greater than the upper limit, the upper limit is set to the sum of the current available power values ​​of the first power supply system 3 and the second power supply system 4, and an alarm signal is output.

[0049] The power allocation module 300 is used to separate the low-frequency power instruction from the total power demand instruction and form a first power demand pre-instruction for the power supply device. It is also used to calculate the difference between the total power demand instruction and the low-frequency power instruction as a second power demand pre-instruction for the power supply device.

[0050] Specifically, in order to extract the power demand from the total power demand command that conforms to the operating characteristics of the first power supply system 3, thereby enabling the first power supply system 3 to operate in its optimal state, improve its thermodynamic efficiency, and extend its lifespan, in one structure of the power distribution module 300, such as... Figure 2 As shown, the power distribution module 300 includes a slope controller 301. The input of the slope controller 301 is electrically connected to the total power limiting and alarm module 200, and the output of the slope controller 301 is electrically connected to a low-pass filter 302. The output of the low-pass filter 302 is electrically connected to the first power supply system 3. The slope controller 301 can limit the speed of power demand to meet the response speed of the first power supply system 3, and the low-pass filter 302 can extract the slow variable power from the total power demand command. In another structure of the power distribution module 300, as shown... Figure 2 As shown, in addition to the slope controller 301 and the low-pass filter 302, the power distribution module 300 includes a first power supply device limiting module 303. The first power supply device limiting module 303 is electrically connected to the low-pass filter 302. The first power supply device limiting module 303 is used to prevent power from flowing back into the first power supply device, and the power limiting range of the first power supply device limiting module 303 is from zero to the maximum power allowed by the first power supply device.

[0051] At this time, as Figure 3 As shown, after the slow variable power is extracted, the blocked fast variable power, that is, the difference between the total power demand command and the slow variable power, is allocated to the second power supply system 4 to form the power demand pre-command of the second power supply device.

[0052] Specifically, the second power supply device power limiting module 400 determines the current available power value of the second power supply device based on its state of charge, controls the state of the second power supply system 4, and outputs a power demand command for the second power supply device. Figure 4As shown, the second power supply device's charge state includes three states: sufficient power, normal power, and low power. When the second power supply system 4 is in the sufficient power or normal power state, the current available power value of the second power supply device generated by the power limiting module 400 is the maximum allowable power value of the second power supply system 4. The maximum allowable power value of the second power supply system 4 is controlled and limited by the current management system (BMS), and the second power supply system 4 can provide power to the electrical device 2 in both states. When the second power supply system 4 is in the low power state, the current available power value of the second power supply device generated by the power limiting module 400 is zero, and it cannot provide power to the electrical device 2. It should be noted that when the second power supply system 4 is in the sufficient power state, if the load generates feedback energy, the second power supply system 4 cannot absorb the feedback energy. It can only absorb feedback energy when the second power supply system 4 is in the normal power or low power state.

[0053] Under normal conditions, the current available power value of the second power supply device is to meet the transient changes in the load (i.e., fast variable power). Therefore, the power demand pre-instruction of the second power supply device is within the current available power value of the second power supply device. At this time, the power demand instruction of the second power supply device output by the power limiting module 400 of the second power supply device is equal to the power demand pre-instruction of the second power supply device.

[0054] However, when the pre-command for the power demand of the second power supply device exceeds the current available power value of the second power supply device, the power supply of the second power supply system 4 cannot meet the pre-command for the power demand of the second power supply device. In this case, the power demand command output by the second power supply system 4 is equal to the current available power value of the second power supply device. The difference between the pre-command for the power demand of the second power supply device and the current available power value of the second power supply device needs to be forcibly allocated to the first power supply system 3 and provided by the first power supply system 3. Therefore, if... Figure 2 As shown, in another structure of the power distribution system 1, the power distribution system 1 further includes a power overflow compensation module 500. The power overflow compensation module 500 is used to calculate the difference between the power demand pre-instruction of the second power supply device and the current power available value of the second power supply device as a power overflow compensation value when the power demand pre-instruction of the second power supply device is greater than the current power available value of the second power supply device. The power overflow compensation value is output and superimposed with the power demand pre-instruction of the first power supply device as the power demand instruction of the first power supply device.

[0055] The combined power generation system designed in this specific embodiment manages the total power demand of the load and adopts a power allocation strategy in which the first power supply device undertakes slow-changing, low-frequency power commands and the second power supply device undertakes transient, high-frequency power commands. This fully leverages the advantages of the first power supply device having a large specific energy and the second power supply device having a large specific power, so that the two energy advantages complement each other to deal with the transient loads that appear in the corresponding loads, ensuring the stability of the combined power generation system and guaranteeing the normal operation of each load. Example 2:

[0056] This embodiment provides a power allocation method for a combined power generation system. The power allocation method of this embodiment uses the power allocation system 1 in embodiment 1 to allocate the power generation power of the first power supply system 3 and the second power supply system 4 according to the total power demand of the load connected to the electrical equipment 2.

[0057] In the power distribution method of the combined power generation system described below, the first power supply device is a micro gas turbine, and the second power supply device is a chemical battery or a supercapacitor. Of course, the first power supply device can also be other power generation equipment that can generate slow power, and the second power supply device can also be other energy storage batteries. There are no restrictions on them here.

[0058] like Figure 5 As shown, the power allocation method includes the following steps:

[0059] S1. Collect the voltage feedback signal of the load power supply bus and obtain the current available power value of the micro gas turbine and the current available power value of the battery.

[0060] Specifically, the sum of the current available power of the micro gas turbine and the current available power of the battery is less than or equal to the sum of the maximum power of the micro gas turbine and the maximum power of the battery.

[0061] Furthermore, the method for obtaining the current available power value of the battery is as follows: based on the battery's state of charge, when the current charge value of the battery is less than the lower threshold, the current available power value of the battery is zero; when the upper threshold is greater than or equal to the battery charge value and greater than or equal to the lower threshold, the current available power value of the battery is the maximum power value allowed by the battery.

[0062] Furthermore, when the current charge of the battery is less than the lower threshold, a battery charging signal is generated and output. Upon receiving this signal, the power distribution system charges the battery via a micro gas turbine or other charging equipment to ensure that the battery meets the instantaneous high-frequency power demands of the load during subsequent use. The method by which the micro gas turbine charges the battery is as follows: when the maximum output power of the micro gas turbine exceeds the power required in the micro gas turbine power demand command, it indicates that the micro gas turbine still has the capacity to charge the battery, and in this case, the battery can be charged via the micro gas turbine.

[0063] It should be noted that the state of charge of the battery in this step is the same as that in Example 1, and will not be described again here.

[0064] S2. Compare the voltage feedback signal with the preset voltage command value to generate a total power demand pre-command.

[0065] Specifically, the total power demand pre-command is generated and output by the bus voltage controller 102 after the voltage feedback signal is compared with the preset voltage command value by the comparison module 101.

[0066] S3. Generate a total power demand command based on the total power demand pre-command, the current available power value of the micro gas turbine, and the current available power value of the battery.

[0067] Specifically, the method for generating the total power demand command is as follows: compare the total power demand pre-command with the current total available power value. If the total power demand pre-command is greater than the current total available power value, an alarm signal is generated and output; if the current total available power value is greater than or equal to the total power demand pre-command and greater than 0, then the total power demand pre-command is the total power demand command.

[0068] S4. Separate the low-frequency power command within the total power demand command as the micro gas turbine power demand pre-command, and calculate the difference between the total power demand command and the low-frequency power command as the battery power demand pre-command.

[0069] In this step, the total power demand command is obtained by extracting and separating the slow variable power through the power allocation module 300, which yields the micro gas turbine power demand pre-command. For details, please refer to the description of the power allocation module 300 in Example 1.

[0070] S5. Based on the current available power value of the battery, generate a power demand command for the micro gas turbine and a power demand command for the battery.

[0071] In this step, the methods for generating the micro gas turbine power demand command and the battery power demand command are as follows:

[0072] S501. Compare the battery power demand pre-command with the battery current available power value. If the battery power demand pre-command is less than or equal to the battery current available power value, proceed to step S502. If the battery power demand pre-command is greater than the battery current available power value, proceed to step S503.

[0073] S502, the micro gas turbine power demand pre-command is the micro gas turbine power demand command, and the battery power demand pre-command is the battery power demand command;

[0074] S503. The current available power value of the battery is the battery power demand. The difference between the pre-instruction for battery power demand and the current available power value of the battery is used as the power overflow compensation value. The sum of the power overflow compensation value and the pre-instruction for micro gas turbine power demand is used as the micro gas turbine power demand instruction.

[0075] S6. Output the power demand command of the micro gas turbine to the micro gas turbine, and output the power demand command of the battery to the battery.

[0076] S7. Repeat steps S1 to S6 until the load stops receiving power.

[0077] The power allocation method of the combined power generation system provided in this embodiment manages the total power demand of the load and adopts a power allocation strategy in which a micro gas turbine undertakes slow-changing, low-frequency power commands and a battery undertakes transient, high-frequency power commands. This fully leverages the advantages of the high specific energy of the micro gas turbine and the high specific power of the battery, allowing the two energy sources to complement each other to handle transient loads, ensuring the stability of the combined power generation system and guaranteeing the normal operation of each load.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0079] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method of power distribution for a combined power generation system, characterized by, Includes the following steps: S1. Collect the voltage feedback signal of the load power supply bus, and obtain the current available power value of the first power supply device and the current available power value of the second power supply device; S2. Compare the voltage feedback signal with the preset voltage command value to generate a total power demand pre-command; S3. Generate a total power demand instruction based on the total power demand pre-instruction, the current available power value of the first power supply device, and the current available power value of the second power supply device; S4. Separate the low-frequency power command within the total power demand command as the first power demand pre-command for the power supply device, and calculate the difference between the total power demand command and the low-frequency power command as the second power demand pre-command for the power supply device. S5. Based on the current available power value of the second power supply device, generate the power demand command for the first power supply device and the power demand command for the second power supply device. S6. Output the power demand command of the first power supply device to the first power supply device, and output the power demand command of the second power supply device to the second power supply device; S7. Repeat steps S1 to S6 until the load stops receiving power; In step S3, the method for generating the total power demand instruction is as follows: compare the total power demand pre-instruction with the current total available power value. If the total power demand pre-instruction is greater than the current total available power value, then an alarm signal is generated and output; if the current total available power value is greater than or equal to the total power demand pre-instruction and greater than 0, then the total power demand pre-instruction is the total power demand instruction. In step S5, the methods for generating the power demand command of the first power supply device and the power demand command of the second power supply device are as follows: S501. Compare the power demand pre-command of the second power supply device with the current available power value of the second power supply device. If the power demand pre-command of the second power supply device is less than or equal to the current available power value of the second power supply device, then proceed to step S502. If the power demand pre-command of the second power supply device is greater than or equal to the current available power value of the second power supply device, then proceed to step S503. S502, the power demand pre-instruction of the first power supply device is the power demand instruction of the first power supply device, and the power demand pre-instruction of the second power supply device is the power demand instruction of the second power supply device. S503. The current available power value of the second power supply device is the power demand instruction of the second power supply device. The difference between the power demand pre-instruction of the second power supply device and the current available power value of the second power supply device is used as the power overflow compensation value. The sum of the power overflow compensation value and the power demand pre-instruction of the first power supply device is used as the power demand instruction of the first power supply device. The first power supply device is a micro gas turbine, and the second power supply device is a storage battery.

2. The power distribution method of claim 1, wherein, In step S1, the sum of the current available power of the first power supply device and the current available power of the second power supply device is less than or equal to the sum of the maximum power of the first power supply device and the maximum power of the second power supply device.

3. The power distribution method of claim 2, wherein, In step S1, the method for obtaining the current available power value of the second power supply device is as follows: based on the state of charge of the second power supply device, when the current charge value of the second power supply device is less than the lower threshold, the current available power value of the second power supply device is zero; when the upper threshold is greater than or equal to the current charge value of the second power supply device and greater than or equal to the lower threshold, the current available power value of the second power supply device is the maximum power value allowed by the second power supply device.

4. The power distribution method of claim 3, wherein, When the current charge value of the second power supply device is less than the lower threshold, a charging signal for the second power supply device is also generated and output.

5. A combined power generation system for implementing the power distribution method of any one of claims 1-4, characterized by: The combined power generation system includes a power distribution system. The input end of the power distribution system is electrically connected to the electrical equipment, and the output end is connected to the first power supply system and the second power supply system, respectively. The power distribution system is used to distribute the output power of the first power supply device in the first power supply system and the second power supply device in the second power supply system according to the total power demand of the electrical equipment. It includes a power demand acquisition module, a total power limiting and alarm module, a power distribution module, and a second power supply device power limiting module. The power demand acquisition module is used to acquire the voltage feedback signal of the power load bus in real time and generate a total power demand pre-instruction. The total power limiting and alarm module is used to judge the total power demand pre-instruction and generate the total power demand instruction; The power allocation module is used to separate the low-frequency power instruction from the total power demand instruction and form a first power demand pre-instruction for the power supply device. It is also used to calculate the difference between the total power demand instruction and the low-frequency power instruction as a second power demand pre-instruction for the power supply device. The second power supply device power limiting module forms the current available power value of the second power supply device based on the state of charge of the second power supply device, controls the state of the second power supply device, and outputs the power demand command of the second power supply device.

6. The combined power generation system of claim 5, wherein: The power distribution module includes a slope controller. The input terminal of the slope controller is electrically connected to the total power limiting and alarm module. The output terminal of the slope controller is electrically connected to a low-pass filter, and the output terminal of the low-pass filter is electrically connected to the first power supply device.

7. The combined power generation system of claim 5, wherein: The power distribution system also includes a power overflow compensation module. The power overflow compensation module is used to calculate the difference between the power demand pre-instruction of the second power supply device and the current power available value of the second power supply device as a power overflow compensation value when the power demand pre-instruction of the second power supply device is greater than the current power available value of the second power supply device. The power overflow compensation value is output and superimposed with the power demand pre-instruction of the first power supply device as the power demand instruction of the first power supply device.

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