A method of controlling a power generation system and a power generation system

Abstract

The application relates to the technical field of hot gas engines and relates to a power generation system control method and a power generation system. The method comprises the following steps: opening a hot gas engine short circuit valve and charging to a first working medium pressure, and continuing to charge to a second working medium pressure after a permanent magnet motor drives the hot gas engine to a first rotating speed. After ignition succeeds, the permanent magnet motor and the hot gas engine are controlled to operate within a rated rotating speed, a third working medium pressure is calculated in real time according to parameters such as fuel flow, control calculation results and heater tube wall temperature, and the third working medium pressure is set, a direct current voltage control value is calculated in real time based on direct current bus voltage related parameters, a voltage control word is determined, and a load power gear is adjusted. When stopping, the stopping process is subdivided into multiple stages, and different control strategies are adopted for each stage, so that the power generation system can stop quickly. The method not only effectively avoids the problem that heat is accumulated on the heater tube wall of the hot gas engine for a long time and the problem that the hot gas engine heater is damaged due to overheating, but also prolongs the service life of the storage battery.

Description

Technical Field

[0001] This application relates to the field of hot air engine technology, and further to a power generation system control method and power generation system. Background Technology

[0002] Currently, to achieve miniaturization and high power density in the coupled gas turbine and permanent magnet motor power generation system, its combustion chamber is designed to be relatively compact. This results in a rapid rise in the temperature of the gas turbine heater tube wall after the power generation system starts and ignites successfully. If heat accumulates on the gas turbine heater tube wall for an extended period, it may damage the gas turbine heater. Simultaneously, during the operation of the coupled gas turbine and permanent magnet motor power generation system, the load power cannot respond quickly to changes in the DC bus voltage. This situation causes variations in battery capacity, thereby reducing battery life. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a power generation system control method and a power generation system, which improves the service life of the hot air engine heater.

[0004] In a first aspect, this application provides a power generation system control method, comprising: opening a short-circuit valve of a hot air engine and charging the hot air engine until the working fluid pressure of the hot air engine reaches a first working fluid pressure; driving the hot air engine through a permanent magnet motor, and continuing to charge the hot air engine when the hot air engine reaches a first speed until the working fluid pressure of the hot air engine reaches a second working fluid pressure; after the power generation system is successfully ignited, controlling the permanent magnet motor and the hot air engine to operate within the rated speed range, and calculating a third working fluid pressure in real time based on the hot air engine fuel flow rate value, the first control calculation result, the current temperature and rated temperature of the hot air engine heater tube wall, and the tube wall temperature control dead zone value of the hot air engine heater; setting the working fluid pressure of the hot air engine to the third working fluid pressure so that the tube wall temperature of the hot air engine heater is within the first rated temperature range, and calculating the current DC bus voltage control value in real time based on the current DC bus voltage value, the DC bus voltage value of the previous measurement cycle, the measurement cycle and the second control calculation result, the DC bus voltage control value, and the DC bus voltage control dead zone value; and based on the current DC bus voltage control value, The system determines the voltage control word and adjusts the load power level based on it. When the power generation system shuts down and the current wall temperature of the gas turbine heater is lower than the first preset temperature, the gas turbine is vented until the working fluid pressure reaches the fourth working fluid pressure. The gas turbine short-circuit valve is then opened, and the permanent magnet motor is controlled to run within the first speed range before the gas turbine short-circuit valve is closed. During the power generation system shutdown, if the current DC bus voltage is lower than the first preset voltage for a first preset time, all load power levels are closed. During the power generation system shutdown, if the current wall temperature of the gas turbine heater is lower than the second preset temperature for a second preset time, the permanent magnet motor is controlled to run at the second speed. During the power generation system shutdown, if the current wall temperature of the gas turbine heater is lower than the third preset temperature for a second preset time, the permanent magnet motor is controlled to run at the third speed. During the power generation system shutdown, if the current wall temperature of the gas turbine heater is lower than the fourth preset temperature for a second preset time, the gas turbine short-circuit valve is opened and the permanent magnet motor is stopped.

[0005] The above power generation system control method, during the power generation system startup phase, first opens the hot air blower short-circuit valve, then charges the hot air blower until the working fluid pressure reaches the first working fluid pressure. When the hot air blower reaches the first speed, charging continues until the working fluid pressure reaches the second working fluid pressure. This series of operations ensures that the working fluid in the hot air blower begins to flow before the power generation system ignites, and can promptly absorb the heat generated on the wall of the hot air blower heater after successful ignition. This effectively avoids prolonged heat accumulation on the wall of the hot air blower heater, thus preventing damage due to overheating and significantly improving the service life of the hot air blower heater. Simultaneously, this also reduces the performance requirements of the hot air blower heater materials, thereby saving on the production cost of the hot air blower and reducing the difficulty of its widespread adoption.

[0006] Furthermore, this embodiment calculates the third working fluid pressure in real time, determines the current DC bus voltage control value based on the third working fluid pressure, obtains the voltage control word based on the current DC bus voltage control value, and finally adjusts the load power level based on the voltage control word. This process cleverly establishes a mapping relationship between the DC bus voltage control value and the load power level, enabling changes in the load power level to quickly respond to changes in the DC bus voltage, achieving precise and stable control of the DC bus voltage. Because the DC bus voltage is stable, the battery voltage also remains stable, which helps to improve the battery's lifespan.

[0007] Furthermore, during the shutdown process of the power generation system, this embodiment of the application subdivides the shutdown process into multiple stages and adopts different control strategies for each stage. Specifically, when the power generation system shuts down and the current temperature of the pipe wall of the hot air blower heater is lower than the first preset temperature, the hot air blower is vented until the working fluid pressure reaches the fourth working fluid pressure, and the hot air blower short-circuit valve is opened. The permanent magnet motor is then controlled to run within the first speed range before the short-circuit valve is closed. If the current DC bus voltage value is lower than the first preset voltage and remains lower than the first preset time during the shutdown process, all load power levels are closed. If the current temperature of the pipe wall of the hot air blower heater is lower than the second preset temperature and remains lower than the second preset time, the permanent magnet motor is controlled to run at the second speed. If the current pipe wall temperature is lower than the third preset temperature and remains lower than the second preset time, the permanent magnet motor is controlled to run at the third speed. If the current pipe wall temperature is lower than the fourth preset temperature and remains lower than the second preset time, the short-circuit valve is opened and the permanent magnet motor is stopped. This phased and refined control strategy not only enables the power generation system to shut down quickly, but also makes the temperature change of the pipe wall of the hot air engine heater more stable, further improving the service life of the hot air engine heater and enhancing the reliability and stability of the entire power generation system.

[0008] In one implementation, after the power generation system is successfully ignited, the permanent magnet motor and the hot air engine are controlled to operate within their rated speed range. Specifically, this includes: when the working fluid pressure of the hot air engine reaches the second working fluid pressure, closing the hot air engine short-circuit valve and controlling the power generation system to ignite; after the power generation system is successfully ignited, the current operating speed of the hot air engine is calculated in real time based on the first speed, the current temperature of the hot air engine heater tube wall, the temperature of the hot air engine heater tube wall in the previous timing period, the first working fluid pressure, the second working fluid pressure, and the timing period; based on the current operating speed of the hot air engine, the speeds of the hot air engine and the permanent magnet motor are adjusted until the permanent magnet motor and the hot air engine operate within their rated speed range.

[0009] In one implementation, the working fluid pressure of the hot air engine is set to a third working fluid pressure, specifically including: when the working fluid pressure of the hot air engine is less than the third working fluid pressure, charging the hot air engine until the working fluid pressure of the hot air engine reaches the third working fluid pressure; when the working fluid pressure of the hot air engine is greater than the third working fluid pressure, controlling the hot air engine to exhaust gas until the working fluid pressure of the hot air engine reaches the third working fluid pressure.

[0010] In one implementation, the method further includes: dividing the DC bus voltage control range into multiple voltage intervals based on the DC bus voltage control dead zone value; determining a voltage control word based on the current DC bus voltage control value; and adjusting the load power level based on the voltage control word. Specifically, this includes: determining a voltage interval based on the current DC bus voltage control value; determining a voltage control word based on the voltage interval; converting the voltage control word into a binary number; and adjusting the load power level according to the binary number.

[0011] In one implementation, the method further includes: increasing / decreasing the control voltage word by a preset value for each voltage interval shift of the current DC bus voltage control value; increasing the control voltage word by a preset value every third preset time interval when the current DC bus voltage control value is greater than the upper limit of multiple voltage intervals; decreasing the control voltage word by a preset value every fourth preset time interval when the current DC bus voltage control value is less than the lower limit of multiple voltage intervals; assigning the voltage control word the first threshold value when it is not less than the first threshold value; and assigning the voltage control word the second threshold value when it is not greater than the second threshold value.

[0012] The above power generation system control method divides the DC bus voltage control range into multiple voltage intervals based on the DC bus voltage control dead zone value. It determines the corresponding voltage interval based on the current DC bus voltage control value, then determines the voltage control word, and finally converts the voltage control word into a binary number to adjust the load power level. This achieves refined and dynamic adjustment of the load power level. This control method allows the load power to respond more accurately to changes in the DC bus voltage, effectively improving the accuracy and stability of DC bus voltage control, thereby ensuring battery voltage stability, extending battery life, and improving the performance and reliability of the entire power generation system. Furthermore, when the current DC bus voltage control value moves by one voltage interval, the control voltage word is increased or decreased by a preset value. When the voltage control value exceeds the upper or lower limit of the voltage interval, the increase or decrease of the voltage control word is controlled by a third and fourth preset time, further enhancing the system's adaptability and adjustment flexibility to voltage changes. Simultaneously, setting a first and second threshold for the voltage control word avoids abnormal fluctuations, ensuring stable system operation and further improving the control performance and stability of the power generation system.

[0013] In one implementation, the method further includes: determining a first voltage threshold based on the lower limit of the DC bus voltage control dead zone value and the DC bus voltage control range value; determining a second voltage threshold based on the DC bus voltage control value and the DC bus voltage control dead zone value; determining a third voltage threshold based on the DC bus voltage control dead zone value and the upper limit of the DC bus voltage control range value; stopping the calculation of the current DC bus voltage control value when the current DC bus voltage value is not greater than the first voltage threshold and continues for a fifth preset time; setting the current DC bus voltage value within the first preset voltage range according to the current DC bus voltage control value when the current DC bus voltage value is not less than the second voltage threshold and continues for a fifth preset time; issuing an alarm when the current DC bus voltage value is not less than the third voltage threshold and continues for a sixth preset time; and shutting down all load power levels and controlling the power generation system to supply power to the battery when the voltage control word is assigned a value of 0.

[0014] In one implementation, the method further includes: when the current temperature of the tube wall of the hot air engine heater reaches the sum of the rated temperature and the bias value of the tube wall of the hot air engine heater, and this continues for a seventh preset time, performing a step of real-time calculation of the third working fluid pressure.

[0015] Secondly, this application provides a power generation system, comprising: a hot air engine and a permanent magnet motor coaxially integrated, a battery, and a load; a converter, the input of which is connected to the permanent magnet motor, and the output of which is connected to the battery and the load respectively via a DC bus; a system controller, which is connected to the hot air engine, the permanent magnet motor, the converter, the battery, and the load respectively; the system controller is configured to open the hot air engine short-circuit valve and charge the hot air engine until the working fluid pressure of the hot air engine reaches a first working fluid pressure; the system controller is configured to drive the hot air engine through the permanent magnet motor, and when the hot air engine runs to a first speed, continue to charge the hot air engine until the working fluid pressure of the hot air engine reaches a second speed. Working fluid pressure; the system controller is configured to control the permanent magnet motor and the hot air engine to operate within the rated speed range after successful ignition of the power generation system, and to calculate the third working fluid pressure in real time based on the hot air engine fuel flow rate, the first control calculation result, the current and rated pipe wall temperatures of the hot air engine heater, and the dead zone value of the pipe wall temperature control of the hot air engine heater; the system controller is configured to set the working fluid pressure of the hot air engine to the third working fluid pressure so that the pipe wall temperature of the hot air engine heater is within the first rated temperature range, and to calculate the third working fluid pressure based on the current DC bus voltage value, the DC bus voltage value of the previous measurement cycle, the measurement cycle, the second control calculation result, the DC bus voltage control value, and the DC bus... The system controller is configured to: control the dead zone value of the line voltage and calculate the current DC bus voltage control value in real time; determine the voltage control word based on the current DC bus voltage control value and adjust the load power level based on the voltage control word; discharge the gas from the gas turbine when the power generation system is shut down and the current wall temperature of the gas turbine heater is lower than the first preset temperature, until the working fluid pressure of the gas turbine reaches the fourth working fluid pressure, open the gas turbine short-circuit valve, control the permanent magnet motor to run within the first speed range, and then close the gas turbine short-circuit valve; and close the gas turbine short-circuit valve if, during the power generation system shutdown process, the current DC bus voltage value is lower than the first preset voltage and remains below the first preset voltage for a certain period of time. When a preset time is reached, all load power levels are shut down; the system controller is configured to, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air blower heater is lower than a second preset temperature and remains so for a second preset time, control the permanent magnet motor to run at a second speed; the system controller is configured to, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air blower heater is lower than a third preset temperature and remains so for a second preset time, control the permanent magnet motor to run at a third speed; the system controller is configured to, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air blower heater is lower than a fourth preset temperature and remains so for a second preset time, open the hot air blower short-circuit valve and control the permanent magnet motor to stop.

[0016] In one implementation, the permanent magnet motor is used to drive the hot air engine when it is in the first operating state, and when it is in the second operating state, it is used to convert the mechanical energy output by the hot air engine into electrical energy output.

[0017] In one implementation, the load is used to consume the electrical energy output by the permanent magnet motor when it is in the second operating state; the load is set with multiple load power levels, and each load power level has a corresponding control channel in the system controller; the system controller adjusts the multiple load power levels of the load through the multiple control channels.

[0018] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0019] 1. During the startup phase of the power generation system, the short-circuit valve of the hot air engine is first opened, followed by charging the hot air engine until the working fluid pressure reaches the first working fluid pressure. When the hot air engine reaches the first speed, charging continues until the working fluid pressure reaches the second working fluid pressure. This series of operations ensures that the working fluid in the hot air engine begins to flow before the power generation system ignites, allowing it to promptly absorb the heat generated on the heater tube wall after successful ignition. This effectively prevents heat from accumulating on the heater tube wall for extended periods, thus preventing damage to the heater due to overheating and significantly extending its service life. Simultaneously, this reduces the performance requirements for the heater materials, thereby saving on production costs and lowering the difficulty of its widespread adoption.

[0020] Furthermore, this embodiment calculates the third working fluid pressure in real time, determines the current DC bus voltage control value based on the third working fluid pressure, obtains the voltage control word based on the current DC bus voltage control value, and finally adjusts the load power level based on the voltage control word. This process cleverly establishes a mapping relationship between the DC bus voltage control value and the load power level, enabling changes in the load power level to quickly respond to changes in the DC bus voltage, achieving precise and stable control of the DC bus voltage. Because the DC bus voltage is stable, the battery voltage also remains stable, which helps to improve the battery's lifespan.

[0021] Furthermore, during the shutdown process of the power generation system, this embodiment of the application subdivides the shutdown process into multiple stages and adopts different control strategies for each stage. Specifically, when the power generation system shuts down and the current temperature of the pipe wall of the hot air blower heater is lower than the first preset temperature, the hot air blower is vented until the working fluid pressure reaches the fourth working fluid pressure, and the hot air blower short-circuit valve is opened. The permanent magnet motor is then controlled to run within the first speed range before the short-circuit valve is closed. If the current DC bus voltage value is lower than the first preset voltage and remains lower than the first preset time during the shutdown process, all load power levels are closed. If the current temperature of the pipe wall of the hot air blower heater is lower than the second preset temperature and remains lower than the second preset time, the permanent magnet motor is controlled to run at the second speed. If the current pipe wall temperature is lower than the third preset temperature and remains lower than the second preset time, the permanent magnet motor is controlled to run at the third speed. If the current pipe wall temperature is lower than the fourth preset temperature and remains lower than the second preset time, the short-circuit valve is opened and the permanent magnet motor is stopped. This phased and refined control strategy not only enables the power generation system to shut down quickly, but also makes the temperature change of the pipe wall of the hot air engine heater more stable, further improving the service life of the hot air engine heater and enhancing the reliability and stability of the entire power generation system.

[0022] 2. Based on the DC bus voltage control dead zone value, the DC bus voltage control range is divided into multiple voltage intervals. The corresponding voltage interval is determined according to the current DC bus voltage control value, and then the voltage control word is determined. This voltage control word is then converted into a binary number to adjust the load power level, achieving fine-grained and dynamic adjustment of the load power level. This control method allows the load power to respond more accurately to changes in the DC bus voltage, effectively improving the accuracy and stability of DC bus voltage control, thereby ensuring battery voltage stability, extending battery life, and improving the performance and reliability of the entire power generation system. Furthermore, when the current DC bus voltage control value moves one voltage interval, the control voltage word is increased or decreased by a preset value. When the voltage control value exceeds the upper or lower limit of the voltage interval, the increase or decrease of the voltage control word is controlled by a third and fourth preset time, further enhancing the system's adaptability to voltage changes and its adjustment flexibility. Simultaneously, setting a first and second threshold for the voltage control word avoids abnormal fluctuations, ensuring stable system operation and further improving the control performance and stability of the power generation system. Attached Figure Description

[0023] The preferred embodiments will now be described in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of the present invention.

[0024] Figure 1 This illustration shows a structural schematic diagram of a coupled power generation system of a hot air engine and a permanent magnet motor provided in an embodiment of this application;

[0025] Figure 2 A flowchart of a power generation system control method provided in an embodiment of this application is shown;

[0026] Figure 3 This document illustrates a flowchart of adjusting a hot air engine and a permanent magnet motor to their rated speed range, according to an embodiment of this application.

[0027] Figure 4 A flowchart of a power generation system control method provided in an embodiment of this application is shown;

[0028] Figure 5 This illustration shows a schematic diagram of an independent isolated grid application of a hot air engine coupled with a permanent magnet motor for power generation, provided by an embodiment of this application. Detailed Implementation

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0030] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0031] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0032] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0035] As an external combustion engine, the hot air engine has attracted much attention in the energy field due to its wide adaptability to energy sources and excellent environmental characteristics. When a hot air engine is coaxially integrated with a permanent magnet motor, a hot air engine-permanent magnet motor coupled power generation system is formed, for example... Figure 5 This diagram illustrates an independent isolated grid application of a gas turbine coupled with a permanent magnet motor for power generation. Currently, to achieve miniaturization and high power density in this system, the combustion chamber is designed to be quite compact. However, this compact design also presents certain challenges. After the power generation system starts and successfully ignites, the temperature of the gas turbine heater tube wall rises rapidly. If heat accumulates on the gas turbine heater tube wall for an extended period, it may damage the heater. Of course, using high-performance materials for the gas turbine heater can effectively avoid this problem. However, the use of high-performance materials undoubtedly increases the production cost of the gas turbine, which to some extent hinders the large-scale adoption of the gas turbine heater.

[0036] Another pressing issue arises during the operation of a coupled gas turbine and permanent magnet motor power generation system: the load power cannot respond quickly to changes in the DC bus voltage. This causes fluctuations in battery capacity, thereby reducing battery lifespan. Therefore, to ensure stable system operation and a long battery life, the power generation capacity must be matched to the load. Especially when the power generation level changes, the load power level needs to adjust rapidly to maintain stable battery capacity.

[0037] Therefore, this application provides a power generation system control method and a power generation system to solve the problems of damage to the heater of the hot air engine and low battery life in the prior art.

[0038] The following explanation is based on the accompanying diagram:

[0039] Reference Appendix Figure 1 This illustration shows a structural schematic diagram of a coupled power generation system of a hot air engine and a permanent magnet motor provided in an embodiment of this application. Figure 1 As shown, the system includes: a heat exchanger, a permanent magnet motor, a converter, a battery, a load, and a system controller. The heat exchanger and permanent magnet motor are integrated coaxially. The converter's input is connected to the permanent magnet motor, and its output is connected to the battery and the load via a DC bus. The system controller is connected to the heat exchanger, permanent magnet motor, converter, battery, and load.

[0040] The hot air engine is equipped with a short-circuit valve. When the short-circuit valve is closed, the working gas in the hot air engine is isolated; when the short-circuit valve is open, the working gas in the hot air engine is connected. The converter is used to convert the DC power from the battery to AC power to supply the permanent magnet motor during startup. After startup, it is used to convert the AC power output from the permanent magnet motor back to DC power to supply the battery or load.

[0041] The permanent magnet motor functions as both a motor and a generator. During system startup, the permanent magnet motor operates in its first state (or as a motor), driving the heat pump. Once the heat pump's working cycle is established, the permanent magnet motor operates in its second state (or as a generator), converting the mechanical work output by the heat pump into electrical energy. When the system shuts down, the permanent magnet motor first operates in its second state, converting the energy accumulated within the heat pump into electrical energy. Once the energy accumulated inside the heat pump is depleted, the permanent magnet motor switches back to its first state, driving the heat pump and ensuring the heater wall temperature reaches a safe shutdown temperature. The battery provides power to the permanent magnet motor when it is in its first state; when it is in its second state, it acts as a load consuming the energy output by the permanent magnet motor. The load consumes the energy output by the permanent magnet motor and has multiple different power levels.

[0042] The system controller has multiple control channels, each corresponding to a specific load power level. When any control channel is activated, the corresponding load power level begins operating, consuming power from the DC bus and thus reducing the DC bus voltage. Conversely, when any control channel is deactivated, the corresponding load power level ceases operation, no longer consuming power from the DC bus, thereby increasing the DC bus voltage. Furthermore, the system controller also controls the short-circuit valve, fuel flow, ignition, and working fluid pressure of the hot air engine. It also measures the engine's temperature, pressure, flow rate, speed, and power, and monitors the status of the permanent magnet motor, converter, DC bus, battery, and load.

[0043] Reference Appendix Figure 2 The document illustrates a flowchart of a power generation system control method provided in an embodiment of this application. This method is applied to the aforementioned embodiment of a power generation system coupled with a hot air engine and a permanent magnet motor (hereinafter referred to as the power generation system), such as... Figure 2 As shown, it includes:

[0044] S200, open the hot air engine short-circuit valve and charge the hot air engine until the working fluid pressure of the hot air engine reaches the first working fluid pressure;

[0045] S210 drives the hot air engine through a permanent magnet motor, and continues to charge the hot air engine when it reaches the first speed until the working fluid pressure of the hot air engine reaches the second working fluid pressure.

[0046] S220, after the power generation system is successfully ignited, controls the permanent magnet motor and the hot air engine to operate within the rated speed range, and calculates the third working fluid pressure in real time based on the hot air engine fuel flow rate, the first control calculation result, the current and rated pipe wall temperature of the hot air engine heater, and the pipe wall temperature control dead zone value of the hot air engine heater.

[0047] S230 sets the working fluid pressure of the hot air engine to the third working fluid pressure so that the tube wall temperature of the hot air engine heater is within the first rated temperature range, and calculates the current DC bus voltage control value in real time based on the current DC bus voltage value, the DC bus voltage value of the previous measurement cycle, the measurement cycle and the second control calculation result, the DC bus voltage control value, and the DC bus voltage control dead zone value.

[0048] S240 determines the voltage control word based on the current DC bus voltage control value, and adjusts the load power level based on the voltage control word;

[0049] S250, when the power generation system is shut down and the current temperature of the tube wall of the hot air engine heater is lower than the first preset temperature, exhaust gas from the hot air engine until the working fluid pressure of the hot air engine reaches the fourth working fluid pressure, and open the hot air engine short-circuit valve, control the permanent magnet motor to run within the first speed range, and then close the hot air engine short-circuit valve.

[0050] S260: During the shutdown of the power generation system, if the current voltage value of the DC bus is less than the first preset voltage and remains so for a first preset time, all load power levels shall be turned off.

[0051] S270, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air engine heater is lower than the second preset temperature and continues for the second preset time, the permanent magnet motor is controlled to run at the second speed.

[0052] S280, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air engine heater is lower than the third preset temperature and continues for the second preset time, control the permanent magnet motor to run at the third speed.

[0053] S290, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air engine heater is lower than the fourth preset temperature and continues for the second preset time, the hot air engine short-circuit valve is opened and the permanent magnet motor is stopped.

[0054] When the power generation system starts up, the system controller closes all load power settings and opens the battery power supply switch, allowing the battery to supply DC power to the converter via the DC bus. The converter, according to the system controller's control commands, converts the DC power supplied by the DC bus into AC power suitable for the permanent magnet motor. The system controller opens the hot air blower short-circuit valve and charges the hot air blower, bringing its working fluid pressure to the first working fluid pressure. The system controller then controls the permanent magnet motor via the converter, which in turn drives the hot air blower. When the hot air blower reaches its first operating speed, charging continues until the working fluid pressure reaches the second working fluid pressure. Finally, the system controller closes the hot air blower short-circuit valve to initiate ignition. Once the power generation system successfully ignites, the system controller can calculate the current operating speed of the hot air blower in real time. Furthermore, the system controller uses a converter to control the permanent magnet motor to operate at the current operating speed of the hot air engine until the current operating speed of the hot air engine reaches its rated speed range. At this point, the permanent magnet motor is controlled to operate within the rated speed range of the hot air engine, which can be the rated speed v2 ± 1 r / min. At this time, the permanent magnet motor enters a stable speed state (or enters its second operating state), which means the hot air engine's working cycle is established (or the power generation system startup is complete).

[0055] After the power generation system starts up, the system controller sets the rated wall temperature (or rated wall temperature value) of the hot air engine heater to T3, the bias value to a, where a ≥ k6b, k6 is a constant, the seventh preset time (or duration) to t1, and sets the DC bus voltage control value to c, the DC bus voltage control dead zone value to d, and the DC bus voltage control range value to ef. Based on the DC bus voltage control dead zone value d, the DC bus voltage control range value ef is divided into multiple voltage intervals, and the initial value of the voltage control word is set to 0. The system controller measures the current wall temperature of the hot air engine heater. When the current wall temperature of the hot air engine heater reaches the rated wall temperature T3 + bias value a, and remains at the seventh preset time, the third working fluid pressure is calculated in real time based on the hot air engine fuel flow rate, the first control calculation result, the current wall temperature and rated wall temperature of the hot air engine heater, and the wall temperature control dead zone value. The specific formula is P. SET =k1*Y ACT +k2*T PID +k3*(T4-T3) / b, where P SET Y is the pressure of the third working fluid (or the working fluid pressure required by the hot air engine). ACT T represents the fuel flow rate of the hot air engine. PIDThe first control calculation result (or the PID control calculation result for the pipe wall temperature of the hot air engine heater) is given, where T4 is the current pipe wall temperature of the hot air engine heater, T3 is the rated pipe wall temperature of the hot air engine heater, b is the dead zone value for the pipe wall temperature control of the hot air engine heater, and k1, k2, and k3 are constants. Based on the calculation result, the system controller sets the working fluid pressure of the hot air engine to the third working fluid pressure and keeps the pipe wall temperature of the hot air engine heater within the first rated temperature range, which is the rated pipe wall temperature T3 ± the dead zone value b.

[0056] Then, the system controller measures the current DC bus voltage value s(t) and, based on the current DC bus voltage value s(t), the DC bus voltage value of the previous measurement cycle, the measurement cycle, the second control calculation result, the DC bus voltage control value c, and the DC bus voltage control dead zone value d, calculates the current DC bus voltage control value in real time. The specific formula is as follows:

[0057] Where y(t) is the current DC bus voltage control value, s(t) is the current DC bus voltage value, s(t-1) is the DC bus voltage value in the previous measurement cycle, T is the measurement cycle (or sampling cycle), and s(t) PID The result of the second control calculation (or the result of PID control calculation of the current DC bus voltage value s(t) and the DC bus voltage control value c) is given, where k4 and k5 are constants. Further, the voltage control word is determined based on the current DC bus voltage control value. The process is as follows: when the current DC bus voltage control value y(t) increases from one voltage range to an adjacent voltage range, the voltage control word increases by 1; when the current DC bus voltage control value y(t) decreases from one voltage range to an adjacent voltage range, the voltage control word decreases by 1. The system controller converts the obtained voltage control word into a binary number. Each bit of the binary number corresponds to a load power level. If the bit is 0, the system controller disables the corresponding load power level; if the bit is 1, the system controller enables the corresponding load power level, thereby increasing or decreasing the total load power to keep the DC bus voltage within the range of c ± d.

[0058] In other words, the process of changing the current DC bus voltage control value y(t) can include: during the power generation process, the system controller increases the fuel supply to the gas turbine, causing the current temperature of the gas turbine heater tube wall to rise, which in turn increases the calculated value of the third working fluid pressure. Based on the calculated value of the third working fluid pressure, the system controller controls the gas turbine to perform an intake operation, thereby reducing the current temperature of the gas turbine heater tube wall to a certain temperature control range. Because the system controller increases the fuel supply to the gas turbine and controls the gas turbine to perform an intake operation, the fuel flow rate and working fluid pressure of the gas turbine increase, which in turn increases the mechanical energy output by the gas turbine and the electrical energy output by the permanent magnet motor. The increase in electrical energy output by the permanent magnet motor not only increases the voltage on the DC bus but also increases the current DC bus voltage control value y(t), thus causing a change in the voltage control word obtained by the system controller. The system controller converts the voltage control word into a binary number, opens the load power level corresponding to 1 in the binary number, and closes the load power level corresponding to 0 in the binary number. This increases the electrical energy consumed by the load, reduces the voltage on the DC bus to a voltage control range, and maintains stability.

[0059] During the power generation process, the system controller reduces the fuel supply to the gas turbine, causing a decrease in the current temperature of the gas turbine heater tube wall, which in turn reduces the calculated pressure of the third working fluid. Based on the calculated pressure of the third working fluid, the system controller controls the gas turbine to perform an exhaust operation, thereby raising the current temperature of the gas turbine heater tube wall to another temperature control range. Because the system controller reduces the fuel supply to the gas turbine and controls the gas turbine to perform an exhaust operation, the fuel flow and working fluid pressure of the gas turbine decrease, resulting in a decrease in both the mechanical energy output by the gas turbine and the electrical energy output by the permanent magnet motor. The decrease in electrical energy output by the permanent magnet motor not only lowers the voltage on the DC bus but also lowers the current DC bus voltage control value y(t), causing a change in the voltage control word acquired by the system controller. The system controller converts the voltage control word into a binary number and opens the load power level corresponding to 1 in the binary number and closes the load power level corresponding to 0 in the binary number, reducing the electrical energy consumed by the load and lowering the DC bus voltage to another voltage control range, maintaining stability thereafter.

[0060] When the power generation system shuts down, the system controller shuts off the fuel supply to the gas turbine and continues to control the permanent magnet motor to operate stably at the gas turbine's rated speed v2, ceasing the calculation of the third working fluid pressure. Simultaneously, based on the calculated current DC bus voltage control value, the DC bus voltage is controlled within the range of c±d. When the system controller receives a voltage control word of 1, it stops calculating the current DC bus voltage control value. The voltage control word remains at 1, and the system controller activates the load power level corresponding to this voltage control word.

[0061] When the current temperature of the tube wall of the hot air engine heater is lower than the first preset temperature (the first preset temperature can be the rated temperature of the tube wall of the hot air engine heater, T3-300℃), the hot air engine is vented until the working fluid pressure of the hot air engine reaches the fourth working fluid pressure (the fourth working fluid pressure can be P9), and the hot air engine short-circuit valve is opened. The permanent magnet motor is then controlled to run within the first speed range (the first speed range can be the rated speed of the hot air engine, v2-500r / min) before the hot air engine short-circuit valve is closed.

[0062] During the shutdown of the power generation system, if the current DC bus voltage is less than the first preset voltage (which can be cd / 2) for a first preset time (which can be 45s), all load power levels are shut down. During the shutdown of the power generation system, if the current temperature of the gas turbine heater wall is less than the second preset temperature (which can be 250℃) for a second preset time (which can be 5s), the permanent magnet motor is controlled to run at the second speed (which can be 800r / min). During the shutdown of the power generation system, if the current temperature of the gas turbine heater wall is less than the third preset temperature (which can be 180℃) for a second preset time, the permanent magnet motor is controlled to run at the third speed (which can be 500r / min). During the shutdown of the power generation system, if the current temperature of the gas turbine heater wall is less than the fourth preset temperature (which can be 100℃) for a second preset time, the gas turbine short-circuit valve is opened and the permanent magnet motor is stopped. The specific values ​​in the embodiments of this application are only for illustrative purposes and are not limited thereto. The settings of various parameters can be set according to user needs.

[0063] In this embodiment of the application, during the startup phase of the power generation system, the short-circuit valve of the hot gas turbine is first opened, and then gas is introduced into the hot gas turbine until the working fluid pressure reaches the first working fluid pressure. When the hot gas turbine reaches the first speed, gas is continued to be introduced into the hot gas turbine until the working fluid pressure reaches the second working fluid pressure. This series of operations ensures that the working fluid in the hot gas turbine begins to flow before the power generation system ignites, and can promptly absorb the heat generated on the wall of the hot gas turbine heater after successful ignition. In this way, heat is effectively prevented from accumulating on the wall of the hot gas turbine heater for a long time, thereby preventing the hot gas turbine heater from being damaged due to overheating and significantly improving the service life of the hot gas turbine heater. At the same time, this also reduces the performance requirements of the hot gas turbine heater material, thereby saving the production cost of the hot gas turbine and reducing the difficulty of its promotion.

[0064] Furthermore, this embodiment calculates the third working fluid pressure in real time, determines the current DC bus voltage control value based on the third working fluid pressure, obtains the voltage control word based on the current DC bus voltage control value, and finally adjusts the load power level based on the voltage control word. This process cleverly establishes a mapping relationship between the DC bus voltage control value and the load power level, enabling changes in the load power level to quickly respond to changes in the DC bus voltage, achieving precise and stable control of the DC bus voltage. Because the DC bus voltage is stable, the battery voltage also remains stable, which helps to improve the battery's lifespan.

[0065] Furthermore, during the shutdown process of the power generation system, this embodiment of the application subdivides the shutdown process into multiple stages and adopts different control strategies for each stage. Specifically, when the power generation system shuts down and the current temperature of the pipe wall of the hot air blower heater is lower than the first preset temperature, the hot air blower is vented until the working fluid pressure reaches the fourth working fluid pressure, and the hot air blower short-circuit valve is opened. The permanent magnet motor is then controlled to run within the first speed range before the short-circuit valve is closed. If the current DC bus voltage value is lower than the first preset voltage and remains lower than the first preset time during the shutdown process, all load power levels are closed. If the current temperature of the pipe wall of the hot air blower heater is lower than the second preset temperature and remains lower than the second preset time, the permanent magnet motor is controlled to run at the second speed. If the current pipe wall temperature is lower than the third preset temperature and remains lower than the second preset time, the permanent magnet motor is controlled to run at the third speed. If the current pipe wall temperature is lower than the fourth preset temperature and remains lower than the second preset time, the short-circuit valve is opened and the permanent magnet motor is stopped. This phased and refined control strategy not only enables the power generation system to shut down quickly, but also makes the temperature change of the pipe wall of the hot air engine heater more stable, further improving the service life of the hot air engine heater and enhancing the reliability and stability of the entire power generation system.

[0066] Reference Appendix Figure 3 The document illustrates a flowchart illustrating how to adjust a hot air engine and a permanent magnet motor to their rated speed range, as provided in an embodiment of this application. Figure 3 As shown, after the power generation system successfully ignites, it controls the permanent magnet motor and the hot air engine to operate within their rated speed range, specifically including:

[0067] S300: When the working fluid pressure of the hot air engine reaches the second working fluid pressure, the hot air engine short-circuit valve is closed, and the power generation system is controlled to ignite.

[0068] S310, after the power generation system is successfully ignited, the current operating speed of the hot air engine is calculated in real time based on the first speed, the current temperature of the tube wall of the hot air engine heater, the tube wall temperature of the hot air engine heater in the previous timing period, the first working fluid pressure, the second working fluid pressure and the timing period.

[0069] S320 adjusts the speeds of the gas engine and the permanent magnet motor based on the current operating speed of the gas engine until the permanent magnet motor and the gas engine are operating within their rated speed range.

[0070] Once the working fluid pressure of the hot air engine reaches the second working fluid pressure, the system controller closes the hot air engine short-circuit valve to initiate ignition. After successful ignition of the power generation system, the system controller calculates the current operating speed of the hot air engine in real time based on the first speed, the current tube wall temperature of the hot air engine heater, the tube wall temperature of the hot air engine heater during the previous timing period, the first working fluid pressure, the second working fluid pressure, and the timing period. The specific formula is as follows: Where v t Here, v1 is the calculated operating speed, T2 is the current wall temperature of the gas turbine heater, T1 is the wall temperature of the gas turbine heater during the previous timing period, P1 is the first working fluid pressure, P2 is the second working fluid pressure, s is the timing period, and k is the proportional coefficient. The system controller controls the permanent magnet motor to operate at the current operating speed of the gas turbine through the converter until the current operating speed of the gas turbine reaches the rated speed range of the gas turbine. At this point, the permanent magnet motor enters the stable speed state (or the permanent magnet motor enters the second working state), which is also the establishment of the gas turbine working cycle (or the completion of the power generation system startup).

[0071] In some embodiments of this application, the working fluid pressure of the hot air engine is set to a third working fluid pressure, specifically including: when the working fluid pressure of the hot air engine is less than the third working fluid pressure, charging the hot air engine until the working fluid pressure of the hot air engine reaches the third working fluid pressure; when the working fluid pressure of the hot air engine is greater than the third working fluid pressure, controlling the hot air engine to exhaust gas until the working fluid pressure of the hot air engine reaches the third working fluid pressure.

[0072] After calculating the third working fluid pressure, the third working fluid pressure is compared with the current working fluid pressure of the hot air engine. When the third working fluid pressure is greater than the current working fluid pressure of the hot air engine, the system controller controls the hot air engine to charge, increasing the working fluid pressure of the hot air engine until the working fluid pressure of the hot air engine reaches the third working fluid pressure, thereby increasing the heat absorption and work capacity of the hot air engine and keeping the tube wall temperature of the hot air engine heater within the first rated temperature range. When the third working fluid pressure is less than the current working fluid pressure of the hot air engine, the system controller controls the hot air engine to discharge, reducing the working fluid pressure of the hot air engine until the working fluid pressure of the hot air engine reaches the third working fluid pressure, thereby reducing the heat absorption and work capacity of the hot air engine and keeping the tube wall temperature of the hot air engine heater within the first rated temperature range.

[0073] In some embodiments of this application, the method further includes: dividing the DC bus voltage control range value into multiple voltage intervals based on the DC bus voltage control dead zone value; determining a voltage control word based on the current DC bus voltage control value; and adjusting the load power level based on the voltage control word. Specifically, this includes: determining a voltage interval based on the current DC bus voltage control value; determining a voltage control word based on the voltage interval; converting the voltage control word into a binary number; and adjusting the load power level according to the binary number.

[0074] In some embodiments of this application, the method further includes: increasing / decreasing the control voltage word by a preset value for each voltage interval shift of the current DC bus voltage control value; increasing the control voltage word by a preset value every third preset time interval when the current DC bus voltage control value is greater than the upper limit of multiple voltage intervals; decreasing the control voltage word by a preset value every fourth preset time interval when the current DC bus voltage control value is less than the lower limit of multiple voltage intervals; assigning the voltage control word the first threshold value when it is not less than the first threshold value; and assigning the voltage control word the second threshold value when it is not greater than the second threshold value.

[0075] Based on the DC bus voltage control dead zone value, the DC bus voltage control range is divided into multiple voltage intervals. For example, the DC bus voltage control range e~f can be 580VDC~620VDC, and the DC bus voltage control dead zone value d can be 5VDC. That is, the divided voltage intervals can be 580~585VDC, 585~590VDC, 590~595VDC, 595~600VDC, 600~605VDC, 605~610VDC, 610~615VDC, and 615~620VDC, respectively. The corresponding load power levels for these voltage intervals are 1kW, 2kW, 2kW, 5kW, 5kW, 10kW, 10kW, and 20kW, respectively, with an initial voltage control word value of 0. Simultaneously, the system controller has 8 control channels that correspond one-to-one with the load power levels, as detailed in the table below:

[0076] Control Channel 8 7 6 5 4 3 2 1 Load power settings 20kW 10kW 10kW 5kW 5kW 2kW 2kW 1kW

[0077] Based on the current DC bus voltage control value, a corresponding voltage range is determined. Then, the corresponding voltage control word is determined based on this voltage range. The voltage control word is then converted to a binary number, and the load power level is adjusted accordingly. For example, if the voltage control word is 10, the system controller converts the obtained voltage control word into the binary number 1010. The correspondence between the system controller's control channels, load power levels, and binary numbers is shown in the table below:

[0078] Control Channel 8 7 6 5 4 3 2 1 Load power settings 20kW 10kW 10kW 5kW 5kW 2kW 2kW 1kW binary number 1 0 1 0

[0079] At this point, the system controller opens control channels 1 and 4, and closes all other control channels, thus enabling a total load power of 5kW + 2kW = 7kW to be engaged.

[0080] Furthermore, the specific process of determining the voltage control word can be as follows: when the current DC bus voltage control value moves by one voltage range, the voltage control word is increased / decreased by a preset value. For example, when the current DC bus voltage control value increases from the 580-585VDC range to the adjacent 585-590VDC range, the voltage control word increases by 1 accordingly. When the current DC bus voltage control value decreases from the 610-615VDC range to the adjacent 605-610VDC range, the voltage control word decreases by 1 accordingly.

[0081] Simultaneously, when the current DC bus voltage control value is greater than the upper limit of multiple voltage ranges, the voltage control word increases by one preset value every third preset time interval; when the current DC bus voltage control value is less than the lower limit of multiple voltage ranges, the voltage control word decreases by one preset value every fourth preset time interval. For example, when the current DC bus voltage control value increases upward to the highest voltage range of 615-620VDC and is greater than the upper limit f = 620VDC, the voltage control word increases by 1 correspondingly every third preset time interval g = 40s; when the current DC bus voltage control value decreases downward to the lowest voltage range of 580-585VDC and is less than the lower limit e = 580VDC, the voltage control word decreases by 1 correspondingly every fourth preset time interval h = 30s. When the voltage control word is not less than the first threshold, the voltage control word is assigned the first threshold value; when the voltage control word is not greater than the second threshold, the voltage control word is assigned the second threshold value. For example, if the voltage control word is increased to a value of 256 or higher, then the voltage control word is assigned the value 256; if the voltage control word is decreased to a value of 1 or lower, then the voltage control word is assigned the value 1.

[0082] Finally, the system controller converts the obtained voltage control word into a binary number. Each bit of the binary number corresponds to a load power level. If the bit is 0, the system controller turns off the load power level corresponding to that bit; if the bit is 1, the system controller turns on the load power level corresponding to that bit, thereby increasing or decreasing the total load power and keeping the DC bus voltage within the range of c±d.

[0083] This application's embodiments divide the DC bus voltage control range into multiple voltage intervals based on the DC bus voltage control dead zone value. The corresponding voltage interval is determined according to the current DC bus voltage control value, and then a voltage control word is determined. This voltage control word is then converted into a binary number to adjust the load power level, achieving refined and dynamic adjustment of the load power level. This control method allows the load power to respond more accurately to changes in the DC bus voltage, effectively improving the accuracy and stability of DC bus voltage control, thereby ensuring battery voltage stability, extending battery life, and improving the performance and reliability of the entire power generation system. Furthermore, when the current DC bus voltage control value moves by one voltage interval, the control voltage word is increased or decreased by a preset value. When the voltage control value exceeds the upper or lower limit of the voltage interval, the increase or decrease of the voltage control word is controlled by a third and fourth preset time, further enhancing the system's adaptability to voltage changes and its adjustment flexibility. Simultaneously, setting a first threshold and a second threshold for the voltage control word avoids abnormal fluctuations in the voltage control word, ensuring stable system operation and further improving the control performance and stability of the power generation system.

[0084] Reference Appendix Figure 4 The diagram illustrates a flowchart of a power generation system control method provided in an embodiment of this application. Figure 4 As shown, it includes:

[0085] S400 determines the first voltage threshold based on the DC bus voltage control dead zone value and the lower limit value of the DC bus voltage control range value.

[0086] S410 determines the second voltage threshold based on the DC bus voltage control value and the DC bus voltage control dead zone value.

[0087] S420 determines the third voltage threshold based on the upper limit of the DC bus voltage control dead zone value and the DC bus voltage control range value.

[0088] S430: When the current voltage value of the DC bus is not greater than the first voltage threshold and continues for a fifth preset time, stop calculating the current voltage control value of the DC bus.

[0089] S440, when the current voltage value of the DC bus is not less than the second voltage threshold and continues for a fifth preset time, the current voltage value of the DC bus is set within the first preset voltage range according to the current voltage control value of the DC bus.

[0090] S450: When the current voltage value of the DC bus is not less than the third voltage threshold and continues for a sixth preset time, an alarm is issued.

[0091] When the voltage control word is set to 0, the S460 shuts down all load power levels and controls the power generation system to supply power to the battery.

[0092] Based on the DC bus voltage control dead zone value d and the lower limit e of the DC bus voltage control range e to f, a first voltage threshold is determined, which can be e-2d. Based on the DC bus voltage control value c and the DC bus voltage control dead zone value d, a second voltage threshold is determined, which can be c+2d. Based on the DC bus voltage control dead zone value d and the upper limit f of the DC bus voltage control range e to f, a third voltage threshold is determined, which can be f+2d. After the system controller measures the current DC bus voltage value s(t), if the current DC bus voltage value s(t) is not greater than the first voltage threshold and remains so for a fifth preset time (the fifth preset time can be 60s), the calculation of the current DC bus voltage control value is stopped. When the current DC bus voltage value is not less than the second voltage threshold and remains so for a fifth preset time, the current DC bus voltage value is set within a first preset voltage range, which can be c±d. When the current DC bus voltage is not less than the third voltage threshold and remains above it for a sixth preset time (the sixth preset time can be 30 seconds), the system controller issues an alarm. When the voltage control word is set to 0, all load power levels are shut down, and the power generation system is controlled to prioritize power supply to the battery.

[0093] In some embodiments of this application, the method further includes: when the current temperature of the tube wall of the hot air engine heater reaches the sum of the rated temperature and the bias value of the tube wall of the hot air engine heater, and this continues for a seventh preset time, performing a step of real-time calculation of the third working fluid pressure.

[0094] When the current temperature of the tube wall of the hot air engine heater reaches the rated temperature T3 + bias value a of the hot air engine heater tube wall, and remains there for a seventh preset time t1, the step of real-time calculation of the third working fluid pressure is executed. Meanwhile, the purpose of this application embodiment is to ensure the normality of the second control calculation result during the real-time calculation of the current DC bus voltage control value, that is, to ensure that the PID control calculation result of the current DC bus voltage value s(t) and the DC bus voltage control value c is normal.

[0095] This application provides a power generation system, including: a coaxially integrated hot air engine and permanent magnet motor, a battery, and a load; a converter, the input of which is connected to the permanent magnet motor, and the output of which is connected to the battery and the load via a DC bus; a system controller, which is connected to the hot air engine, the permanent magnet motor, the converter, the battery, and the load; the system controller is configured to open the hot air engine's short-circuit valve and charge the hot air engine until the working fluid pressure of the hot air engine reaches a first working fluid pressure; the system controller is configured to drive the hot air engine through the permanent magnet motor, and when the hot air engine runs to a first speed, continue to charge the hot air engine until the working fluid pressure of the hot air engine reaches a second working fluid pressure. Pressure; The system controller is configured to control the permanent magnet motor and the hot air engine to operate within the rated speed range after successful ignition of the power generation system, and to calculate the third working fluid pressure in real time based on the hot air engine fuel flow rate, the first control calculation result, the current and rated pipe wall temperatures of the hot air engine heater, and the dead zone value of the pipe wall temperature control of the hot air engine heater; The system controller is configured to set the working fluid pressure of the hot air engine to the third working fluid pressure so that the pipe wall temperature of the hot air engine heater is within the first rated temperature range, and to calculate the third working fluid pressure based on the current DC bus voltage value, the DC bus voltage value of the previous measurement cycle, the measurement cycle, the second control calculation result, the DC bus voltage control value, and the DC bus... The system controller is configured to: determine the voltage control word based on the current DC bus voltage control value, and adjust the load power level based on the voltage control word; discharge gas from the hot air blower when the power generation system is shut down and the current wall temperature of the hot air blower heater is lower than the first preset temperature, until the working fluid pressure of the hot air blower reaches the fourth working fluid pressure, open the hot air blower short-circuit valve, control the permanent magnet motor to run within the first speed range, and then close the hot air blower short-circuit valve; and, during the power generation system shutdown process, if the current DC bus voltage value is lower than the first preset voltage and remains below the first preset voltage for a certain period of time... When a preset time is reached, all load power levels are shut down; the system controller is configured to, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air blower heater is lower than a second preset temperature and remains so for a second preset time, control the permanent magnet motor to run at a second speed; the system controller is configured to, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air blower heater is lower than a third preset temperature and remains so for a second preset time, control the permanent magnet motor to run at a third speed; the system controller is configured to, during the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air blower heater is lower than a fourth preset temperature and remains so for a second preset time, open the hot air blower short-circuit valve and control the permanent magnet motor to stop.

[0096] The detailed content of the embodiments of this application has been described in the foregoing embodiments, and will not be repeated here.

[0097] In some embodiments of this application, when the permanent magnet motor is in a first working state, it is used to drive a hot air engine; when the permanent magnet motor is in a second working state, it is used to convert the mechanical energy output by the hot air engine into electrical energy output.

[0098] In some embodiments of this application, the load is used to consume the electrical energy output by the permanent magnet motor when it is in the second working state; the load is provided with multiple load power levels, and each load power level has a corresponding control channel in the system controller; the system controller adjusts the multiple load power levels of the load through the multiple control channels.

[0099] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a power generation system, characterized in that, include: Open the hot air engine short-circuit valve and charge the hot air engine until the working fluid pressure of the hot air engine reaches the first working fluid pressure; The hot air engine is driven by a permanent magnet motor, and when the hot air engine runs to the first speed, air continues to be supplied to the hot air engine until the working fluid pressure of the hot air engine reaches the second working fluid pressure. After the power generation system is successfully ignited, the permanent magnet motor and the hot air engine are controlled to operate within the rated speed range. Based on the hot air engine fuel flow rate, the first control calculation result, the current temperature and rated temperature of the hot air engine heater tube wall, and the dead zone value of the hot air engine heater tube wall temperature control, the third working fluid pressure is calculated in real time. The working fluid pressure of the hot air engine is set to the third working fluid pressure so that the tube wall temperature of the hot air engine heater is within the first rated temperature range. Based on the current DC bus voltage value, the DC bus voltage value of the previous measurement cycle, the measurement cycle and the second control calculation result, the DC bus voltage control value, and the DC bus voltage control dead zone value, the current DC bus voltage control value is calculated in real time. Based on the current DC bus voltage control value, determine the voltage control word, and based on the voltage control word, adjust the load power level; When the power generation system shuts down and the current temperature of the tube wall of the hot air engine heater is lower than the first preset temperature, the hot air engine is vented until the working fluid pressure of the hot air engine reaches the fourth working fluid pressure, and the short-circuit valve of the hot air engine is opened. After the permanent magnet motor is controlled to run within the first speed range, the short-circuit valve of the hot air engine is closed. During the shutdown of the power generation system, if the current voltage value of the DC bus is less than the first preset voltage and remains so for a first preset time, all load power settings shall be turned off. During the shutdown of the power generation system, if the current temperature of the tube wall of the hot air engine heater is lower than the second preset temperature and remains lower for the second preset time, the permanent magnet motor is controlled to run at the second speed. During the shutdown of the power generation system, if the current temperature of the tube wall of the hot air engine heater is lower than the third preset temperature and continues for a second preset time, the permanent magnet motor is controlled to run at the third speed. During the shutdown of the power generation system, if the current temperature of the pipe wall of the hot air engine heater is lower than the fourth preset temperature and continues for the second preset time, the hot air engine short-circuit valve is opened and the permanent magnet motor is controlled to stop.

2. The power generation system control method according to claim 1, characterized in that, After the power generation system is successfully ignited, controlling the permanent magnet motor and the hot air engine to operate within their rated speed range specifically includes: When the working fluid pressure of the hot air engine reaches the second working fluid pressure, the short-circuit valve of the hot air engine is closed, and the power generation system is controlled to ignite. Once the power generation system is successfully ignited, the current operating speed of the hot air engine is calculated in real time based on the first rotational speed, the current temperature of the tube wall of the hot air engine heater, the tube wall temperature of the hot air engine heater during the previous timing period, the first working fluid pressure, the second working fluid pressure, and the timing period. Based on the current operating speed of the hot air engine, adjust the speeds of the hot air engine and the permanent magnet motor until the permanent magnet motor and the hot air engine are operating within their rated speed range.

3. The power generation system control method according to claim 1, characterized in that, Setting the working fluid pressure of the hot air engine to the third working fluid pressure specifically includes: When the working fluid pressure of the hot air engine is less than the third working fluid pressure, the hot air engine is charged with air until the working fluid pressure of the hot air engine reaches the third working fluid pressure. When the working fluid pressure of the hot air engine is greater than the third working fluid pressure, the hot air engine is controlled to exhaust until the working fluid pressure of the hot air engine reaches the third working fluid pressure.

4. The power generation system control method according to claim 1, characterized in that, Also includes: Based on the DC bus voltage control dead zone value, the DC bus voltage control range value is divided into multiple voltage intervals; The process of determining a voltage control word based on the current DC bus voltage control value, and adjusting the load power level based on the voltage control word, specifically includes: Based on the current DC bus voltage control value, a voltage range is determined; The voltage control word is determined based on the voltage range. The voltage control word is converted into a binary number, and the load power level is adjusted according to the binary number.

5. The power generation system control method according to claim 4, characterized in that, Also includes: When the current voltage control value of the DC bus moves by one voltage range, the voltage control word is increased / decreased by a preset value. When the current voltage control value of the DC bus is greater than the upper limit of the multiple voltage ranges, the voltage control word is increased by a preset value every third preset time interval. When the current voltage control value of the DC bus is less than the lower limit of the multiple voltage ranges, the voltage control word is reduced by a preset value every fourth preset time interval. When the voltage control word is not less than the first threshold, the voltage control word is assigned the value of the first threshold. When the voltage control word is not greater than the second threshold, the voltage control word is assigned the value of the second threshold.

6. The power generation system control method according to claim 1, characterized in that, Also includes: The first voltage threshold is determined based on the lower limit of the DC bus voltage control dead zone value and the DC bus voltage control range value. A second voltage threshold is determined based on the DC bus voltage control value and the DC bus voltage control dead zone value; The third voltage threshold is determined based on the upper limit of the DC bus voltage control dead zone value and the DC bus voltage control range value. When the current voltage value of the DC bus is not greater than the first voltage threshold and continues for a fifth preset time, the calculation of the current voltage control value of the DC bus is stopped. When the current voltage value of the DC bus is not less than the second voltage threshold and continues for a fifth preset time, the current voltage value of the DC bus is set within a first preset voltage range according to the current voltage control value of the DC bus. An alarm is issued when the current voltage value of the DC bus is not less than the third voltage threshold and remains so for a sixth preset time. When the voltage control word is set to 0, all load power levels are turned off, and the power generation system is controlled to supply power to the battery.

7. The power generation system control method according to any one of claims 1-6, characterized in that, Also includes: When the current temperature of the tube wall of the hot air engine heater reaches the sum of the rated temperature and the deviation of the tube wall of the hot air engine heater, and this continues for a seventh preset time, the step of calculating the third working fluid pressure in real time is executed.

8. A power generation system, characterized in that, include: The hot air engine and permanent magnet motor, battery and load are coaxially integrated; A converter, the input of which is connected to the permanent magnet motor, and the output of which is connected to the battery and the load respectively via a DC bus; A system controller, which is connected to the hot air engine, the permanent magnet motor, the converter, the battery, and the load; The system controller is configured to open the hot air engine short-circuit valve and charge the hot air engine until the working fluid pressure of the hot air engine reaches the first working fluid pressure. The system controller is configured to drive the hot air machine via a permanent magnet motor, and continue to charge the hot air machine with air when the hot air machine runs to a first speed, until the working fluid pressure of the hot air machine reaches a second working fluid pressure; The system controller is configured to control the permanent magnet motor and the hot air engine to operate within the rated speed range after the power generation system is successfully ignited, and to calculate the third working fluid pressure in real time based on the hot air engine fuel flow rate, the first control calculation result, the current temperature and rated temperature of the hot air engine heater tube wall, and the dead zone value of the hot air engine heater tube wall temperature control. The system controller is configured to set the working fluid pressure of the hot air engine to the third working fluid pressure so that the tube wall temperature of the hot air engine heater is within the first rated temperature range, and to calculate the current DC bus voltage control value in real time based on the current DC bus voltage value, the DC bus voltage value of the previous measurement cycle, the measurement cycle and the second control calculation result, the DC bus voltage control value, and the DC bus voltage control dead zone value. The system controller is configured to determine a voltage control word based on the current DC bus voltage control value, and to adjust the load power level based on the voltage control word; The system controller is configured to, when the power generation system is shut down and the current temperature of the tube wall of the hot air engine heater is less than a first preset temperature, exhaust the hot air engine until the working fluid pressure of the hot air engine reaches a fourth working fluid pressure, open the hot air engine short-circuit valve, control the permanent magnet motor to run within a first speed range, and then close the hot air engine short-circuit valve. The system controller is configured to shut down all load power levels if the current DC bus voltage is less than a first preset voltage and remains so for a first preset time during the shutdown of the power generation system. The system controller is configured to control the permanent magnet motor to run at a second speed if, during the shutdown of the power generation system, the current temperature of the tube wall of the hot air engine heater is lower than a second preset temperature and this temperature remains lower than a second preset time. The system controller is configured to control the permanent magnet motor to run at a third speed if, during the shutdown of the power generation system, the current temperature of the tube wall of the hot air engine heater is lower than a third preset temperature and this temperature remains lower for a second preset time. The system controller is configured to, during the shutdown of the power generation system, if the current temperature of the tube wall of the hot air engine heater is lower than a fourth preset temperature and this temperature remains lower than a second preset time, open the hot air engine short-circuit valve and control the permanent magnet motor to stop.

9. The power generation system according to claim 8, characterized in that, When the permanent magnet motor is in the first working state, it is used to drive the hot air engine. When the permanent magnet motor is in the second working state, it is used to convert the mechanical energy output by the hot air engine into electrical energy output.

10. The power generation system according to claim 9, characterized in that, The load is used to consume the electrical energy output by the permanent magnet motor when it is in the second working state; The load is configured with multiple load power levels, and each load power level has a corresponding control channel in the system controller. The system controller adjusts multiple load power levels of the load through multiple control channels.

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