A parallel hybrid power system

Abstract

This application provides a parallel hybrid power system, relating to the field of power system energy management technology. The system includes a turboshaft engine, a generator, a drive motor, a mechanical coupling device, and a hybrid energy storage module. The turboshaft engine and the generator are coaxially connected. The generator is used to charge the hybrid energy storage module or supply power to the drive motor, and the turboshaft engine is used to output mechanical power. The drive motor and the turboshaft engine are connected in parallel through the mechanical coupling device, and are used to provide energy to the load through the turboshaft engine and / or the drive motor according to the load conditions. The hybrid energy storage module is connected to the generator and the drive motor respectively, and is used to receive electrical energy from the generator or provide energy to the drive motor to improve fuel economy.

Description

Technical Field

[0001] This application relates to the field of power system energy management technology, and more specifically, to a parallel hybrid power system. Background Technology

[0002] With stringent global restrictions on carbon emissions and noise pollution in the aviation industry, green aviation has become a crucial direction for industry development. Hybrid electric power systems, as a key technology for achieving green aviation, have received widespread attention. However, their pulse loads are characterized by high amplitude, narrow pulse width, and drastic changes, which can cause problems such as engine dynamic response lag, increased impact on the mechanical transmission system, and decreased system fuel economy. Energy management strategies are a vital foundation for ensuring the efficient operation of hybrid electric power systems, playing a significant role in improving system energy utilization, extending equipment lifespan, and reducing carbon emissions.

[0003] In related technologies, energy management methods fail to fully consider the high-frequency and high-amplitude characteristics of aviation pulse loads and are also difficult to effectively coordinate the transient power distribution between the engine and the energy storage system, resulting in poor fuel economy. Summary of the Invention

[0004] The problem addressed in this application is how to improve fuel economy.

[0005] To address the aforementioned issues, this application provides a parallel hybrid power system.

[0006] In a first aspect, this application provides a parallel hybrid power system, comprising: It includes a turboshaft engine, generator, drive motor, mechanical coupling device, and hybrid energy storage module; The turboshaft engine and the generator are coaxially connected. The generator is used to charge the hybrid energy storage module or supply power to the drive motor, and the turboshaft engine is used to output mechanical power. The drive motor and the turboshaft engine are connected in parallel through the mechanical coupling device, and are used to provide energy to the load through the turboshaft engine and / or the drive motor according to the load conditions; The hybrid energy storage module is connected to the generator and the drive motor respectively, and is used to receive electrical energy from the generator or to provide energy to the drive motor.

[0007] Optionally, the drive motor includes an electric mode and a power generation mode; When the pulse load meets the peak stage conditions, the drive motor is in the electric mode, and the drive motor provides auxiliary torque to drive the load together with the turboshaft engine. When the pulse load meets the valley stage condition, the drive motor is in the power generation mode. Under the preset torque balance constraint, the drive motor outputs power generation torque to provide power to the hybrid energy storage module.

[0008] Optionally, the torque balance constraint conditions include: The load demand torque is equal to the sum of the output torque of the turboshaft engine and the generated torque of the drive motor, wherein the load demand torque is determined by the real-time power demand of the load and the load speed.

[0009] Optionally, the peak stage condition includes a zero-mean pulse power component greater than 0; The valley phase condition includes the zero-mean pulse power component being less than 0.

[0010] Optionally, the hybrid energy storage module includes a supercapacitor and a battery; The turboshaft engine is also used to increase the output power of the turboshaft engine and charge the battery through the generator when the battery's state of charge is not within the preset safe operating range, until the battery's state of charge is within the safe operating range.

[0011] Optionally, the hybrid energy storage module includes a supercapacitor and a battery; The hybrid energy storage module is also used to adjust the output power distribution ratio between the battery and the supercapacitor according to the state of charge when the battery is in a preset second operating range.

[0012] Optionally, the turboshaft engine is used to operate within the economic operating range. When the real-time power demand of the load is greater than the output power of the turboshaft engine, the drive motor generates auxiliary torque to meet the real-time power demand of the load. When the real-time power demand of the load is less than the output power of the turboshaft engine, the generator charges the hybrid energy storage module, wherein the economic operating range is determined based on a pre-calibrated engine operating characteristic curve.

[0013] Optionally, the parallel hybrid power system shown also includes a processor, the processor being used for: Obtain the real-time power requirement of the load; The real-time power demand of the load is filtered in the first stage to obtain the steady-state average power component and the zero-mean pulse power component. The zero-mean pulse power component is filtered in a second stage to obtain high-frequency and low-frequency components. The steady-state average power component is converted into a power-torque to obtain a reference torque command, which is then executed by the turboshaft engine. The battery power allocation command is generated based on the low-frequency component and executed by the battery. The hybrid energy storage module includes a battery and a supercapacitor. A supercapacitor power allocation command is generated based on the high-frequency components, and the supercapacitor power allocation command is executed through the supercapacitor.

[0014] Optionally, the processor is further configured to: Based on a preset low-pass filter time constant, the real-time power demand of the load is low-pass filtered to obtain the low-frequency component. The value of the low-pass filter time constant is determined by the state of charge of the battery or the total charging and discharging power of the battery and the supercapacitor.

[0015] Optionally, the parallel hybrid power system shown also includes a power converter, which includes a generator-side rectifier, a drive motor-side inverter, and an energy storage-side DC converter.

[0016] The beneficial effects of the parallel hybrid power system of this application are: By coaxially connecting the turboshaft engine and generator, energy transfer links are reduced, minimizing mechanical transmission losses. The mechanical power output of the turboshaft engine can directly drive the load, while a portion of the mechanical power is converted into electrical energy by the coaxial generator, ensuring a relatively stable operating point for the turboshaft engine and avoiding frequent power fluctuations. The drive motor and turboshaft engine are connected in parallel via a mechanical coupling device. When the load power demand is low, the turboshaft engine operates independently; when the load power demand is high, the drive motor starts to provide auxiliary output power. The hybrid energy storage module acts as an energy buffer unit, receiving and storing the electrical energy generated by the generator. When needed, it releases energy to the drive motor, storing the electrical energy generated during periods of surplus power from the turboshaft engine and releasing it for use during periods of high load. When the load power demand is stable, the generator converts the surplus mechanical energy of the turboshaft engine into electrical energy to charge the hybrid energy storage module; when the load power demand suddenly increases, the generator can directly supply power to the drive motor, reducing conversion losses in the energy storage process. When load power demand changes, the output power of the drive motor is adjusted first, while the turboshaft engine maintains a relatively stable power output. This avoids frequent power adjustments by the turboshaft engine and reduces its operating time under inefficient conditions. The turboshaft engine can operate at its optimal fuel economy point for extended periods, and the drive motor utilizes the rapid response characteristics of electrical energy to cope with load changes, resulting in a significant improvement in overall fuel economy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the parallel hybrid power system according to an embodiment of this application; Figure 2 This is a flowchart illustrating the processing of the processor in an embodiment of this application. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of this application more apparent and understandable, specific embodiments of this application are described in detail below with reference to the accompanying drawings. Although some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the accompanying drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0019] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.

[0020] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first," "second," etc., mentioned in this application are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0021] It should be noted that the terms "one" and "more" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0022] The names of messages or information exchanged between multiple devices in the embodiments of this application are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0023] like Figure 1 As shown in the figure, an embodiment of this application provides a parallel hybrid power system, including a turboshaft engine, a generator, a drive motor, a mechanical coupling device, and a hybrid energy storage module; The turboshaft engine and the generator are coaxially connected. The generator is used to charge the hybrid energy storage module or supply power to the drive motor, and the turboshaft engine is used to output mechanical power.

[0024] In some embodiments, the turboshaft engine serves as the primary power source, outputting mechanical power through its rotating shaft to meet the basic energy requirements of the load. The generator and turboshaft engine are coaxially connected, sharing the same rotating shaft. The generator has two functions: firstly, it converts part of the mechanical energy of the turboshaft engine into electrical energy to charge the hybrid energy storage module; secondly, it directly supplies electrical energy to the drive motor when needed.

[0025] The drive motor and the turboshaft engine are connected in parallel via the mechanical coupling device, and are used to provide energy to the load through the turboshaft engine and / or the drive motor according to the load conditions.

[0026] In some embodiments, the drive motor serves as an auxiliary power source, connected in parallel with the turboshaft engine via a mechanical coupling device. The mechanical coupling device employs a gear set or clutch structure to superimpose the mechanical power output from the turboshaft engine and the drive motor, jointly providing energy to the load. Depending on changes in load power demand, various operating modes can be implemented, including the turboshaft engine operating alone, the drive motor operating alone, or both operating in tandem.

[0027] The hybrid energy storage module is connected to the generator and the drive motor respectively, and is used to receive electrical energy from the generator or to provide energy to the drive motor.

[0028] In some embodiments, the hybrid energy storage module includes two energy storage elements: a lithium-ion battery and a supercapacitor, which are electrically connected to the generator and the drive motor, respectively. The hybrid energy storage module receives and stores electrical energy from the generator and provides energy to the drive motor when the load requires additional power. Through energy storage and release, the hybrid energy storage module achieves peak shaving and valley filling functions, reducing the instantaneous power burden on the turboshaft engine.

[0029] In actual operation, the turboshaft engine continuously outputs mechanical power, while the generator converts some of the mechanical energy into electrical energy and stores it in the hybrid energy storage module. When the turboshaft engine cannot meet the load power demand, the drive motor obtains electrical energy from the hybrid energy storage module, converts it into mechanical power output, and combines this with the mechanical power of the turboshaft engine through a mechanical coupling device to jointly meet the load demand. When the turboshaft engine can meet the load power demand, the excess mechanical energy is converted into electrical energy by the generator and stored in the hybrid energy storage module, achieving energy recovery and utilization. The hybrid power system, through the coordinated work of the turboshaft engine and the drive motor, combined with the energy buffering function of the hybrid energy storage module, achieves efficient energy utilization and flexible load power distribution.

[0030] In this embodiment, the turboshaft engine and generator are coaxially connected, reducing energy transfer links and minimizing mechanical transmission losses. The mechanical power output by the turboshaft engine can directly drive the load, while a portion of the mechanical power is converted into electrical energy by the coaxial generator, making the turboshaft engine's operating point relatively stable and avoiding frequent power fluctuation adjustments. The drive motor and turboshaft engine are connected in parallel via a mechanical coupling device. When the load power demand is low, the turboshaft engine operates independently; when the load power demand is high, the drive motor starts to provide auxiliary output power. The hybrid energy storage module acts as an energy buffer unit, receiving and storing the electrical energy generated by the generator, and releasing energy to the drive motor when needed. It stores the electrical energy generated by the turboshaft engine during periods of surplus power and releases it for use during periods of high load. When the load power demand is stable, the generator converts the surplus mechanical energy of the turboshaft engine into electrical energy to charge the hybrid energy storage module; when the load power demand suddenly increases, the generator can directly supply power to the drive motor, reducing conversion losses in the energy storage process. When load power demand changes, the output power of the drive motor is adjusted first, while the turboshaft engine maintains a relatively stable power output. This avoids frequent power adjustments by the turboshaft engine and reduces its operating time under inefficient conditions. The turboshaft engine can operate at its optimal fuel economy point for extended periods, and the drive motor utilizes the rapid response characteristics of electrical energy to cope with load changes, resulting in a significant improvement in overall fuel economy.

[0031] Optionally, the drive motor includes an electric mode and a power generation mode; When the pulse load meets the peak stage conditions, the drive motor is in the electric mode, and the drive motor provides auxiliary torque to drive the load together with the turboshaft engine. When the pulse load meets the valley stage condition, the drive motor is in the power generation mode. Under the preset torque balance constraint, the drive motor outputs power generation torque to provide power to the hybrid energy storage module.

[0032] The drive motor has two operating modes: electric mode and generator mode. In electric mode, the drive motor converts electrical energy into mechanical energy and outputs driving torque; in generator mode, the drive motor converts mechanical energy into electrical energy and outputs generator torque.

[0033] Pulsating load indicates a condition where the load power demand fluctuates periodically, including peak and trough phases. During the peak phase of the pulsed load, the drive motor switches to electric mode. The drive motor draws electrical energy from the hybrid energy storage module to generate auxiliary torque. This auxiliary torque is superimposed on the mechanical torque output by the turboshaft engine through a mechanical coupling device, jointly meeting the high power demand of the load. In this mode, the drive motor handles the instantaneous increase in load power, while the turboshaft engine maintains a stable base power output.

[0034] When the pulse load is at its lowest point, the drive motor switches to generator mode. Under torque balance constraints, the drive motor utilizes the surplus mechanical power of the turboshaft engine to generate generator torque, converting mechanical energy into electrical energy to charge the hybrid energy storage module. The torque balance constraint means that the generator torque output by the drive motor does not exceed the limit of the surplus torque of the turboshaft engine, ensuring a dynamic balance between the output torque of the turboshaft engine and the torque required by the load.

[0035] By intelligently switching the operating modes of the drive motor, proactive adjustment of load power fluctuations is achieved. During peak periods, electrical energy is used to supplement mechanical power gaps, and during off-peak periods, excess mechanical energy is recovered and converted into electrical energy, forming an energy recycling mechanism and improving overall energy utilization efficiency.

[0036] Optionally, the torque balance constraint conditions include: The load demand torque is equal to the sum of the output torque of the turboshaft engine and the generated torque of the drive motor, wherein the load demand torque is determined by the real-time power demand of the load and the load speed.

[0037] Load demand torque represents the total driving torque required by the load under current operating conditions. Its value is determined by the real-time power demand of the load and the load speed through a power-torque conversion relationship. The real-time power demand of the load reflects the power consumption characteristics of the load at different times, while the load speed is the rotational speed parameter of the load.

[0038] The output torque of a turboshaft engine represents the mechanical torque generated by the turboshaft engine under current operating conditions, which is transmitted to the load end through a mechanical coupling device. The generating torque of the drive motor is the braking torque generated by the drive motor in generator mode. The torque direction is opposite to the output torque of the turboshaft engine, and it is used to convert part of the mechanical energy into electrical energy.

[0039] The mathematical expression of the torque balance constraint is: the load demand torque equals the algebraic sum of the turboshaft engine's output torque and the drive motor's generated torque. In practical implementation, the load demand torque is calculated by real-time monitoring of the load speed and power demand; the output torque of the turboshaft engine is determined based on its operating state; and, under the premise of satisfying the torque balance constraint, the magnitude of the drive motor's generated torque is adjusted to ensure that the three satisfy the above equation.

[0040] In one embodiment, the torque balance constraint condition is expressed as: T eng (t)+T mot (t)=T req (t), Among them, T eng (t) represents the actual output torque of the engine, T mot(t) represents the actual output torque of the drive motor, which is positive in electric mode and negative in generator mode. req (t) represents the load demand torque, and t represents time.

[0041] Optionally, the peak stage condition includes a zero-mean pulse power component greater than 0; The valley phase condition includes the zero-mean pulse power component being less than 0.

[0042] In one embodiment, the peak stage condition is expressed as: P pulse (t)>0, The valley phase condition is expressed as: P pulse (t)<0, Among them, P pulse (t) represents the zero-mean pulse power component that varies with time t.

[0043] Optionally, the hybrid energy storage module includes a supercapacitor and a battery; The turboshaft engine is also used to increase the output power of the turboshaft engine and charge the battery through the generator when the battery's state of charge is not within the preset safe operating range, until the battery's state of charge is within the safe operating range.

[0044] In one embodiment, the hybrid energy storage module consists of a supercapacitor and a battery. The supercapacitor has high power density and fast charge / discharge capability, making it suitable for handling instantaneous power fluctuations; the battery has high energy density, making it suitable for storing a large capacity of electrical energy. The two complement each other to form a hybrid energy storage module.

[0045] State of Charge (SOC) represents the ratio of a battery's current remaining charge to its rated capacity, reflecting the degree of charge and discharge. The safe operating range is a predetermined range of SOC values; operation within this range ensures the battery's cycle life and safety. For example, setting it to [SOC...] min SOC max If the SOC is within this range, it means the battery's SOC is in a safe operating range. If the SOC is below this range, the battery is in a safe operating range. min or higher than SOC max When this occurs, it indicates that intervention is needed regarding the battery's SOC.

[0046] When the battery's state of charge (SOC) falls below or rises above a preset safe operating range, the turboshaft engine adjusts its output power. Specifically, the turboshaft engine increases its mechanical output power, which is converted into electrical energy via a coaxially connected generator to charge the battery in the hybrid energy storage module. The charging process continues until the battery's SOC returns to the safe operating range.

[0047] By utilizing a turboshaft engine as a controllable energy source, the power generation is actively adjusted when the battery's state of charge is abnormal, maintaining the battery's operation within a suitable charge and discharge range. Through coordinated control of the turboshaft engine, generator, and hybrid energy storage module, the reliability of the energy storage unit is ensured, while performance degradation caused by battery overcharging or over-discharging is avoided.

[0048] Optionally, the hybrid energy storage module includes a supercapacitor and a battery; The hybrid energy storage module is also used to adjust the output power distribution ratio between the battery and the supercapacitor according to the state of charge when the battery is in a preset second operating range.

[0049] When a hybrid energy storage module supplies power to an external load, the power output contribution ratio between the battery and the supercapacitor can vary depending on the load size or the battery's state of charge (SOC). Adjusting the power distribution ratio directly affects the power output contribution of both energy storage components.

[0050] When the battery's state of charge (SOC) falls into a preset second operating range, the hybrid energy storage module dynamically adjusts the output power distribution ratio between the battery and the supercapacitor based on the real-time SOC value. Specifically, it reduces the battery's proportion of total output power and correspondingly increases the supercapacitor's power output weight. The closer the SOC is to the lower limit of the second operating range, the greater the reduction in the battery's output power distribution ratio.

[0051] In one embodiment, the second operating range is used to determine the state of the battery being in a safe operating range but with the SOC close to the limit boundary. For example, when the safe operating range is [10%, 90%], the second operating range is (10%, 20%] ∪ [80%, 90%).

[0052] By linking state-of-charge sensing with power allocation ratio control, supercapacitors are prioritized to handle load power demands when the battery is in an intermediate state of charge. This helps alleviate charge-discharge cycle stress on the battery, extending its lifespan, while leveraging the high-power characteristics of supercapacitors to improve the overall response capability and operational reliability of the hybrid energy storage module.

[0053] Optionally, the turboshaft engine is used to operate within the economic operating range. When the real-time power demand of the load is greater than the output power of the turboshaft engine, the drive motor generates auxiliary torque to meet the real-time power demand of the load. When the real-time power demand of the load is less than the output power of the turboshaft engine, the generator charges the hybrid energy storage module, wherein the economic operating range is determined based on a pre-calibrated engine operating characteristic curve.

[0054] The economic operating range refers to the operating area where a turboshaft engine operates with relatively low fuel consumption and high efficiency within a specific speed and power range. The economic operating range is determined based on a pre-calibrated engine operating characteristic curve, which is obtained through experimental testing and reflects the relationship between fuel consumption, output power, and speed of the turboshaft engine under different operating conditions.

[0055] The real-time power demand of a load represents the total input power required by the load at the current moment, which changes dynamically with the load's operating conditions. The output power of a turboshaft engine is the mechanical power that the turboshaft engine can stably provide within its economic operating range.

[0056] When the real-time power demand of the load exceeds the output power of the turboshaft engine, the drive motor operates in electric mode, generating auxiliary torque to make up for the power shortfall. The auxiliary torque is transmitted to the load end through a mechanical coupling device, and is superimposed on the output torque of the turboshaft engine to jointly meet the total power demand of the load.

[0057] When the real-time power demand of the load is lower than the output power of the turboshaft engine, the excess mechanical power generated by the turboshaft engine is converted into electrical energy through a coaxially connected generator, which then charges the hybrid energy storage module. The charging process stores temporarily excess mechanical energy as electrical energy, preventing energy waste.

[0058] By limiting the turboshaft engine to its economic operating range, and combining the auxiliary torque generation of the drive motor with the energy recovery function of the generator, dynamic matching of load power demand is achieved. This ensures both the efficient operation of the turboshaft engine and improves the overall energy utilization efficiency through the energy conversion process.

[0059] Optionally, such as Figure 2 As shown, the parallel hybrid power system further includes a processor, which is used for: Obtain the real-time power requirement of the load; The real-time power demand of the load is filtered in the first stage to obtain the steady-state average power component and the zero-mean pulse power component. The zero-mean pulse power component is filtered in a second stage to obtain high-frequency and low-frequency components. The steady-state average power component is converted into a power-torque to obtain a reference torque command, which is then executed by the turboshaft engine. The battery power allocation command is generated based on the low-frequency component and executed by the battery. The hybrid energy storage module includes a battery and a supercapacitor. A supercapacitor power allocation command is generated based on the high-frequency components, and the supercapacitor power allocation command is executed through the supercapacitor.

[0060] The processor represents the core computing unit that executes signal processing and control instruction generation, and is responsible for decomposing and distributing the load power demand. The real-time load power demand represents the total power required by the load instantaneously during operation, and this value fluctuates dynamically with changes in load conditions.

[0061] The first-stage filtering process involves frequency domain decomposition of the real-time power demand of the load, separating the original power signal into a steady-state average power component and a zero-mean pulse power component. The steady-state average power component reflects the long-term average trend of the load power demand, while the zero-mean pulse power component represents the instantaneous fluctuations around the average value.

[0062] In one embodiment, the first-level decomposition is performed using a moving average filter, as follows: , , Among them, P avg (t) represents the steady-state average power component, P pulse (t) represents the zero-mean pulse power component, T W P represents the length of the moving average window, the value of which is determined based on the periodic characteristics of the pulse load and the engine's dynamic response capability. req (t) represents the real-time power demand of the load, and τ represents the integral variable.

[0063] The second-stage filtering process further divides the zero-mean pulse power component into frequency domain components, separating it into high-frequency and low-frequency components. The high-frequency components correspond to the faster-changing parts of the power fluctuation, while the low-frequency components correspond to the slower-changing parts.

[0064] In one embodiment, the second-level decomposition is performed using low-pass filtering, as follows: PLPF(t) = LPF(Ppulse(t), τ c ), PHPF(t) = Ppulse(t) - PLPF(t), Where PLPF(t) represents the low-frequency component, PHPF(t) represents the high-frequency component, LPF represents the low-pass filter, and τ c This represents the time constant of the low-pass filter.

[0065] The power-to-torque conversion is a calculation process that converts power values ​​into torque values. The conversion relationship is determined based on the load speed parameters. The reference torque command indicates the target torque value that the turboshaft engine needs to output. This command drives the turboshaft engine to adjust its operating state to output the corresponding torque.

[0066] In one embodiment, the conversion formula is expressed as: Teng_ref (t)=P avg (t) / ω(t)+ΔT SOC (t), Where ω(t) represents the current speed of the load, and ΔT SOC (t) represents the feedback correction term based on the state of charge (SOC) of the energy storage system. When the battery's state of charge deviates from the safe operating range, the engine output power is used through the feedback correction term to gradually restore the state of charge to the reference value.

[0067] The battery power allocation command indicates the target power output or absorption value allocated to the battery. It is generated based on the amplitude and direction of the low-frequency components and controls the battery's charging and discharging operations. The supercapacitor power allocation command indicates the target power output or absorption value allocated to the supercapacitor. It is generated based on the amplitude and direction of the high-frequency components and controls the supercapacitor to achieve a rapid power response.

[0068] In one embodiment, low-frequency components are assigned to the lithium-ion batteries in the hybrid energy storage system, and a battery health protection strategy is implemented: when the battery SOC exceeds a preset safety range or the charging / discharging power exceeds a limit, the low-pass filter time constant τ is adjusted. c Alternatively, the battery power command can be directly limited, and the excess power can be transferred to the supercapacitor.

[0069] In one embodiment, high-frequency components are distributed to supercapacitors in the hybrid energy storage system, utilizing the high power density and fast response characteristics of supercapacitors to absorb transient power fluctuations of pulsed loads.

[0070] In one embodiment, in addition to the battery and supercapacitor, power is also distributed to the drive motor, including... The power component P borne by the drive motor mot (t) is: P mot (t)=P pulse (t) P bat (t) P uc (t), Among them, P bat (t) and P uc (t) represents the actual output power of the battery and the supercapacitor, respectively.

[0071] The processor acquires the load power demand signal in real time, and separates it into a steady-state average power component and a zero-mean pulse power component through a first-stage filter. The steady-state average power component is converted into a reference torque command through a power-torque converter and sent to the turboshaft engine for execution. The zero-mean pulse power component is decomposed into high-frequency and low-frequency components through a second-stage filter, which generate supercapacitor power allocation commands and battery power allocation commands, respectively, which are executed by the supercapacitor and the battery.

[0072] By decomposing the load power demand according to frequency domain characteristics through multi-stage filtering, differentiated power allocation is achieved for different energy storage components. The turboshaft engine handles the steady-state average power demand, the battery processes low-frequency power fluctuations, and the supercapacitor addresses high-frequency power fluctuations, fully leveraging the performance advantages of each component and improving the overall operating efficiency and response characteristics of the power system.

[0073] Optionally, the processor is further configured to: Based on a preset low-pass filter time constant, the real-time power demand of the load is low-pass filtered to obtain the low-frequency component. The value of the low-pass filter time constant is determined by the state of charge of the battery or the total charging and discharging power of the battery and the supercapacitor.

[0074] The larger the time constant of the low-pass filter, the slower the filter output follows changes in the input, and the lower the cutoff frequency. The real-time power demand of the load represents the total power required instantaneously during operation, fluctuating dynamically with changes in load conditions. The low-frequency component represents the slowly changing part of the real-time power demand retained after low-pass filtering, reflecting the low-to-mid-frequency fluctuation characteristics of the load power demand.

[0075] The state of charge (SOC) of a battery represents the ratio of its current stored capacity to its rated capacity, reflecting the degree of charge and discharge. The total charge and discharge power of the battery and supercapacitor is the algebraic sum of the charge and discharge power of the two energy storage elements in the hybrid energy storage module, representing the overall energy flow state of the hybrid energy storage module.

[0076] The processor dynamically sets the low-pass filter time constant based on the battery's state of charge (SOC) or the total charge / discharge power of the battery and supercapacitor. When the battery's SOC is high or the total charge / discharge power of the hybrid energy storage module is low, the low-pass filter time constant is increased to make low-frequency component extraction smoother; when the battery's SOC is low or the total charge / discharge power of the hybrid energy storage module is high, the low-pass filter time constant is decreased to allow low-frequency components to follow changes in load power demand more quickly.

[0077] The processor applies the set low-pass filter time constant to the low-pass filter to filter the real-time power demand of the load, outputting a low-frequency component. This low-frequency component is used to generate subsequent battery power allocation instructions, guiding the battery to undertake the corresponding power regulation tasks.

[0078] By correlating the low-pass filter time constant with the battery's state of charge or the overall charge / discharge power of the hybrid energy storage module, adaptive adjustment of the filter parameters is achieved. This strategy enables the extraction of low-frequency components to be dynamically optimized based on the actual state of the energy storage elements, ensuring both the rationality of battery power allocation and improving the overall coordinated control performance of the hybrid energy storage module.

[0079] Optionally, the parallel hybrid power system further includes a power converter, which includes a generator-side rectifier, a drive motor-side inverter, and an energy storage-side DC converter.

[0080] A power converter is a power electronic device that realizes the conversion of electrical energy form and the control of energy flow. It is used to connect generators, drive motors and hybrid energy storage modules to complete the mutual conversion between AC and DC power and the regulation of DC voltage levels.

[0081] The generator-side rectifier is connected to the generator output terminal to convert the three-phase AC power generated by the generator into DC power, which is then supplied to the DC bus. It adjusts the input current or maintains stable DC bus voltage according to the control strategy.

[0082] The inverter on the drive motor side is connected to the input terminal of the drive motor and is used to convert the DC power on the DC bus into three-phase AC power with adjustable frequency and amplitude to drive the motor.

[0083] The energy storage-side DC-DC converter is connected between the hybrid energy storage module and the DC bus, and is used to regulate the charging and discharging current and voltage of the hybrid energy storage module. This converter is a bidirectional DC-DC converter, enabling energy to flow bidirectionally between the DC bus and the hybrid energy storage module, and controlling the charging and discharging power of the battery and supercapacitor according to power distribution commands.

[0084] Although the above disclosure is provided, the scope of protection of this application is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this application, and all such changes and modifications will fall within the scope of protection of this application.

Claims

1. A parallel hybrid power system, characterized in that, It includes a turboshaft engine, generator, drive motor, mechanical coupling device, and hybrid energy storage module; The turboshaft engine and the generator are coaxially connected. The generator is used to charge the hybrid energy storage module or supply power to the drive motor, and the turboshaft engine is used to output mechanical power. The drive motor and the turboshaft engine are connected in parallel through the mechanical coupling device, and are used to provide energy to the load through the turboshaft engine and / or the drive motor according to the load conditions; The hybrid energy storage module is connected to the generator and the drive motor respectively, and is used to receive electrical energy from the generator or to provide energy to the drive motor.

2. The parallel hybrid power system according to claim 1, characterized in that, The drive motor includes an electric mode and a power generation mode; When the pulse load meets the peak stage conditions, the drive motor is in the electric mode, and the drive motor provides auxiliary torque to drive the load together with the turboshaft engine. When the pulse load meets the valley stage condition, the drive motor is in the power generation mode. Under the preset torque balance constraint, the drive motor outputs power generation torque to provide power to the hybrid energy storage module.

3. The parallel hybrid power system according to claim 2, characterized in that, The torque balance constraint conditions include: The load demand torque is equal to the sum of the output torque of the turboshaft engine and the generated torque of the drive motor, wherein the load demand torque is determined by the real-time power demand of the load and the load speed.

4. The parallel hybrid power system according to claim 2, characterized in that, The peak stage condition includes a zero-mean pulse power component greater than 0; The valley phase condition includes the zero-mean pulse power component being less than 0.

5. The parallel hybrid power system according to claim 1, characterized in that, The hybrid energy storage module includes a supercapacitor and a battery; The turboshaft engine is also used to increase the output power of the turboshaft engine and charge the battery through the generator when the battery's state of charge is not within the preset safe operating range, until the battery's state of charge is within the safe operating range.

6. The parallel hybrid power system according to claim 1, characterized in that, The hybrid energy storage module includes a supercapacitor and a battery; The hybrid energy storage module is also used to adjust the output power distribution ratio between the battery and the supercapacitor according to the state of charge when the battery is in a preset second operating range.

7. The parallel hybrid power system according to claim 1, characterized in that, The turboshaft engine is used to operate within the economic operating range. When the real-time power demand of the load is greater than the output power of the turboshaft engine, the drive motor generates auxiliary torque to meet the real-time power demand of the load. When the real-time power demand of the load is less than the output power of the turboshaft engine, the generator charges the hybrid energy storage module, wherein the economic operating range is determined based on a pre-calibrated engine operating characteristic curve.

8. The parallel hybrid power system according to claim 1, characterized in that, It also includes a processor, which is used for: Obtain the real-time power requirement of the load; The real-time power demand of the load is filtered in the first stage to obtain the steady-state average power component and the zero-mean pulse power component. The zero-mean pulse power component is filtered in a second stage to obtain high-frequency and low-frequency components. The steady-state average power component is converted into a power-torque to obtain a reference torque command, which is then executed by the turboshaft engine. The battery power allocation command is generated based on the low-frequency component and executed by the battery. The hybrid energy storage module includes a battery and a supercapacitor. A supercapacitor power allocation command is generated based on the high-frequency components, and the supercapacitor power allocation command is executed through the supercapacitor.

9. The parallel hybrid power system according to claim 8, characterized in that, The processor is also used for: Based on a preset low-pass filter time constant, the real-time power demand of the load is low-pass filtered to obtain the low-frequency component. The value of the low-pass filter time constant is determined by the state of charge of the battery or the total charging and discharging power of the battery and the supercapacitor.

10. The parallel hybrid power system according to claim 1, characterized in that, It also includes a power converter, which comprises a generator-side rectifier, a drive motor-side inverter, and an energy storage-side DC-DC converter.

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