A general hybrid system performance analysis method and system

Abstract

The application discloses a kind of general hybrid power system performance analysis method and system, belong to hybrid power analysis technical field, method includes: the power source signal of the hybrid power system, direct electric energy signal and storage electric energy signal are collected;The piston displacement signal is converted into piston position;According to the piston position, the direct electric energy signal and the storage electric energy signal are combined to the hybrid power system and are analyzed thermodynamically and are analyzed energy flow, wherein the system thermodynamic analysis includes combustion performance analysis, thermodynamic performance analysis, emission performance analysis, the system energy flow analysis includes power analysis, efficiency analysis and stability analysis;The result obtained by analysis is shown.Performance analysis applicable scope is improved, and performance analysis means and method of total energy cycle are provided, and the performance analysis cost of different hybrid power systems is reduced.

Description

Technical Field

[0001] This invention belongs to the field of hybrid power analysis technology, specifically relating to a generalized hybrid power system performance analysis method and system. Background Technology

[0002] In recent years, hybrid power systems, as an important technological stage in the process of vehicle electrification, have become a key research focus for scholars and automotive companies. A hybrid power system mainly consists of a thermal power source, an electric power source, and energy processing and storage devices. Conventional thermal power sources are rotary gasoline or diesel engines, and the corresponding electric power source is a rotary generator. The rotary thermal power source converts the chemical energy of fuel into mechanical energy, which is then further converted into electrical energy by the electric power source. Linear internal combustion generator systems, as a new type of hybrid power system, highly integrate thermal and electric power sources. The piston in the combustion cylinder of the thermal power source is directly fixed to the moving parts of the electric power source (linear motor). The combustion pressure generated in the combustion cylinder drives the piston and the moving parts of the electric power source to reciprocate, realizing the conversion from chemical energy to electrical energy.

[0003] Current performance analysis of hybrid power systems mainly focuses on the thermal power source of traditional rotary hybrid power systems, emphasizing combustion and emission performance. Monitoring and data analysis of the overall performance of rotary hybrid power systems are lacking, hindering the improvement and evaluation of overall system efficiency. Furthermore, existing analytical devices can only analyze and process data from rotary hybrid power systems, using angle signals and angle-related evaluation indicators for system data mining, performance analysis, and evaluation. However, linear internal combustion generator systems involve only linear motion, with piston strokes that can flexibly change within maximum mechanical limits. Their position signals cannot be converted into angles, therefore current analytical devices cannot analyze the thermal power source of this new type of hybrid power system. Additionally, linear internal combustion generator systems exhibit a large speed variation range during reciprocating motion, resulting in significant voltage distortion and power generation characteristics that differ considerably from traditional rotary generators. Traditional analytical methods are no longer applicable, causing inconvenience for the characteristic analysis and performance improvement of linear internal combustion generator systems. Developing dedicated performance analysis devices for different types of hybrid power systems is costly and lacks versatility.

[0004] In summary, current hybrid power system performance analysis relies excessively on angle-based characterization methods, which have limited applicability. Since linear internal combustion power generation systems involve only linear motion, the piston stroke can vary flexibly within maximum mechanical limits, and its position signal cannot be converted into an angle. Therefore, performance analysis of linear internal combustion hybrid power systems is not feasible. The analysis results mainly focus on the thermal power source of traditional rotary hybrid power systems, lacking monitoring and data analysis of the overall performance of the hybrid power system. Summary of the Invention

[0005] To address the limitations of existing general-purpose hybrid power system performance analysis methods, which have limited applicability and cannot perform performance analysis on linear internal combustion power generation systems, and whose traditional analysis methods primarily focus on the thermal power source of conventional rotary hybrid power systems, lacking technical capabilities for monitoring and data analysis of the overall performance of hybrid power systems, this invention provides a general-purpose hybrid power system performance analysis method and system.

[0006] First aspect

[0007] This invention provides a generalized performance analysis method for hybrid power systems, applied to a hybrid power analysis device. The hybrid power analysis device includes a signal acquisition module, an analysis and processing module, and an interactive display module. The interactive display module is used to display the analysis results and receive the user's initial parameter settings. The method includes:

[0008] S101: Collects power source signals, direct electrical energy signals, and stored electrical energy signals of the hybrid power system. The power source signals include piston displacement signals, cylinder pressure signals, cylinder wall temperature signals, fuel injection control signals, ignition control signals, air-fuel ratio signals, and exhaust gas signals. The direct electrical energy signals include motor phase current signals and motor phase voltage signals on the generator side of the power source. The stored electrical energy signals include DC bus current signals and bus voltage signals. The hybrid power system includes a conventional hybrid power system or a linear internal combustion hybrid power system. The piston displacement signals include crankshaft angle signals of the conventional hybrid power system and piston position signals of the linear internal combustion hybrid power system.

[0009] S102: Convert the piston displacement signal into piston position;

[0010] S103: Based on the piston position, combined with other power source signals, direct electrical energy signals and stored electrical energy signals, perform system thermodynamic analysis and system energy flow analysis on the hybrid power system. The system thermodynamic analysis includes combustion performance analysis, thermodynamic performance analysis and emission performance analysis, while the system energy flow analysis includes power analysis, efficiency analysis and stability analysis.

[0011] S104: Present the results of the analysis.

[0012] Second aspect

[0013] The present invention provides a generalized hybrid power system performance analysis system for performing the generalized hybrid power system performance analysis method in the first aspect.

[0014] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0015] In this invention, by converting the piston displacement signal collected by the sensor into a piston position signal, it is no longer limited to angular representation and uses positional expression to realize the analysis of the combustion performance and thermodynamic performance of the power source, thereby realizing the performance analysis of the linear internal combustion power generation system. It can be applied to the performance analysis of both traditional hybrid power systems and crankless linear internal combustion power generation systems. It effectively converts different types of displacement signals into piston positions, and provides power and efficiency data for the power processing and output side of the hybrid power system. It provides various performance analysis methods and means for the entire energy cycle of hybrid power systems, with a wide range of applications and diversified analysis results, and can accurately complete the performance analysis of various hybrid power systems. Attached Figure Description

[0016] 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.

[0017] Figure 1 This is a flowchart illustrating a generalized hybrid power system performance analysis method provided by the present invention;

[0018] Figure 2 This is a schematic diagram of a hybrid power analysis device provided by the present invention. Detailed Implementation

[0019] 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.

[0020] 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."

[0021] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] 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.

[0023] Furthermore, in the description of this invention, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0024] Example 1

[0025] In one embodiment, refer to the appendix to the specification. Figure 1 This diagram illustrates a flowchart of the universal hybrid power system performance analysis method provided by the present invention. (See attached specification.) Figure 2 The diagram shows a schematic of the structure of a hybrid power analysis device provided by the present invention.

[0026] This invention provides a generalized hybrid power system performance analysis method, which is applied to a hybrid power analysis device. The hybrid power analysis device includes a signal acquisition module, an analysis and processing module, and an interactive display module. The interactive display module is used to display the analysis results and receive the user's initial parameter settings.

[0027] The signals acquired by the signal acquisition module are used by the backend analysis and processing module. The analysis and processing module includes two parts: system thermodynamic / combustion analysis and system energy flow analysis. The analysis and processing results are displayed and stored in the interactive display module. The interactive display module supports user operation and result display, including: system parameter settings, online analysis results, offline retrieval, and data reprocessing.

[0028] User parameter settings primarily involve configuring basic parameters for the hybrid power system, operating condition parameters, and enabling / disabling functions for the analysis and processing modules. Basic hybrid power system parameter settings include hybrid power system type, number of power cylinders, and position sensor parameters. If the hybrid power system is a linear internal combustion hybrid, further settings are required, including cylinder displacement, piston area, and maximum permissible stroke. If the hybrid power system is a conventional hybrid, further settings are required for cylinder displacement, connecting rod length, crankshaft radius, piston-crankshaft eccentricity, and piston stroke. Position sensor parameters mainly include sensor type and sensor resolution. Operating condition parameter settings include fuel type, ignition method, injection coefficient, intake air temperature, injection pulse width, and ignition position. Analysis and processing module function selection allows users to choose whether to enable signal detection in the signal acquisition module and whether to enable performance analysis in the analysis and processing module. Online analysis results are mainly used to display the results of online analysis in the analysis and processing module, for hybrid power system performance analysis and evaluation. Offline invocation and data processing are mainly used for user-programmed data processing. This part stores all the data collected and processed by the signal acquisition module and the analysis and processing module, and stores them with corresponding variable names. This part supports users to call the variables and perform self-programmed data reprocessing.

[0029] The methods include:

[0030] S101: Collects power source signals, direct electrical energy signals, and stored electrical energy signals of the hybrid power system. Power source signals include piston displacement signals, cylinder pressure signals, cylinder wall temperature signals, fuel injection control signals, ignition control signals, air-fuel ratio signals, and exhaust gas signals. Direct electrical energy signals include motor phase current signals and motor phase voltage signals on the generator side of the power source. Stored electrical energy signals include DC bus current signals and bus voltage signals on the DC side.

[0031] The hybrid system includes a conventional hybrid system or a linear internal combustion hybrid system. The piston displacement signal includes the crankshaft angle signal of the conventional hybrid system and the piston position signal of the linear internal combustion hybrid system.

[0032] The power source signals encompass parameters and data related to the internal combustion engine portion of the hybrid system, including: piston displacement position signals (for understanding piston movement); cylinder pressure signals (for measuring pressure within each cylinder); cylinder wall temperature signals (for measuring cylinder wall temperature); fuel injection control signals (for monitoring fuel injection control); ignition control signals (for monitoring ignition system operation); in-cylinder air-fuel ratio signals (for controlling the mixture composition); exhaust gas signals (for monitoring emissions data); direct electrical energy signals (covering current and voltage information on the motor side, typically from the electric motor in the hybrid system, used for energy generation and transmission); and stored electrical energy signals (covering DC bus current and voltage, typically from energy storage devices, used for energy storage and management).

[0033] These signal acquisition processes may involve the use of various sensors and monitoring devices, such as displacement sensors, cylinder pressure sensors, temperature sensors, current sensors, and voltage sensors, to obtain data related to the hybrid system performance in real time. S101 is the starting step of a generalized hybrid system performance analysis method. It acquires data on various aspects of the hybrid system by collecting multiple signals, providing the necessary input for subsequent performance analysis. These signals can help analysts or system implementers understand the system's operating status for more in-depth performance evaluation and optimization.

[0034] In one possible implementation, S101 specifically includes:

[0035] S1011: Piston displacement signal is acquired by a displacement sensor installed on the piston linkage component, cylinder pressure signal is acquired by a cylinder pressure sensor installed on the cylinder head, cylinder wall temperature is acquired by a thermocouple sensor installed at the cylinder block and cylinder head, injection control signal, injection pulse width and ignition control signal are acquired by a weak voltage sensor installed in the injection drive signal and ignition drive signal circuit, in-cylinder air-fuel ratio signal is acquired by an oxygen sensor installed on the exhaust pipe, and exhaust gas signal is acquired by an exhaust gas analyzer installed at the rear end of the exhaust pipe.

[0036] S1012: The motor phase current signal is acquired by a high-voltage current sensor installed on the motor side output wire, and the motor phase voltage signal is acquired by a high-voltage voltage sensor connected in parallel to the motor side circuit.

[0037] S1013: The bus current signal is acquired by a high-voltage current sensor installed on the input conductor of the energy storage device, and the bus voltage signal is acquired by a high-voltage voltage sensor connected in parallel to the side circuit of the energy storage device.

[0038] In one possible implementation, the displacement sensor includes, but is not limited to, Hall effect crankshaft position sensors, photoelectric crankshaft position sensors, electromagnetic crankshaft position sensors, magnetic scales, optical scales, or resolver position sensors.

[0039] Understandably, multiple sensors are used to collect key signals from the hybrid power system, including piston position, cylinder pressure, cylinder wall temperature, fuel injection control, ignition control, and in-cylinder air-fuel ratio, to analyze combustion and thermodynamic performance. Phase current and voltage signals from the motor side are collected to monitor motor performance. Bus current and voltage signals from the energy storage device side are collected to analyze the performance and status of the energy storage device. This data provides essential information for the performance analysis of the hybrid power system.

[0040] S102: Convert the piston displacement signal into piston position.

[0041] The piston displacement signal is an electrical signal generated by a sensor, used to measure or record the change in the piston's position within the engine over time. This signal, based on the piston's motion, can be represented as the piston's displacement relative to its initial position. In traditional rotary internal combustion engines, crankshaft angle signals are typically used to represent piston displacement. This signal reflects the piston's vertical movement within the engine and is a key input for performance analysis. Piston position refers to the actual position of the piston relative to a reference point within the engine; it is a value calculated from the piston displacement signal or data from other sensors. Piston position information is crucial for understanding engine operating conditions, the combustion process, and the performance of the entire hybrid powertrain system.

[0042] It's important to note that using piston position signals instead of angle signals broadens the applicability of performance analysis methods. This is particularly useful for linear motion systems such as linear internal combustion hybrid systems, where piston stroke can vary freely within maximum mechanical constraints and cannot be simply represented as an angle. A key difference between linear internal combustion hybrid systems and traditional rotary hybrid systems is that they use linearly moving pistons instead of rotating crankshafts to generate power. This difference limits the application of angle-based characterization methods in the performance analysis of linear internal combustion hybrid systems. Using piston position signals allows for a more comprehensive analysis of hybrid system performance, including understanding the precise piston position and providing detailed analysis of engine duty cycles, combustion processes, and in-cylinder pressures, rather than solely relying on crankshaft angles. For systems other than rotary hybrid systems, such as linear internal combustion hybrid systems, performance analysis using piston position signals can monitor and optimize the overall performance of these systems. This comprehensive data analysis helps improve system efficiency, stability, and emissions. Furthermore, this approach avoids the cost increases associated with customizing performance analysis methods for different hybrid systems, significantly reducing R&D and performance monitoring costs.

[0043] In one possible implementation, S102 specifically includes:

[0044] S1021: When the piston displacement signal is a crankshaft angle signal, the conversion method is as follows:

[0045]

[0046] θ = r s n s sign(dn s )

[0047] Where x0 represents the initial piston position, θ represents the crankshaft angle, R represents the crankshaft radius, L represents the connecting rod length, and O f The piston-crankshaft eccentricity, r s n represents the resolution of the displacement sensor. s dn represents the number of counting pulses of the displacement sensor. s This indicates the rate of change of the number of counting pulses from the displacement sensor.

[0048] S1022: When the piston displacement signal is a piston position signal, the conversion method is as follows:

[0049] x = x0 + r s n s sign(dn s ).

[0050] It should be noted that for different types of hybrid power systems, two different conversion methods are provided to convert piston displacement signals into piston positions for subsequent system thermodynamic and energy flow analyses. These methods adapt to different types of hybrid power systems based on the type of piston displacement signal (crankshaft angle signal or piston position signal). This improves the applicability of the method, allowing it to be applied to a wider range of hybrid power systems, regardless of whether their motion characteristics are based on crankshaft angle or piston position. This flexibility facilitates a more comprehensive analysis of hybrid power system performance.

[0051] S103: Based on the piston position, combined with signals from other power sources, direct electrical energy signals, and stored electrical energy signals, perform system thermodynamic analysis and system energy flow analysis on the hybrid power system.

[0052] The system thermodynamic analysis includes combustion performance analysis, thermodynamic performance analysis, and emission performance analysis, while the system energy flow analysis includes power analysis, efficiency analysis, and stability analysis.

[0053] It should be noted that for linear internal combustion power generation systems, this method provides a displacement signal conversion method that converts piston displacement signals into piston positions. This method allows for precise measurement and analysis of the piston position in linear motion, solving the problem that linear internal combustion hybrid power systems cannot be simply represented by angles. The reason why this method can be used for hybrid power system performance analysis, including performance analysis of traditional rotary hybrid power systems and novel linear internal combustion power generation systems, is that it overcomes the limitations of traditional angle-based characterization methods, converting various forms of piston displacement signals into specific piston positions. This enables the simultaneous performance analysis of multiple forms of hybrid power systems, making multi-performance analysis possible.

[0054] Furthermore, this method not only includes combustion performance analysis and thermodynamic performance analysis, but also covers performance analysis in multiple aspects such as emission performance analysis, power analysis, efficiency analysis, and stability analysis, providing a comprehensive understanding of the operating characteristics and performance of hybrid power systems. The data processing and calculation methods provided by this method, such as the calculation of instantaneous combustion heat release rate, estimation of maximum cylinder pressure, and efficiency calculation, can deeply mine data and provide detailed performance evaluations. Special analysis for linear internal combustion power generation systems: This method provides analysis methods applicable to linear motion and power output characteristics, taking into account the special properties of linear internal combustion power generation systems, thereby fully leveraging the performance advantages of linear internal combustion hybrid power systems. Through diverse data acquisition methods, displacement signal conversion, multiple performance analyses, and advanced data processing methods, it can handle different types of hybrid power systems, including linear internal combustion hybrid systems, providing comprehensive performance analysis and evaluation, which helps to deeply understand and optimize the working principles and performance characteristics of hybrid power systems. This contributes to improving the overall efficiency, reliability, and environmental friendliness of hybrid power systems.

[0055] In one possible implementation, the combustion performance analysis includes instantaneous combustion heat release rate, maximum combustion heat release rate and corresponding piston position, cumulative combustion heat release at time k, cumulative combustion heat release during the cycle, combustion heat release at the user-set position, combustion start position, combustion end position, combustion end angle, combustion duration, mass fraction of burned fuel at time k, and piston position for a user-set fixed percentage of combustion heat release; the thermodynamic performance analysis includes instantaneous cylinder pressure change rate, maximum cylinder pressure change rate and corresponding piston position, maximum cylinder pressure and corresponding piston position, cycle indicated work, average effective cylinder pressure, instantaneous in-cylinder temperature estimation, and maximum instantaneous in-cylinder temperature and corresponding piston position; the emission performance analysis includes air-fuel ratio analysis, nitrogen oxide emissions, carbon dioxide emissions, exhaust gas concentration, and particulate matter content.

[0056] In one possible implementation, the instantaneous combustion heat release rate is calculated as follows:

[0057]

[0058] Among them, P i P represents the cylinder pressure at the current moment. i-1 V represents the cylinder pressure at the previous moment. i V represents the current volume of the cylinder. i-1 γ represents the cylinder volume calculated from the piston area and piston position at the previous moment, and γ represents the gas adiabatic index.

[0059] The maximum heat release rate dQ is calculated based on the instantaneous heat release rate. cmax and the piston position X corresponding to the maximum combustion heat release rate dQcmax :

[0060] dQ cmax =max(dQ) ci )

[0061] X dQcmax =x(dQ) cmax );

[0062] The cumulative heat released by combustion at time k is Q ck The calculation method is as follows:

[0063]

[0064] The cumulative heat released by combustion in the cycle, Q c The calculation method is as follows:

[0065]

[0066] The heat release at the user-defined location is calculated by accumulating the heat release at time k.

[0067] The moment when the instantaneous heat release rate is greater than zero at the beginning of the cycle is taken as the combustion start time t. s The combustion start position is the position corresponding to the moment when combustion begins, i.e., x. s =x(t) s Correspondingly, the combustion end time t is defined as the last moment in the cycle when the instantaneous heat release rate is greater than zero. e The combustion end position is the position corresponding to the moment when combustion ends, i.e., x. e =x(t) e );

[0068] The duration of combustion, t, is calculated based on the start and end times of combustion. d :

[0069] t d =t e -t s ;

[0070] At time k, the mass fraction of burned fuel X k The calculation method is as follows:

[0071] X k =Q ck / Q c ;

[0072] User-defined piston position x for a fixed percentage of heat released during combustion n The calculation method is as follows:

[0073] x n =x(X) k ==n%);

[0074] Instantaneous cylinder pressure change rate dpi The calculation method is as follows:

[0075] dp i =p i -p i-1 / Δt

[0076] Where Δt represents the sampling interval duration, p i and p i-1 These represent the cylinder pressure at time i and time i-1, respectively;

[0077] The maximum cylinder pressure change rate dp is calculated based on the instantaneous cylinder pressure change rate. max and the piston position X corresponding to the maximum cylinder pressure change rate dpmax :

[0078] dp max =max(dp) i )

[0079] X dpmax =x(dp) max );

[0080] Maximum cylinder pressure dp max and its corresponding piston position X pmax The calculation method is as follows:

[0081] dp max =max(p i )

[0082] X pmax =x(p max );

[0083] Cyclic Indicator Work W ec The calculation method is as follows:

[0084]

[0085] Where A represents the piston area and p represents the cylinder pressure measured by the cylinder pressure sensor;

[0086] The mean effective cylinder pressure (IMEP) is calculated as follows:

[0087] IMEP=W ec / V maxc

[0088] Among them, V maxc This indicates the maximum working volume in the current loop;

[0089] Instantaneous cylinder temperature T k The estimation is calculated as follows:

[0090] T k =p k Vk / m k R

[0091]

[0092] Where R represents the gas constant under the current working fluid, m k The mass of the working fluid in the cylinder at the current moment is represented by t. fuel This indicates the injection time detected by the low-voltage sensor. The AFR indicates the injection flow rate of the fuel injector and the air-fuel ratio obtained by the oxygen sensor.

[0093] Maximum instantaneous in-cylinder temperature T max and the corresponding piston position X Tmax The calculation method is as follows:

[0094]

[0095] The air-fuel ratio, nitrogen oxide emissions, carbon dioxide emissions, exhaust gas concentration, and particulate matter content are calculated using an exhaust gas analyzer.

[0096] The instantaneous combustion heat release rate calculates the combustion heat release rate at each time point, including the current cylinder pressure, the cylinder pressure at the previous time point, the cylinder volume, and the influence of the gas adiabatic index. The maximum combustion heat release rate and corresponding piston position are determined based on the instantaneous combustion heat release rate calculation. The cumulative combustion heat release at time k is the accumulated combustion heat release within a given time period k. The cumulative combustion heat release during the cycle is the accumulated combustion heat release throughout the entire cycle. The combustion heat release at the user-defined position is the combustion heat release at the user-specified piston position. The combustion start and end positions are calculated based on the combustion start and end times and the time when the instantaneous heat release rate is greater than zero, determining the piston positions at the start and end of combustion. The combustion duration is the combustion duration calculated based on the combustion start and end times. The burned fuel mass fraction at time k is the fuel mass fraction within a given time period k. The piston position for a user-defined fixed percentage of combustion heat release is calculated based on the user-defined percentage. The instantaneous cylinder pressure change rate calculates the cylinder pressure change rate at each time point, including the sampling interval and the difference between the current cylinder pressure and the cylinder pressure at the previous time point. The maximum cylinder pressure change rate and corresponding piston position are determined based on the instantaneous cylinder pressure change rate. The maximum cylinder pressure and corresponding piston position are calculated. Cycle indicated work is calculated, including the flow cross-sectional area and in-cylinder pressure. Average effective cylinder pressure is calculated, including the maximum working volume for the current cycle. Instantaneous in-cylinder temperature estimation estimates the in-cylinder temperature at each time point, including the gas constant and the influence of the current working fluid mass. The maximum instantaneous in-cylinder temperature and corresponding piston position are calculated. Emissions performance analysis includes air-fuel ratio analysis, nitrogen oxide emissions, carbon dioxide emissions, exhaust gas concentration, and particulate matter content. These data are typically collected and calculated using an exhaust gas analyzer. The calculation methods for these performance indicators and parameters help to gain a deeper understanding of the hybrid power system's operation, including combustion efficiency, thermodynamic characteristics, and emissions, thereby enabling performance optimization and improvement.

[0097] In one possible implementation, the power analysis includes power source engine-side indicated power analysis, power source engine-side indicated power, power source generator-side electrical power analysis, power source generator-side electrical energy analysis, energy storage device-side electrical power analysis, and energy storage device-side electrical energy analysis; the efficiency analysis includes power system energy conversion efficiency analysis, combustion efficiency analysis, indicated thermal efficiency analysis, and electrical energy storage efficiency analysis; the stability analysis includes power source misfire rate analysis and power source knock rate analysis.

[0098] In one possible implementation, the power source engine side indicates the power W. e The calculation method is as follows:

[0099]

[0100] Where p represents the cylinder pressure measured by the cylinder pressure sensor, and N represents the number of thermodynamic cycles collected under the current operating conditions;

[0101] Power source engine side indicated power P e The calculation method is as follows:

[0102] P e =W e / T

[0103] Where T represents the time consumed to collect N thermal cycles under the current operating conditions;

[0104] Power source generator side electrical power P g The calculation method is as follows:

[0105]

[0106] Among them, U i I represents the voltage of the generator. i The generator current is represented by , a, b, and c represent the A, B, and C phases of the generator, respectively; ab represents phase AB of the generator, ac represents phase AC of the generator, bc represents phase BC of the generator, ba represents phase BA of the generator, and t c This indicates the duration of a thermodynamic cycle.

[0107] Power source generator side electrical energy W g The calculation method is as follows:

[0108]

[0109] Energy storage device side power P b The calculation method is as follows:

[0110]

[0111] Among them, U dc and I dc These represent the bus voltage and bus current of the energy storage device, respectively.

[0112] Energy storage device side electrical energy W b The calculation method is as follows:

[0113]

[0114] Power system energy conversion efficiency η g The calculation method is as follows:

[0115] η g =W e / Wg ;

[0116] Combustion efficiency η c The calculation method is as follows:

[0117]

[0118] Among them, Q in C represents the fuel energy entering the system. lhv This indicates the fuel has a low calorific value;

[0119] Indicating thermal efficiency η i The calculation method is as follows:

[0120]

[0121] Energy storage efficiency η b The calculation method is as follows:

[0122] η b =W b / W g ;

[0123] Power source misfire rate F mis The calculation method is as follows:

[0124] F mis =N mis / N

[0125]

[0126]

[0127] Where, N mis This indicates the number of times the power source misfires within a time duration T. i This indicates the criteria for determining a single fire. This indicates that the piston position is x during the current cyclic expansion phase. max -x ig Cylinder pressure at / 2 This indicates that the piston position is x during the current compression cycle. max -x ig Cylinder pressure at / 2;

[0128] Power source knock rate F kno The calculation method is as follows:

[0129] F kno =N kno / N

[0130]

[0131]

[0132] Where, N kno Kno represents the number of times the power source detonates within a time duration of T. i This indicates the single-shot detonation judgment condition, where t0 represents the start time of the current loop, and t pmax t represents the moment when the maximum cylinder pressure of the current cycle occurs. end Indicates the end time of the current loop, filter highpass (p) represents the high-frequency signal portion of the cylinder pressure retained after passing through a high-pass filter, k thre This indicates the detonation threshold.

[0133] It should be noted that power analysis, efficiency analysis, and stability analysis are performed on the hybrid power system. Power analysis includes several aspects: First, the indicated power of the power source engine is analyzed by monitoring in-cylinder pressure and the number of thermodynamic cycles to calculate the power loss of the power source at the engine side. Then, the indicated power of the power source engine, i.e., the effective output power of the engine, is calculated. Next, the electrical power at the power source generator side and the electrical power at the energy storage device side are analyzed; these analyses help to understand the flow and conversion of energy. Finally, the electrical energy at the energy storage device side is calculated for storing and releasing electrical energy.

[0134] Efficiency analysis encompasses the energy conversion efficiency, combustion efficiency, indicated thermal efficiency, and electrical energy storage efficiency within the power system. These analyses can assess the energy utilization efficiency of hybrid power systems, including the conversion efficiency from chemical energy to mechanical energy and electrical energy, as well as the efficiency of combustion and electrical energy storage.

[0135] Stability analysis includes the analysis of power source misfire rate and power source knock rate. Misfire rate analysis is used to assess the misfire situation of the power source, while knock rate analysis is used to detect whether knocking has occurred. These are important indicators of the stability of hybrid power systems.

[0136] In one possible implementation, the initial parameters include hybrid system type, number of power cylinders, position sensor parameters, and operating condition parameters.

[0137] Understandably, prior to these analyses, initial parameters of the hybrid power system, such as system type, number of cylinders, position sensor parameters, and operating condition parameters, need to be considered to ensure accuracy and feasibility. This comprehensive performance analysis approach helps to gain a deeper understanding of the hybrid power system's operation, optimize system design, and improve system efficiency and reliability.

[0138] S104: Present the results of the analysis.

[0139] Understandably, presenting the various performance parameters and characteristics of the hybrid power system to users in an intuitive and easy-to-understand manner allows users to better understand the system's operating status and make corresponding decisions and improvements, thereby helping users understand and optimize the performance, efficiency, and stability of the hybrid power system.

[0140] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0141] In this invention, by converting the piston displacement signal collected by the sensor into a piston position signal, it is no longer limited to angular representation and uses positional expression to realize the analysis of the combustion performance and thermodynamic performance of the power source, thereby realizing the performance analysis of the linear internal combustion power generation system. It can be applied to the performance analysis of both traditional hybrid power systems and crankless linear internal combustion power generation systems. It effectively converts different types of displacement signals into piston positions, and provides power and efficiency data for the power processing and output side of the hybrid power system. It provides various performance analysis methods and means for the entire energy cycle of hybrid power systems, with a wide range of applications and diversified analysis results, and can accurately complete the performance analysis of various hybrid power systems.

[0142] Example 2

[0143] In one embodiment, the present invention provides a generalized hybrid power system performance analysis system for executing the generalized hybrid power system performance analysis method in Embodiment 1.

[0144] The generalized hybrid power system performance analysis system provided by this invention can realize the steps and effects of the generalized hybrid power system performance analysis method in Embodiment 1 above. To avoid repetition, this invention will not repeat them.

[0145] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0146] In this invention, by converting the piston displacement signal collected by the sensor into a piston position signal, it is no longer limited to angular representation and uses positional expression to realize the analysis of the combustion performance and thermodynamic performance of the power source, thereby realizing the performance analysis of the linear internal combustion power generation system. It can be applied to the performance analysis of both traditional hybrid power systems and crankless linear internal combustion power generation systems. It effectively converts different types of displacement signals into piston positions, and provides power and efficiency data for the power processing and output side of the hybrid power system. It provides various performance analysis methods and means for the entire energy cycle of hybrid power systems, with a wide range of applications and diversified analysis results, and can accurately complete the performance analysis of various hybrid power systems.

[0147] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0148] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A generalized performance analysis method for hybrid power systems, characterized in that, An application is made in a hybrid power analysis device, which includes a signal acquisition module, an analysis and processing module, and an interactive display module. The interactive display module is used to display analysis results and receive initial parameter settings from the user, and the method includes: S101: Collect the power source signal, direct electrical energy signal, and stored electrical energy signal of the hybrid power system. The power source signal includes piston displacement signal, cylinder pressure signal, cylinder wall temperature signal, fuel injection control signal, ignition control signal, air-fuel ratio signal, and exhaust gas signal. The direct electrical energy signal includes the motor phase current signal and motor phase voltage signal on the generator side of the power source. The stored electrical energy signal includes the DC bus current signal and bus voltage signal on the DC side. The hybrid power system includes a conventional hybrid power system or a linear internal combustion hybrid power system. The piston displacement signal includes the crankshaft angle signal of the conventional hybrid power system and the piston position signal of the linear internal combustion hybrid power system. S102: Convert the piston displacement signal into piston position; S103: Based on the piston position, combined with other power source signals, the direct electrical energy signal, and the stored electrical energy signal, perform system thermodynamic analysis and system energy flow analysis on the hybrid power system. The system thermodynamic analysis includes combustion performance analysis, thermodynamic performance analysis, and emission performance analysis. The system energy flow analysis includes power analysis, efficiency analysis, and stability analysis. S104: Present the results of the analysis; Specifically, S102 includes: S1021: When the piston displacement signal is the crankshaft angle signal, the conversion method is as follows: in, Indicates the initial position of the piston. Indicates crankshaft rotation angle. Indicates the crankshaft radius. Indicates the length of the link. Indicates the piston-crankshaft eccentricity. Indicates the resolution of the displacement sensor. This indicates the number of counting pulses from the displacement sensor. This indicates the rate of change of the number of counting pulses from the displacement sensor. S1022: When the piston displacement signal is the piston position signal, the conversion method is as follows: 。 2. The generalized hybrid power system performance analysis method according to claim 1, characterized in that, S101 specifically includes: S1011: The piston displacement signal is acquired by a displacement sensor installed on the piston linkage component, the cylinder pressure signal is acquired by a cylinder pressure sensor installed on the cylinder head, the cylinder wall temperature is acquired by a thermocouple sensor installed at the cylinder block and cylinder head, the injection control signal, injection pulse width and ignition control signal are acquired by a low voltage sensor installed in the injection drive signal and ignition drive signal circuit, the air-fuel ratio signal is acquired by an oxygen sensor installed on the exhaust pipe, and the exhaust gas signal is acquired by an exhaust gas analyzer installed at the rear end of the exhaust pipe; S1012: The motor phase current signal is acquired by a high-voltage current sensor installed on the motor side output wire, and the motor phase voltage signal is acquired by a high-voltage voltage sensor connected in parallel to the motor side circuit; S1013: The bus current signal is acquired by a high-voltage current sensor installed on the input conductor of the energy storage device, and the bus voltage signal is acquired by a high-voltage voltage sensor connected in parallel to the side circuit of the energy storage device.

3. The generalized hybrid power system performance analysis method according to claim 2, characterized in that, The displacement sensor includes, but is not limited to, Hall effect crankshaft position sensor, photoelectric crankshaft position sensor, electromagnetic crankshaft position sensor, magnetic scale, optical scale, or resolver position sensor.

4. The generalized hybrid power system performance analysis method according to claim 1, characterized in that, The combustion performance analysis includes instantaneous combustion heat release rate, maximum combustion heat release rate and corresponding piston position, cumulative combustion heat release at time k, cumulative combustion heat release during the cycle, combustion heat release at the user-set position, combustion start position, combustion end position, combustion end angle, combustion duration, mass fraction of burned fuel at time k, and piston position for a user-set fixed percentage of combustion heat release; the thermodynamic performance analysis includes instantaneous cylinder pressure change rate, maximum cylinder pressure change rate and corresponding piston position, maximum cylinder pressure and corresponding piston position, cycle indicated work, average effective cylinder pressure, instantaneous in-cylinder temperature estimation, and maximum instantaneous in-cylinder temperature and corresponding piston position; the emission performance analysis includes air-fuel ratio analysis, nitrogen oxide emissions, carbon dioxide emissions, exhaust gas concentration, and particulate matter content.

5. The generalized hybrid power system performance analysis method according to claim 4, characterized in that, The instantaneous combustion heat release rate is calculated as follows: in, This indicates the cylinder pressure at the current moment. This indicates the cylinder pressure at the previous moment. This represents the current volume of the cylinder. This represents the cylinder volume calculated from the piston area and piston position at the previous moment. Indicates the adiabatic index of a gas; The maximum heat release rate is calculated based on the instantaneous heat release rate. and the piston position corresponding to the maximum combustion heat release rate. ; The k Accumulated heat release during combustion The calculation method is as follows: ； The cumulative heat release of the cycle The calculation method is as follows: ； The heat released during combustion at the user-defined location is calculated by accumulating the heat released during combustion at time k. The moment when the instantaneous combustion heat release rate is greater than zero at the beginning of the cycle is taken as the combustion start moment. The combustion start position is the position corresponding to the combustion start time, that is... Accordingly, the last moment of the cycle in which the instantaneous heat release rate of combustion is greater than zero is taken as the combustion end moment. The combustion end position is the position corresponding to the combustion end time, that is... ; The combustion duration is calculated based on the combustion start time and the combustion end time. ; ； k Mass fraction of burned fuel at time The calculation method is as follows: ； The user sets the piston position for a fixed percentage of heat released during combustion. The calculation method is as follows: ； The instantaneous cylinder pressure change rate The calculation method is as follows: in, Indicates the sampling interval duration. and They represent Time and Cylinder pressure at any given moment; The maximum cylinder pressure change rate is calculated based on the instantaneous cylinder pressure change rate. and the piston position corresponding to the maximum cylinder pressure change rate. ; The maximum cylinder pressure and their corresponding piston positions The calculation method is as follows: The cycle indicator work The calculation method is as follows: in, A Indicates the piston area. This indicates the cylinder pressure measured by the cylinder pressure sensor; The average effective cylinder pressure IMEP The calculation method is as follows: in, This indicates the maximum working volume in the current loop; The instantaneous cylinder temperature The estimation is calculated as follows: in, This represents the gas constant under the current working fluid. This indicates the current mass of the working fluid in the cylinder. This indicates the injection time detected by the low-voltage sensor. This indicates the injection flow rate of the fuel injector. This indicates that the oxygen sensor has obtained the air-fuel ratio. express k The cylinder volume is calculated from the piston area and piston position at any given time. express k Mass fraction of burned fuel at any given time express k Cylinder pressure at any given moment; The maximum instantaneous temperature inside the cylinder and corresponding piston position The calculation method is as follows: ； The air-fuel ratio, nitrogen oxide emissions, carbon dioxide emissions, exhaust gas concentration, and particulate matter content are calculated using an exhaust gas analyzer.

6. The generalized hybrid power system performance analysis method according to claim 1, characterized in that, The power analysis includes power source engine-side indicated power analysis, power source engine-side indicated power analysis, power source generator-side electrical power analysis, power source generator-side electrical energy analysis, energy storage device-side electrical power analysis, and energy storage device-side electrical energy analysis; the efficiency analysis includes power system energy conversion efficiency analysis, combustion efficiency analysis, indicated thermal efficiency analysis, and electrical energy storage efficiency analysis; the stability analysis includes power source misfire rate analysis and power source knock rate analysis.

7. The generalized hybrid power system performance analysis method according to claim 6, characterized in that, The power source engine side indicated power The calculation method is as follows: in, This indicates the cylinder pressure measured by the cylinder pressure sensor. This indicates the number of thermal cycles collected under the current operating conditions; The power source engine side indicated power The calculation method is as follows: in, Indicates data collection under current operating conditions. The duration of each thermodynamic cycle; The power source generator side electrical power The calculation method is as follows: in, This indicates the voltage of the generator. This indicates the generator's current. These represent the A, B, and C phase windings of the generator, respectively. This indicates the AB phase of the generator. Indicates the AC phase of the generator. This indicates the BC phase of the generator. This indicates the BA phase of the generator. This indicates the duration of a thermodynamic cycle. The power source generator side electrical energy The calculation method is as follows: The power of the energy storage device side The calculation method is as follows: in, and These represent the bus voltage and bus current of the energy storage device, respectively. The energy storage device side electrical energy The calculation method is as follows: ； The energy conversion efficiency of the power system The calculation method is as follows: ； The combustion efficiency The calculation method is as follows: ;in, This indicates the fuel energy entering the system. This indicates the fuel has a low calorific value; The indicated thermal efficiency The calculation method is as follows: ； The energy storage efficiency The calculation method is as follows: ； The power source misfire rate The calculation method is as follows: in, Indicates in Number of times the power source catches fire within a certain period of time This indicates the criteria for determining a single fire. This indicates the piston position during the current cyclic expansion phase. The cylinder pressure at that time This indicates the piston position during the current compression cycle. The cylinder pressure at that time; The power source detonation rate The calculation method is as follows: in, express Number of times the power source detonates within a given time period This indicates the criteria for determining a single detonation. Indicates the start time of the current loop. This indicates the moment when the maximum in-cylinder pressure of the current cycle occurs. Indicates the end time of the current loop. This represents the high-frequency signal portion of the cylinder pressure retained after passing through a high-pass filter. This indicates the detonation threshold.

8. The generalized hybrid power system performance analysis method according to claim 1, characterized in that, The initial parameters include hybrid power system type, number of power cylinders, position sensor parameters, and operating condition parameters.

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