阅读说明：本技术 一种机载电气系统的地面缩比试验方法 (Ground scale test method for airborne electrical system ) 是由 曾宏刚 陈召斌 左林玄 钟帅 王立志 赵东升 于 2021-09-15 设计创作，主要内容包括：本发明提供一种机载电气系统的地面缩比试验方法,属于航空电气系统领域。根据相似原理,考虑电气系统中各电气设备的用电原理,针对研究目标设定需要控制的典型物理量,设置相应的相似常数,这些相似常数通过控制方程联系,进一步得到各设备的缩比试验机制,根据缩比后设备参数进行选型试验,最终通过缩比试验结果预测实际电气系统的工作特性。(The invention provides a ground scale test method for an airborne electrical system, and belongs to the field of aviation electrical systems. According to a similar principle, considering the electricity utilization principle of each electrical device in the electrical system, setting typical physical quantities to be controlled aiming at a research target, setting corresponding similar constants, connecting the similar constants through a control equation, further obtaining a scaling test mechanism of each device, performing a model selection test according to the device parameters after scaling, and finally predicting the working characteristics of the actual electrical system through a scaling test result.)

1. A ground scaling test method of an airborne electrical system is characterized by specifically comprising the following steps:

in the first step, the scaling quantities such as voltage and power of the test need to be determined;

secondly, determining a scaling mechanism of key parameters of each electrical device in the electrical system according to the similarity principle and the scaling coefficient;

thirdly, selecting the model according to the scaled key parameters of the equipment;

fourthly, testing the selected equipment, and predicting the working characteristics of the actual electrical system according to the test result;

the scaling mechanism of the key parameters of each electrical device in the electrical system is as follows:

setting k as a scaling factor, keeping the voltage unchanged during the test, wherein the power scaling is 1/k of the original system, and the line current is reduced to 1/k of the original system in an equal proportion;

when the storage battery and the storage battery pack are scaled, the capacity scaling of the storage battery and the storage battery pack is considered to be 1/k of the original system;

when the electric pumps are scaled, the similarity criterion is as follows:in the formula N₁、N₂To scale the power of the pump before and after, P₁、P₂Pressure of the pump before and after scaling, q₁、q₂The displacement of the pump before and after scaling, n₁、n₂The rotation speed of the pump before and after scaling; during the test, the pressure of the pump is determined according to the scaling power, and the displacement and the rotating speed of the pump are determined through the model selection of the liquid pump;

when the rectifier converter is scaled, the similar criterion is as follows: b₁＝b₂In the formula b₁、b₂The transformer ratio before and after the compression ratio is kept the same as the coil turn ratio before and after the compression ratio during the test, and the rectification mode is the same;

when the resistance load is scaled, the similarity criterion is as follows:in the formula i₁、R₁、u₁And i₂、R₂、u₂Current, resistance and voltage before and after scaling respectively; the resistance is changed to k times of the original system during the test;

when the capacitance load scaling is carried out, the similarity criterion is as follows:in the formula t₁、R₁、C₁And t₂、R₂、C₂Time, resistance and capacitance before and after scaling respectively; during the test, the capacitance is reduced in equal proportion, and the resistance is changed to k times of the original system;

when scaling the motors, the ratio is changed from UI to E_aI+I²r_aThe similarity index is as follows: c_E＝1，Where U is the motor line-side voltage, I is the current through the motor, E_aIs a back-emf generated in the armature circuit, r_aIs internal resistance, C_EIn terms of the ratio of the voltages at the ends of the line, C_IIs a similar ratio of the currents that is,is the similarity ratio of the internal resistances; during the test, the current is reduced in equal proportion, and the internal resistance of the coil is changed to k times of that of the original system;

when the generators are scaled down, the U is equal to E_a-I_aR_a-2ΔU_bThe similarity index is as follows: c_E＝1，C_ΔU1, where U is the line-side voltage of the generator, E_aIs the electromotive force of the generator, I_aIs a current, R_aIs internal resistance, Δ U_bFor brush voltage drop, C_EFor a similar ratio of the line-side voltages,being a similar ratio of currents, C_RThe similarity ratio of internal resistances, C_ΔUIs the similarity ratio of the brush voltage drops; during the test, the current is reduced in equal proportion, and the internal resistance of the generator is changed to k times of that of the original system;

when the power supply line is scaled, the power supply line is the same as a resistance load.

2. The ground scale test method of the airborne electric system according to claim 1, wherein the cross-sectional area of the power supply line and the resistance load is considered to be reduced to 1/k of the original system in an equal proportion during the ground scale test of the airborne electric system.

3. The ground scaling test method of the airborne electric system according to claim 1, wherein the ground scaling test method of the airborne electric system is characterized in that the cross-sectional area of the coil of the motor is changed into 1/k of the original system in consideration of the situation that the number of turns is unchanged and the rotating speed is unchanged.

4. The ground scaling test method of the airborne electric system according to claim 1, characterized in that the cross-sectional area of the coil of the generator is changed into 1/k of the original system when the ground scaling test of the airborne electric system is considered, the number of turns is not changed, and the rotating speed is not changed.

Technical Field

The invention belongs to the field of aviation electrical systems, and particularly relates to a ground scale test method of an airborne electrical system.

Background

The aircraft electrical system is an important component of the aircraft, and the stability and the reliability of the operation of the aircraft electrical system are related to the performance and the flight safety of the whole aircraft. And with the development of multi-electric/all-electric aircraft, the traditional pneumatic, hydraulic and mechanical driving systems are replaced by electric systems to improve the reliability, maintainability and flexibility of the aircraft, which puts more strict requirements on the power supply capacity and quality of the electric systems.

The ground test of the airborne electrical system is an important way for checking whether the design of the electrical system meets the requirements, but if the test object is the electrical system with high power requirement, because the system comprises high-power equipment such as high-energy weapons and the like, the cost for carrying out the real test of the whole electrical system is high, and the power supply power which is difficult to meet the requirements in a common test site needs a ground scale test method for the design of the electrical system. Through the scaling test, the power supply characteristics and power supply capacity of an actual electrical system can be reflected, and important data support is provided for aircraft development and test flight.

Disclosure of Invention

The invention aims to provide a ground scale test method of an airborne electric system, namely the ground scale test method of the airborne electric system is designed based on a scale similarity theory according to the electricity utilization principle of each electric device in the electric system, so that the cost and the test difficulty can be reduced, and the power supply characteristics and the power supply capacity of the actual electric system can be reflected.

The technical scheme adopted by the invention is as follows:

a ground scale test method of an airborne electric system is characterized in that according to a similarity principle, the electricity utilization principle of each electric device in the electric system is considered, typical physical quantities needing to be controlled are set aiming at a research target, corresponding similarity constants are set and are linked through a control equation, a scale test mechanism of each device is further obtained, a model selection test is carried out according to device parameters after scaling, and finally the working characteristics of the actual electric system are predicted through a scale test result.

A ground scale test method for an airborne electrical system specifically comprises the following steps:

in the first step, the scaling quantities such as voltage and power of the test need to be determined;

secondly, determining a scaling mechanism of key parameters of each electrical device in the electrical system according to the similarity principle and the scaling coefficient;

thirdly, selecting the model according to the scaled key parameters of the equipment;

and fourthly, testing the selected equipment, and predicting the working characteristics of the actual electrical system according to the test result.

The scaling mechanism of the key parameters of each electrical device in the electrical system is as follows:

setting k as a scaling factor, keeping the voltage unchanged during the test, wherein the power scaling is 1/k of the original system, and the line current is reduced to 1/k of the original system in an equal proportion;

when the storage battery and the storage battery pack are scaled, the capacity scaling of the storage battery and the storage battery pack is considered to be 1/k of the original system.

When the electric pumps are scaled, the similarity criterion is as follows:in the formula N₁、N₂To scale the power of the pump before and after, P₁、P₂Pressure of the pump before and after scaling, q₁、q₂The displacement of the pump before and after scaling, n₁、n₂The rotation speed of the pump before and after scaling. During the test, the pressure of the pump is determined according to the scaling power, and the displacement and the rotating speed of the pump are determined through the type selection of the liquid pump.

When the rectifier converter is scaled, the similar criterion is as follows: b₁＝b₂In the formula b₁、b₂The winding turns ratio before and after the compression ratio is kept the same during the test, and the rectification mode is the same.

When the resistance load is scaled, the similarity criterion is as follows:in the formula i₁、R₁、u₁And i₂、R₂、u₂Current, resistance and voltage before and after scaling, respectively. The resistance was changed to k times of the original system during the test.

When the capacitance load scaling is carried out, the similarity criterion is as follows:in the formula t₁、R₁、C₁And t₂、R₂、C₂Time before and after scaling, resistance and capacitance, respectively. During the test, the capacitance is reduced in equal proportion, and the resistance is changed to k times of the original system.

When scaling the motors, the ratio is changed from UI to E_aI+I²r_aThe similarity index is as follows: c_E＝1，Where U is the motor line-side voltage, I is the current through the motor, E_aIs a back-emf generated in the armature circuit, r_aIs internal resistance, C_EIn terms of the ratio of the voltages at the ends of the line, C_IIs a similar ratio of the currents that is,the similarity ratio of the internal resistances. During the test, the current is reduced in equal proportion, and the internal resistance of the coil is changed to k times of that of the original system.

When the generators are scaled down, the U is equal to E_a-I_aR_a-2ΔU_bThe similarity index is as follows: c_E＝1，C_ΔU1, where U is the line-side voltage of the generator, E_aIs the electromotive force of the generator, I_aIs a current, R_aIs internal resistance, Δ U_bFor brush voltage drop, C_EFor a similar ratio of the line-side voltages,being a similar ratio of currents, C_RThe similarity ratio of internal resistances, C_ΔUIs a similar ratio of brush voltage drops. During the test, the current is reduced in equal proportion, and the internal resistance of the generator is changed to k times of that of the original system.

When the power supply line is scaled, the power supply line is similar to a resistance load.

Preferably, the cross-sectional areas of the power supply line and the resistance loads are considered to be reduced to 1/k of the original system in an equal proportion in the ground scale test of the airborne electric system.

Preferably, in the ground scale test of the onboard electrical system, when the cross-sectional area of the coil of the motor is 1/k of that of the original system, the number of turns is not changed, and the rotating speed is not changed.

Preferably, when the cross-sectional area of the coils of the generators is 1/k of the original system in the ground scale test of the airborne electric system, the number of turns is not changed, and the rotating speed is not changed.

The beneficial technical effects of the invention are embodied in the following aspects: by adopting the ground scale test method of the airborne electrical system, the scale test result can effectively reflect the working characteristics of the original electrical system, and meanwhile, the test cost and difficulty can be reduced, the test period is shortened, and the test safety is improved.

Drawings

FIG. 1 is a schematic diagram of a ground scale test of an onboard electrical system.

Fig. 2 is a flowchart of a scaling test of an onboard electrical system.

Detailed Description

Referring to fig. 1, when a ground scaling test with power reduced by 10 times is performed on a certain onboard electrical system, the output voltage and frequency of a left generator and a right generator are kept unchanged to 115V/400Hz, the capacity of a storage battery is 1/10 of the original system, a transformer rectifier outputs 270V direct-current voltage, the transformer ratio and the rectification mode are the same as those of the original system, the resistance value of a resistor load is 10 times that of the original system, the capacitance load capacitance is 1/10 of the original system, the resistance value of a line load is 10 times that of the original system, the sectional area of the line is 1/10 of the original system, the pressure of an electric pump is selected from 1/10 of the original power, and the displacement and the rotating speed of the pump are determined through the type selection of a liquid pump. The direct current motor is taken as an example of the motor and the generator, the power of the motor is changed into 1/10 of the original system, the voltage is kept unchanged, the current is changed into 1/10 of the original system, the internal resistance is changed into 10 times of the original system, the power of the generator is changed into 1/10 of the original system, the voltage is kept unchanged, the current is changed into 1/10 of the original system, the internal resistance is changed into 10 times of the original system, and the brush voltage drop is kept unchanged.

Referring to fig. 2, in a scaling test process of an onboard electrical system, a first step is to determine a scaling quantity such as voltage and power of a test, a second step is to determine a scaling mechanism of key parameters of each electrical device in the electrical system according to a similar principle and a scaling coefficient, a third step is to select a model according to the scaled key parameters of the devices, and finally, the selected model devices are tested, and the working characteristics of the actual electrical system are predicted according to a test result.

It should be understood that parts of the specification not set forth in detail are well within the prior art.

It should be understood that the above description of the preferred embodiments is given for clarity and not for any purpose of limitation, and that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.