CN115980572A - Simulation test device and simulation test method for load characteristics of propeller - Google Patents

Abstract

The invention discloses a propeller load characteristic simulation test device and a test method. The device includes a mounting base, a first bracket and a second bracket are fixed on the mounting base, and a There is a basic inertia disk, and an arc-shaped segmented stator is arranged on the upper and lower sides of the basic inertia disk, and the two ends of the output shaft of the inertia disk pass through an axially slidable rolling bearing and the first bracket and The second bracket is connected, two electromagnets with the same structure are located on one side of the basic inertia disk, the motor under test is fixed on the installation base through the third bracket, and the output shaft of the motor under test is passed through a coupling It is connected with the output shaft of the inertia disk. The device has the advantages of simple structure, controllable increase and decrease of load and its own stress, and strong resistance to changes in external environmental factors.

Description

Propeller load characteristics simulation test device and simulation test method

Technical Field

The present invention relates to the technical field of propeller testing devices, and in particular to a propeller load characteristic simulation test device and a simulation test method.

Background Art

With the increasing maturity of high-power power electronics technology and the rapid development of high-power variable frequency drive technology, the electrification of aircraft has received extensive attention and research. All-electric/multi-electric aircraft with electric propulsion as the main feature continue to emerge. They have outstanding advantages such as simple power system structure, high degree of integration, and strong controllability. They are an important development direction for future aircraft. The flight operation altitude range of all-electric/multi-electric aircraft covers from near the ground to the near-space environment. The wide altitude range makes its working environment complex and changeable: from normal temperature and pressure in the ground environment to low temperature (-80℃) and low pressure (2.5kpa) in near-space. Therefore, all-electric/multi-electric aircraft have very strict requirements on the performance of their core components-electric propulsion systems.

Testing the electric propulsion system with propeller load to verify its dynamic and static performance indicators is a very important part of the design of all-electric/multi-electric aircraft. By building a propeller load simulation device and combining it with environmental test simulation equipment, we can build environmental conditions at all altitudes, simulate the torque, speed, and force of the propeller under real working conditions, and load it on the propulsion motor system to make it similar to the propulsion conditions of the actual aircraft. This can truly simulate the actual flight conditions of the aircraft and verify whether the key performance of the tested propulsion motor system meets the requirements.

In general, the motor output performance test equipment mainly includes magnetic powder brakes, reluctance dynamometers, eddy current dynamometers, electric dynamometers, etc. Taking the electric dynamometer as an example, it uses a towing method to perform load tests, that is, a generator is connected to the output shaft of the motor being tested as a load motor. During the test, the motor being tested can be used to drag the load motor to rotate at the same speed, and the load motor can be controlled to generate torque to achieve the test of the torque and speed output performance of the motor being tested; however, this method cannot simulate the complete characteristics of the propeller load. In addition to the torque and speed characteristics, the rotational inertia of the propeller during operation and the axial tension it generates, the eccentric force generated by the imbalance of the blades, and the bending moment caused by irregular airflow will all affect the propulsion motor.

On the other hand, due to the huge difference in air density between the ground environment and the high-altitude environment, if the propulsion motor is used directly on the ground to drive the propeller to rotate for testing, the propeller cannot run at full speed, that is, it is impossible to achieve full-state testing. In addition, the propeller is generally large in size, and it is impossible to use an environmental test chamber to test the propeller load operating characteristics at all altitudes.

Therefore, there is a need to design a propeller load simulation test device with a simple structure, which can control the increase and decrease of load and its own stress conditions and has a strong ability to withstand changes in external environmental factors. The device can be used to completely simulate the rotational inertia, torque characteristics and external force conditions of the propeller load in the full altitude environment in the laboratory.

Summary of the invention

The technical problem to be solved by the present invention is how to provide a propeller load characteristic simulation test device which has a simple structure, can control the increase and decrease of load and its own stress conditions, and has a strong ability to withstand changes in external environmental factors.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a propeller load characteristic simulation test device, characterized in that: it includes a mounting base, a first bracket and a second bracket are fixed on the mounting base, a basic inertia disc is arranged between the first bracket and the second bracket, an arc-shaped segmented stator is arranged on the mounting base on the lower side of the basic inertia disc, an arc-shaped segmented stator is fixed on the first bracket on the upper side of the basic inertia disc, an inertia disc output shaft is arranged on the axis of the basic inertia disc, the two ends of the inertia disc output shaft are respectively connected to the first bracket and the second bracket through an axially slidable rolling bearing, the end of the inertia disc output shaft extends to the outside of the first bracket, and the end is provided with a position sensor, and the two structures are the same The electromagnet is located on one side of the basic inertia disc, facing the edge of the basic inertia disc surface and symmetrical about the rotation axis. Equal direct current is passed through the two electromagnets to generate the same suction force on the inertia disc. The generated resultant force is perpendicular to the inertia disc surface and located at the axis center. The suction force is changed by changing the magnitude of the direct current, thereby realizing the simulation of the tension exerted on the propeller load; the motor under test is fixed to the mounting base through a third bracket, the output shaft of the motor under test is connected to the output shaft of the inertia disc through a coupling, and the drive controller is connected to the simulation control host computer through a communication bus; the drive controller is connected to the bus power supply, the arc segmented stator and the electromagnet through power cables, and the drive controller uploads the collected speed signal to the simulation control host computer through the communication bus for processing.

A further technical solution is that the basic inertia disc includes a disc body, an inertia disc output shaft is fixed at the center of the disc body, N and S magnetic poles of the same size and evenly arranged alternately are fixed on the outer circumference of the disc body, and the basic inertia disc and the arc-shaped segmented stator constitute a surface-mounted inner rotor permanent magnet synchronous motor structure; four identical and symmetrically installed compensation sector discs are fixed on one surface of the disc body, and the simulation of the rotational inertia of different propeller loads is achieved by changing their weight.

A further technical solution is that a counterweight is fixed near the edge of the disc body, and the eccentric force of the propeller is simulated by changing its weight.

A further technical solution is that the compensating sector disc and the counterweight block are fixed to the disc body by bolts.

A further technical solution is that the axially slidable rolling bearing comprises a sliding bearing located at an inner ring and a rolling bearing fixed to an outer ring of the sliding bearing, and the inner ring of the sliding bearing is fixedly connected to the inertia disc output shaft.

The present invention also discloses a method for testing using the propeller load characteristic simulation test device described in the claims, characterized in that the simulation of the eccentric force on the propeller comprises the following steps:

Step 1: Obtain the propeller eccentric force F ₁ through static balance test and dynamic balance test;

Step 2: Calculate the required counterweight mass _m1 as:

In the above formula, R ₃ is the distance between the center of the bottom circle of the counterweight block and the center of the output shaft of the inertia disk, and ω is the angular velocity of the propeller;

Step 3: Select a cylinder as the counterweight and calculate its weight l:

In the above formula, r is the radius of the bottom surface of the counterweight;

Step 4: Select a counterweight block with a weight of l and install it in the installation groove reserved in the basic inertia disk. Fix it with bolts to simulate the eccentric force acting on the propeller.

A further technical solution is that the simulation of the moment of inertia includes the following steps:

Step 1: Based on the eccentric force matching, determine the moment of inertia J ₃ of the counterweight:

Step 2: Determine the required moment of inertia of the inertia compensation sector disk ΔJ as:

ΔJ＝J ₁ -J ₂ -J ₃

In the above formula, ΔJ is the moment of inertia of the compensation sector disk, J ₁ is the moment of inertia of the target propeller, J ₂ is the moment of inertia of the basic inertia disk, and the unit of the moment of inertia is kg·m ² ;

Step 3: Based on the calculated moment of inertia of the compensation sector disk, calculate the weight h of the compensation sector disk as:

In the above formula, ρ is the density of the material of the inertia disk and the compensation sector disk; _R2 is the outer radius of the compensation sector disk; _R1 is the inner radius of the compensation sector disk, and γ is the central angle of the compensation sector disk;

Step 4: Select 4 compensating sector discs with a weight of h and install them in the mounting stoppers reserved in the base inertia disc. Fix them with bolts to simulate the propeller load rotational inertia.

A further technical solution is that the simulation of torque characteristics includes the following steps:

上位机根据预先保存的T-I曲线得到该转矩对应的输入电流指令值，根据公式计算得到弧形分段定子的d、q轴电流指令值

并通过通信总线传递给驱动控制器；Step 1: Set the torque required for the basic inertia disc to output in the host computer

The host computer obtains the input current command value corresponding to the torque according to the pre-saved TI curve, and calculates the d and q axis current command values of the arc segmented stator according to the formula

And transmitted to the drive controller through the communication bus;

Step 2: The motor under test gradually accelerates to a stable speed n according to the propeller speed command n ^* , obtains the current speed n through the position sensor and transmits it to the drive controller through the communication line;

Step 3: The drive controller samples the current DC bus voltage U _dc and the current dq axis currents _id and i _q through a sampling circuit;

分别与当前dq轴电流i_d与i_q作差，利用dq轴电流PI控制器进行闭环控制，得到弧形分段定子永磁同步电机定子dq轴电压指令信号u_d、u_q：Step 4: Set the dq axis current command

The current dq axis currents i _d and i _q are subtracted respectively, and the dq axis current PI controller is used for closed-loop control to obtain the arc-shaped segmented stator permanent magnet synchronous motor stator dq axis voltage command signals u _d and u _q :

In the above formula, k _pd , k _id are the proportional coefficient and integral coefficient of the d-axis current pd link respectively; k _pd , k _id are the proportional coefficient and integral coefficient of the d-axis current pd link respectively;

Step 5: The arc segmented stator (4) voltage command signals u _d (s) and u _q (s) obtained in step 4 are input into the SVPWM link. The microprocessor generates 6 PWM drive control signals using a spatial modulation algorithm and outputs them to the power drive circuit, thereby controlling the on and off of each power device of the three-phase full-controlled bridge, thereby realizing closed-loop control of the arc segmented stator permanent magnet synchronous motor.

A further technical solution is that the simulation of the pulling force on the propeller includes the following steps:

根据公式计算得到两组电磁铁绕组的目标电流值

Step 1: Set the tension value required by the electromagnet in the host computer

The target current values of the two sets of electromagnet windings are calculated according to the formula

In the above formula, _KTH is the proportionality coefficient, which is a constant under the premise that the electromagnet core is not saturated and can be measured by experiment;

Step 2: Send the target current value to the drive controller by using the communication bus; the drive controller obtains the current DC bus voltage U _DC and the current current values I _TH7 and I _TH8 of the two electromagnet windings by sampling through the sampling circuit;

与当前绕组电流I_TH作差，利用PI控制器进行闭环控制，得到电磁铁绕组输入电压指令信号U_TH Step 3: Set the winding current command value

Subtract the current _ITH from the current winding current and use the PI controller for closed-loop control to obtain the electromagnetic winding input voltage command signal UTH _.

In the above formula, k _pTH , k _iTH are the proportional coefficient and integral coefficient of the closed-loop PI link;

Step 4: Compare the electromagnetic winding input voltage command signal U _TH obtained in step 3 with the current DC bus voltage U _DC to obtain the current duty cycle command value of the power device:

Step 5: Control the on and off of the power devices in the two electromagnet drive circuits at the same time according to the calculated duty cycle _DTH ; implement closed-loop control of the two electromagnet winding currents and output suction forces to simulate the axial tension on the propeller.

A further technical solution is that a method for simulating the dynamic bending moment of a propeller due to aerodynamic imbalance comprises the following steps:

Step 1: Set the amplitude T _BE and frequency f of the fluctuating bending moment in the host computer, and calculate the target current value in the two electromagnet windings according to the formula

In the above formula, K _BE is the proportional coefficient, which is a constant under the premise that the electromagnet core is not saturated and can be measured by experiment;

Step 2: The host computer sends the target current value to the drive controller via the communication bus; the drive controller obtains the current DC bus voltage U _DC and the current winding current value i _BE in the electromagnet through sampling circuit;

与当前绕组电流i_BE作差，利用PI控制器进行闭环控制，得到电磁铁(7)绕组输入电压指令信号u_BE：Step 3: Set the winding current command value

Subtract the current i _BE from the current winding current and use the PI controller for closed-loop control to obtain the electromagnet (7) winding input voltage command signal u _BE :

In the above formula, k _pBE , k _iBE are the proportional coefficient and integral coefficient of the closed-loop PI link;

Step 4: Compare the electromagnetic winding input voltage command signal u _BE obtained in step 3 with the current DC bus voltage U _DC to obtain the current duty cycle command value d _BE of the power device:

Step 5: Control the on and off of the power device according to the calculated duty cycle d _BE to achieve closed-loop control of the electromagnet winding current and output suction. The dynamic bending moment of the propeller is simulated by controlling the amplitude and frequency of the difference in output suction between the two electromagnets.

The beneficial effect of adopting the above technical solution is that the device of the present invention can simulate the propeller load characteristics in three aspects: moment of inertia, output torque and force. If combined with an environmental test chamber to simulate the atmospheric pressure and ambient temperature at different altitudes, the operation state of the propulsion motor with the propeller can be accurately simulated and analyzed under ground conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

FIG1 is a schematic diagram of the exploded structure of a propeller load characteristic simulation device according to an embodiment of the present invention;

FIG2 is a diagram showing the connection relationship between the drive controller and various components in the device according to an embodiment of the present invention;

FIG3 is a schematic diagram of the exploded structure of the basic inertia disk in the device according to an embodiment of the present invention;

FIG4 is a schematic diagram of the structure of an axially slidable rolling bearing in the device according to an embodiment of the present invention;

FIG5 is a block diagram of a control strategy for a segmented arc stator permanent magnet motor in the device according to an embodiment of the present invention;

FIG6 is a block diagram of an electromagnet current control strategy in the device according to an embodiment of the present invention;

Among them: 1. Mounting base; 2. First bracket; 3. Second bracket; 4. Basic inertia disc; 4-1. Inertia disc output shaft; 4-2. Disc body; 4-3. Magnetic pole; 4-4. Compensation sector disc; 4-5. Counterweight; 4-6. Bolt; 5. Arc segmented stator; 6. Axially slidable rolling bearing; 6-1. Sliding bearing; 6-2. Rolling bearing; 7. Position sensor; 8. Electromagnet; 9. Motor under test; 10. Third bracket; 11. Coupling; 12. Drive controller;

13. Host computer.

DETAILED DESCRIPTION

The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

As shown in Figure 1, an embodiment of the present invention discloses a propeller load characteristic simulation test device, including a mounting base 1, and other components in the device are fixed to the mounting base; a first bracket 2 and a second bracket 3 are fixed on the mounting base 1, and a basic inertia disk 4 is arranged between the first bracket 2 and the second bracket 3, an arc-shaped segmented stator 5 is arranged on the mounting base 1 on the lower side of the basic inertia disk 4, and an arc-shaped segmented stator 5 is fixed on the first bracket 2 on the upper side of the basic inertia disk 4, and the upper and lower arc-shaped segmented stators 5 have the same structure; an inertia disk output shaft 4-1 is arranged on the axis of the basic inertia disk 4, and the two ends of the inertia disk output shaft 4-1 are respectively connected to the first bracket 2 and the second bracket 3 through an axially slidable rolling bearing 6; further, a horizontal portion is formed on the upper side of the first bracket 2, and the arc-shaped segmented stator 5 on the upper side is fixed on the horizontal portion.

The end of the inertia disc output shaft 4-1 extends to the outside of the first bracket 2, and a position sensor 7 is provided at the end. Two electromagnets 8 with the same structure are located on one side of the basic inertia disc 4, facing the edge of the basic inertia disc 4 and symmetrical about the inertia disc output shaft 4-1. Equal direct currents are passed through the two electromagnets to generate the same suction force on the inertia disc 4. The resultant force generated is perpendicular to the disc surface of the basic inertia disc 4 and is located at the axis. The suction force is changed by changing the magnitude of the direct current, thereby achieving the effect of adjusting the inertia disc 4. Simulation of the tension exerted on the propeller load; the motor 9 under test is fixed to the mounting base 1 through the third bracket 10, the output shaft of the motor 9 under test is connected to the inertia disc output shaft 4-1 through the coupling 11, and the drive controller 12 is connected to the simulation control host computer 13 through a communication bus; the drive controller 12 is connected to the bus power supply, the arc segmented stator 5 and the electromagnet 8 through a power cable, and the drive controller 12 uploads the collected position signal and speed signal to the simulation control host computer 13 through the communication bus for processing.

Furthermore, as shown in Figures 1 and 3, the basic inertia disc 4 includes a disc body 4-2, the center of which is fixed with an inertia disc output shaft 4-1, and the outer periphery of the disc body 4-2 is fixed with N and S poles 4-3 of the same size and evenly and alternately arranged; the basic inertia disc 4 and the arc-shaped segmented stator 5 constitute a surface-mounted inner rotor permanent magnet synchronous motor structure; four identical and symmetrically installed compensation sector discs 4-4 are fixed on one surface of the disc body 4-2, and the simulation of the rotational inertia of different propeller loads is achieved by changing their weight; a counterweight block 4-5 is fixed near the edge of the disc body 4-2, and the simulation of the propeller eccentric force is achieved by changing its weight; the compensation sector disc 4-4 and the counterweight block 4-5 are fixed to the disc body 4-2 by bolts 4-6.

The inertia disc output shaft 4-1 is connected to the output shaft of the motor 9 under test by a coupling 11. The motor 9 under test is in an electric state and drives the inertia disc to rotate in the same direction and speed at a specified speed n. The basic inertia disc output shaft 4-1 has the same speed as the output shaft of the motor 9 under test, and the torque direction is opposite. At this time, controlling the basic inertia disc 4 to output a specified torque can cause the motor 9 under test to be subjected to a reverse torque, simulating the torque characteristics of the propeller load.

Two identical arc-shaped segmented stators 5 are installed directly above and below the basic inertia disc 4, respectively, and are symmetrically distributed to offset the unilateral magnetic pull. The two arc-shaped segmented stators 5 are respectively wound with completely identical symmetrical A, B, and C three-phase windings; therefore, the structure composed of the basic inertia disc 4, magnetic poles, and arc-shaped segmented stators 5 can be regarded as an arc-shaped segmented permanent magnet synchronous motor. Symmetrical three-phase currents are passed through the windings of the two three-phase stator modules, and the currents of the same phases are kept equal. By changing the amplitude, phase, and frequency of the phase current, a stable torque is applied to the basic inertia disc to simulate the propeller load torque characteristics.

In order to simulate the eccentric force characteristics of the propeller caused by manufacturing, a counterweight block 4-5 is added near the edge of the basic inertia disk 4, and the eccentric force of the propeller is simulated by changing its weight. The counterweight block 4-5 is fixed to the basic inertia disk 4 with bolts 4-6.

In order to compensate for the difference between the basic inertia disc 4 and the actual propeller load moment of inertia, four identical and symmetrically installed compensation sector discs 4-4 are added to the basic inertia disc 4. By changing their weight, the simulation of the moment of inertia of different propeller loads is achieved. The compensation sector disc 4-4 is fixed to the basic inertia disc 4 with bolts 4-6.

In order to simulate the axial tension on the propeller during operation, two electromagnets 8 are installed facing the edge of the basic inertia disk 4 and symmetrically about the rotating axis. Equal DC current is passed through the two electromagnets 8 to generate the same suction force on the basic inertia disk 4. The resultant force generated is perpendicular to the surface of the inertia disk and located at the axis. The suction force is changed by changing the magnitude of the DC current, thereby achieving the simulation of the tension on the propeller load. In addition, the basic inertia disk 4 is supported by a pair of axially slidable rolling bearings 6, the rolling bearings are installed outside the sliding bearings, and the sliding bearings are installed outside the output shaft of the inertia disk, thereby achieving the transmission of the axial force on the inertia disk to the motor 9 under test, so as to simulate the characteristics of the motor 9 under the action of the propeller tension.

Further, as shown in FIG. 4 , the axially slidable rolling bearing 6 includes a sliding bearing 6-1 located at the inner ring and a rolling bearing 6-2 fixed to the outer ring of the sliding bearing 6-1, and the inner ring of the sliding bearing 6-1 is fixedly connected to the inertia disc output shaft 4-1.

In order to simulate the dynamic bending moment characteristics imposed on the propulsion motor due to the aerodynamic imbalance when the propeller is running, a DC biased fluctuating current can be applied to an electromagnet 8, so that the suction force of the electromagnet 8 on the inertia disk fluctuates, and then the combined force of the two electromagnets will generate an axial force of additional bending moment on the inertia disk 4. By changing the amplitude and frequency of the current fluctuation, the simulation of the unbalanced aerodynamic bending moment characteristics of the propeller is achieved.

In summary, the propeller load characteristic simulation test device of the present invention can simulate the propeller load characteristics in three aspects: moment of inertia, output torque, and force conditions. If combined with an environmental test chamber to simulate the atmospheric pressure and ambient temperature at different altitudes, the operation state of the propulsion motor with the propeller can be accurately simulated and analyzed under ground conditions.

Taking a certain type of propeller with known parameters as an example, the test process of the propeller load characteristic simulation test device based on the arc segmented stator permanent magnet synchronous motor of the present invention is as follows:

1. Simulation of the eccentric force on the propeller

Step 1: Obtain the propeller eccentric force F ₁ through static balance test and dynamic balance test.

Step 2: Calculate the required counterweight 4-5 mass _m1 as:

In the above formula, R ₃ is the distance between the center of the bottom circle of the counterweight block and the center of the inertia disk output shaft 4-1, and ω is the angular velocity of propeller rotation.

Step 3: Select a cylinder for the counterweight 4-5 and calculate its weight l:

In the above formula, r is the bottom radius of the counterweight block 4-5.

Step 4: Select a counterweight block 4-5 with a weight of l and install it in the reserved installation stop of the basic inertia disk 4, and fix it with bolts 4-6 to simulate the eccentric force on the propeller.

2. Simulation of the moment of inertia

Step 1: Based on the completed eccentric force matching, determine the moment of inertia of the counterweight 4-5:

Step 2: Determine the required moment of inertia ΔJ of the inertia compensation sector disk 4-4:

ΔJ＝J ₁ -J ₂ -J ₃

In the above formula, ΔJ is the moment of inertia of the compensation sector disk 4-4, _J1 is the moment of inertia of the target propeller, _J2 is the moment of inertia of the basic inertia disk, and the unit of the moment of inertia is kg· ^m2 ;

Step 3: Based on the calculated moment of inertia of the compensating sector disk 4-4, the weight h of the compensating sector disk 4-4 is calculated as:

In the above formula, ρ is the density of the inertia disk and the compensation sector disk material; _R2 is the outer radius of the compensation sector disk; _R1 is the inner radius of the compensation sector disk, and γ is the central angle of the compensation sector disk.

Step 4: Select 4 compensating sector disks 4-4 with a weight of h and install them in the mounting stoppers reserved in the basic inertia disk, and fix them with bolts 4-6 to simulate the propeller load rotational inertia.

3. Simulation of torque characteristics

上位机13根据预先保存的T-I曲线得到该转矩对应的输入电流指令值，根据公式计算得到弧形分段定子的d、q轴电流指令值

并通过通信总线传递给驱动控制器12。Step 1: Set the torque required to be output by the inertia disc 4 in the host computer 13

The host computer 13 obtains the input current command value corresponding to the torque according to the pre-stored TI curve, and calculates the d-axis and q-axis current command values of the arc segmented stator according to the formula

And transmitted to the drive controller 12 through the communication bus.

Step 2: The motor 9 under test gradually accelerates to a stable speed n according to the received propeller speed command n ^* , obtains the current speed n through the position sensor 7 and transmits it to the drive controller 12 through the communication line.

Step 3: The drive controller 12 obtains the current DC bus voltage U _dc and the current dq axis currents _id and i _q by sampling through a sampling circuit.

分别与当前dq轴电流i_d与i_q作差，利用dq轴电流PI控制器进行闭环控制，得到弧形分段定子永磁同步电机定子dq轴电压指令信号u_d、u_q：Step 4: Set the dq axis current command

The current dq axis currents i _d and i _q are subtracted respectively, and the dq axis current PI controller is used for closed-loop control to obtain the arc-shaped segmented stator permanent magnet synchronous motor stator dq axis voltage command signals u _d and u _q :

In the above formula, k _pd , k _id are the proportional coefficient and integral coefficient of the d-axis current pd link respectively; k _pd , k _id are the proportional coefficient and integral coefficient of the d-axis current pd link respectively.

Step 5: The arc segmented stator 5 voltage command signals u _d (s) and u _q (s) obtained in step 4 are input into the SVPWM link. The microprocessor uses the spatial modulation algorithm to generate 6-channel PWM drive control signals and outputs them to the power drive circuit, thereby controlling the on and off of each power device of the three-phase full-controlled bridge to achieve closed-loop control of the arc segmented stator permanent magnet synchronous motor.

Therefore, the output torque of the inertia disc 4 is controlled by controlling the input current in the arc segmented stator 5 to make it equal to the torque of the propeller load under the actual working condition, thereby realizing the simulation of the propeller load torque characteristics.

4. Simulation of the propeller tension

根据公式计算得到电磁铁8绕组的目标电流值

Step 1: Set the tension value required for the electromagnet to output in the host computer 13

The target current value of the electromagnet 8 winding is calculated according to the formula

In the above formula, K _TH is a proportionality coefficient, which is a constant under the premise that the core of the electromagnet 8 is not saturated and can be measured through experiments.

Step 2: Send the target current value to the drive controller 12 by using the communication bus; the drive controller 12 obtains the current DC bus voltage U _DC and the current winding current values I _TH7 and I _TH8 of the electromagnet 8 by sampling through a sampling circuit.

与当前绕组电流I_TH作差，利用PI控制器进行闭环控制，得到电磁铁绕组输入电压指令信号U_TH Step 3: Set the winding current command value

Subtract the current _ITH from the current winding current and use the PI controller for closed-loop control to obtain the electromagnetic winding input voltage command signal UTH _.

In the above formula, k _pTH , k _iTH are the proportional coefficient and integral coefficient of the closed-loop PI link.

Step 4: Compare the electromagnetic winding input voltage command signal UTH obtained in step 3 _with the current _DC bus voltage UDC to obtain the current duty cycle command value of the power device:

Step 5: According to the calculated duty cycle D _TH, the power devices in the driving circuits of the two electromagnets 8 are controlled to be turned on and off at the same time, so as to realize the closed-loop control of the winding current and the output suction of the two electromagnets 8 and simulate the axial tension of the propeller.

5. Simulation of dynamic bending moment of propeller due to aerodynamic imbalance

Step 1: Set the amplitude T _BE and frequency f of the fluctuating bending moment in the host computer, and calculate the target current value in the winding of the electromagnet 8 according to the formula

In the above formula, K _BE is a proportionality coefficient, which is a constant under the premise that the core of the electromagnet 8 is not saturated and can be measured through experiments.

Step 2: The host computer 13 sends the target current value to the drive controller 12 via the communication bus; the drive controller 12 obtains the current DC bus voltage U _DC and the current winding current value i _BE of one of the two electromagnets by sampling through a sampling circuit.

与当前绕组电流i_BE作差，利用PI控制器进行闭环控制，得到电磁铁绕组输入电压指令信号u_BE：Step 3: Set the winding current command value

Subtract the current from the current winding current i _BE and use the PI controller for closed-loop control to get the electromagnet winding input voltage command signal u _BE :

In the above formula, k _pBE and k _iBE are the proportional coefficient and integral coefficient of the closed-loop PI link.

Step 4: Compare the electromagnetic winding input voltage command signal u _BE obtained in step 3 with the current DC bus voltage U _DC to obtain the current duty cycle command value d _BE of the power device:

Step 5: Control the on and off of the power device according to the calculated duty cycle d _BE to achieve closed-loop control of the electromagnet winding current and output suction. The dynamic bending moment of the propeller is simulated by controlling the amplitude and frequency of the difference in output suction between the two electromagnets.

Fig. 5 is a block diagram of propeller torque characteristic control. The propeller torque characteristic simulation control strategy of the present invention includes torque command input, current command calculation, PI link, SVPWM link, etc. Among them, the torque command setting and target current calculation are completed in the host computer 13, and the PI link, SVPWM link, etc. are completed in the microprocessor.

The drive controller 12 includes a speed/DC bus voltage/AC current sampling circuit, a microprocessor, a power drive circuit and a three-phase fully controlled bridge. The sampling circuit collects the three-phase current of the segmented arc stator 5 and inputs it into the microprocessor. According to the current command signal, the d and q axis current closed-loop control is applied respectively and 6 PWM drive signals are generated and input into the power drive circuit, thereby controlling the opening and closing of the three-phase fully controlled bridge to realize closed-loop control of the three-phase current of the segmented arc stator 5.

Since the torque sensor cannot be used in a low temperature environment, the output torque value of the current inertia disc 4 cannot be viewed in real time during the environmental test. Therefore, before actually conducting the propeller load characteristic simulation test in a full altitude environment, the current of the arc segmented stator 5 needs to be calibrated first.

Step 1: Under normal temperature and pressure conditions, a torque-speed sensor is connected between the inertia disk output shaft 4-1 and the output shaft 9 of the motor under test. At this time, the phase current amplitude of the three-phase winding of the arc segmented stator 5 is changed, and the output torque value corresponding to each phase current is measured to form a set of T-I curves and save them in the host computer. This T-I curve is used as the basis for the input current during the formal load test.

Step 2: When the propeller load characteristic simulation test under the full altitude environment is formally carried out, the torque value required to be output by the inertia disk 4 is input into the upper computer 13, and the upper computer 13 obtains the corresponding current value from the T-I curve under normal temperature and pressure as the theoretical command value of the current three-phase winding current of the arc segmented stator 5.

Step 3: The magnetic properties of permanent magnets are greatly affected by temperature. According to the relationship between the magnetic properties of permanent magnets and temperature, the theoretical command value is appropriately compensated, and the compensation value is used as the current command value of the three-phase winding of the arc-shaped segmented stator 5.

Figure 6 is a block diagram of the electromagnet current control strategy. The control strategy of the propeller load characteristic simulation device of the present invention includes output command input, current command calculation, and PI control link. Among them, the tension and bending moment command setting and target current calculation are all completed in the host computer 13, and the PI link is completed in the microprocessor.

The drive controller 12 includes a DC bus voltage/DC current sampling circuit, a microprocessor, a power drive circuit and a DC-DC conversion circuit. The sampling circuit collects the electromagnet winding current and inputs it into the microprocessor. According to the current command signal, current closed-loop control is applied and a drive signal is generated and input into the power drive circuit, thereby controlling the on and off of the power devices in the DC-DC conversion circuit to achieve closed-loop control of the DC current in the electromagnet.

Claims (10)

1. A propeller load characteristic simulation test device is characterized in that: the disc type electromagnetic vibration absorber comprises a mounting base (1), wherein a first support (2) and a second support (3) are fixed on the mounting base (1), a basic inertia disc (4) is arranged between the first support (2) and the second support (3), an arc-shaped segmented stator (5) is arranged on the mounting base (1) on the lower side of the basic inertia disc (4), the arc-shaped segmented stator (5) is fixed on the first support (2) on the upper side of the basic inertia disc (4), an inertia disc output shaft (4-1) is arranged at the axis of the basic inertia disc (4), two ends of the disc output shaft (4-1) are respectively connected with the first support (2) and the second support (3) through an axial sliding rolling bearing (6), the end of the inertia disc output shaft (4-1) extends to the outer side of the first support (2), a position sensor (7) is arranged at the end of the disc output shaft, two electromagnets (8) with the same structure are positioned on one side of the basic inertia disc (4), the edge of the basic inertia disc output shaft (4) is positioned on the outer side of the first support (2), the edge of the basic inertia disc (4), the two electromagnets are symmetrically positioned in the axial sliding bearing (4), and the axial sliding rolling bearing and generate two axial resultant forces which are opposite to the axis of the two electromagnets (4) and generate the same size, and the two axial direction of the two electromagnets which are positioned in the same as that are positioned in the axial direction of the disc output shaft, the suction force is changed by changing the magnitude of the direct current, so that the simulation of the tension borne by the propeller load is realized; a tested motor (9) is fixed on the mounting base (1) through a third support (10), an output shaft of the tested motor (9) is connected with the inertia disc output shaft (4-1) through a coupling (11), and a driving controller (12) is connected with an analog control upper computer (13) through a communication bus; the driving controller (12) is connected with the bus power supply, the arc-shaped segmented stator (5) and the electromagnet (8) through power cables, and the driving controller (12) transmits the collected position signals and the collected rotating speed signals to the analog control upper computer (13) through a communication bus for processing.

2. The propeller load characteristic simulation test apparatus according to claim 1, wherein: the basic inertia disc (4) comprises a disc body (4-2), an inertia disc output shaft (4-1) is fixed at the center of the disc body (4-2), N and S magnetic poles (4-3) which are same in size and are uniformly and alternately arranged are fixed on the periphery of the disc body (4-2), and the basic inertia disc (4) and the arc-shaped segmented stator (5) form a surface-mounted inner rotor permanent magnet synchronous motor structure; 4 identical and symmetrically-installed compensation sector plates (4-4) are fixed on one surface of the disc body (4-2), and the weight of the compensation sector plates is changed to simulate the load moment of inertia of different propellers.

3. The propeller load characteristic simulation test apparatus according to claim 2, wherein: a balancing weight (4-5) is fixed at the edge close to the disc body (4-2), and the eccentric force of the propeller is simulated by changing the weight of the balancing weight.

4. A propeller load characteristic simulation test device according to claim 3, wherein: the compensation sector disc (4-4) and the balancing weight (4-5) are fixed on the disc body (4-2) by bolts (4-6).

5. The propeller load characteristic simulation test device according to claim 1, characterized in that: the rolling bearing (6) capable of axially sliding comprises a sliding bearing (6-1) positioned at an inner ring and a rolling bearing (6-2) fixed at an outer ring of the sliding bearing (6-1), wherein the inner ring of the sliding bearing (6-1) is fixedly connected with the inertia disc output shaft (4-1).

6. A method for testing by using the propeller load characteristic simulation test device of any one of claims 1 to 5, wherein the simulation of the eccentric force applied to the propeller comprises the following steps:

step 1: the eccentric force F of the propeller is obtained through a static balance test and a dynamic balance test ₁ ；

And 2, step: calculating the mass m of the required counterweight (4-5) ₁ Comprises the following steps:

in the above formula, R ₃ The distance between the center of the circle at the bottom of the balancing weight and the axis of an output shaft (4-1) of the inertia disc is shown, and omega is the rotation angular speed of the propeller;

and step 3: the cylinder is selected as the balancing weight (4-5), and the weight l is calculated as follows:

in the above formula, r is the radius of the bottom surface of the balancing weight (4-5);

and 4, step 4: and a balancing weight (4-5) with the weight of l is selected to be arranged in a reserved mounting groove of the basic inertia disc (4) and fixed by a bolt (4-6), so that the simulation of the eccentric force borne by the propeller is realized.

7. The propeller load characteristic simulation test method of claim 6, wherein the simulation of the moment of inertia comprises the steps of:

step 1: on the basis of completed eccentric force matching, the moment of inertia J of the balancing weight (4-5) is determined ₃ ：

And 2, step: determining the required moment of inertia Δ J of the compensating sector disc (4-4) as:

ΔJ＝J ₁ -J ₂ -J ₃

in the above formula, Δ J is the moment of inertia of the compensating sector plate (4-4), J ₁ Moment of inertia of the target propeller, J ₂ Is the moment of inertia of the basic inertia disc, and the unit of the moment of inertia is kg.m ² ；

And step 3: according to the calculated rotational inertia of the compensation sector disc (4-4), calculating the weight h of the compensation sector disc (4-4) as follows:

in the above formula, rho is the density of the inertia disc and the compensation sector disc material; r ₂ To compensate for the outer radius of the sector disc; r ₁ The radius is the inner radius of the compensation sector disc, and gamma is the central angle of the compensation sector disc;

and 4, step 4: 4 compensation fan-shaped discs (4-4) with the weight of h are selected to be installed in a reserved installation spigot of a basic inertia disc and fixed by bolts (4-6), so that the simulation of the load rotary inertia of the propeller is realized.

8. The propeller load characteristic simulation test method of claim 6, wherein the simulation of the torque characteristic includes the steps of:

step 1: setting the torque required to be output by the basic inertia disc (4) in the upper computer (13)

The upper computer (13) obtains an input current instruction value corresponding to the torque according to a pre-stored T-I curve, and calculates d and q axis current instruction values ^ based on the arc-shaped segmented stator (5) according to a formula>

And transferred to the drive controller (12) via a communication bus;

step 2: the tested motor (9) is used for receiving a propeller rotating speed instruction n ^* Gradually accelerating to a stable rotating speed n, obtaining the current rotating speed n through a position sensor (7) and transmitting the current rotating speed n to a driving controller (12) through a communication line;

and 3, step 3: the drive controller (12) obtains the current DC bus voltage U by sampling through a sampling circuit _dc And the present dq-axis current i _d 、i _q ；

And 4, step 4: the dq-axis current being commanded

Respectively with the present dq axis current i _d And i _q Performing difference, and performing closed-loop control by using a dq-axis current PI controller to obtain a dq-axis voltage command signal u of the stator of the arc-shaped segmented stator permanent magnet synchronous motor _d 、u _q ：

In the above formula, k _pd ，k _id Respectively is a proportionality coefficient and an integral coefficient of a pd link of the d-axis current; k is a radical of _pd ，k _id Respectively is a proportionality coefficient and an integral coefficient of a pd link of the d-axis current;

and 5: the voltage command signal u of the arc-shaped segmented stator (5) obtained in the step 4 is processed _d (s)、u _q And(s) is input into an SVPWM link, and the microprocessor generates 6 paths of PWM driving control signals by using a spatial modulation algorithm and outputs the signals to the power driving circuit, so that the on-off of each power device of the three-phase full-control bridge is controlled, and the closed-loop control of the arc-shaped segmented stator permanent magnet synchronous motor is realized.

9. The propeller load characteristic simulation test method of claim 6, wherein the simulation of the tension applied to the propeller comprises the steps of:

step 1: the upper computer (13) sets the tension value needing to be output by the electromagnet

Calculating and obtaining the target current value (or/and) of the two groups of electromagnet windings according to a formula>

In the above formula, K _TH The constant is a proportionality coefficient and is a constant under the condition that the electromagnet iron core is unsaturated, and can be measured by tests;

step 2: transmitting the target current value to a drive controller (12) using a communication bus; the drive controller (12) obtains the current DC bus voltage U by sampling through a sampling circuit _DC And the current values I of the two electromagnet windings _TH7 、I _TH8 ；

And 3, step 3: the winding current command value

With the current winding current I _TH Performing difference, performing closed-loop control by using a PI controller to obtain an input voltage command signal U of the electromagnet winding _TH

In the above formula, k _pTH ，k _iTH Proportional coefficient and integral coefficient of closed loop PI link;

and 4, step 4: inputting the electromagnet winding input voltage command signal U obtained in the step 3 _TH And the current DC bus voltage U _DC And (3) comparing to obtain a duty ratio command value of the current power device:

and 5: according to the calculated duty ratio D _TH Controlling the on-off of power devices in the two electromagnet driving circuits at the same time; the closed-loop control of the current of the two electromagnet windings and the output suction force is realized, and the axial tension borne by the propeller is simulated.

10. The method for simulation test of the load characteristics of the propeller as recited in claim 6, wherein the method for simulation of the dynamic bending moment applied to the propeller due to aerodynamic imbalance comprises the steps of:

step 1: setting the amplitude T of the fluctuation bending moment in the upper computer _BE And frequency f, calculating to obtain target current value in two electromagnet windings according to formula

In the above formula, K _BE The constant is a proportionality coefficient and is a constant under the condition that the electromagnet iron core is unsaturated, and can be measured by tests;

step 2: the upper computer (13) sends the target current value to the driving controller (12) by using a communication bus; the drive controller (12) obtains the current DC bus voltage U by sampling through a sampling circuit _DC And the current value i of the winding current in the electromagnet _BE ；

And step 3: the winding current command value

With the current winding current i _BE Making difference, and performing closed-loop control by using a PI controller to obtain an input voltage command signal u of the winding of the electromagnet (7) _BE ：

In the above formula, k _pBE ，k _iBE Proportional coefficient and integral coefficient of closed loop PI link;

and 4, step 4: inputting the electromagnet winding input voltage command signal u obtained in the step 3 _BE And the current DC bus voltage U _DC Obtaining the duty ratio command value d of the current power device by comparison _BE ：

And 5: according to the calculated duty ratio d _BE The on-off of the power device is controlled, closed-loop control over the current of the winding of the electromagnet (8) and the output suction is achieved, and the dynamic bending moment borne by the propeller is simulated by controlling the amplitude and the frequency of the difference value of the output suction between the two electromagnets (8).

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