A test method for a moving magnet linear generator coupled with each other as load air

Abstract

The application relates to the technical field of generator testing, in particular to a dynamic-magnetic linear generator mutual-load pneumatic coupling test method, which obtains performance parameters of a to-be-tested motor through a pneumatic coupling mode, omits an intermediate transmission mechanism, and can jointly adjust a test frequency through inflation pressure and a variable-frequency driver, can adjust the oscillation stroke ratio of two motor movers through the area ratio of coupling pistons, can truly simulate the working condition of a linear motor in a free-piston Stirling generator, and can obtain more sufficient test data; in addition, the two linear motors are arranged to form a symmetrical structure test platform, and through transformation of a driving motor and the to-be-tested motor, the test data can be compared, so that the consistency of a prototype development and production can be verified.

Description

Technical Field

[0001] This application relates to the field of generator testing technology, and more specifically, to a method for aerodynamic coupling testing of moving-magnet linear generators as loads. Background Technology

[0002] Cylindrical moving magnet linear generators are linear motion components widely used in Stirling generators. They are efficiently coupled with Stirling engines to achieve thermoelectric conversion. As a key component for electromechanical conversion, the performance parameters of the linear generator, such as conversion efficiency, directly affect the efficiency / power of the Stirling generator.

[0003] During the design process, the output characteristics of the linear generator need to be tested to verify the rationality of the design. For high-power linear motors, achieving high-frequency, long-stroke linear reciprocating motion often requires an intermediate conversion mechanism, which has low transmission efficiency and requires larger drive equipment, resulting in higher costs.

[0004] Furthermore, for linear generators used in free-piston Stirling generators, the mechanical transmission mechanism used to drive the linear motor often fails to accurately simulate the actual working conditions of the motor driven by gas in real-world applications, resulting in differences in the characteristic parameters obtained from the tests. Summary of the Invention

[0005] This application provides a test method for aerodynamic coupling of moving magnet linear generators as loads, which can realistically simulate aerodynamic coupling conditions and obtain more accurate measurement parameters.

[0006] To achieve the above objectives, this application provides a method for aerodynamic coupling testing of a moving-magnet linear generator as a load, comprising the following steps: Step 1: Two piston-cylinder assemblies are fixedly installed inside a pressure housing. Each piston-cylinder assembly consists of a piston and an inner cylinder. The inner cylinder is fixed inside the pressure housing via a flange and includes a first inner cylinder and a second inner cylinder, which are positioned opposite each other. A piston is positioned inside the cylinder and includes a first piston and a second piston. The first piston and the first inner cylinder are fitted with a clearance fit, and the second piston and the second inner cylinder are fitted with a clearance fit. The first and second pistons are positioned opposite each other, and a coupling working chamber is formed in the middle region. Step 2: A drive motor is assembled with the piston-cylinder assembly, connecting the mover of the drive motor to the first piston. The inner yoke, coil, and outer yoke of the drive motor are sequentially arranged around the outer wall of the first inner cylinder. Step 3: The motor to be tested is assembled with the piston-cylinder assembly, connecting the motor to be tested... Step 4: After assembly, the pressure housing is divided into three chambers. A first gas spring chamber is formed between the drive motor and the pressure housing, a second gas spring chamber is formed between the motor under test and the pressure housing, and a coupling working chamber is formed between the first piston and the second piston. Step 5: The drive motor is connected to the frequency converter outside the pressure housing, and the motor under test is connected to the electrical parameter measuring device outside the pressure housing. Gas working fluid is injected into the pressure housing. Step 6: The drive motor is powered by the frequency converter. The drive motor drives the first piston to reciprocate, thereby generating an alternating pressure wave in the coupling working chamber. This drives the second piston to reciprocate, outputting AC power. The output AC power is measured by the electrical parameter measuring device to verify and evaluate the performance of the motor under test.

[0007] Furthermore, both the drive motor and the motor under test are cylindrical moving magnet linear motors.

[0008] Furthermore, there is no mechanical connection between the drive motor and the motor under test.

[0009] Furthermore, in step 2, the moving part of the drive motor achieves radial support through the clearance fit between the first piston and the first inner cylinder.

[0010] Furthermore, in step 3, the mover of the motor under test is radially supported by the clearance fit between the second piston and the second inner cylinder.

[0011] Furthermore, in step 5, the inherent oscillation frequency of the drive motor can be changed by adjusting the pressure of the gas working medium inside the pressure housing.

[0012] The present invention provides a method for aerodynamic coupling testing of moving-magnet linear generators as mutual loads, which has the following beneficial effects:

[0013] This application obtains the performance parameters of the motor under test through pneumatic coupling, eliminating the intermediate transmission mechanism. The test frequency can be adjusted by both the air pressure and the frequency converter. The oscillation stroke ratio of the two motors can be adjusted by the ratio of the cross-sectional areas of the coupling pistons. This can realistically simulate the working conditions of the linear motor in a free-piston Stirling generator and obtain more comprehensive test data. In addition, the two linear motors form a symmetrical test platform. By changing the drive motor and the motor under test, the test data can be compared, thereby verifying the consistency of the prototype development and production. Attached Figure Description

[0014] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:

[0015] Figure 1 This is a schematic diagram of the aerodynamic coupling structure of the moving magnet linear generator with mutual loads according to the embodiments of this application;

[0016] In the figure: 1-Drive motor, 2-Motor under test, 3-First inner cylinder, 4-Second inner cylinder, 5-First piston, 6-Second piston, 7-Coupling working chamber, 8-First gas spring chamber, 9-Second gas spring chamber, 10-Motor, 11-Inner yoke, 12-Coil, 13-Outer yoke, 14-Pressure housing. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0019] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0020] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0021] In addition, the term "multiple" should mean two or more.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] In existing technologies, linear generator performance testing typically involves converting rotary motion into linear motion using a rotary motor and a crank-connecting rod mechanism to drive the linear motor for testing. However, due to the low efficiency of the intermediate transmission mechanism, a higher-power rotary motor is required for high-power linear motors, leading to higher test platform costs. Furthermore, the mechanical connection between the linear motor and the crank-connecting rod mechanism usually results in a fixed oscillation stroke, limiting test data. In contrast, the pneumatic coupling test method for a moving-magnet linear generator with mutual load provided in this application embodiment... Figure 1As shown, two axially opposed linear motors are used for pneumatic coupling testing, which eliminates the intermediate transmission mechanism. Furthermore, the two opposed linear motors can drive each other and act as loads, with an adjustable test frequency. This method can realistically simulate the operating conditions of linear motors in a free-piston Stirling generator, obtaining more comprehensive test data. The specific steps include the following:

[0024] Step 1: Two piston cylinder assemblies are fixedly installed inside the pressure housing 14. The piston cylinder assembly consists of a piston and an inner cylinder. The inner cylinder is fixed inside the pressure housing 14 by a flange and includes a first inner cylinder 3 and a second inner cylinder 4, which are arranged opposite to each other. The piston is arranged inside the cylinder and includes a first piston 5 and a second piston 6. The first piston 5 and the first inner cylinder 3 are clearance-fitted, and the second piston 6 and the second inner cylinder 4 are clearance-fitted. The first piston 5 and the second piston 6 are arranged opposite to each other, and the intermediate area forms a coupling working chamber 7.

[0025] Step 2: Assemble the drive motor 1 with the piston cylinder assembly, so that the mover 10 of the drive motor 1 is connected to the first piston 5, and the inner yoke 11, coil 12 and outer yoke 13 of the drive motor 1 are arranged in sequence around the outer wall of the first inner cylinder 3.

[0026] Step 3: Assemble the motor 2 to be tested with the piston cylinder assembly, so that the mover 10 of the motor 2 to be tested is connected to the second piston 6. The inner yoke 11, coil 12 and outer yoke 13 of the motor 2 to be tested are arranged in sequence around the outer wall of the second inner cylinder 4.

[0027] Step 4: After assembly, the pressure housing 14 is divided into three chambers. The first gas spring chamber 8 is formed between the drive motor 1 and the pressure housing 14, the second gas spring chamber 9 is formed between the motor to be tested 2 and the pressure housing 14, and the coupling working chamber 7 is formed between the first piston 5 and the second piston 6.

[0028] Step 5: Connect the drive motor 1 to the frequency converter outside the pressure housing 14, connect the motor to be tested 2 to the electrical parameter measuring device outside the pressure housing 14, and fill the pressure housing 14 with gaseous working fluid.

[0029] Step 6: Power is applied to the drive motor 1 through the frequency converter driver. The drive motor 1 will drive the first piston 5 to reciprocate and oscillate, thereby generating an alternating pressure wave in the coupling working chamber 7, which in turn drives the second piston 6 to drive the motor under test 2 to reciprocate and oscillate, outputting AC power. The output AC power is measured by the electrical parameter measuring device to verify and evaluate the performance of the motor under test 2.

[0030] Furthermore, both the drive motor 1 and the test motor 2 are cylindrical moving-magnet linear motors. In this embodiment, the main focus is on measuring the parameters of the moving-magnet linear motor under aerodynamic coupling conditions. To ensure better connection and cooperation between the drive motor 1 and the test motor 2 and the piston cylinder assembly, both the drive motor 1 and the test motor 2 are preferably cylindrical moving-magnet linear motors. The two motors do not need to meet the same size requirements; a universal interface can be set according to the actual test conditions for installation and fixation to the piston cylinder assembly.

[0031] Furthermore, there is no mechanical connection between the drive motor 1 and the test motor 2. The drive motor 1 and the test motor 2 are driven by the gaseous working fluid inside the working chamber 7 coupled between the pistons. The two motors can drive each other and act as coupled loads.

[0032] Furthermore, in step 2, the mover 10 of the drive motor 1 achieves radial support through the clearance fit between the first piston 5 and the first inner cylinder 3. The mover 10 of the drive motor 1 is fixedly connected to the first piston 5, which is located inside the first inner cylinder 3 and has a clearance fit with the first inner cylinder 3, thereby enabling axial reciprocating vibration. The provided radial support allows the mover 10 of the drive motor 1 to suspend within the air gap.

[0033] Furthermore, in step 3, the mover 10 of the motor under test 2 achieves radial support through the clearance fit between the second piston 6 and the second inner cylinder 4. The mover 10 of the motor under test 2 is fixedly connected to the second piston 6, which is located inside the second inner cylinder 4 and has a clearance fit with the second inner cylinder 4, thereby enabling axial reciprocating vibration function, and the provided radial support allows the mover 10 of the motor under test 2 to suspend within the air gap.

[0034] Specifically, in order to adapt to the testing of linear motors of various specifications, the dimensions of the first piston 5, the first inner cylinder 3, the second piston 6, and the second inner cylinder 4 can be set according to the actual testing requirements, and do not need to be consistent; and by using various combinations of the cross-sectional areas of the first piston 5 and the second piston 6, the stroke ratio of the drive motor 1 and the mover 10 of the motor under test 2 can be adjusted.

[0035] Furthermore, in step 5, the inherent oscillation frequency of the drive motor 1 can be changed by adjusting the pressure of the gas working medium inside the pressure housing 14. After the overall structure is assembled, the pressure housing 14 is divided into three chambers: the first gas spring chamber 8 is formed between the drive motor 1 and the pressure housing 14; the second gas spring chamber 9 is formed between the motor 2 under test and the pressure housing 14; and the coupling working chamber 7 is formed between the first piston 5 and the second piston 6. During operation, high-pressure gas working medium is injected into the pressure housing 14. The gas working medium enters the coupling working chamber 7 through the gap between the piston and the inner cylinder. When the drive motor 1 drives the first piston 5 to oscillate back and forth, the axial force generated by the alternating pressure waves of the gas spring chambers on both sides is equivalent to the action of a spring, which can provide part of the axial spring stiffness. By adjusting the pressure of the gas working medium entering the pressure housing 14, that is, adjusting the pressure of the gas working medium inside the gas spring chambers on both sides, the axial stiffness of the gas spring can be adjusted, thereby changing the inherent oscillation frequency of the drive motor 1 and realizing testing under multiple frequency conditions.

[0036] More specifically, the drive motor 1 and the motor under test 2 are set opposite each other and driven by a piston and a high-pressure gas working medium, serving as loads for each other. When the two motors are linear motors of the same specifications, they can be interchanged, that is, the motor under test 2 can be used as the drive motor 1, and the drive motor 1 can be used as the motor under test 2, forming a symmetrical test platform. The consistency of the prototype development and production can be verified based on the comparative test data.

[0037] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for testing the aerodynamic coupling of a moving magnet linear generator under load, characterized in that, Includes the following steps: Step 1: Fix two piston cylinder assemblies inside the pressure housing. Each piston cylinder assembly consists of a piston and an inner cylinder, wherein: The inner cylinder is fixed inside the pressure housing by a flange, and includes a first inner cylinder and a second inner cylinder, which are arranged opposite to each other. The piston is disposed inside the cylinder body and includes a first piston and a second piston. The first piston and the first inner cylinder are in clearance fit, and the second piston and the second inner cylinder are in clearance fit. The first piston and the second piston are arranged opposite to each other, and the intermediate region forms a coupling working chamber; Step 2: Assemble the drive motor and the piston cylinder assembly, so that the mover of the drive motor is connected to the first piston, and the inner yoke, coil and outer yoke of the drive motor are arranged in sequence around the outer wall of the first inner cylinder. Step 3: Assemble the motor to be tested with the piston cylinder assembly, so that the mover of the motor to be tested is connected to the second piston. The inner yoke, coil and outer yoke of the motor to be tested are arranged in sequence around the outer wall of the second inner cylinder. Step 4: After assembly, the pressure housing is divided into three chambers. The first gas spring chamber is formed between the drive motor and the pressure housing, the second gas spring chamber is formed between the motor to be tested and the pressure housing, and the coupling working chamber is formed between the first piston and the second piston. Step 5: Connect the drive motor to the frequency converter outside the pressure housing, connect the motor to be tested to the electrical parameter measuring device outside the pressure housing, and fill the pressure housing with gaseous working fluid. Step 6: Power the drive motor through the frequency converter driver. The drive motor will drive the first piston to reciprocate and oscillate, thereby generating an alternating pressure wave in the coupling working chamber. This will drive the second piston to drive the motor under test to reciprocate and oscillate, outputting AC power. The output AC power will be measured by an electrical parameter measuring device to verify and evaluate the performance of the motor under test.

2. The method of claim 1, wherein the dynamic magnetic linear generator is a dynamic magnetic linear generator with a load coupled to the dynamic magnetic linear generator. Both the drive motor and the motor under test are cylindrical moving magnet linear motors.

3. The aerodynamic coupling test method for mutual loads of moving magnet linear generators according to claim 2, characterized in that, There is no mechanical connection between the drive motor and the motor under test.

4. The method of claim 1, wherein the dynamic magnetic linear generator is a dynamic magnetic linear generator with a load coupled to the dynamic magnetic linear generator. In step 2, the moving part of the drive motor is radially supported by the clearance fit between the first piston and the first inner cylinder.

5. The method of claim 1, wherein the dynamic magnetic linear generator is a dynamic magnetic linear generator with a load coupled to the dynamic magnetic linear generator. In step 3, the moving part of the motor under test is radially supported by the clearance fit between the second piston and the second inner cylinder.

6. The method of claim 1, wherein the dynamic magnetic linear generator is a dynamic magnetic linear generator with a load coupled to the dynamic magnetic linear generator. In step 5, the inherent oscillation frequency of the drive motor can be changed by adjusting the pressure of the gas working medium inside the pressure housing.

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