A Performance Testing Method for High Power Density Servo Drives

Abstract

The present invention relates to the technical field of testing characteristic parameters of electronic devices, and particularly to a performance testing method for a high-power density servo driver, which includes the following steps: constructing a servo driver testing device and establishing an electrical connection between the servo driver testing device and the servo driver to be tested; the servo driver testing device includes a load unit and a power supply unit; the power supply unit is used for power supply during the testing process; screening the power transistor most affected by stray inductance in the power topology unit as the target power transistor; taking the target power transistor as the test object and testing the maximum operating current of the servo driver to be tested through a double-pulse signal; taking the target power transistor as the test object and testing the maximum operating voltage of the servo driver to be tested through a single-pulse signal; generating a test result based on the maximum operating current and the maximum operating voltage. By adopting this solution, the testing cost of the performance indicators of the servo driver can be reduced, and the accuracy of the test result can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of testing characteristic parameters of electronic devices, and particularly relates to a method for testing the performance of a high-power density servo driver. Background Art

[0002] With the rapid development of industrial automation and intelligent manufacturing technologies, as a core power control component, the performance of a servo driver directly affects the efficiency, accuracy, and reliability of the entire system. In recent years, the market demand for servo drivers has gradually shifted from traditional low-power applications to high-power, high-density, and high-efficiency directions. Especially in the fields of new energy, electric vehicles, aerospace, high-end equipment manufacturing, etc., the demand for high-power density servo drivers is becoming increasingly urgent. However, the design and testing of high-power density servo drivers face many challenges, and the accurate evaluation of power indicators and the optimization of testing methods have become key issues that need to be solved urgently.

[0003] Currently, the power indicators (such as voltage, current, etc.) of servo drivers are mainly determined by two methods: design assurance and motor load testing. The design assurance method relies on theoretical calculations and simulation analyses. Although the power parameters can be quickly determined in the design stage, due to the differences between the actual operating environment and the theoretical model, there are often large deviations between the actual performance of the driver and the design indicators. Such deviations may manifest as too high or too low power indicators, which not only affect the performance optimization of the driver but also may cause it to fail to meet the requirements in specific application scenarios, and even lead to system failures. Therefore, the design assurance method is difficult to comprehensively and accurately reflect the true performance of the servo driver.

[0004] Another commonly used method is motor load testing, that is, testing the servo driver through an actual motor load to obtain its power indicators. Although this method can reflect the actual performance of the driver to a certain extent, its limitations are also very obvious. First, the test data depends on a specific type or model of motor, resulting in a limited scope of application of the test results and being difficult to generalize to other types of drivers or motor combinations. Second, the motor load testing process is complex, requiring the construction of a special test platform, with low test efficiency and high costs. Especially in the testing of high-power servo drivers with high voltage and large current, the implementation difficulty of motor load testing is greater, and the costs and safety requirements of the test equipment are also significantly increased. In addition, motor load testing is highly dependent on the test environment, and environmental factors (such as temperature, humidity, electromagnetic interference, etc.) may have a greater impact on the test results, further reducing the reliability and universality of the test data.

[0005] In view of the above problems, there is an urgent need to provide a method for testing the performance of a high-power density servo driver, which can reduce the test cost of the servo driver performance indicators and improve the accuracy of the test results. Summary of the Invention

[0006] The present invention provides a performance testing method for a high-power density servo driver, which can reduce the testing cost of the performance indicators of the servo driver and improve the accuracy of the test results.

[0007] In order to achieve the above object, the present application provides the following technical solutions:

[0008] A performance testing method for a high-power density servo driver, used to test the performance indicators of the servo driver to be tested. The servo driver to be tested includes a main control unit, a drive unit, and a power topology unit, and includes the following steps:

[0009] Construct a servo driver testing device and establish an electrical connection between the servo driver testing device and the servo driver to be tested; the servo driver testing device includes a load unit and a power supply unit; the power supply unit is used for power supply during the testing process;

[0010] Select the power transistor in the power topology unit that is most affected by stray inductance as the target power transistor;

[0011] Taking the target power transistor as the test object, test the maximum operating current of the servo driver to be tested through a double-pulse signal;

[0012] Taking the target power transistor as the test object, test the maximum operating voltage of the servo driver to be tested through a single-pulse signal;

[0013] Generate a test result based on the maximum operating current and the maximum operating voltage;

[0014] Selecting the power transistor in the power topology unit that is most affected by stray inductance as the target power transistor includes:

[0015] The main control unit sends test pulse signals to each power topology unit to respectively control the opening and closing of each power transistor in the power topology unit;

[0016] Measure the Vdsc voltage value when each power transistor is turned off;

[0017] Select the power transistor with the largest Vdsc voltage value as the target power transistor.

[0018] Further, the load unit includes a load inductor Lload1, a load inductor Lload2, a single switch K1, a single switch K3, and a three-switch K2;

[0019] The single switch K1, the load inductor Lload1, the load inductor Lload2, and the single switch K3 are connected in series in sequence; the other ends of the single switch K1 and the single switch K3 are both connected to the servo driver to be tested; one end of the three-switch K2 is connected to the connection intersection of the load inductor Lload1 and the load inductor Lload2, and the other end is connected to the output phase of the servo driver to be tested.

[0020] Further, when the main control unit sends a test pulse signal to each power topology unit, the current pulse width of the test pulse signal is one-half of the rated current of the corresponding power transistor, and the voltage provided by the power supply unit is one-half of the rated voltage of the corresponding power transistor.

[0021] Further, taking the target power transistor as the test object, the maximum operating current of the servo driver under test is tested through a double-pulse signal, including:

[0022] S301, the main control unit sequentially generates a first pulse signal and a second pulse signal, which are sent to the power topology unit after power amplification by the drive unit to control the opening and closing of the target power transistor in the power topology unit;

[0023] S302, measure the Idsc current value of the target power transistor when the second pulse signal is turned on;

[0024] S303, analyze whether the measured Idsc current value is equal to the rated current of the target power transistor. If so, execute S304. If not, adjust the pulse rise time of the first pulse signal and return to execute S301;

[0025] S304, measure the Ids current of the target power transistor and use the measured Ids current as the maximum operating current of the servo driver under test.

[0026] Further, taking the target power transistor as the test object, the maximum operating voltage of the servo driver under test is tested through a single-pulse signal, including:

[0027] S401, the main control unit generates a third pulse signal, which is sent to the power topology unit after power amplification by the drive unit to control the opening and closing of the target power transistor in the power topology unit;

[0028] S402, measure the Vdsc voltage value when the target power transistor is turned off;

[0029] S403, analyze whether the measured Vdsc voltage value is equal to the rated voltage of the target power transistor. If so, execute S404. If not, adjust the voltage provided by the power supply unit and return to execute S401;

[0030] S404, measure the Vds voltage of the target power transistor and use the measured Vds voltage as the maximum operating voltage of the servo driver under test.

[0031] Further, the power supply unit adopts a DC power supply; the positive terminal of the DC power supply is connected to the single switch K1, and the negative terminal is connected to the single switch K3.

[0032] The principle and advantages of the present invention are as follows:

[0033] 1. Simple operation and low test cost: In this solution, by constructing a test device including a load unit and a power supply unit, the maximum operating current and voltage of the servo driver are respectively tested using double-pulse and single-pulse signals. Its operation process is simple and reduces complex manual intervention. In addition, compared with traditional motor load test methods, the test device adopted in the present invention has a simple structure, does not require complex test equipment or high-cost load simulation devices, and significantly reduces the test cost.

[0034] 2. Reliable data: By screening the power transistor in the power topology unit that is most affected by stray inductance as the target power transistor and performing double-pulse and single-pulse tests on it, the maximum operating current and maximum operating voltage of the servo driver can be accurately measured. During the test process, by adjusting the rise time of the pulse signal and the power supply voltage, it is ensured that the measured value is consistent with the preset rated value, thus guaranteeing the accuracy and reliability of the test data. Compared with traditional design guarantee methods, this solution avoids the deviation between the design index and the real data, ensuring the authenticity and reliability of the driver index.

[0035] 3. High versatility: This method is applicable to various types of servo drivers and has high versatility. By analyzing the stray inductance value or Vdsc voltage value of each power transistor in the power topology unit and screening out the power transistor most affected by stray inductance as the test object, it can be applicable to servo drivers with different power topology structures. In addition, the load unit and power supply unit in the test device can be adjusted according to the requirements of different servo drivers, further enhancing the applicability of this solution.

[0036] 4. Wide applicability: Compared with traditional motor load test methods, the test indexes obtained in the present invention have wider applicability. Motor load test methods usually rely on specific motor loads, and the test results are greatly affected by motor characteristics. However, in the present invention, the load unit is used to simulate the load, and the test results are not restricted by specific motor characteristics and are applicable to a wider range of servo driver application scenarios.

[0037] In summary, this solution has the advantages of simple operation, low test cost, reliable data, high versatility, etc., and can effectively improve the efficiency and accuracy of servo driver performance testing. Brief Description of the Drawings

[0038] Figure 1 It is a flowchart of an embodiment of a method for testing the performance of a high-power density servo driver of the present invention.

[0039] Figure 2 It is a circuit schematic diagram of a test system in an embodiment of a method for testing the performance of a high-power density servo driver of the present invention. Detailed Embodiment

[0040] The following is a further detailed description through specific embodiments:

[0041] The marks in the attached drawings of the specification include: main control unit 1, drive unit 2, power topology unit 3, servo drive to be tested 4, load unit 5, servo drive test device 6, and power supply unit 7.

[0042] Embodiment 1:

[0043] Embodiment 1 is basically as shown in the attached Figure 1 drawing:

[0044] In this embodiment, the IDS current represents the conduction current of the power transistor, directly reflecting the actual load current of the power device; the IDSC current value represents the surge current, that is, the maximum current value of the target power transistor when the pulse current is turned on; the VDS voltage represents the voltage stress borne by the power transistor, that is, the voltage difference between the drain and source of the power transistor; the VDSC voltage value represents the dynamic suppression voltage, that is, the maximum voltage value when the target power transistor is turned off.

[0045] A high-power density servo drive performance test method is used to test the performance indicators of the servo drive to be tested 4, as Figure 1 shown, and includes the following steps:

[0046] S100, construct a servo drive test device 6 and establish an electrical connection between the servo drive test device 6 and the servo drive to be tested 4; as Figure 2 shown, the servo drive to be tested 4 includes a main control unit 1, a drive unit 2, and a power topology unit 3, and the servo drive test device 6 includes a load unit 5 and a power supply unit 7.

[0047] Specifically, the load unit 5 includes a load inductor Lload1, a load inductor Lload2, a single switch K1, a single switch K3, and a triple switch K2. The current-carrying capacity of the load inductor matches the specifications of the servo driver 4 to be tested to prevent damage during the test. The single switch K1, the load inductor Lload1, the load inductor Lload2, and the single switch K3 are connected in series in sequence; the other ends of the single switch K1 and the single switch K3 are both connected to the servo driver 4 to be tested; one end of the triple switch K2 is connected to the connection intersection of the load inductor Lload1 and the load inductor Lload2, and the other end is connected to the output of the servo driver 4 to be tested (connected to the U phase, V phase, or W phase in the power topology unit 3 of the servo driver 4 to be tested according to actual test requirements). The single switch K1 and the single switch K3 are used when testing the power half-bridge. When testing the upper transistor, the single switch K1 is closed, and when testing the lower transistor, the single switch K3 is closed, and the rest of the states are open. The power supply unit 7 uses a DC power supply; the positive terminal of the DC power supply is connected to the single switch K1, and the negative terminal is connected to the single switch K3 for power supply during the test to ensure the normal test operation of the servo driver 4 to be tested.

[0048] In addition, Figure 2 There are also several stray inductances in it. The stray inductances are generated by the system wiring, cannot be eliminated, and are not actual set components. Here, they are only shown in the figure to make the circuit clearer and facilitate subsequent calculation of the stray inductance of the loop corresponding to each power transistor. In practical applications, the stray inductance cannot be eliminated, but it should be controlled to the minimum as much as possible.

[0049] After completing the electrical connection between the servo driver test device 6 and the servo driver 4 to be tested, check whether it can operate normally and conduct an electrical connection inspection on the two to make the connection reliable.

[0050] S200, select the power transistor in the power topology unit 3 that is most affected by the stray inductance as the target power transistor. In this solution, the analysis method or test method can be selected according to actual needs to confirm the target power transistor. Specifically:

[0051] The analysis method is: analyze the stray inductance values received by each power transistor in the power topology unit 3; select the power transistor with the largest stray inductance value as the target power transistor.

[0052] The test method is as follows: The main control unit 1 sends test pulse signals to each power topology unit 3 to respectively control the opening and closing of each power transistor in the power topology unit 3; measure the Vdsc voltage value when each power transistor is turned off. The largest Vdsc voltage value indicates that the power transistor is subject to the largest stray inductance; select the power transistor with the largest Vdsc voltage value as the target power transistor. In this embodiment, when the main control unit 1 sends test pulse signals to each power topology unit 3, the current pulse width of the test pulse signal is one-half of the rated current of the corresponding power transistor, and the voltage provided by the power supply unit 7 is one-half of the rated voltage of the corresponding power transistor.

[0053] S300, taking the target power transistor as the test object, test the maximum operating current of the servo drive 4 to be measured through double-pulse signals; in this embodiment, the power voltage provided by the power supply unit 7 is one-half of the rated voltage of the target power transistor, and the starting value of the power current provided is one-half of the rated current of the target power transistor. S300 includes:

[0054] S301, the main control unit 1 sequentially generates a first pulse signal and a second pulse signal, which are sent to the power topology unit 3 after power amplification through the drive unit 2 to control the opening and closing of the target power transistor in the power topology unit 3; among them, the purpose of the first pulse signal is to establish a current load, and the purpose of the second pulse signal is to turn on the drive with load.

[0055] In this embodiment, considering that the stray inductance will affect the voltage drop when the current changes, and further affect the change rate of the current, therefore, combining the stray inductance value suffered by the target power transistor, the actual voltage applied to the target power transistor is:

[0056]

[0057] Calculate the optimal pulse rise time according to the stray inductance value suffered by the target power transistor, the rated current of the target power transistor, and the rated voltage of the target power transistor.

[0058] According to the above formula, it can be obtained that:

[0059]

[0060] In the formula, is the rated voltage of the target power transistor, is the voltage drop on the stray inductance, is the stray inductance value suffered by the target power transistor, is the rated current of the target power transistor, is the optimal pulse rise time, is the change rate of the current, is a proportionality coefficient less than 1, representing the ratio of the actual voltage to the supply voltage (taking into account the influence of stray inductance). In the actual operation process, it is determined through experiments or simulations. In this embodiment, 。

[0061] Therefore, in this application, according to the calculated optimal pulse rise time, the main control unit 1 is controlled to generate a first pulse signal to more accurately control the current to reach the rated current of the target power transistor.

[0062] S302. Measure the Idsc current value of the target power transistor when the second pulse signal is turned on.

[0063] S303. Analyze whether the measured Idsc current value is equal to the rated current of the target power transistor. If so, execute S304. If not, adjust the pulse rise time of the first pulse signal and return to execute S301.

[0064] S304. Measure the Ids current of the target power transistor and use the measured Ids current as the maximum operating current of the servo drive 4 to be tested.

[0065] S400. Take the target power transistor as the test object and test the maximum operating voltage of the servo drive 4 to be tested through a single pulse signal; in this embodiment, the starting value of the power supply voltage provided by the power supply unit 7 is half of the rated voltage of the target power transistor, and the signal on width during the test process satisfies the maximum operating current of the servo drive 4 obtained in S300. S400 includes:

[0066] S401. The main control unit 1 generates a third pulse signal, which is sent to the power topology unit 3 after power amplification through the drive unit 2 to control the opening and closing of the target power transistor in the power topology unit 3. The purpose of the third pulse signal is to establish a current load.

[0067] S402. Measure the Vdsc voltage value when the target power transistor is turned off.

[0068] S403. Analyze whether the measured Vdsc voltage value is equal to the rated voltage of the target power transistor. If so, execute S404. If not, adjust the voltage provided by the power supply unit 7 and return to execute S401.

[0069] S404. Measure the Vds voltage of the target power transistor and use the measured Vds voltage as the maximum operating voltage of the servo drive 4 to be tested.

[0070] S500. Generate a test result based on the maximum operating current and the maximum operating voltage.

[0071] The above are only embodiments of the present invention. Specific structures and common knowledge such as characteristics that are well-known in the art are not described in detail herein. Those of ordinary skill in the art know all the general technical knowledge in the technical field to which the invention pertains before the filing date or the priority date, can acquire all the prior art in this field, and have the ability to apply conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application, combine their own abilities to complete and implement this solution. Some typical well-known structures or well-known methods should not become obstacles for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope claimed in this application should be based on the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. A high power density servo drive performance test method, used to test the performance indicators of a servo drive to be tested, wherein the servo drive to be tested includes a main control unit, a drive unit and a power topology unit, and is characterized in that: The following steps are involved: Constructing a servo drive test device and establishing an electrical connection between the servo drive test device and the servo drive to be tested; the servo drive test device includes a load unit and a power supply unit; the power supply unit is used for power supply during the test; The power tube most affected by stray inductance in the screening power topology unit is selected as the target power tube; Taking the target power tube as the test object, the maximum working current of the servo drive to be tested is tested through a double pulse signal; Taking the target power tube as the test object, the maximum operating voltage of the servo drive to be tested is tested through a single pulse signal; Generate test results based on maximum operating current and maximum operating voltage; The power tubes most affected by stray inductance in the screening power topology unit are the target power tubes, including: The main control unit sends a test pulse signal to each power topology unit to control the opening and closing of each power tube in the power topology unit respectively; Measure the Vdsc voltage value when each power tube is turned off; The power tube with the largest Vdsc voltage value is selected as the target power tube.

2. The high power density servo drive performance testing method according to claim 1, characterized in that: The load unit includes a load inductor Lload1, a load inductor Lload2, a single switch K1, a single switch K3 and three switches K2; The single switch K1, the load inductor Lload1, the load inductor Lload2 and the single switch K3 are connected in series in sequence; the other ends of the single switch K1 and the single switch K3 are connected to the servo driver to be tested; one end of the three switches K2 is connected to the connection intersection of the load inductor Lload1 and the load inductor Lload2, and the other end is connected to the output of the servo driver to be tested.

3. The high power density servo drive performance testing method according to claim 1, characterized in that: When the main control unit sends a test pulse signal to each power topology unit, the current pulse width of the test pulse signal is half of the rated current of the corresponding power tube, and the voltage provided by the power supply unit is half of the rated voltage of the corresponding power tube.

4. The high power density servo drive performance testing method according to claim 1, characterized in that: Taking the target power tube as the test object, the maximum operating current of the servo drive to be tested is tested through a double pulse signal, including: S301, the main control unit generates a first pulse signal and a second pulse signal in sequence, and sends them to the power topology unit after power amplification by the driving unit to control the on / off of the target power tube in the power topology unit; S302, measuring the Idsc current value of the target power tube when the second pulse signal is turned on; S303, analyzing whether the measured Idsc current value is equal to the rated current of the target power tube, if so, executing S304, if not, adjusting the pulse rise time of the first pulse signal, and returning to execute S301; S304, measuring the Ids current of the target power tube, and using the measured Ids current as the maximum operating current of the servo driver to be tested.

5. The high power density servo drive performance testing method according to claim 1, characterized in that: Taking the target power tube as the test object, the maximum operating voltage of the servo drive to be tested is tested through a single pulse signal, including: S401, the main control unit generates a third pulse signal, which is sent to the power topology unit after power amplification by the driving unit to control the on / off of the target power tube in the power topology unit; S402, measuring the Vdsc voltage value when the target power tube is turned off; S403, analyzing whether the measured Vdsc voltage value is equal to the rated voltage of the target power tube, if so, executing S404, if not, adjusting the voltage provided by the power supply unit, and returning to execute S401; S404, measuring the Vds voltage of the target power tube, and using the measured Vds voltage as the maximum operating voltage of the servo driver to be tested.

6. The high power density servo drive performance testing method according to claim 2, characterized in that: The power supply unit adopts a DC power supply; the positive terminal of the DC power supply is connected to the single switch K1, and the negative terminal is connected to the single switch K3.

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