Method and system for fine servo overload determination

Abstract

The application discloses a fine servo overload judgment method and system, which comprises the following steps: S1, collecting IGBT module temperature; S2, collecting motor U-phase and V-phase currents and calculating torque current; S3, servo reading servo rated current, motor rated current, overload curve number and overload time saved in ferroelectric and / or FLASH; S4, calculating servo current standard value according to motor rated current, servo rated current and motor real-time current; S5, entering different curve calculation integrals according to curve number, overload time and servo current standard value; S6, calculating servo overload threshold value according to different curves; and S7, judging whether servo overload threshold needs to be reduced based on the module temperature detection result of the above step S1. The application is used to solve the problems that servo overload protection in the prior art is not suitable for field application and is single. Moreover, the temperature factor is considered, the servo driver is timely protected, the driving capacity of the servo is fully exerted and the use efficiency of the IGBT is improved.

Description

Technical Field

[0001] This invention relates to the field of industrial servo control technology, and more specifically, to a refined method and system for determining servo overload. Background Technology

[0002] Servo overload protection is a crucial safety mechanism for servo drives and a vital guarantee for the stability and reliability of servo products. Common servo overload protection methods include integrating torque to calculate the root mean square (RMS) value; an alarm is triggered if the value exceeds a threshold. Alternatively, current is used for protection, with an overload condition determined if the current exceeds a certain limit. These methods are often too simplistic and do not fully utilize the servo's driving capabilities. Integrating torque results in a fixed integral curve, which is limited, and the protection method is too simplistic and unsuitable for various applications. Furthermore, temperature factors are not taken into account. Summary of the Invention

[0003] In view of this, the present invention provides a refined method and system for determining servo overload, which addresses the problems of existing servo overload protection technologies being unsuitable for field applications and lacking versatility. Furthermore, it incorporates temperature factors, ensuring timely protection of the servo driver while fully utilizing the servo's driving capabilities and improving IGBT efficiency.

[0004] To solve the above technical problems, the present invention provides

[0005] A refined method for determining servo overload includes:

[0006] S1: Collect the temperature of the IGBT module;

[0007] S2: Collect the U-phase and V-phase currents of the motor and calculate the torque current;

[0008] S3: Servo reads the servo rated current, motor rated current, overload curve number and overload time stored in ferroelectric and / or FLASH;

[0009] S4: Calculate the per-unit value of the servo current based on the motor rated current, servo rated current, and motor real-time current.

[0010] S5: Calculate the integral based on the curve number, overload time, and per-unit value of servo current;

[0011] S6: Calculate the servo overload threshold value based on different curves;

[0012] S7: Based on the module temperature detection results of step S1 above, determine whether it is necessary to reduce the servo overload threshold.

[0013] As an optional approach, in step S4 above, the per-unit value of the servo current is calculated as follows:

[0014]

[0015] in, I is the per-unit value of the servo current. q For torque current, This is the rated current of the motor. This is the servo rated current.

[0016] As an optional method, the torque current is the current value after CLARK and PARK transformation.

[0017] As an optional approach, in step S5 above, the integral of the curve is calculated as follows:

[0018]

[0019] in, Where is the value of the servo current, and W is the calculated servo overload value.

[0020] As an optional approach, in step S6 above, the alarm threshold value for each curve is calculated based on a three-second operation time at three times the servo rated current.

[0021] As an optional approach, step S7 above also includes determining whether the integral value exceeds the overload threshold; if it does, an alarm is triggered.

[0022] On the other hand, the present invention also provides a refined servo overload determination system, comprising:

[0023] The data acquisition module includes a temperature acquisition module and a power acquisition module; the temperature acquisition module is used to acquire IGBT temperature; the power acquisition module is used to acquire power information.

[0024] The servo reading module is used to read pre-stored current and overload information;

[0025] The per-unit calculation module is used to calculate the per-unit value of the servo current based on the rated current information and the real-time current information.

[0026] The curve calculation module is used to calculate the integral value and overload threshold value of different curves;

[0027] The judgment module is used to determine the motor's temperature, integral value, and the magnitude of the corresponding preset value.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention addresses different application scenarios. For example, in situations with good or excellent heat dissipation (large servo heatsinks and a well-designed forced airflow), a low-order curve is used, allowing the servo driver to operate above its rated current for a longer period, thus enhancing its overload capacity. Furthermore, the IGBT temperature is taken into account; when the IGBT temperature exceeds a preset temperature, the servo overload threshold is immediately shortened, achieving rapid protection. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the refined servo overload determination method provided in an embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0032] Example

[0033] Please see Figure 1 This embodiment provides a refined method for determining servo overload, including:

[0034] S1: Collect the temperature of the IGBT module;

[0035] S2: Collect the U-phase and V-phase currents of the motor and calculate the torque current;

[0036] S3: Servo reads the servo rated current, motor rated current, overload curve number and overload time stored in ferroelectric and / or FLASH;

[0037] S4: Calculate the per-unit value of the servo current based on the motor rated current, servo rated current, and motor real-time current.

[0038] S5: Calculate the integral based on the curve number, overload time, and per-unit value of servo current;

[0039] S6: Calculate the servo overload threshold value based on different curves;

[0040] S7: Based on the module temperature detection results of step S1 above, determine whether it is necessary to reduce the servo overload threshold.

[0041] In step S4 above, the per-unit value of the servo current is calculated as follows:

[0042]

[0043] in, I is the per-unit value of the servo current. q For torque current, This is the rated current of the motor. This is the servo rated current.

[0044] The torque current is the current value after transformation from CLARK and PARK, and its calculation method is as follows:

[0045]

[0046]

[0047] Where u, v, and w are the motor currents.

[0048] Please refer to it again. Figure 1 This embodiment uses five curves for illustration. Therefore, in step S5 above, the integral is calculated as follows:

[0049]

[0050] in, Where is the value of the servo current, and W is the calculated servo overload value.

[0051] The integral of curve 1 is calculated as follows: (I) 2 -1); the integral of curve 2 is calculated as (I 3 -1); the integral calculation method for curve 3 is (I 4 -1); the integral calculation method for curve 4 is (I 5 -1); the integral calculation method for curve 5 is (I 6 -1).

[0052] In the above formula, I represents the servo current value. When the servo current value is less than or equal to the rated current, the integral formula will be less than or equal to 0, and will never exceed the servo overload threshold. Therefore, it can run continuously. Higher-order integral functions operate for longer periods as the servo current value decreases, reaching the servo overload threshold in a longer time, making them suitable for applications with excellent heat dissipation. Lower-order integral functions reach the servo overload threshold in a shorter time as the servo current value decreases, making them suitable for applications with poor heat dissipation.

[0053] Table 1 - Servo overload time under different curves

[0054]

[0055]

[0056] Table 1 shows the overload time for other current values ​​when a 3x servo current and a 3-second overload time are both required. In other words, selecting different curves allows the servo to achieve different operating times when the current is below 3x the rated current. Both the curve and the 3x 3-second time are configurable, thus greatly refining the servo overload determination, fully utilizing the servo's driving capabilities, and adapting to application scenarios with varying heat dissipation conditions.

[0057] Therefore, in step S6, based on the overall requirement of operating at 3 times the servo rated current for 3 seconds, the alarm threshold values ​​for curves 1-5 are calculated. Then, based on the module temperature, it is determined whether the servo overload thresholds for curves 1, 2, 3, 4, and 5 need to be reduced.

[0058] Furthermore, to better protect the power devices, in this embodiment, if the temperature rises further when the alarm threshold exceeds 85 degrees Celsius, the power devices will easily burn out instantly due to the thermal effect. Therefore, the operating time needs to be shortened in this case. When the temperature is greater than 85 degrees Celsius, the threshold value is reduced to one-third of 85 degrees Celsius. The time shown in Table 1 will be shortened accordingly. Afterward, it is determined whether the integral value exceeds the overload threshold. If it does, an alarm is triggered; otherwise, the next detection is performed.

[0059] Furthermore, this embodiment also provides a refined servo overload determination system to support the implementation of the above scheme, including: a data acquisition module, comprising a temperature acquisition module and an energy acquisition module; the temperature acquisition module is used to acquire IGBT temperature; the energy acquisition module is used to acquire energy information; a servo reading module is used to read pre-stored current information and overload information; a per-unit calculation module is used to calculate the per-unit value of servo current based on rated current information and real-time current information; a curve calculation module is used to calculate the integral value and overload threshold value of different curves; and a judgment module is used to judge the motor temperature, integral value, and the magnitude of the corresponding preset value.

[0060] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A refined method for determining servo overload, characterized in that, include: S1: Collect the temperature of the IGBT module; S2: Collect the U-phase and V-phase currents of the motor and calculate the torque current; S3: Servo reads the servo rated current, motor rated current, overload curve number and overload time stored in ferroelectric and / or FLASH; S4: Calculate the per-unit value of the servo current based on the motor's rated current, the servo's rated current, and the motor's real-time current. The calculation method for the per-unit value of the servo current is as follows: , This is the per-unit value of the servo current. For torque current, This is the rated current of the motor. This is the servo's rated current. S5: Substitute the curve number, overload time, and servo current per-unit value into different curves to calculate the integral. The integral calculation method for the curves is as follows: , Where is the value of the servo current, and W is the calculated servo overload value; S6: Calculate the servo overload threshold value based on different curves; S7: Based on the module temperature detection results of step S1 above, determine whether it is necessary to reduce the servo overload threshold.

2. The refined servo overload determination method according to claim 1, characterized in that, The torque current is the current value after CLARK and PARK conversion.

3. The refined servo overload determination method according to claim 1, characterized in that, In step S6 above, based on a three-second operation time at three times the servo rated current, the alarm threshold value for each curve is calculated.

4. The refined servo overload determination method according to claim 1, characterized in that, In step S7 above, it is also necessary to determine whether the integral value exceeds the overload threshold. If it exceeds the overload threshold, an alarm will be triggered.

5. A sophisticated servo overload determination system, characterized in that, include: The data acquisition module includes a temperature acquisition module and an electrical energy acquisition module; The temperature acquisition module is used to acquire the IGBT temperature; The power acquisition module is used to acquire power information; The servo reading module is used to read pre-stored current and overload information; The per-unit calculation module is used to calculate the per-unit value of the servo current based on the rated current information and the real-time current information. The calculation method for the per-unit value of the servo current is as follows: , This is the per-unit value of the servo current. For torque current, This is the rated current of the motor. This is the servo's rated current. The curve calculation module is used to calculate the integral values ​​and overload threshold values ​​of different curves. The integral calculation method for the curves is as follows: , Here, W represents the value of the servo current, and W represents the calculated servo overload value. The judgment module is used to determine the motor's temperature, integral value, and the magnitude of the corresponding preset value.

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