Discharge resistor open-loop control method, device, servo motor and storage medium

Abstract

The embodiment of the present invention proposes a bleeder resistor open-loop control method, device, servo motor and storage medium, which relates to the technical field of servo motor control. The bleeder resistor open-loop control method is to detect the bus voltage of the servo driver in real time after the servo driver is started; if the real-time detection value of the bus voltage exceeds the preset bleeder resistor start threshold value, the bleeder resistor of the servo driver is started to release the voltage across the bus capacitor of the servo driver to the two ends of the bleeder resistor; during the working process of the bleeder resistor, the net energy value of the bleeder resistor is calculated in real time; if it is determined that the servo driver cannot continue to operate according to the net energy value, the main power supply of the servo driver is cut off to shut down the servo driver, thereby eliminating the need to arrange temperature feedback elements and related sampling circuits, and reducing the cost of bleeder resistor control.

Description

Technical Field

[0001] The present invention relates to the technical field of servo motor control, and in particular to a method and device for open-loop control of a bleeder resistor, a servo motor and a storage medium. Background Art

[0002] In the control system of the servo drive, the bleeder resistor is a very important component. Its main function is to release the high voltage on the bus capacitor in time during the deceleration process of the servo drive to prevent the capacitor from being damaged due to overvoltage. The traditional control method usually adopts closed-loop control, that is, the temperature of the bleeder resistor is monitored by a temperature sensor. When the temperature exceeds the safe range, the power supply is cut off and an alarm is issued. However, this method requires additional temperature sensors and sampling circuits, which increases the cost of the system. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a method and device for open-loop control of a bleeder resistor, a servo motor and a storage medium.

[0004] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0005] In a first aspect, the present invention provides a method for open-loop control of a discharge resistor, the method comprising:

[0006] After the servo drive is started, the bus voltage of the servo drive is detected in real time;

[0007] If the real-time detection value of the bus voltage exceeds the preset discharge resistance start threshold value, the discharge resistance of the servo drive is started to release the voltage across the bus capacitor of the servo drive to the two ends of the discharge resistance;

[0008] During the operation of the discharge resistor, the net energy value of the discharge resistor is calculated in real time;

[0009] If it is determined according to the net energy value that the servo drive cannot continue to operate, the main power supply of the servo drive is cut off to shut down the servo drive.

[0010] Optionally, the step of calculating the net energy value of the discharge resistor in real time includes:

[0011] The net energy value of the discharge resistor is obtained based on the resistance value of the discharge resistor, the voltage across the bus capacitor of the servo drive, the working time of the discharge resistor and the working time of the servo drive.

[0012] Optionally, the net energy value of the discharge resistor satisfies the following formula:

[0013]

[0014] Among them, Q is the net energy value of the discharge resistor, U is the voltage across the bus capacitor of the servo drive, R is the resistance of the discharge resistor, t1 is the working time of the discharge resistor, t2 is the working time of the servo drive, and a and b are constants.

[0015] Optionally, the method further comprises:

[0016] If the net energy value exceeds the preset discharge resistance energy threshold value, it is determined that the servo drive cannot continue to operate.

[0017] Optionally, the method further comprises:

[0018] During the operation of the bleeder resistor, if the real-time detected value of the bus voltage is lower than a preset bleeder resistor closing threshold value, the bleeder resistor is controlled to stop operating.

[0019] In a second aspect, the present invention provides a discharge resistor open-loop control device, the device comprising:

[0020] A detection module, used for detecting the bus voltage of the servo drive in real time after the servo drive is started;

[0021] A starting module, used for starting the bleeder resistor of the servo drive to release the voltage across the bus capacitor of the servo drive to the two ends of the bleeder resistor if the real-time detection value of the bus voltage exceeds a preset bleeder resistor starting threshold value;

[0022] The processing module is used to calculate the net energy value of the discharge resistor in real time during the operation of the discharge resistor; if it is determined according to the net energy value that the servo driver cannot continue to operate, the main power supply of the servo driver is cut off to stop the servo driver.

[0023] Optionally, the device further comprises a determination module;

[0024] The determination module is used to determine that the servo drive cannot continue to operate if the net energy value exceeds a preset discharge resistance energy threshold value.

[0025] Optionally, the processing module is further configured to control the bleeder resistor to stop working if the real-time detected value of the bus voltage is lower than a preset bleeder resistor closing threshold value during the operation of the bleeder resistor.

[0026] In a third aspect, the present invention provides a servo motor, comprising a servo drive, wherein the servo drive comprises a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor can execute the machine executable instructions to implement the open-loop control method of the discharge resistor described in the first aspect.

[0027] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method for open-loop control of a bleeder resistor as described in the first aspect above is implemented.

[0028] The embodiment of the present invention provides a bleeder resistor open-loop control method: after the servo drive is started, the bus voltage of the servo drive is detected in real time; if the real-time detection value of the bus voltage exceeds the preset bleeder resistor start threshold value, the bleeder resistor of the servo drive is started to release the voltage across the bus capacitor of the servo drive to the two ends of the bleeder resistor; during the working process of the bleeder resistor, the net energy value of the bleeder resistor is calculated in real time; if it is determined that the servo drive cannot continue to operate according to the net energy value, the main power supply of the servo drive is cut off to shut down the servo drive. Since the embodiment of the present invention detects the bus voltage after the servo drive is started in real time, and starts the bleeder resistor when the detected bus voltage exceeds the preset bleeder resistor start threshold value, and calculates the net energy value of the bleeder resistor in real time during the working process of the bleeder resistor, and cuts off the main power supply of the servo drive when the net energy value reflects that the servo drive cannot continue to operate, shutting down the servo drive, there is no need to arrange temperature feedback elements and related sampling circuits, reducing the cost of bleeder resistor control.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic block diagram of the structure of a servo driver in a servo motor provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of a discharge resistor open-loop control method provided by an embodiment of the present invention Figure 1 ;

[0033] Figure 3A cooling curve diagram of a discharge resistor provided by an embodiment of the present invention;

[0034] Figure 4 A cooling rate curve diagram of a discharge resistor provided by an embodiment of the present invention;

[0035] Figure 5 A cooling speed curve diagram of a discharge resistor during operation provided by an embodiment of the present invention;

[0036] Figure 6 A schematic diagram of a discharge resistor open-loop control method provided by an embodiment of the present invention Figure 2 ;

[0037] Figure 7 A functional module block diagram of a discharge resistor open-loop control device provided in an embodiment of the present invention.

[0038] Icons: 100 - servo drive; 110 - memory; 120 - processor; 130 - communication module; 200 - discharge resistor open-loop control device; 201 - detection module; 202 - start module; 203 - processing module; 204 - determination module. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0041] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0042] Please refer to Figure 1, is a block diagram of a servo driver 100 included in a servo motor provided in an embodiment of the present invention. The servo driver 100 includes a memory 110, a processor 120 and a communication module 130. The memory 110, the processor 120 and the communication module 130 are electrically connected to each other directly or indirectly to achieve data transmission.

[0043] The memory 110 is used to store programs or data. The memory 110 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0044] The processor 120 is used to read / write data or programs stored in the memory 110 and execute corresponding functions.

[0045] The communication module 130 is used to establish a communication connection between the servo drive and other communication terminals through the network, and to send and receive data through the network.

[0046] It should be understood that Figure 1 The structure shown is only a schematic diagram of the structure of the servo drive, and the servo drive may also include Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown. Figure 1 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0047] In order to avoid arranging additional temperature sensors and sampling circuits and reduce system costs, an embodiment of the present invention provides a bleeder resistor open-loop control method, which will be described in detail below.

[0048] Please refer to Figure 2 The discharge resistor open-loop control method includes steps S101 to S104.

[0049] S101, after the servo drive is started, the bus voltage of the servo drive is detected in real time.

[0050] The bus voltage refers to the voltage on the bus capacitor in the servo drive.

[0051] S102, if the real-time detection value of the bus voltage exceeds the preset discharge resistance start threshold value, the discharge resistance of the servo drive is started to release the voltage across the bus capacitor of the servo drive to the two ends of the discharge resistance.

[0052] The preset bleeder resistor startup threshold value is set according to actual needs. For example, for a servo system with a main power input of three-phase 380VAC, the bleeder resistor startup threshold value is usually set to about 700VDC.

[0053] Start the bleeder resistor, and the voltage across the bus capacitor will be applied to the bleeder resistor. At the same time, t1 starts timing, and t2 also starts timing. As long as t1 starts timing, regardless of whether t1 stops timing or not, t2 will continue to count, where t1 is the working time of the bleeder resistor, and t2 is the working time of the servo driver.

[0054] S102, during the operation of the discharge resistor, calculating the net energy value of the discharge resistor in real time.

[0055] The net energy value of the bleeder resistor refers to the total amount of energy consumed by the bleeder resistor. The bleeder resistor acts as a load and converts energy into heat energy and dissipates it by generating heat. The net energy value of the bleeder resistor can be understood as the energy value actually consumed by the bleeder resistor during the entire bleed process.

[0056] In a possible implementation, the implementation process of step S102 is to obtain the net energy value of the bleeder resistor based on the resistance of the bleeder resistor, the voltage across the bus capacitor of the servo drive, the working time of the bleeder resistor and the working time of the servo drive.

[0057] Among them, the net energy value of the discharge resistor satisfies the following formula:

[0058]

[0059] Among them, Q is the net energy value of the bleeder resistor, U is the voltage across the bus capacitor of the servo drive, R is the resistance of the bleeder resistor, t1 is the working time of the bleeder resistor, t2 is the working time of the servo drive, and a and b are constants.

[0060] As a possible implementation manner, the value of a may be 1.386, and the value of b may be 11960.

[0061] The above formula is obtained by testing the servo drive. The process of obtaining the formula is introduced below.

[0062] First, it is necessary to measure the heat absorbed by the bleeder resistor to reach the set temperature protection value.

[0063] If 220V AC is passed to both ends of the bleeder resistor, use a temperature inspection meter to measure the surface temperature of the bleeder resistor shell, and record the time T when the temperature reaches 200℃. Due to thermal inertia, after power is off, the bleeder resistor shell temperature will continue to rise for a period of time, and the highest temperature reached by the bleeder resistor shell is recorded. Repeat the test several times until the exact time T when the shell rises to 250℃ is measured. Among them, 250℃ is the highest protection temperature of the bleeder resistor used in the test, and the measured time T is 58 seconds.

[0064] Calculate the heat absorbed when the temperature rises to the highest point. Joule, Q 吸 As the energy threshold value of the discharge resistor.

[0065] Then, measure the cooling curve of the bleeder resistor.

[0066] The time starts when the temperature of the bleeder resistor shell reaches 250°C. The time is recorded every time the temperature drops by 10°C. The measured temperature-time data are as follows:

[0067]

[0068] By processing the measured temperature-time data, the fitting results are as follows Figure 3 The cooling curve shown in Figure 2 has a corresponding fitting function:

[0069] Next, the cooling curve is operated to calculate the cooling speed function after the servo is started.

[0070] The cooling rate of the bleeder resistor is usually fast in the high temperature stage and slow in the low temperature stage. The servo drive starts at room temperature, and the starting point of the cooling stage should be from room temperature. However, the cooling starting point of the cooling curve starts from the highest temperature point. Therefore, it is necessary to calculate the fitting function of the cooling curve to obtain the real cooling curve after the bleeder resistor starts from room temperature.

[0071] right Derivation, we get Figure 4 The cooling curve shown in Figure 2 corresponds to the cooling rate function:

[0072] The actual cooling curve after the discharge resistor is running is as follows Figure 5 As shown, the actual cooling function of the corresponding discharge resistor after operation is A function symmetrical along t = T1 / 2 (T1 is the total time for cooling from 250°C to 25°C, the total cooling time measured here is T1 = 11960 seconds)

[0073]

[0074] Finally, the bleeder resistor open-loop control formula is composed of the bleeder resistor heat absorption formula and the cooling speed function after the servo drive is running:

[0075]

[0076] It should be noted that since the heat absorbed by the bleeder resistor will not be less than 0, if the Q value calculated by the open-loop formula is less than zero, the Q value is set to 0.

[0077] S104: If it is determined according to the net energy value that the servo drive cannot continue to operate, the main power supply of the servo drive is cut off to stop the servo drive.

[0078] Among them, "the servo drive cannot continue to run" means that the calculated net energy value of the bleeder resistor exceeds the preset bleeder resistor energy threshold value, that is, Q>Q 吸 .

[0079] When the net energy value of the bleeder resistor exceeds the preset bleeder resistor energy threshold value, it means that the bleeder resistor temperature exceeds the allowable value of the bleeder resistor. If the servo drive continues to run, the bleeder resistor temperature will be too high, and then the bleeder resistor will be burned. Even after the bleeder resistor is burned, the high voltage at both ends of the bus capacitor cannot be discharged in time and explodes, thereby damaging the entire servo system. At this time, the main power supply needs to be cut off, the servo bleeder overload fault is reported, and the servo drive is shut down.

[0080] Please refer to Figure 6 The discharge resistor open-loop control method further includes arranging S105.

[0081] S105, during the operation of the bleeder resistor, if the real-time detection value of the bus voltage is lower than a preset bleeder resistor closing threshold value, the bleeder resistor is controlled to stop operating.

[0082] The preset bleeder resistor closing threshold value is set according to actual needs. For example, for a servo system with a three-phase 380VAC main power input, the bleeder resistor closing threshold value is usually set to about 620VDC.

[0083] It is understandable that during the operation of the bleeder resistor, the real-time detection value of the bus voltage needs to be compared with the preset bleeder resistor closing threshold value, and the net energy value of the bleeder resistor needs to be calculated in real time and compared with the preset bleeder resistor energy threshold value.

[0084] If the bleeder resistor is in working state and the real-time detection value of the bus voltage is lower than the preset bleeder resistor closing threshold value, the bleeder resistor is controlled to stop working, otherwise the bleeder resistor continues to be in working state.

[0085] If the bleeder resistor is in working state and the net energy value of the bleeder resistor calculated in real time exceeds the preset bleeder resistor energy threshold value, the main power supply is cut off, a servo bleeder overload fault is reported, and the servo drive is shut down.

[0086] In order to execute the corresponding steps in the above embodiments and various possible methods, a method for implementing the discharge resistor open-loop control device 200 is given below. Figure 7 , Figure 7 This is a functional module diagram of a bleeder resistor open-loop control device 200 provided in an embodiment of the present invention. It should be noted that the basic principle and technical effects of the bleeder resistor open-loop control device 200 provided in this embodiment are the same as those of the above embodiment. For the sake of brief description, for parts not mentioned in this embodiment, reference can be made to the corresponding contents in the above embodiment. The bleeder resistor open-loop control device 200 includes:

[0087] The detection module 201 is used to detect the bus voltage of the servo drive in real time after the servo drive is started.

[0088] A starting module 202 is used to start the bleeder resistor of the servo drive if the real-time detection value of the bus voltage exceeds a preset bleeder resistor starting threshold value, so as to release the voltage across the bus capacitor of the servo drive to the two ends of the bleeder resistor;

[0089] The processing module 203 is used to calculate the net energy value of the discharge resistor in real time during the operation of the discharge resistor; if it is determined according to the net energy value that the servo driver cannot continue to operate, the main power supply of the servo driver is cut off to stop the servo driver.

[0090] The determination module 204 is used to determine that the servo drive cannot continue to operate if the net energy value exceeds a preset discharge resistance energy threshold value.

[0091] The processing module 203 is further configured to control the bleeding resistor to stop working if the real-time detected value of the bus voltage is lower than a preset bleeding resistor closing threshold value during the bleeding resistor working process.

[0092] Optionally, the above modules can be stored in the form of software or firmware. Figure 1 The memory 110 shown in the figure may be fixed in the operating system (OS) of the servo drive 100 and may be Figure 1 Meanwhile, the data and program codes required for executing the above modules may be stored in the memory 110.

[0093] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0094] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0095] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a processor of a servo drive included in a servo motor to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A discharge resistor open-loop control method, characterized in that: The method comprises: After the servo drive is started, the bus voltage of the servo drive is detected in real time; If the real-time detection value of the bus voltage exceeds the preset discharge resistance start threshold value, the discharge resistance of the servo drive is started to release the voltage across the bus capacitor of the servo drive to the two ends of the discharge resistance; During the operation of the discharge resistor, the net energy value of the discharge resistor is calculated in real time; If it is determined according to the net energy value that the servo drive cannot continue to operate, the main power supply of the servo drive is cut off to shut down the servo drive.

2. The open-loop control method for discharge resistance according to claim 1, characterized in that: The step of calculating the net energy value of the discharge resistor in real time comprises: The net energy value of the discharge resistor is obtained based on the resistance value of the discharge resistor, the voltage across the bus capacitor of the servo drive, the working time of the discharge resistor and the working time of the servo drive.

3. The open-loop control method for discharge resistance according to claim 2, characterized in that: The net energy value of the discharge resistor satisfies the following formula: Among them, Q is the net energy value of the discharge resistor, U is the voltage across the bus capacitor of the servo drive, R is the resistance of the discharge resistor, t1 is the working time of the discharge resistor, t2 is the working time of the servo drive, and a and b are constants.

4. The open-loop control method for discharge resistance according to claim 1, characterized in that: The method further comprises: If the net energy value exceeds the preset discharge resistance energy threshold value, it is determined that the servo drive cannot continue to operate.

5. The open-loop control method for discharge resistance according to claim 1, characterized in that: The method further comprises: During the operation of the bleeder resistor, if the real-time detected value of the bus voltage is lower than a preset bleeder resistor closing threshold value, the bleeder resistor is controlled to stop operating.

6. A discharge resistor open-loop control device, characterized in that: The device comprises: A detection module, used for detecting the bus voltage of the servo drive in real time after the servo drive is started; A starting module, used for starting the bleeder resistor of the servo drive to release the voltage across the bus capacitor of the servo drive to the two ends of the bleeder resistor if the real-time detection value of the bus voltage exceeds a preset bleeder resistor starting threshold value; The processing module is used to calculate the net energy value of the discharge resistor in real time during the operation of the discharge resistor; if it is determined according to the net energy value that the servo driver cannot continue to operate, the main power supply of the servo driver is cut off to stop the servo driver.

7. The discharge resistor open-loop control device according to claim 6, characterized in that: The device also includes a determination module; The determination module is used to determine that the servo drive cannot continue to operate if the net energy value exceeds a preset discharge resistance energy threshold value.

8. The discharge resistor open-loop control device according to claim 6, characterized in that: The processing module is further configured to control the bleeder resistor to stop working if the real-time detected value of the bus voltage is lower than a preset bleeder resistor closing threshold value during the bleeder resistor working process.

9. A servo motor, characterized in that: It comprises a servo driver, the servo driver comprises a processor and a memory, the memory stores machine executable instructions that can be executed by the processor, and the processor can execute the machine executable instructions to implement the bleeder resistor open-loop control method according to any one of claims 1-5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the open-loop control method for the bleeder resistor as claimed in any one of claims 1 to 5 is implemented.

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