Motor starting control method and system

Abstract

The present invention provides a motor starting control method and system, belonging to the technical field of motor starting control. The scheme first draws a voltage-time waveform diagram according to the voltage information of the motor at each moment; then determines whether the power shaking condition is met according to the voltage-time waveform diagram; if the power shaking condition is met, the motor is controlled to restart. The present invention can determine whether power shaking occurs only based on the voltage-time waveform diagram. Compared with the existing scheme, it can determine whether power shaking occurs only based on the voltage-time waveform, which not only reduces the time of the judgment process, but also reduces the complexity of the data acquisition process, and further reduces the memory occupied by the judgment process.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor starting control, and in particular relates to a motor starting control method and system. Background Art

[0002] The power supply grid of industrial enterprises often experiences short-term voltage drops and fluctuations (commonly known as "electrical shaking") due to lightning strikes, short circuits, reclosing, startup of the same section of equipment, or fault removal. When an electric shaking occurs, the grid voltage drops instantly, and "electrical shaking" is inevitable and unpredictable. Low-voltage motors are important mechanical traction components of industrial enterprises, and are mostly controlled by AC contactors. Electric shaking can cause the AC contactors to release and cause the motors to stop operating. In particular, the shutdown of important motors can cause the shutdown of electrical equipment and the chain action of production processes during the production process, forcing the production process to stop. Electric shaking seriously affects the safe, stable, and long-term operation of industrial enterprises, and can cause secondary accidents such as equipment damage, environmental pollution, and even casualties, causing huge economic losses to production enterprises.

[0003] At present, there are three methods for judging electric shaking. One of them is to determine whether electric shaking occurs by judging whether the auxiliary contact of the contactor is disconnected or whether the running signal contact of the inverter is disconnected. This method has the risk of misjudgment. Although it is judged that there is no electric shaking, the restart command is disconnected instantaneously, but during the misjudgment of instantaneous closure, there may be a safety hazard that the vehicle cannot stop. Another method is to separate the two end terminals when detecting a pair of normally open contacts of the contactor and issuing a restart command. This results in the need to occupy a pair of normally open contacts of the on-site contactor. In fact, the on-site contactor may not have extra normally open auxiliary contacts. If the acquisition status requires a pair of independent normally open contacts, an extended relay must be added, which increases the difficulty of on-site operation and also adds a fault point (newly added extended relay). The third method is to determine the change law between the voltage information of the motor and the auxiliary contact action information of a pair of normally open contacts on the contactor in the motor or the voltage information at both ends of the auxiliary contacts, and based on the change law, judge whether the motor has electric shaking. However, in the actual judgment process, it is also necessary to determine the voltage change law, the action change law and the related characteristics. Obviously, the above scheme has the problem of complex judgment. Summary of the invention

[0004] Based on the above technical problems, the present invention provides a motor starting control method and system to quickly and accurately determine whether power shaking occurs.

[0005] The present invention provides a motor starting control method, the method comprising:

[0006] Collect the voltage information of the motor at each moment.

[0007] Draw a voltage-time waveform diagram based on the voltage information of the motor at each moment.

[0008] Whether the power shake condition is met is determined based on the voltage-time waveform; if the power shake condition is met, the motor is controlled to restart.

[0009] Optionally, the method further comprises:

[0010] When a power shake occurs, the number of power shakes is recorded.

[0011] Determine whether the number of power shakes within the set time is greater than or equal to the preset number; if the number of power shakes within the set time is less than the preset number, control the motor to restart; if the number of power shakes within the set time is greater than or equal to the preset number, control the motor to stop working.

[0012] Optionally, judging whether the power shaking condition is met according to the voltage-time waveform diagram; if the power shaking condition is met, controlling the motor to restart specifically includes:

[0013] Step S31: Determine whether the first power swing condition is met based on the voltage-time waveform; if the first power swing condition is met, it means that the voltage suddenly rises and a power swing occurs, and the motor is controlled to restart; if the first power swing condition is not met, execute "Step S32".

[0014] Step S32: Determine whether the second power swing condition is met based on the voltage-time waveform; if the second power swing condition is met, it means that the voltage has dropped suddenly and a power swing has occurred, and the motor is controlled to restart; if the second power swing condition is not met, execute "Step S33".

[0015] Step S33: Determine whether the third power swing condition is met based on the voltage-time waveform; if the third power swing condition is met, it indicates a short power outage and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, execute "Step S34".

[0016] Step S34: judging whether the fourth power fluctuation condition is satisfied according to the voltage-time waveform; if the fourth power fluctuation condition is satisfied, it indicates that the voltage flickers and power fluctuation occurs, and the motor is controlled to restart.

[0017] Optionally, the voltage-time waveform diagram is used to determine whether the first power-sway condition is met; if the first power-sway condition is met, it indicates that the voltage suddenly rises and power-sway occurs, and the motor is controlled to restart; if the first power-sway condition is not met, "step S32" is executed, which specifically includes:

[0018] Step S311: Determine two adjacent inflection points and the slope l between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0019] Step S312: Determine the time difference Δt1 between two adjacent inflection points and the voltage effective value V corresponding to the highest point max The voltage V corresponding to the lowest point min .

[0020] Step S313: Based on the time difference Δt1 between two adjacent inflection points and the slope l 斜 , the voltage effective value corresponding to the highest point V max The voltage V corresponding to the lowest point min Determine whether the first power swing condition is met; if the first power swing condition is met, it means that the voltage suddenly rises and a power swing occurs, and the motor is controlled to restart; if the first power swing condition is not met, execute "step S32".

[0021] Optionally, the voltage-time waveform diagram is used to determine whether the second power swing condition is met; if the second power swing condition is met, it indicates that the voltage has dropped suddenly and power swing has occurred, and the motor is controlled to restart; if the second power swing condition is not met, "step S33" is executed, which specifically includes:

[0022] Step S321: Determine two adjacent inflection points and the slope l' between the two inflection points according to the voltage-time waveform diagram 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0023] Step S322: Determine the time difference Δt2 between two adjacent inflection points and the voltage effective value U corresponding to the highest point max The voltage effective value U corresponding to the lowest point min .

[0024] Step S323: Based on the time difference Δt2 between two adjacent inflection points and the slope l' 斜 , the voltage effective value corresponding to the highest point is U max The voltage effective value U corresponding to the lowest point min Determine whether the second power swing condition is met; if the second power swing condition is met, it means that the voltage has dropped suddenly and a power swing has occurred, and the motor is controlled to restart; if the second power swing condition is not met, execute "step S33".

[0025] Optionally, the voltage-time waveform diagram is used to determine whether the third power-sway condition is met; if the third power-sway condition is met, it indicates that a short power outage has occurred and a power-sway has occurred, and the motor is controlled to restart; if the third power-sway condition is not met, "step S34" is executed, which specifically includes:

[0026] Step S331: Determine whether there is a waveform with a slope of zero within a certain period of time according to the voltage-time waveform diagram; if there is a waveform with a slope of zero, execute "step S332"; if there is no waveform with a slope of zero, no processing is required.

[0027] Step S332: Determine whether the third power fluctuation condition is met during this period of time; if the third power fluctuation condition is met, it indicates a short power outage and a power fluctuation has occurred, and the motor is controlled to restart; if the third power fluctuation condition is not met, execute "Step S34".

[0028] The present invention also provides a motor starting control system, the system comprising:

[0029] The acquisition module is used to collect the voltage information of the motor at each moment.

[0030] A waveform drawing module is used to draw a voltage-time waveform according to the voltage information of the motor at each moment;

[0031] The first judgment module is used to judge whether the power shaking condition is met according to the voltage-time waveform diagram; if the power shaking condition is met, the motor is controlled to restart.

[0032] Optionally, the system further comprises:

[0033] The power shaking frequency recording module is used to record the number of power shaking when power shaking occurs.

[0034] The second judgment module is used to judge whether the number of power shakes within the set time is greater than or equal to the preset number; if the number of power shakes within the set time is less than the preset number, the motor is controlled to restart; if the number of power shakes within the set time is greater than or equal to the preset number, the motor is controlled to stop working.

[0035] Optionally, the first judgment module specifically includes:

[0036] The first judgment unit is used to judge whether the first electric shock condition is met according to the voltage-time waveform diagram; if the first electric shock condition is met, it means that the voltage suddenly rises and an electric shock occurs, and the motor is controlled to restart; if the first electric shock condition is not met, the "second judgment unit" is executed.

[0037] The second judgment unit is used to judge whether the second electric shock condition is met according to the voltage-time waveform diagram; if the second electric shock condition is met, it means that the voltage has dropped suddenly and an electric shock has occurred, and the motor is controlled to restart; if the second electric shock condition is not met, the "third judgment unit" is executed.

[0038] The third judgment unit is used to judge whether the third power swing condition is met according to the voltage-time waveform diagram; if the third power swing condition is met, it indicates that a short power outage has occurred and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, the "fourth judgment unit" is executed.

[0039] The fourth judgment unit is used to judge whether a fourth power swing condition is met according to the voltage-time waveform diagram; if the fourth power swing condition is met, it means that the voltage flickers and a power swing occurs, and the motor is controlled to restart.

[0040] Optionally, the first judging unit specifically includes:

[0041] The first slope calculation subunit is used to determine two adjacent inflection points and the slope l between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0042] The first parameter determination subunit is used to determine the time difference Δt1 between two adjacent inflection points and the voltage effective value V corresponding to the highest point max The voltage V corresponding to the lowest point min .

[0043] The first judgment subunit is used to determine the time difference Δt1 between two adjacent inflection points and the slope l 斜 , the voltage effective value corresponding to the highest point V max The voltage V corresponding to the lowest point min Determine whether the first power swing condition is met; if the first power swing condition is met, it means that the voltage suddenly rises and a power swing occurs, and the motor is controlled to restart; if the first power swing condition is not met, execute the "second judgment unit".

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention provides a motor start control method and system. First, a voltage-time waveform is drawn according to the voltage information of the motor at each moment; then, whether the power shaking condition is met is determined according to the voltage-time waveform; if the power shaking condition is met, the motor is controlled to restart. The present invention can determine whether power shaking occurs only based on the voltage-time waveform. Compared with the existing scheme, it can determine whether power shaking occurs only based on the voltage-time waveform, which not only reduces the time of the judgment process, but also reduces the complexity of the data acquisition process, and further reduces the memory occupied by the judgment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flow chart of a motor starting control method of the present invention;

[0047] Figure 2This is a structural diagram of a motor starting control system of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with specific implementation cases and drawings, but the present invention is not limited to these embodiments.

[0049] Example 1

[0050] like Figure 1 As shown, the present invention discloses a motor starting control method, the method comprising:

[0051] Step S1: Collecting the voltage information of the motor at each moment.

[0052] Step S2: Draw a voltage-time waveform diagram according to the voltage information of the motor at each moment.

[0053] Step S3: judging whether the power shaking condition is met according to the voltage-time waveform; if the power shaking condition is met, controlling the motor to restart.

[0054] The following is a detailed discussion of each step:

[0055] In addition to the above steps, the motor starting control method of the present invention also includes:

[0056] Step S4: When power fluctuation occurs, the number of power fluctuations is recorded.

[0057] Step S5: Determine whether the number of power shakes within the set time is greater than or equal to the preset number; if the number of power shakes within the set time is less than the preset number, control the motor to restart; if the number of power shakes within the set time is greater than or equal to the preset number, control the motor to stop working.

[0058] In this embodiment, the motor is generally started within 6 times per hour. Too frequent starting will cause certain losses, because the starting current of the motor is 5-7 times the rated current, and even 2-3 times when starting without load. In addition, since frequent starting will also cause irreversible damage to the motor, the present invention needs to record the number of power swings. When the number of power swings within the set time is greater than or equal to the preset number, the motor is controlled to stop working, further reducing the degree of damage to the motor and extending the service life of the motor.

[0059] Furthermore, the preset number of times and the set time are set according to the limit time and the limit number of times marked on the motor, and data less than the limit time and the limit number of times can be set, but must not exceed the limit time and the limit number of times.

[0060] Step S2: Draw a voltage-time waveform diagram according to the voltage information of the motor at each moment.

[0061] In this embodiment, the horizontal axis in the voltage-time waveform diagram represents time, and the vertical axis represents voltage; in addition, the software for drawing the voltage-time waveform diagram can adopt a fitting method or a rotating vector method, which can be selected according to actual needs; in addition, MATLAB software can be used for drawing, and other drawing software can also be used, which can be selected according to actual needs.

[0062] In this embodiment, the main factors affecting the electric shaking include voltage surge, voltage sag, short-term power outage and voltage flicker. If the judgment is inaccurate, it will directly lead to misjudgment, which will not only affect the service life of the motor, but also affect the entire operating system. Therefore, the present invention provides specific steps for judging the electric shaking based on the above factors, and can quickly and accurately judge whether the electric shaking occurs. If the electric shaking occurs, the motor is directly controlled to restart. If the change is not caused by the electric shaking, the motor is controlled to stop running. The specific detailed steps are as follows:

[0063] Step S3: judging whether the power shaking condition is met according to the voltage-time waveform; if the power shaking condition is met, controlling the motor to restart, specifically including:

[0064] Step S31: judging whether the first power fluctuation condition is met according to the voltage-time waveform; if the first power fluctuation condition is met, it means that the voltage suddenly rises and power fluctuation occurs, and the motor is controlled to restart; if the first power fluctuation condition is not met, executing "step S32", which specifically includes:

[0065] Step S311: Determine two adjacent inflection points and the slope l between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0066] Step S312: Determine the time difference Δt1 between two adjacent inflection points and the voltage effective value V corresponding to the highest point max The voltage V corresponding to the lowest point min .

[0067] In this embodiment, the time difference Δt1 is equal to the time t corresponding to the highest point max Subtract the time t corresponding to the lowest point min difference.

[0068] Step S313: Based on the time difference Δt1 between two adjacent inflection points and the slope l 斜 , the voltage effective value corresponding to the highest point V max The voltage V corresponding to the lowest point min Determine whether the first power swing condition is met; if the first power swing condition is met, it means that the voltage suddenly rises and a power swing occurs, and the motor is controlled to restart; if the first power swing condition is not met, execute "step S32".

[0069] The specific formula for the first electric shock condition is:

[0070] Among them, t max Indicates the end time of the waveform with a slope greater than zero, that is, the time corresponding to the highest point, t min Indicates the start time of the waveform with a slope greater than zero, that is, the time corresponding to the lowest point, T represents the period, V 标 Indicates the nominal voltage of the motor.

[0071] In this embodiment, when the slope is greater than zero, it indicates an upward trend, and therefore whether a voltage surge occurs during power shaking is subsequently determined based on the time difference of the rise and the change in the effective voltage amplitude.

[0072] Step S32: judging whether the second power swing condition is met according to the voltage-time waveform; if the second power swing condition is met, it means that the voltage drops suddenly and power swing occurs, and the motor is controlled to restart; if the second power swing condition is not met, executing "step S33", which specifically includes:

[0073] Step S321: Determine two adjacent inflection points and the slope l' between the two inflection points according to the voltage-time waveform diagram 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0074] Step S322: Determine the time difference Δt2 between two adjacent inflection points and the voltage effective value U corresponding to the highest point max The voltage effective value U corresponding to the lowest point min .

[0075] In this embodiment, the time difference Δt2 is equal to the time t′ corresponding to the lowest point max Subtract the time t′ corresponding to the highest point min difference.

[0076] Step S323: Based on the time difference Δt2 between two adjacent inflection points and the slope l′ 斜 , the voltage effective value corresponding to the highest point is U max The voltage effective value U corresponding to the lowest point min Determine whether the second power swing condition is met; if the second power swing condition is met, it means that the voltage drops suddenly and power swing occurs, and the motor is controlled to restart; if the second power swing condition is not met, execute "step S33";

[0077] The specific formula for the second electric shock condition is:

[0078] Among them, t′ maxIndicates the end time of the waveform with a slope less than zero, that is, the time corresponding to the lowest point, t' min Indicates the start time of the waveform with a slope less than zero, that is, the time corresponding to the highest point, T represents the period, V 标 Indicates the nominal voltage of the motor.

[0079] In this embodiment, when the slope is less than zero, it indicates a downward trend, and therefore whether a voltage drop occurs during power shaking is subsequently determined based on the time difference of the drop and the change in the effective voltage amplitude.

[0080] Step S33: judging whether the third power swing condition is met according to the voltage-time waveform; if the third power swing condition is met, it means that a short power outage has occurred and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, executing "step S34", which specifically includes:

[0081] Step S331: Determine whether there is a waveform with a slope of zero within a certain period of time according to the voltage-time waveform diagram; if there is a waveform with a slope of zero, execute "step S332"; if there is no waveform with a slope of zero, no processing is required.

[0082] Step S332: Determine whether the third power fluctuation condition is met during this period of time; if the third power fluctuation condition is met, it indicates a short power outage and a power fluctuation has occurred, and the motor is controlled to restart; if the third power fluctuation condition is not met, execute "Step S34".

[0083] The specific formula for the third electric sway condition is: 0.5T≤Δt3=t j -t k ≤3s; where Δt3 represents the time period corresponding to the waveform with a slope of zero, t k Indicates the start time of the waveform with a slope of zero, t j It indicates the end time of the waveform with a slope of zero, and T indicates the period.

[0084] Step S34: Determine whether the fourth power swing condition is met based on the voltage-time waveform; if the fourth power swing condition is met, it means that the voltage flickers and a power swing has occurred, and the motor is controlled to restart; if the fourth power swing condition is not met, determine whether the voltage is abnormal based on the voltage-time waveform, and if it is abnormal, control the motor to stop working.

[0085] The fourth electric shaking condition is that the waveform envelope changes regularly or the voltage amplitude changes randomly, which can be selected according to the specific actual application environment.

[0086] The technical solution disclosed in the present invention can determine whether an electric shock occurs only based on the voltage-time waveform. Compared with the existing solutions, it can determine whether an electric shock occurs only based on the voltage-time waveform, which not only reduces the time of the judgment process, but also reduces the complexity of the data acquisition process, and further reduces the memory occupied by the judgment process.

[0087] Example 2

[0088] like Figure 2 As shown, the present invention also provides a motor starting control system, the system comprising:

[0089] The acquisition module 201 is used to acquire the voltage information of the motor at each moment.

[0090] The waveform drawing module 202 is used to draw a voltage-time waveform according to the voltage information of the motor at each moment.

[0091] The first judgment module 203 is used to judge whether the power shaking condition is met according to the voltage-time waveform diagram; if the power shaking condition is met, the motor is controlled to restart.

[0092] As an optional implementation, the system of the present invention further includes:

[0093] The power fluctuation times recording module 204 is used to record the times of power fluctuations when power fluctuations occur.

[0094] The second judgment module 205 is used to judge whether the number of power shakes within the set time is greater than or equal to the preset number; if the number of power shakes within the set time is less than the preset number, the motor is controlled to restart; if the number of power shakes within the set time is greater than or equal to the preset number, the motor is controlled to stop working.

[0095] As an optional implementation manner, the first determination module 203 of the present invention specifically includes:

[0096] The first judgment unit is used to judge whether the first electric shock condition is met according to the voltage-time waveform diagram; if the first electric shock condition is met, it means that the voltage suddenly rises and an electric shock occurs, and the motor is controlled to restart; if the first electric shock condition is not met, the "second judgment unit" is executed.

[0097] The second judgment unit is used to judge whether the second electric shock condition is met according to the voltage-time waveform diagram; if the second electric shock condition is met, it means that the voltage has dropped suddenly and an electric shock has occurred, and the motor is controlled to restart; if the second electric shock condition is not met, the "third judgment unit" is executed.

[0098] The third judgment unit is used to judge whether the third power swing condition is met according to the voltage-time waveform diagram; if the third power swing condition is met, it indicates that a short power outage has occurred and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, the "fourth judgment unit" is executed.

[0099] The fourth judgment unit is used to judge whether a fourth power swing condition is met according to the voltage-time waveform diagram; if the fourth power swing condition is met, it means that the voltage flickers and a power swing occurs, and the motor is controlled to restart.

[0100] As an optional implementation manner, the first judgment unit of the present invention specifically includes:

[0101] The first slope calculation subunit is used to determine two adjacent inflection points and the slope l between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0102] The first parameter determination subunit is used to determine the time difference Δt1 between two adjacent inflection points and the voltage effective value V corresponding to the highest point max The voltage V corresponding to the lowest point min .

[0103] The first judgment subunit is used to determine the time difference Δt1 between two adjacent inflection points and the slope l 斜 , the voltage effective value corresponding to the highest point V max The voltage V corresponding to the lowest point min Determine whether the first power swing condition is met; if the first power swing condition is met, it means that the voltage suddenly rises and a power swing occurs, and the motor is controlled to restart; if the first power swing condition is not met, execute the "second judgment unit".

[0104] As an optional implementation manner, the second determination unit of the present invention specifically includes:

[0105] The second slope calculation subunit is used to determine two adjacent inflection points and the slope l' between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point.

[0106] The second parameter determination subunit is used to determine the time difference Δt2 between two adjacent inflection points and the voltage effective value U corresponding to the highest point max The voltage effective value U corresponding to the lowest point min .

[0107] The second judgment subunit is used to determine the time difference Δt2 between two adjacent inflection points and the slope l' 斜 , the voltage effective value corresponding to the highest point is U max The voltage effective value U corresponding to the lowest pointmin Determine whether the second power swing condition is met; if the second power swing condition is met, it means that the voltage has dropped suddenly and a power swing has occurred, and the motor is controlled to restart; if the second power swing condition is not met, execute the "third judgment unit".

[0108] As an optional implementation manner, the third judgment unit of the present invention specifically includes:

[0109] The third judgment subunit is used to judge whether there is a waveform with a slope of zero within a certain period of time according to the voltage-time waveform diagram; if there is a waveform with a slope of zero, execute the "fourth judgment subunit"; if there is no waveform with a slope of zero, no processing is required.

[0110] The fourth judgment subunit is used to judge whether the third power shaking condition is met during this period of time; if the third power shaking condition is met, it means that there is a short power outage and a power shaking has occurred, and the motor is controlled to restart; if the third power shaking condition is not met, the "fourth judgment unit" is executed.

[0111] 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 motor starting control method, characterized in that: The method comprises: Collect the voltage information of the motor at each moment; Draw a voltage-time waveform diagram according to the voltage information of the motor at each moment; Determine whether the power shaking condition is met according to the voltage-time waveform; if the power shaking condition is met, control the motor to restart, specifically including: Step S31: judging whether the first power fluctuation condition is met according to the voltage-time waveform; if the first power fluctuation condition is met, it means that the voltage suddenly rises and power fluctuation occurs, and the motor is controlled to restart; if the first power fluctuation condition is not met, executing "step S32", which specifically includes: Step S311: Determine two adjacent inflection points and the slope l between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point; Step S312: Determine the time difference Δt1 between two adjacent inflection points and the voltage effective value V corresponding to the highest point max The voltage V corresponding to the lowest point min ; Step S313: Based on the time difference Δt1 between two adjacent inflection points and the slope l 斜 , the voltage effective value corresponding to the highest point V max The voltage V corresponding to the lowest point min Determine whether the first power shaking condition is met; if the first power shaking condition is met, it means that the voltage suddenly rises and power shaking occurs, and the motor is controlled to restart; if the first power shaking condition is not met, execute "step S32"; Step S32: judging whether the second power swing condition is met according to the voltage-time waveform; if the second power swing condition is met, it means that the voltage suddenly drops and power swing occurs, and the motor is controlled to restart; if the second power swing condition is not met, executing "step S33"; Step S33: judging whether the third power swing condition is met according to the voltage-time waveform; if the third power swing condition is met, it means that a short power outage has occurred and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, executing "step S34"; Step S34: judging whether the fourth power fluctuation condition is satisfied according to the voltage-time waveform; if the fourth power fluctuation condition is satisfied, it indicates that the voltage flickers and power fluctuation occurs, and the motor is controlled to restart.

2. A motor starting control method according to claim 1, characterized in that: The method further comprises: When power shaking occurs, the number of power shaking is recorded; Determine whether the number of power shakes within the set time is greater than or equal to the preset number; if the number of power shakes within the set time is less than the preset number, control the motor to restart; if the number of power shakes within the set time is greater than or equal to the preset number, control the motor to stop working.

3. A motor starting control method according to claim 1, characterized in that: The method further comprises: determining whether the second power swing condition is met according to the voltage-time waveform diagram; if the second power swing condition is met, it means that the voltage drops suddenly and a power swing occurs, and the motor is controlled to restart; if the second power swing condition is not met, executing "step S33", which specifically includes: Step S321: Determine two adjacent inflection points and the slope l' between the two inflection points according to the voltage-time waveform diagram 斜 ; Two adjacent inflection points include the highest point and the lowest point; Step S322: Determine the time difference Δt2 between two adjacent inflection points and the voltage effective value U corresponding to the highest point max The voltage effective value U corresponding to the lowest point min ; Step S323: Based on the time difference Δt2 between two adjacent inflection points and the slope l' 斜 , the voltage effective value corresponding to the highest point is U max The voltage effective value U corresponding to the lowest point min Determine whether the second power swing condition is met; if the second power swing condition is met, it means that the voltage has dropped suddenly and a power swing has occurred, and the motor is controlled to restart; if the second power swing condition is not met, execute "step S33".

4. A motor starting control method according to claim 1, characterized in that: The method further comprises: determining whether the third power swing condition is met according to the voltage-time waveform diagram; if the third power swing condition is met, it indicates that a short power outage has occurred and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, executing "step S34", which specifically includes: Step S331: judging whether there is a waveform with a slope of zero within a certain period of time according to the voltage-time waveform diagram; if there is a waveform with a slope of zero, executing "step S332"; if there is no waveform with a slope of zero, no processing is required; Step S332: Determine whether the third power swing condition is met during this period of time; if the third power swing condition is met, it means that there is a short power outage and a power swing has occurred, and the motor is controlled to restart; if the third power swing condition is not met, execute "step S34".

5. A motor starting control system, characterized in that: For executing the motor starting control method according to any one of claims 1 to 4, the system comprises: A collection module is used to collect the voltage information of the motor at each moment; A waveform drawing module is used to draw a voltage-time waveform according to the voltage information of the motor at each moment; The first judgment module is used to judge whether the power shaking condition is met according to the voltage-time waveform diagram; if the power shaking condition is met, the motor is controlled to restart.

6. A motor starting control system according to claim 5, characterized in that: The system further comprises: The power shaking times recording module is used to record the times of power shaking when power shaking occurs; The second judgment module is used to judge whether the number of power shakes within the set time is greater than or equal to the preset number; if the number of power shakes within the set time is less than the preset number, the motor is controlled to restart; if the number of power shakes within the set time is greater than or equal to the preset number, the motor is controlled to stop working.

7. A motor starting control system according to claim 5, characterized in that: The first judgment module specifically includes: The first judgment unit is used to judge whether the first power fluctuation condition is met according to the voltage-time waveform diagram; if the first power fluctuation condition is met, it means that the voltage suddenly rises and power fluctuation occurs, and the motor is controlled to restart; if the first power fluctuation condition is not met, the "second judgment unit" is executed; The second judgment unit is used to judge whether the second power shaking condition is met according to the voltage-time waveform diagram; if the second power shaking condition is met, it means that the voltage suddenly drops and power shaking occurs, and the motor is controlled to restart; if the second power shaking condition is not met, the "third judgment unit" is executed; The third judgment unit is used to judge whether the third power shaking condition is met according to the voltage-time waveform diagram; if the third power shaking condition is met, it means that a short power outage has occurred and a power shaking has occurred, and the motor is controlled to restart; if the third power shaking condition is not met, the "fourth judgment unit" is executed; The fourth judgment unit is used to judge whether a fourth power swing condition is met according to the voltage-time waveform diagram; if the fourth power swing condition is met, it means that the voltage flickers and a power swing occurs, and the motor is controlled to restart.

8. A motor starting control system according to claim 7, characterized in that: The first judgment unit specifically includes: The first slope calculation subunit is used to determine two adjacent inflection points and the slope l between the two inflection points according to the voltage-time waveform diagram. 斜 ; Two adjacent inflection points include the highest point and the lowest point; The first parameter determination subunit is used to determine the time difference Δt1 between two adjacent inflection points and the voltage effective value V corresponding to the highest point max The voltage V corresponding to the lowest point min ; The first judgment subunit is used to determine the time difference Δt1 between two adjacent inflection points and the slope l 斜 , the voltage effective value corresponding to the highest point V max The voltage V corresponding to the lowest point min Determine whether the first power shake condition is met; if the first power shake condition is met, it means that the voltage suddenly rises and a power shake occurs, and the motor is controlled to restart; if the first power shake condition is not met, execute the "second judgment unit".

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