CN113300636B - Star-angle conversion starting method and device for motor and compressor system - Google Patents
Star-angle conversion starting method and device for motor and compressor system Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P1/00—Arrangements for starting electric motors or dynamo-electric converters
- H02P1/16—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters
- H02P1/26—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual polyphase induction motor
- H02P1/32—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual polyphase induction motor by star/delta switching
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P1/00—Arrangements for starting electric motors or dynamo-electric converters
- H02P1/02—Details of starting control
- H02P1/022—Security devices, e.g. correct phase sequencing
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Abstract
The invention relates to the technical field of motor control, in particular to a star-delta conversion starting method and device for a motor and a compressor system, and aims to solve the problem of how to safely and reliably finish starting of the motor. The invention detects the phase current of the motor in real time when the motor starts star-shaped running, calculates the deviation between the phase current and rated current, judges whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and decides whether to perform planetary angle conversion on the motor winding according to the judging result so as to finish the motor starting. If the ratio is larger than or equal to a preset first percentage, the current phase current and the rated current are larger in phase difference, and the motor is not started and completed yet, so that planetary angle conversion is not performed; when the ratio is smaller than the preset first percentage, whether planetary angle conversion is performed or not is further judged according to the change amount of the phase current in a certain period of time, and starting of the motor is completed, so that misjudgment caused by normal fluctuation of the phase current can be effectively avoided.
Description
Technical Field
The invention relates to the technical field of motor control, in particular to a star-delta conversion starting method and device for a motor and a compressor system.
Background
In the starting process of the motor, a large starting moment is required from static to rated rotation speed, and correspondingly generated starting current is also large, so that in order to reduce the impact of the starting current on the motor, a star-delta conversion starting method is generally adopted to start the motor. Specifically, when the motor starts to start, the three-phase winding of the motor is switched into star connection, 380V voltage applied to the motor can be converted into 220V voltage through star starting, and under the condition that the impedance of the motor is unchanged, the starting current is greatly reduced due to the fact that the voltage is obviously reduced, and larger current impact on the motor is avoided. When the rotating speed of the motor under star-type starting reaches the rated rotating speed, the three-phase winding of the motor is switched into angle connection, so that 220V voltage applied to the motor is converted into 380V voltage, and the motor starting is completed. In the process, the running time of the motor under star-shaped starting (the time for the motor to reach the rated rotating speed from rest) is set before the motor leaves the factory, and cannot be adjusted according to the actual running condition of the motor, so that the situation that the motor is switched to angle-shaped running after the motor does not reach the rated rotating speed (the starting is not completed) due to the fact that the load is large and the like possibly exists, the voltage applied to the motor after the motor is switched to the angle-shaped running is converted from 220V to 380V, the generated impact current far exceeds the bearable range of the contactor, the service life of the contactor is shortened, and the motor is damaged.
Accordingly, there is a need in the art for a new motor star-delta switching start scheme to address the above-described problems.
Disclosure of Invention
The present invention has been made to overcome the above-mentioned drawbacks, and an object of the present invention is to provide a motor star-delta starting method, apparatus and compressor system that solve or at least partially solve the problem of how to safely and reliably complete motor starting.
In a first aspect, a star-delta conversion starting method for a motor is provided, which includes:
switching the motor winding into star connection according to the received starting instruction, and then controlling the motor to start to run;
detecting phase current in the running process of the motor in real time and calculating deviation of the phase current and rated current;
And judging whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and determining whether to perform planetary angle conversion on the motor winding according to a judging result so as to finish motor starting.
In one embodiment of the foregoing method, the step of determining whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and determining whether to perform the planetary angle conversion on the motor winding according to the determination result specifically includes:
and if the ratio of the deviation to the rated current is greater than or equal to the preset first percentage, continuously maintaining the motor winding to be in star connection without planetary angle conversion.
In one embodiment of the foregoing method, the step of determining whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and determining whether to perform the planetary angle conversion on the motor winding according to the determination result specifically includes:
If the ratio of the deviation to the rated current is smaller than the preset first percentage, performing planetary angle conversion on the motor winding, and switching the motor winding into angle connection to finish motor starting; or alternatively
If the ratio of the deviation to the rated current is smaller than the preset first percentage, acquiring the phase current detected within a certain period of time after the detection time of the phase current corresponding to the ratio, and judging whether the variation delta It of each phase current within the certain period of time is smaller than the preset second percentage; if yes, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed; if not, continuing to maintain the motor winding to be in star connection without planetary angle conversion;
Wherein, The I t and I t-1 are phase currents detected at times t and t-1, respectively, within the certain period of time.
In one embodiment of the above method, the first predetermined percentage is ± 10% and the second predetermined percentage is ± 5%.
In a second aspect, there is provided a motor star-delta conversion starting device, the device comprising:
The motor operation control module is configured to switch the motor winding into star connection according to the received starting instruction and then control the motor to start operation;
a current detection processing module configured to detect a phase current during operation of the motor in real time and calculate a deviation of the phase current from a rated current;
And the star-delta conversion judging module is configured to judge whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and determine whether to perform star-delta conversion on the motor winding according to a judging result so as to finish motor starting.
In one embodiment of the above apparatus, the star-delta conversion determination module is configured to continue to maintain the motor winding in a star connection without performing a star-delta conversion after determining that the ratio of the deviation to the rated current is greater than or equal to the preset first percentage.
In one embodiment of the above apparatus, the star-delta conversion determining module is configured to perform a star-delta conversion on the motor winding after determining that the ratio of the deviation to the rated current is less than the preset first percentage, and switch the motor winding to an angular connection to complete motor starting; or alternatively
The star-to-angle conversion determination module is configured to, after determining that the ratio of the deviation to the rated current is less than the preset first percentage, perform the following operations:
If the ratio of the deviation to the rated current is smaller than the preset first percentage, acquiring the phase current detected within a certain period of time after the detection time of the phase current corresponding to the ratio, and judging whether the variation delta I t of each phase current within the certain period of time is smaller than the preset second percentage; if yes, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed; if not, continuing to maintain the motor winding to be in star connection without planetary angle conversion;
Wherein, The I t and I t-1 are phase currents detected at times t and t-1, respectively, within the certain period of time.
In a third aspect, a compressor system is provided, where the system includes a compressor, a current detection device, and a motor star-delta conversion starting device according to the foregoing embodiment;
the current detection device is configured to detect a phase current of a motor in the compressor and output the detected phase current to the motor star-delta conversion starting device;
the motor star-delta conversion starting device is configured to start the compressor according to the received compressor starting instruction and the phase current output by the current detection device.
In a fourth aspect, a storage device is provided, where a plurality of program codes are stored, and the program codes are adapted to be loaded and executed by a processor to perform the motor star-delta conversion starting method according to the above embodiment.
In a fifth aspect, a control device is provided, the control device comprising a processor and a storage device, the storage device being adapted to store a plurality of program codes, the program codes being adapted to be loaded and executed by the processor to perform the motor star-delta conversion starting method according to the above embodiment.
The technical scheme provided by the invention has at least one or more of the following beneficial effects:
In the technical scheme of implementing the invention, when the motor starts star-shaped operation (the motor winding is in star connection), the phase current of the motor is detected in real time, the deviation between the phase current and the rated current is calculated, whether the ratio of the deviation to the rated current is smaller than a preset first percentage is judged, and whether the motor winding is subjected to planetary angle conversion is determined according to the judgment result so as to finish the motor starting. If the ratio is greater than or equal to a preset first percentage, the current phase current and the rated current are larger in phase difference, and the motor is not started and completed yet, so that the motor winding needs to be continuously maintained to be in star connection, and the planetary angle conversion is not performed. If the value is smaller than the preset first percentage, the current phase current is indicated to be close to the rated current, the motor phase current is more and more close to the rated current and tends to be stable along with the further operation of the motor, the motor rotating speed is also indicated to be more and more close to the rated rotating speed, and the motor can be subjected to planetary angle conversion, so that the motor is started.
Further, when the ratio is smaller than the preset first percentage, whether planetary angle conversion is performed or not can be judged according to the change amount of the phase current in a certain time period, and the motor is started, so that misjudgment caused by normal fluctuation of the phase current can be effectively avoided. Specifically, the phase current detected in a certain time period after the detection time of the phase current corresponding to the ratio is obtained, and whether the variation delta It of each phase current in the certain time period is smaller than a preset second percentage is judged; if yes, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed; if not, the motor winding is continuously maintained to be in star connection, and the planetary angle conversion is not performed.
Drawings
Embodiments of the invention are described below with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of main steps of a star-delta switching start method for a motor according to an embodiment of the present invention;
fig. 2 is a schematic diagram of the main structure of a motor star-delta conversion starting device according to an embodiment of the present invention;
FIG. 3 is a schematic illustration of an application scenario of the present invention;
List of reference numerals:
11: a motor operation control module; 12: a current detection processing module; 13: and the star-delta conversion judging module.
Detailed Description
Some embodiments of the invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention.
In the description of the present invention, a "module," "processor" may include hardware, software, or a combination of both. A module may comprise hardware circuitry, various suitable sensors, communication ports, memory, or software components, such as program code, or a combination of software and hardware. The processor may be a central processor, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. The processor has data and/or signal processing functions. The processor may be implemented in software, hardware, or a combination of both. Non-transitory computer readable storage media include any suitable medium that can store program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, and the like. The term "a and/or B" means all possible combinations of a and B, such as a alone, B alone or a and B. The term "at least one A or B" or "at least one of A and B" has a meaning similar to "A and/or B" and may include A alone, B alone or A and B. The singular forms "a", "an" and "the" include plural referents.
In the star-angle conversion starting process of the motor in the prior art, the running time of the motor under star-shaped starting is set before the motor leaves the factory, and cannot be adjusted according to the actual running condition of the motor, so that the situation that the motor is switched to angle-shaped running when the rated rotating speed is not reached yet (the motor is not started completely) due to the fact that the load is large and the like possibly exists, the voltage applied to the motor after the motor is switched to angle-shaped running is converted from 220V to 380V, the generated impact current is far more than the bearable range of a star contactor (a motor winding is switched to a star-shaped connected contactor, such as a star contactor KM3 in fig. 3), the service life of the contactor is reduced, the motor is damaged, and safe and reliable motor starting cannot be realized.
In the embodiment of the invention, when the motor starts star-shaped operation (the motor winding is in star-shaped connection), the phase current of the motor can be detected in real time, the deviation between the phase current and the rated current is calculated, whether the ratio of the deviation to the rated current is smaller than the preset first percentage is judged, and whether the motor winding is subjected to planetary angle conversion is determined according to the judgment result so as to finish the motor starting. If the ratio is greater than or equal to a preset first percentage, the current phase current and the rated current are larger in phase difference, and the motor is not started and completed yet, so that the motor winding needs to be continuously maintained to be in star connection, and the planetary angle conversion is not performed. If the ratio is less than a preset first percentage, the current phase current is indicated to be close to the rated current, the motor phase current is more and more close to the rated current and tends to be stable along with the further operation of the motor, the motor rotating speed is also indicated to be more and more close to the rated rotating speed, and the motor can be subjected to planetary angle conversion, so that the motor is started.
Further, since the phase current may fluctuate normally during actual operation, if it is determined whether to perform the planetary angle conversion or not only according to the comparison result of the ratio and the preset first percentage, erroneous judgment may be caused. Therefore, when the ratio is smaller than the preset first percentage, the embodiment of the invention can also judge whether the planetary angle conversion is performed according to the variation (fluctuation condition) of the phase current in a certain time period, and finish the motor start, thereby effectively avoiding misjudgment caused by normal fluctuation of the phase current.
Referring to fig. 3, fig. 3 is a schematic view of an application scenario of the present invention. As shown in fig. 3, the water-cooled screw water chilling unit mainly comprises a screw compressor, a high-current and high-power motor is arranged in the screw compressor, and a large starting moment is required when the screw compressor is started, so as to reduce the impact of starting current on the motor in the starting process; and then detecting W-phase current in the running process of the compressor in real time through a current detection device, judging the running state of the compressor according to the deviation between the W-phase current and rated current, and if the W-phase current is close to the rated current, controlling the star contactor KM3 to be opened and the angular contactor KM2 to be closed, switching a motor winding into angular connection, and completing the starting of the compressor. Wherein the power contactor QF is used to turn on or off a power supply line between the power supply and the compressor.
Referring to fig. 1, fig. 1 is a diagram of a motor star-delta conversion starting method according to an embodiment of the present invention. As shown in fig. 1, the method for starting star-delta conversion of a motor according to the embodiment of the invention may include the following steps:
step S101: and switching the motor winding into star connection according to the received starting instruction, and then controlling the motor to start running.
The star connection refers to a connection mode that the tail ends of three-phase windings of a three-phase motor are connected together to form a common point, and then an end wire is led out from the head ends of the three-phase windings respectively. The start command refers to a command for controlling the motor to start running after the motor is powered on.
The angle connection refers to a connection mode that the tail end of each phase winding of the three-phase motor is connected with the head end of a subsequent phase winding.
Step S102: and detecting phase current in the running process of the motor in real time and calculating deviation of the phase current and rated current.
The rated current refers to the current when the motor operates at rated voltage according to rated power, and if the phase current reaches the rated current, the output power of the motor reaches the rated power, that is, the motor is started completely, the load can be normally driven. In addition, since the current fluctuates during the operation of the motor, the deviation of the phase current from the rated current may be positive or negative. The deviation of the phase current from the rated current can be expressed as Δi=i p-Ir,Ip being the phase current of the p-phase, I r being the rated current.
Step S103: and judging whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and determining whether the motor winding is subjected to planetary angle conversion according to a judging result so as to finish motor starting. The ratio of the deviation to the rated current can be expressed as
The smaller the preset first percentage, the better, if the preset first percentage is a smaller value, when the ratio k is smaller than the preset first percentage, the phase current I p is indicated to be close to the rated current I r, and the output power of the motor is also indicated to be close to the rated power. Therefore, the motor winding can be switched into angular connection according to planetary angle conversion of the motor winding, and motor starting is completed. When the ratio k is greater than or equal to a preset first percentage, it indicates that the phase current I p is not close to the rated current I r, and the motor has not completed starting, so that the planetary angle conversion cannot be performed. One example is: the preset first percentage is 10%.
Since the phase current will normally fluctuate during actual operation, if it is determined whether to perform the planetary angle conversion or not only according to the comparison result of the ratio and the preset first percentage, erroneous judgment may be caused. Thus, in one embodiment, when the deviation k is less than the preset first percentage, it may be further determined whether to perform the planetary angle conversion by:
Step 31: the phase current detected within a certain period of time, e.g., 5s, after the detection timing of the phase current I p corresponding to the ratio k is acquired.
Step 32: judging whether the variation delta I t of each phase current in the certain time period is smaller than a preset second percentage or not; if the variation Δi t is smaller than the preset second percentage, go to step 33; if the variation Δi t is greater than or equal to the preset second percentage, go to step 34.
Wherein,I t and I t-1 are the phase currents detected at times t and t-1, respectively, over the period of time.
The smaller the value of the preset second percentage, the better, if the preset second percentage is a smaller value, when the variation Δi t is smaller than the preset second percentage, the smaller the fluctuation range of the phase current I p is, and the stability is already achieved. When the variation Δi t is equal to or larger than the preset second percentage, it is indicated that the fluctuation range of the phase current I p is relatively large, and has not yet tended to stabilize, and the "deviation k is smaller than the preset first percentage" may be due to the large fluctuation of the phase current I p. One example is: the second predetermined percentage is 5%.
Step 33: and (3) performing planetary angle conversion on the motor winding, and switching the motor winding into angle connection to finish motor starting.
Step 34: and continuously maintaining the motor winding to be in star connection without planetary angle conversion.
When the ratio k is smaller than the preset first percentage, the embodiment of the invention can judge whether the planetary angle conversion is performed according to the change quantity delta I t of the phase current within a certain period of time, so that the motor is started, and erroneous judgment caused by normal fluctuation of the phase current can be effectively avoided.
It should be noted that, although the foregoing embodiments describe the steps in a specific order, it will be understood by those skilled in the art that, in order to achieve the effects of the present invention, the steps are not necessarily performed in such an order, and may be performed simultaneously (in parallel) or in other orders, and these variations are within the scope of the present invention.
Referring to fig. 2, fig. 2 is a schematic diagram of a main structure of a star-delta switching starting device of a motor according to an embodiment of the present invention. As shown in fig. 2, the star-delta conversion starting device for a motor in the embodiment of the invention mainly comprises a motor operation control module 11, a current detection processing module 12 and a star-delta conversion judging module 13. For simplicity, although the processor and memory are not shown in FIG. 2, those skilled in the art will appreciate that the motor star point switch actuation device may be part of the processor and/or memory. For example, in some embodiments, one or more of the motor operation control module 11, the current detection processing module 12, and the star-to-angle conversion determination module 13 may be part of a processor. In some embodiments, these modules may correspond to a portion of the electronic circuitry in the processor that performs the signal or data processing, respectively, or to associated program code stored on a computer readable medium (e.g., memory). In some embodiments, one or more of the motor operation control module 11, the current detection processing module 12, and the star-delta conversion determination module 13 may be combined together into one module. In some embodiments, the motor operation control module 11 may be configured to switch the motor winding to a star connection according to the received start command, and then control the motor to start operation; the current detection processing module 12 may be configured to detect phase currents during operation of the motor in real time and calculate deviations of the phase currents from the rated current; the star-delta conversion determining module 13 may be configured to determine whether the ratio of the deviation to the rated current is smaller than a preset first percentage, and determine whether to perform the star-delta conversion on the motor winding according to the determination result, so as to complete the motor start. In one embodiment, the description of the specific implementation functions may be described with reference to step S101-step S103.
In one embodiment, the star-delta determination module 13 may be configured to continue to maintain the motor winding in a star connection without performing a star-delta transition after determining that the ratio of the deviation to the rated current is greater than or equal to a preset first percentage. After the ratio of the deviation to the rated current is smaller than the preset first percentage, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed. In one embodiment, the description of the specific implementation function may be described with reference to step S103.
In one embodiment, the star-to-angle conversion determination module 13 may be configured to, after determining that the ratio of the deviation to the rated current is less than a preset first percentage, perform the following operations:
If the ratio of the deviation to the rated current is smaller than a preset first percentage, acquiring the phase current detected within a certain period of time after the detection time of the phase current corresponding to the ratio, and judging whether the variation delta I t of each phase current within the certain period of time is smaller than a preset second percentage; if yes, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed; if not, the motor winding is continuously maintained to be in star connection, and the planetary angle conversion is not performed. In one embodiment, the specific implementation functions may be described with reference to steps 31-34.
The foregoing motor star-delta conversion starting device is used for executing the embodiment of the motor star-delta conversion starting method shown in fig. 1, and the technical principles of the two are similar to each other, the technical problems to be solved and the technical effects to be produced are similar, and those skilled in the art can clearly understand that, for convenience and brevity of description, the specific working process and related description of the motor star-delta conversion starting device can refer to the description of the embodiment of the motor star-delta conversion starting method, and the description is omitted herein.
Further, in one embodiment of the compressor system of the present invention, the compressor system may include a compressor, a current detection device, and a motor star point switch starting device as described in the above embodiments of the motor star point switch starting device. The current detecting means may be configured to detect a phase current of the motor in the compressor and output the detected phase current to the motor star-delta starting means, and the motor star-delta starting means may be configured to start the compressor according to the received compressor starting instruction and the phase current output from the current detecting means.
Further, in one storage device embodiment of the present invention, the storage device may store a plurality of program codes adapted to be loaded and executed by a processor to perform the motor star point transition start method described in the above embodiment of the motor star point transition start method.
Further, in one control device embodiment of the present invention, the control device may comprise a processor and a memory device, the memory device being adapted to store a plurality of program codes adapted to be loaded by the processor and to run the motor star point transition starting method described in the above embodiments of the motor star point transition starting method.
It will be appreciated by those skilled in the art that the present invention may implement all or part of the above-described methods according to the above-described embodiments, or may be implemented by means of a computer program for instructing relevant hardware, where the computer program may be stored in a computer readable storage medium, and where the computer program may implement the steps of the above-described embodiments of the method when executed by a processor. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include: any entity or device, medium, usb disk, removable hard disk, magnetic disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier wave signals, telecommunications signals, software distribution media, and the like capable of carrying the computer program code. It should be noted that the computer readable medium contains content that can be appropriately scaled according to the requirements of jurisdictions in which such content is subject to legislation and patent practice, such as in certain jurisdictions in which such content is subject to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.
Further, it should be understood that, since the respective modules are merely set for illustrating the functional units of the system of the present invention, the physical devices corresponding to the modules may be the processor itself, or a part of software in the processor, a part of hardware, or a part of a combination of software and hardware. Accordingly, the number of individual modules in the figures is merely illustrative.
Those skilled in the art will appreciate that the various modules in the system may be adaptively split or combined. Such splitting or combining of specific modules does not cause the technical solution to deviate from the principle of the present invention, and therefore, the technical solution after splitting or combining falls within the protection scope of the present invention.
According to the embodiment of the invention, when the motor starts star-shaped operation (the motor winding is in star-shaped connection), the phase current of the motor can be detected in real time, the deviation between the phase current and the rated current is calculated, whether the ratio of the deviation to the rated current is smaller than the preset first percentage is judged, and whether the motor winding is subjected to planetary angle conversion is determined according to the judgment result so as to finish motor starting. If the ratio is greater than or equal to a preset first percentage, the current phase current and the rated current are larger in phase difference, and the motor is not started and completed yet, so that the motor winding needs to be continuously maintained to be in star connection, and the planetary angle conversion is not performed. If the ratio is less than a preset first percentage, the current phase current is indicated to be close to the rated current, the motor phase current is more and more close to the rated current and tends to be stable along with the further operation of the motor, the motor rotating speed is also indicated to be more and more close to the rated rotating speed, and the motor can be subjected to planetary angle conversion, so that the motor is started. Further, when the ratio is smaller than the preset first percentage, the embodiment of the invention can judge whether the planetary angle conversion is performed according to the variation (fluctuation condition) of the phase current in a certain time period, and finish the motor start, so that misjudgment caused by normal fluctuation of the phase current can be effectively avoided.
Thus far, the technical solution of the present invention has been described in connection with one embodiment shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will fall within the scope of the present invention.
Claims (6)
1. A method for starting star-delta conversion of a motor, the method comprising:
switching the motor winding into star connection according to the received starting instruction, and then controlling the motor to start to run;
detecting phase current in the running process of the motor in real time and calculating deviation of the phase current and rated current;
judging whether the ratio of the deviation to the rated current is smaller than a preset first percentage, determining whether the output power of the motor is close to the rated power according to a judging result, and determining whether planetary angle conversion is performed on a motor winding so as to finish motor starting;
If the ratio of the deviation to the rated current is greater than or equal to the preset first percentage, continuously maintaining the motor winding to be in star connection without planetary angle conversion;
If the ratio of the deviation to the rated current is smaller than the preset first percentage, acquiring the phase current detected within a certain period of time after the detection time of the phase current corresponding to the ratio, and judging whether the variation delta I t of each phase current within the certain period of time is smaller than the preset second percentage; if yes, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed; if not, continuing to maintain the motor winding to be in star connection without planetary angle conversion; wherein, The I t and I t-1 are phase currents detected at times t and t-1, respectively, within the certain period of time.
2. The motor star-to-angle conversion starting method according to claim 1, wherein the preset first percentage is ±10%, and the preset second percentage is ±5%.
3. A motor star-delta conversion starting device, the device comprising:
The motor operation control module is configured to switch the motor winding into star connection according to the received starting instruction and then control the motor to start operation;
a current detection processing module configured to detect a phase current during operation of the motor in real time and calculate a deviation of the phase current from a rated current;
The star-delta conversion judging module is configured to judge whether the ratio of the deviation to the rated current is smaller than a preset first percentage, determine whether the output power of the motor is close to the rated power according to a judging result, and determine whether to perform star-delta conversion on the motor winding so as to finish motor starting;
the star-delta conversion judging module is configured to continuously maintain the motor winding to be in star connection without planetary-delta conversion after judging that the ratio of the deviation to the rated current is greater than or equal to the preset first percentage;
The star-to-angle conversion determination module is configured to, after determining that the ratio of the deviation to the rated current is less than the preset first percentage, perform the following operations:
If the ratio of the deviation to the rated current is smaller than the preset first percentage, acquiring the phase current detected within a certain period of time after the detection time of the phase current corresponding to the ratio, and judging whether the variation delta I t of each phase current within the certain period of time is smaller than the preset second percentage; if yes, planetary angle conversion is carried out on the motor winding, the motor winding is switched into angle connection, and motor starting is completed; if not, continuing to maintain the motor winding to be in star connection without planetary angle conversion; wherein, The I t and I t-1 are phase currents detected at times t and t-1, respectively, within the certain period of time.
4. A compressor system comprising a compressor, a current detection device, and the motor star-delta conversion starting device of claim 3;
the current detection device is configured to detect a phase current of a motor in the compressor and output the detected phase current to the motor star-delta conversion starting device;
the motor star-delta conversion starting device is configured to start the compressor according to the received compressor starting instruction and the phase current output by the current detection device.
5. A storage device having stored therein a plurality of program codes, wherein the program codes are adapted to be loaded and executed by a processor to perform the motor star-delta conversion starting method of any one of claims 1 to 2.
6. A control device comprising a processor and a storage device, the storage device being adapted to store a plurality of program codes, characterized in that the program codes are adapted to be loaded and executed by the processor to perform the motor star-to-angle conversion starting method of any one of claims 1 to 2.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87212289U (en) * | 1987-08-27 | 1988-07-20 | 张惠芬 | Multifunctional power-saving controller for electrical machinery |
| JP2008144602A (en) * | 2006-12-06 | 2008-06-26 | Hitachi Industrial Equipment Systems Co Ltd | Starting device of screw compressor |
| CN101304225A (en) * | 2008-06-04 | 2008-11-12 | 沈阳天成自动化工程有限公司 | Motor energy-saving converting controller and control method |
| CN105262376A (en) * | 2015-10-20 | 2016-01-20 | 珠海格力电器股份有限公司 | Star-delta starting circuit used for three-phase motor, and starting method thereof |
| CN210075114U (en) * | 2019-08-01 | 2020-02-14 | 大连神通电气有限公司 | Motor starter |
-
2020
- 2020-02-24 CN CN202010113760.9A patent/CN113300636B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87212289U (en) * | 1987-08-27 | 1988-07-20 | 张惠芬 | Multifunctional power-saving controller for electrical machinery |
| JP2008144602A (en) * | 2006-12-06 | 2008-06-26 | Hitachi Industrial Equipment Systems Co Ltd | Starting device of screw compressor |
| CN101304225A (en) * | 2008-06-04 | 2008-11-12 | 沈阳天成自动化工程有限公司 | Motor energy-saving converting controller and control method |
| CN105262376A (en) * | 2015-10-20 | 2016-01-20 | 珠海格力电器股份有限公司 | Star-delta starting circuit used for three-phase motor, and starting method thereof |
| CN210075114U (en) * | 2019-08-01 | 2020-02-14 | 大连神通电气有限公司 | Motor starter |
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| CN113300636A (en) | 2021-08-24 |
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