CN117767832A - Control method, frequency converter, motor device, and computer-readable storage medium - Google Patents
Control method, frequency converter, motor device, and computer-readable storage medium Download PDFInfo
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Abstract
The invention discloses a control method, a frequency converter, a motor device and a computer readable storage medium. The control method comprises the following steps: determining a given direct-axis current of the motor according to the reactive current of the motor and the given reactive current; the direct-axis current of the motor is adjusted to be given direct-axis current so as to adjust the power factor of the motor. According to the control method, when the motor runs, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor is regulated to the given direct-axis current, so that the effect of regulating the power factor can be achieved, and the dynamic performance and the steady-state performance of the motor are ensured.
Description
Technical Field
The present invention relates to the field of motor control technologies, and in particular, to a control method, a frequency converter, a motor device, and a computer readable storage medium.
Background
Along with the concept of energy saving and consumption reduction, the frequency converter of the permanent magnet synchronous motor is widely applied to various fields. In various application scenarios, performance requirements on the frequency converter of the permanent magnet synchronous motor are higher and higher, wherein the performance requirements comprise controlling the power factor of the motor.
Disclosure of Invention
The present invention provides a control method, a frequency converter, a motor device, and a computer-readable storage medium to solve at least one technical problem as described above.
The control method for the motor comprises the following steps:
determining a given direct-axis current of the motor according to the reactive current of the motor and the given reactive current;
and adjusting the direct-axis current of the motor to be the given direct-axis current so as to adjust the power factor of the motor.
According to the control method, when the motor runs, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor is regulated to the given direct-axis current, so that the effect of regulating the power factor can be achieved, and the dynamic performance and the steady-state performance of the motor are ensured.
In an alternative embodiment of the invention, the given reactive current is determined based on reactive current feed-forward and reactive current compensation of the motor. In this way, a given reactive current can be determined conveniently.
In an alternative solution of the present invention, the control method includes:
the reactive current feed forward is determined based on a given power factor and phase current of the motor. Thus, the current reactive current of the motor can be conveniently determined.
In an alternative solution of the present invention, the control method includes:
and adjusting the reactive current compensation according to the change condition of the reactive current of the motor. In this way, the reactive current compensation corresponding to the present reactive current can be determined in real time.
In an optional aspect of the invention, the step of adjusting the reactive current compensation according to a change condition of the reactive current of the motor includes:
when the reactive current is smaller than a first preset value, the reactive current compensation is increased;
and when the reactive current is larger than the first preset value, adjusting the reactive current compensation according to the current power factor and the given power factor of the motor. Thus, the stable operation of the motor can be ensured.
In an alternative aspect of the present invention, the step of adjusting the reactive current compensation according to the present power factor and the given power factor of the motor includes:
increasing the reactive current compensation by a first step value if the present power factor is greater than a first given power factor;
the reactive current compensation is reduced by a second step value if the present power factor is less than a second given power factor, the first given power factor being greater than or equal to the second given power factor. In this way, large fluctuations in the reactive power of the motor can be avoided.
In an alternative solution of the present invention, the control method includes:
determining the direct current according to the three-phase current of the motor and an estimated electrical angle, wherein the estimated electrical angle is obtained by estimating a rotor of the motor; and/or
And determining the straight shaft current according to the three-phase current and the mechanical angle of the motor, wherein the mechanical angle is obtained by encoding and collecting the rotor of the motor. In this way, the electrical angle of the rotor can be determined conveniently.
In an alternative solution of the present invention, the control method includes:
filtering electric parameters obtained according to the three-phase current and the three-phase voltage of the motor, wherein the electric parameters comprise at least one of active power, reactive power, apparent power, power factor, active current and reactive current. In this way, calculation errors caused by external disturbances can be reduced.
The frequency converter is used for a motor and comprises a control module and an adjusting module, wherein the control module is used for determining a given direct-axis current of the motor according to reactive current and a given reactive current of the motor;
the regulation module is used for regulating the direct-axis current of the motor to the given direct-axis current so as to regulate the power factor of the motor.
According to the frequency converter, when the motor runs, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor is regulated to the given direct-axis current, so that the effect of regulating the power factor can be achieved, and the dynamic performance and the steady-state performance of the motor are ensured.
The frequency converter comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the steps of the control method according to any optional technical scheme when executing the computer program.
The motor device comprises a motor and the frequency converter according to any optional technical scheme.
According to the motor device, when the motor operates, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor is regulated to the given direct-axis current, so that the effect of regulating the power factor can be achieved, and the dynamic performance and the steady-state performance of the motor are ensured.
A computer-readable storage medium of the present invention has stored thereon a computer program which, when executed by a processor, implements the steps of the control method of any of the above-mentioned alternative embodiments.
The computer readable storage medium determines the given direct-axis current through the reactive current and the given reactive current when the motor operates, and adjusts the direct-axis current of the motor to the given direct-axis current, so that the effect of adjusting the power factor can be achieved, and the dynamic performance and the steady-state performance of the motor are ensured.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a vector control block diagram of an electric machine according to an embodiment of the present invention;
FIG. 2 is another vector control block diagram of a motor according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a coordinate transformation of an embodiment of the present invention;
FIG. 4 is a control block diagram of an embodiment of the present invention for determining a given direct current;
FIG. 5 is a flow chart of a control method according to an embodiment of the present invention;
FIG. 6 is a block diagram of a frequency converter and motor according to an embodiment of the invention;
fig. 7 is another block diagram of a frequency converter and motor according to an embodiment of the invention.
Description of main reference numerals:
a frequency converter 100, a motor 200, and a motor device 300;
control module 110, regulation module 120, memory 130, processor 140.
Detailed Description
In the description of the present invention, portions of the disclosure have been represented by corresponding drawings, wherein like or similar reference numerals indicate like or similar elements or elements having like or similar functions throughout. The following description is exemplary in nature and is in no way intended to limit the invention, its application, or the like.
In the description of the present invention, many different matters or examples are disclosed for realizing the different structures of the present invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
Along with the concept of energy saving and consumption reduction, the frequency converter of the permanent magnet synchronous motor is widely applied to various fields. In various application scenarios, performance requirements on the frequency converter of the permanent magnet synchronous motor are higher and higher, wherein the performance requirements comprise controlling the power factor of the motor.
In order to realize the effect of controlling the power factor of the motor, the invention can combine the directional vector control of the rotor magnetic field of the motor, determine the given direct-axis current through the reactive current and the given reactive current of the motor, and adjust the direct-axis current of the motor to the given direct-axis current when the motor is subjected to the vector control, thereby correspondingly adjusting the reactive current. Where a "given" may be that it is desired to achieve a particular value or to remain within a corresponding range, in some cases the particular value or end of the corresponding range may be the nominal value.
Referring to fig. 1 and 2, in fig. 1 and 2, a motor 200 may be connected to a frequency converter 100, and the frequency converter 100 may detect a current and a voltage of the motor 200 and may adjust the current and the voltage of the motor 200, thereby playing a role in frequency conversion of the motor 200.
The pulse width modulation may be SVPWM (Space Vector Pulse Width Modulation ). The motor 200 may be a Permanent magnet synchronous motor 200 (PMSM, permanent-Magnet Synchronous Motor).
In some cases, the present invention may achieve the effect of power factor control of the motor 200 through the following steps:
first, when the motor 200 is running, three-phase current values i of the motor 200 are acquired a 、i b 、i c And a three-phase voltage value u a 、u b 、u c 。
The three-phase current value of the motor 200 may be a current value of each phase in the stator winding of the motor 200, and the three-phase voltage value of the motor 200 may be a voltage value of each phase in the stator winding of the motor 200. The three-phase current value and the three-phase voltage value of the motor 200 may be collected in real time or may be collected at corresponding periodic intervals.
In a second step, electrical parameters of the motor 200 are determined.
After determining the three-phase current values and the three-phase voltage values of the motor 200, the electrical parameters of the motor 200 may be calculated accordingly. The electrical parameters of motor 200 may include the active Power P, the reactive Power Q, the apparent Power S, the Power Factor Power_factor, the active current i of motor 200 P And reactive current i Q 。
Specifically, the electrical parameters of the motor 200 may be obtained by the following formula:
active power p=u a i a +u b i b +u c i c ；
Reactive power
Apparent power
Power Factor power_factor=p/S;
active current
Reactive current
Wherein,mod_u may be the voltage modulus of motor 200.
Additionally, the electrical parameter may include a current effective value I_RMS of the stator of the motor 200. I_RMS can be calculated by the formulaObtained.
In addition, when the electrical parameter of the motor 200 is obtained, the electrical parameter may be subjected to a filter process, such as a low-pass filter process. Specifically, the active Power P after the filtering process may be represented as lpf_p, the reactive Power Q after the filtering process may be represented as lpf_q, the apparent Power S after the filtering process may be represented as lpf_s, the Power Factor power_factor after the filtering process may be represented as lpf_power_factor, and the active current i after the filtering process P Can be expressed as LPF_i P Reactive current i after filtering S Can be expressed as LPF_i S 。
Third, the direct axis current is determined according to the three-phase current value of the motor 200 and the electrical angle of the rotor.
Referring to fig. 1 and 2, after the three-phase current value of the motor 200 is obtained, a correspondence relationship between the three-phase current value of the motor 200 and the ac/dc current using the electrical angle of the rotor as a parameter may be obtained by means of rotation coordinate transformation, and the dc/dc current may be determined according to the correspondence relationship.
Specifically, the above correspondence may be determined by the following formula:
wherein the method comprises the steps of，i α 、i β Respectively representing stationary two-phase currents after clark conversion of three-phase currents of the motor 200,andrespectively represent rotating two-phase current after park conversion of stationary two-phase current, +.>Representing the estimated electrical angle of the rotor (or an estimate of the electrical angle of the rotor). In the above formula, the algebraic notation with the "≡sign indicates that this algebra is an estimate, i.e. the resulting direct current is actually an estimate.
Referring to fig. 3, in fig. 3, S and N represent different poles of the rotor magnetic field, respectively. The α -axis and the β -axis are coordinate axes of stationary coordinates of two-phase currents obtained by clark conversion of stationary coordinates of three-phase currents of the motor 200, respectively. The d-axis and the q-axis are coordinate axes of rotation coordinates of the two-phase current obtained by park-transforming the α -axis and the β -axis, respectively. The direction of the d axis corresponding to the central line of the rotor magnetic pole is the straight axis direction. The direction of the axis between the q-axis corresponding rotor poles is the intersecting axis direction.
In fig. 3, θ represents the actual electrical angle of the rotor, θ err Representing the angular error between the estimated electrical angle and the actual electrical angle of the rotor. In the speed vector-less control, since a speed sensor is not provided to detect the rotational speed and the position of the rotor, it is necessary to estimate the electrical angle of the rotor, and a certain error occurs.
The coordinate axes of the d axis and the q axis are obtained by transforming the coordinate axes of the alpha axis and the beta axis in combination with the estimated electrical angle of the rotor, so that the d axis and the q axis obtained by estimation deviate from the actual d axis and q axis respectively. In fig. 3, the straight axis obtained by estimation is represented asAn axis, expressed as +.>A shaft.
In fig. 1, an estimated electrical angle may be obtained by estimating the angle and speed of the rotorThen the electrical angle will be estimated +.>As the electrical angle θ of the rotor. Estimating electrical angle +.>Can be estimated by a rotor flux linkage observer.
In fig. 2, the mechanical angle θ of the rotor may be acquired by an encoder M_sample Then according to the mechanical angle theta M_sample An angle process is performed to obtain the electrical angle θ of the rotor. The rotor electrical angle θ can be obtained by the following formula:
θ＝[(θ M_sample -θ 0 )*Pn]mod(2π)；
wherein θ 0 An encoder angle value representing when the axis of the rotor magnetic field is aligned with the U-phase axis of motor 200, pn representing the pole pair number of motor 200, mod (2pi) representing the modulo 2pi operation.
And fourthly, determining reactive current feedforward.
Specifically, reactive current feed-forward can be obtained by the following formula:
wherein i is Q_feedforward Representing reactive current feed forward, I RMS represents the current effective value of the electrons,representing a given power factor. In some cases, a given power factor may employ the rated power factor PFn of the motor 200.
And fifthly, determining reactive current compensation.
In some cases, the motor 200 may be operated with reactive current fluctuating due to disturbance or the like, and the change in reactive current may cause the power factor of the motor 200 to change. To ensure that the power factor of the motor 200 does not vary substantially, a portion of the reactive current is supplied to the motor 200, which portion of the reactive current forms reactive current compensation.
Specifically, when the reactive current is less than 0, the reactive current compensation is correspondingly increased, so that the reactive current can be greater than 0. When the reactive current is greater than 0, the reactive current compensation is adjusted according to the power factor of the motor 200, wherein when the power factor is greater than the given power factor, the power factor needs to be correspondingly reduced, so that the reactive current compensation is correspondingly increased, the reactive current is increased, and the power factor can be reduced to the given power factor; when the power factor is smaller than the given power factor, the power factor needs to be increased accordingly, so that the reactive current compensation is reduced accordingly, the reactive current is reduced, and the power factor can be increased to the given power factor.
On the basis of the above, on the premise that the power factor of the motor 200 gradually conforms to the given power factor by adjusting the reactive compensation to change the reactive current accordingly, the reactive current compensation may be determined according to the compensation amount by which the reactive current is compensated by the given power factor and the actual power factor.
In addition, when determining how to adjust the reactive current compensation according to the power factor of the motor 200 and the given power factor, the reactive current compensation may be adjusted stepwise according to the corresponding step value.
Specifically, the control of the motor 200 may be performed in accordance with a control cycle. When it is determined in the current control period that the reactive current compensation needs to be increased, the reactive current compensation is increased by a first step value in the current control period or when the next control period is reached. When it is determined in the current control period that the reactive current compensation needs to be reduced, the reactive current compensation is reduced by a second step value in the current control period or when the next control period is reached. The control period may be an interrupt period of a DSP (Digital Signal Process, digital signal processing) chip.
Sixth, a given reactive current is determined.
Referring to fig. 1, 2 and 4, fig. 4 is a schematic block diagram of the power factor controller in fig. 1 and 2. The power factor controller can be used to determine a given reactive current from the power factor of the motor.
In fig. 4, after determining the reactive current feedforward and the reactive current compensation, respectively, the reactive current feedforward and the reactive current compensation may be added, and the result of the addition may be taken as a given reactive current.
Wherein the reactive current feedforward is determined according to a given power factor, and indicates that the motor 200 is expected to operate in a state in which the reactive current feedforward is an actual reactive current, and the reactive current compensation supplements the reactive current when the reactive current of the motor 200 is disturbed, so that the reactive current can be maintained within a specific current value, or a corresponding current value range. In fig. 4, a given reactive current is denoted as i Q_ref 。
Seventh, a given direct axis current is determined.
Referring to fig. 4, in fig. 4, after determining the given reactive current and reactive current feedback, the given reactive current and reactive current feedback may be subtracted, and the subtracted result may be input into the PI regulator to perform proportional integral calculation, and the calculated result may be output as the given direct current.
The reactive current feedback may be that, when the motor 200 is running, reactive current is calculated according to the reactive power and the voltage value of the motor 200, and then the reactive current is used as the reactive current feedback. When the reactive current feedback is obtained, filtering treatment can be performed on the reactive current feedback, for example, low-pass filtering treatment can be performed. In FIG. 4, the direct axis current is givenDenoted as i * d 。
Eighth, motor 200 is adjusted based on the given direct current and the given quadrature current.
For a given quadrature current, please refer to fig. 1 and 2 in combination, for a speed-free vector control of the motor 200, the speed of the rotor can be obtained from the electrical angle. In fig. 1, the estimated speed of the rotor is obtained and is expressed asIn fig. 2, the speed of the rotor is obtained and is denoted ω; the speed of the rotor may be determined by differentiating the angle of the rotorAnd (5) determining. After determining the speed of the rotor, a given speed ω of the rotor may be determined * And the speed of the rotor is subtracted, the subtraction result is input into the PI regulator for proportional integral calculation, and the calculation result is output as a given quadrature axis current.
On the basis of the above, please combine fig. 1 and fig. 2, a straight axis current i is given * d Can be input into a PI regulator to perform proportional integral calculation to obtain an estimated direct-axis voltageGiven quadrature axis current i * q Can be input into a PI regulator to perform proportional integral calculation to obtain estimated quadrature axis voltage +.>Estimating the direct axis voltage +.>And estimating quadrature axis voltage +.>Then performing inverse park transformation to obtain two-phase current U under static coordinate system α And U β The obtained two-phase current U α And U β The motor 200 is used for performing pulse width modulation processing to obtain a PWM (pulse width modulation ) waveform, the PWM waveform is output to the inverter to form a three-phase voltage waveform to be output to the motor 200, and the motor 200 adjusts the operation state according to the adjusted three-phase voltage, so that the reactive current of the motor itself is changed and can approach to the given reactive current. Accordingly, the power factor will also change and can be close to the given power factor, so that the effect of power factor control can be finally achieved.
On the basis of the foregoing, the technical concept of the present invention can be embodied as follows.
Referring to fig. 1, 2 and 5, a control method provided by the present invention can be used for a motor 200. The control method may include:
01: determining a given direct-axis current of the motor 200 from the reactive current of the motor 200 and the given reactive current;
02: the direct current of motor 200 is adjusted to a given direct current to adjust the power factor of motor 200.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the inverter 100 may be used for the motor 200. The frequency converter 100 may include a control module 110 and an adjustment module 120. The control module 110 may be configured to determine a given direct current of the motor 200 based on the reactive current of the motor 200 and the given reactive current. The adjustment module 120 may be used to adjust the direct current of the motor 200 to a given direct current to adjust the power factor of the motor 200.
According to the control method and the frequency converter 100, when the motor 200 operates, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor 200 is regulated to the given direct-axis current, so that the effect of regulating power control can be achieved, and the dynamic performance and the steady-state performance of the motor 200 are ensured.
Specifically, in the case where power factor adjustment of the motor 200 is required, the power factor may be affected by reactive power, which may be affected by reactive current. In case that the given power factor and the given reactive current are determined, the corresponding direct-axis current may be determined as the given direct-axis current in combination with the reactive current, and the direct-axis current of the motor 200 may be adjusted to the given direct-axis current, so that the power factor may be brought closer to the given power factor in turn, and the given power factor may be finally achieved, to finally achieve the effect of the power factor control of the motor 200.
In addition, in some cases, the control module 110 of the frequency converter 100 may be the power factor controller shown in fig. 1 and 2.
In addition, the direct current may correspond to a direct component of the rotor flux back emf. In the invention, as only the direct axis component of the counter electromotive force of the rotor flux linkage is required to be determined, the calculated amount can be reduced, thus the calculation requirement on the data amount can be reduced, the adjusting target of the direct axis current can be determined more quickly, the adjusting action of the power factor can be responded more quickly, the adjusting period can be shortened, and the cost of a control system can be reduced.
In the present invention, a given reactive current can be determined from the reactive current feed-forward and reactive current compensation of the motor 200.
In this way, a given reactive current can be determined conveniently.
In the present invention, the control method includes:
reactive current feed forward is determined based on a given power factor and phase current of motor 200.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the control module 110 may be configured to determine reactive current feed-forward based on a given power factor and phase current of the motor 200.
In this manner, the present reactive current of the motor 200 can be conveniently determined.
In the present invention, the control method may include:
the reactive current compensation is adjusted according to the change condition of the reactive current of the motor 200.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the adjustment module 120 may be configured to adjust reactive current compensation according to a change in reactive current of the motor 200.
In this way, the reactive current compensation corresponding to the present reactive current can be determined in real time.
In the present invention, the step of adjusting the reactive current compensation according to the variation of the reactive current of the motor 200 may include:
when the reactive current is smaller than a first preset value, increasing reactive current compensation;
when the reactive current is greater than the first preset value, the reactive current compensation is adjusted according to the present power factor and the given power factor of the motor 200.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the adjustment module 120 may be configured to: when the reactive current is smaller than a first preset value, increasing reactive current compensation; when the reactive current is greater than the first preset value, the reactive current compensation is adjusted according to the present power factor and the given power factor of the motor 200.
In this way, stable operation of the motor 200 can be ensured.
In some cases, the first preset value may be 0. In other cases, the first preset value may be adjusted according to specific conditions, or may be calibrated through an actual test.
In the present invention, the step of adjusting the reactive current compensation according to the present power factor and the given power factor of the motor 200 may include:
increasing reactive current compensation by a first step value if the present power factor is greater than a first given power factor;
the reactive current compensation is reduced by a second step value in case the present power factor is smaller than a second given power factor, the first given power factor being larger than or equal to the second given power factor.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the adjustment module 120 may be configured to: increasing reactive current compensation by a first step value if the present power factor is greater than a first given power factor; the reactive current compensation is reduced by a second step value in case the present power factor is smaller than a second given power factor, the first given power factor being larger than or equal to the second given power factor.
In this way, large fluctuations in the reactive power of the motor 200 can be avoided.
It will be appreciated that when the reactive current compensation is adjusted by corresponding step values according to the control period, the effect of the adjustment of the reactive current compensation (including the magnitude relation between the adjusted power factor and the given power factor) may be confirmed in one control period, and further it may be determined how the reactive current compensation needs to be adjusted in the current control period or in the next control period. In this way, reactive power divergence fluctuations due to excessive adjustment amplitude of reactive current compensation can be avoided.
In particular, the first given power factor and the second given power factor may form a power factor range. When the current power factor is larger than the first given power factor, the current power factor can be indicated to be overlarge, the current power factor needs to be reduced, and reactive current compensation can be correspondingly increased; when the current power factor is smaller than the second given power factor, the current power factor may be indicated to be too small, and the current power factor needs to be increased, so that reactive current compensation may be correspondingly reduced.
The first given power factor may also be equal to the second given power factor such that the power factor of the motor 200 may be maintained to fluctuate around the given power factor.
The first step value and/or the second step value can be adjusted according to specific conditions, and can be calibrated through actual tests. In some cases, the first step value may be 0.00001 amps; the second step value may be 0.00001 amps.
In addition, the given power factor may be a rated power factor of the motor 200.
In the present invention, the control method may include:
determining a direct current from the three-phase current of the motor 200 and an estimated electrical angle, which can be obtained by estimating a rotor of the motor 200; and/or
The direct current is determined from the three-phase current of the motor 200 and the mechanical angle, which can be obtained by encoding the rotor of the motor 200.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the control module 110 may be configured to: determining a direct current from the three-phase current of the motor 200 and an estimated electrical angle, which can be obtained by estimating a rotor of the motor 200; and/or determining the direct current from the three-phase current of the motor 200 and the mechanical angle that can be obtained by encoding the rotor of the motor 200.
In this way, the electrical angle of the rotor can be determined conveniently.
In the present invention, the control method may include:
the electric parameters obtained from the three-phase currents and the three-phase voltages of the motor 200 are subjected to a filtering process, and the electric parameters include at least one of active power, reactive power, apparent power, power factor, active current, and reactive current.
The control method of the present invention can be implemented by the frequency converter 100 of the present invention. Specifically, referring to fig. 6, the adjustment module 120 may be configured to: the electric parameters obtained from the three-phase currents and the three-phase voltages of the motor 200 are subjected to a filtering process, and the electric parameters include at least one of active power, reactive power, apparent power, power factor, active current, and reactive current.
In this way, calculation errors caused by external disturbances can be reduced.
Referring to fig. 7, a frequency converter 100 of the present invention may include a memory 130 and a processor 140. The memory 130 stores a computer program. The steps of the control method described above may be implemented when the processor 140 executes a computer program.
For example, in the case where the computer program is executed by a processor, a control method that can be implemented includes:
01: determining a given direct-axis current of the motor 200 from the reactive current of the motor 200 and the given reactive current;
02: the direct current of motor 200 is adjusted to a given direct current to adjust the power factor of motor 200.
According to the control method and the frequency converter 100, when the motor 200 operates, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor 200 is regulated to the given direct-axis current, so that the effect of regulating power control can be achieved, and the dynamic performance and the steady-state performance of the motor 200 are ensured.
Referring to fig. 1, 2, 6 and 7, a motor apparatus 300 of the present invention may include a motor 200 and a frequency converter 100.
In the motor device 300, when the motor 200 is running, a given direct-axis current is determined by the reactive current and the given reactive current, and the direct-axis current of the motor 200 is adjusted to the given direct-axis current, so that the effect of adjusting power control can be achieved, and the dynamic performance and the steady-state performance of the motor 200 are ensured.
It will be appreciated that by providing the frequency converter 100, the motor apparatus 300 can perform speed vector-free control of the motor 200, and in the process, can perform power factor control of the motor 200, so that the operation state of the motor 200 can be ensured.
A computer-readable storage medium of the present invention has a computer program stored thereon. The computer program may, when executed by the processor 140, implement the steps of the control method described above.
For example, in the case where the computer program is executed by a processor, a control method that can be implemented includes:
01: determining a given direct-axis current of the motor 200 from the reactive current of the motor 200 and the given reactive current;
02: the direct current of motor 200 is adjusted to a given direct current to adjust the power factor of motor 200.
According to the control method and the frequency converter 100, when the motor 200 operates, the given direct-axis current is determined through the reactive current and the given reactive current, and the direct-axis current of the motor 200 is regulated to the given direct-axis current, so that the effect of regulating power control can be achieved, and the dynamic performance and the steady-state performance of the motor 200 are ensured.
The computer readable storage medium may be provided in the control module 110 or in other terminals, and the control module 110 may be capable of communicating with other terminals to obtain corresponding programs.
It is understood that the computer-readable storage medium may include: any entity or device capable of carrying a computer program, a recording medium, a USB flash disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a software distribution medium, and so forth. The computer program may comprise computer program code. The computer program code may be in the form of source code, object code, executable files, or in some intermediate form, among others.
In some embodiments of the present invention, the control module 110 may be a single-chip microcomputer chip, integrated with a processor, a memory, a communication module, etc. The processor may be a central processing unit (Central Processing Unit, CPU), may be a graphics processing unit (Graphic Processing Unit, GPU), may be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), ARM processors (Advanced RISC Machines, ARM), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and further implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.
Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, system that includes a processing module, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to the embodiments of the present invention without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (12)
1. A control method for an electric machine, characterized in that the control method comprises:
determining a given direct-axis current of the motor according to the reactive current of the motor and the given reactive current;
and adjusting the direct-axis current of the motor to be the given direct-axis current so as to adjust the power factor of the motor.
2. A control method according to claim 1, characterized in that the given reactive current is determined from reactive current feed-forward and reactive current compensation of the motor.
3. The control method according to claim 2, characterized in that the control method includes:
the reactive current feed forward is determined based on a given power factor and phase current of the motor.
4. The control method according to claim 2, characterized in that the control method includes:
and adjusting the reactive current compensation according to the change condition of the reactive current of the motor.
5. The control method according to claim 4, wherein the step of adjusting the reactive current compensation according to a change condition of the reactive current of the motor includes:
when the reactive current is smaller than a first preset value, the reactive current compensation is increased;
and when the reactive current is larger than the first preset value, adjusting the reactive current compensation according to the current power factor and the given power factor of the motor.
6. The control method according to claim 5, characterized in that the step of adjusting the reactive current compensation according to the present power factor and a given power factor of the motor comprises:
increasing the reactive current compensation by a first step value if the present power factor is greater than a first given power factor;
the reactive current compensation is reduced by a second step value if the present power factor is less than a second given power factor, the first given power factor being greater than or equal to the second given power factor.
7. The control method according to claim 1, characterized in that the control method includes:
determining the direct current according to the three-phase current of the motor and an estimated electrical angle, wherein the estimated electrical angle is obtained by estimating a rotor of the motor; and/or
And determining the straight shaft current according to the three-phase current and the mechanical angle of the motor, wherein the mechanical angle is obtained by encoding and collecting the rotor of the motor.
8. The control method according to claim 1, characterized in that the control method includes:
filtering electric parameters obtained according to the three-phase current and the three-phase voltage of the motor, wherein the electric parameters comprise at least one of active power, reactive power, apparent power, power factor, active current and reactive current.
9. A frequency converter for an electric machine, characterized in that the frequency converter comprises a control module and an adjustment module, the control module being adapted to determine a given direct current of the electric machine from a reactive current of the electric machine and the given reactive current;
the regulation module is used for regulating the direct-axis current of the motor to the given direct-axis current so as to regulate the power factor of the motor.
10. A frequency converter comprising a memory and a processor, the memory storing a computer program, the processor implementing the steps of the control method according to any one of claims 1 to 8 when the computer program is executed.
11. An electrical machine apparatus, comprising:
a motor, and;
a transducer according to claim 9 or 10.
12. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the control method of any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311812733.0A CN117767832A (en) | 2023-12-26 | 2023-12-26 | Control method, frequency converter, motor device, and computer-readable storage medium |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311812733.0A CN117767832A (en) | 2023-12-26 | 2023-12-26 | Control method, frequency converter, motor device, and computer-readable storage medium |
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| Publication Number | Publication Date |
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| CN117767832A true CN117767832A (en) | 2024-03-26 |
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| CN202311812733.0A Pending CN117767832A (en) | 2023-12-26 | 2023-12-26 | Control method, frequency converter, motor device, and computer-readable storage medium |
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| Country | Link |
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| CN (1) | CN117767832A (en) |
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2023
- 2023-12-26 CN CN202311812733.0A patent/CN117767832A/en active Pending
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