阅读说明：本技术 变频器的控制方法及变频器 (Frequency converter control method and frequency converter ) 是由 罗玉均 于 2019-10-18 设计创作，主要内容包括：本申请提出一种变频器的控制方法及变频器。其中,变频器的控制方法,包括：检测变频器的母线的电参数；当所述母线的电参数异常时,切换所述变频器至发电模式,以根据母线电压目标值调节所述变频器输出给电机的三相电的电压和相位。本申请的变频器的控制方法,通过对母线的电参数的检测,可以在母线的电参数出现异常时,使变频器切换到发电模式下运行,以调节输出的三相电的电压和相位与电机反电动势保持合理的相位和压差,从而可以优化电机的电流谐波和功率因素,即确保电机的电流正弦,使电机的发热量等控制在合理范围内,进而,提高机组的可靠性。(The application provides a control method of a frequency converter and the frequency converter. The control method of the frequency converter comprises the following steps: detecting an electrical parameter of a bus of the frequency converter; and when the electrical parameters of the bus are abnormal, switching the frequency converter to a power generation mode so as to regulate the voltage and the phase of the three-phase power output to the motor by the frequency converter according to the target value of the bus voltage. According to the control method of the frequency converter, through detection of the electrical parameters of the bus, when the electrical parameters of the bus are abnormal, the frequency converter is switched to the power generation mode to operate, so that reasonable phase and pressure difference are kept between the voltage and the phase of the output three-phase power and the counter electromotive force of the motor, current harmonics and power factors of the motor can be optimized, namely the current sine of the motor is ensured, the heating amount and the like of the motor are controlled within a reasonable range, and further the reliability of a unit is improved.)

1. A control method of a frequency converter is characterized by comprising the following steps:

detecting an electrical parameter of a bus of the frequency converter;

and when the electrical parameters of the bus are abnormal, switching the frequency converter to a power generation mode so as to regulate the voltage and the phase of the three-phase power output to the motor by the frequency converter according to the target value of the bus voltage.

2. The method of controlling a frequency converter according to claim 1, wherein the electrical parameter of the bus comprises a bus voltage and/or a bus current, the method further comprising:

judging whether the bus voltage is smaller than a first voltage threshold value and/or the bus current is smaller than a first current threshold value;

and if so, determining that the electrical parameter of the bus is abnormal.

3. The method of controlling a frequency converter according to claim 2, further comprising:

judging whether the bus voltage rises to a second voltage threshold value and/or whether the bus current rises to a second current threshold value;

if yes, switching to a deceleration stop mode or an aerodyne starting mode.

4. The method for controlling a frequency converter according to any one of claims 1 to 3, further comprising:

detecting the electric parameters of three-phase power output to the motor by the frequency converter;

and obtaining a motor rotating speed signal according to the electric parameters of the three-phase power output to the motor by the frequency converter.

5. The method of controlling a frequency converter according to claim 1, further comprising:

and determining the bus voltage target value according to the back electromotive force of the motor.

6. A frequency converter, comprising:

the first detection module is used for detecting the electrical parameters of a bus of the frequency converter;

and the controller is used for switching the frequency converter to a power generation mode when the electrical parameters of the bus are abnormal so as to regulate the voltage and the phase of the three-phase power output to the motor by the frequency converter according to the target value of the bus voltage.

7. The frequency converter according to claim 6, wherein the electrical parameter of the bus comprises a bus voltage and/or a bus current, and the controller is configured to determine whether the bus voltage is less than a first voltage threshold and/or the bus current is less than a first current threshold, and if so, determine that the electrical parameter of the bus is abnormal.

8. The frequency converter according to claim 7, wherein the controller is further configured to determine whether the bus voltage rises to a second voltage threshold and/or the bus current rises to a second current threshold, and if so, switch to a deceleration shutdown mode or an aircraft start mode.

9. The frequency converter according to any one of claims 6-8, further comprising:

the controller is also used for obtaining a motor rotating speed signal according to the three-phase electric parameters output to the motor by the frequency converter.

10. The frequency converter of claim 6, wherein the controller is configured to determine the bus voltage target value based on a back-emf of the motor.

11. A computer-readable storage medium, on which a computer program is stored, characterized in that a control program of a frequency converter is stored, which, when being executed by a processor, implements the control method of the frequency converter according to any one of claims 1-5.

Technical Field

The present disclosure relates to the field of frequency conversion control technologies, and in particular, to a control method for a frequency converter and a frequency converter.

Background

Disclosure of Invention

The present application is directed to solving at least one of the above problems.

To this end, an object of the present application is to provide a method for controlling a frequency converter. The method can enable the frequency converter to be switched to the power generation mode to operate when the electrical parameters of the bus are abnormal, optimize the current harmonic waves and power factors of the motor, namely ensure the current sine of the motor, control the heat productivity of the motor and the like within a reasonable range, and further improve the reliability of the unit.

A second object of the present application is to provide a frequency converter.

A third object of the present application is to propose a computer readable storage medium.

In order to achieve the above object, a first aspect of the present application discloses a method for controlling a frequency converter, including: detecting an electrical parameter of a bus of the frequency converter; and when the electrical parameters of the bus are abnormal, switching the frequency converter to a power generation mode so as to regulate the voltage and the phase of the three-phase power output to the motor by the frequency converter according to the target value of the bus voltage.

According to the control method of the frequency converter, through detection of the electrical parameters of the bus, when the electrical parameters of the bus are abnormal, the frequency converter is switched to the power generation mode to operate, so that reasonable phase and pressure difference are kept between the voltage and the phase of the output three-phase power and the counter electromotive force of the motor, current harmonics and power factors of the motor can be optimized, namely the current sine of the motor is ensured, the heating amount and the like of the motor are controlled within a reasonable range, and further the reliability of a unit is improved.

In some examples, the electrical parameter of the bus comprises a bus voltage and/or a bus current, the method further comprising: judging whether the bus voltage is smaller than a first voltage threshold value and/or the bus current is smaller than a first current threshold value; and if so, determining that the electrical parameter of the bus is abnormal.

In some examples, further comprising: judging whether the bus voltage rises to a second voltage threshold value and/or whether the bus current rises to a second current threshold value; if yes, switching to a deceleration stop mode or an aerodyne starting mode.

In some examples, further comprising: detecting the electric parameters of three-phase power output to the motor by the frequency converter; and obtaining a motor rotating speed signal according to the electric parameters of the three-phase power output to the motor by the frequency converter.

In some examples, further comprising: and determining the bus voltage target value according to the back electromotive force of the motor.

A second aspect of the present application discloses a frequency converter, including: the first detection module is used for detecting the electrical parameters of a bus of the frequency converter; and the controller is used for switching the frequency converter to a power generation mode when the electrical parameters of the bus are abnormal so as to regulate the voltage and the phase of the three-phase power output to the motor by the frequency converter according to the target value of the bus voltage.

The utility model provides a frequency converter, through the detection to the electrical parameter of generating line, can make the frequency converter switch to and run under the mode of generating electricity when the electrical parameter of generating line appears unusually to the voltage and the phase place of the three-phase electricity of regulation output and motor back electromotive force keep reasonable phase place and pressure differential, thereby can optimize the current harmonic and the power factor of motor, ensure the electric current sine of motor promptly, make controls such as calorific capacity of motor in reasonable within range, and then, improve the reliability of unit.

In some examples, the electrical parameter of the bus includes a bus voltage and/or a bus current, and the controller is configured to determine whether the bus voltage is less than a first voltage threshold and/or the bus current is less than a first current threshold, and if so, determine that the electrical parameter of the bus is abnormal.

In some examples, the controller is further configured to determine whether the bus voltage rises to a second voltage threshold and/or the bus current rises to a second current threshold, and if so, switch to a deceleration shutdown mode or an aircraft startup mode.

In some examples, further comprising: the controller is also used for obtaining a motor rotating speed signal according to the three-phase electric parameters output to the motor by the frequency converter.

In some examples, the controller is configured to determine the bus voltage target value based on a back-emf of the motor.

A third aspect of the present application discloses a computer-readable storage medium having a computer program stored thereon, characterized in that a control program of a frequency converter is stored thereon, which when executed by a processor implements the control method of the frequency converter described in the first aspect above.

Additional aspects and advantages of the present application 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 present application.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a flow chart of a method of controlling a frequency converter according to an embodiment of the present application;

FIG. 2 is a block diagram of a frequency converter according to one embodiment of the present application;

fig. 3 is a schematic diagram of a frequency converter according to an embodiment of the present application.

Description of reference numerals:

the frequency converter 200, the rectifying module 110, the filtering module 120, the inverting module 130, the controller 140, the motor M, the first detecting module 141, and the second detecting module 142.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be considered limiting of the present application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The following describes a control method of a frequency converter and the frequency converter according to an embodiment of the present application with reference to the drawings.

Before describing a control method of a frequency converter according to an embodiment of the present application, the frequency converter is first explained, and as shown in fig. 3, the frequency converter includes a rectification module 110, a filtering module 120, an inversion module 130, and a controller 140. Wherein, the output side of the inverter module 130 is connected with the motor M to output three-phase power to the motor M.

Fig. 1 is a flowchart of a control method of a frequency converter according to an embodiment of the present application. As shown in fig. 1, a method for controlling a frequency converter according to an embodiment of the present application includes the following steps:

s101: and detecting the electrical parameters of the bus of the frequency converter.

Wherein the electrical parameter of the bus includes, but is not limited to, at least one of bus voltage and bus current. As shown in fig. 3, the electrical parameter of the bus bar can be detected by the first detection module 141, namely: the first detection module 141 detects a bus voltage and/or a bus current.

S102: and when the electrical parameters of the bus are abnormal, switching the frequency converter to a power generation mode so as to regulate the voltage and the phase of the three-phase electricity output to the motor by the frequency converter according to the target value of the bus voltage.

Taking the bus voltage and/or the bus current as an example, the electrical parameter of the bus is determined to be abnormal if the bus voltage is less than the first voltage threshold and/or the bus current is less than the first current threshold.

In a specific example, the first voltage threshold and the first current threshold may be pre-calibrated. For example: through experiments, when the bus voltage is smaller than a certain critical value and/or the bus current is smaller than a certain critical value, the electrical parameter of the bus is considered to be abnormal, and the critical value is used as a first voltage threshold value and a first current threshold value.

Therefore, when the electrical parameters of the bus are abnormal, the working mode of the frequency converter is firstly switched to the power generation mode, and then the voltage and the phase of the three-phase power output to the motor by the frequency converter are regulated according to the target value of the bus voltage. Namely: the frequency converter is controlled to regulate the voltage and the phase of the output three-phase power, and the voltage and the phase of the output three-phase power and the back electromotive force of the motor are kept in reasonable phases and pressure differences, namely, when the frequency converter operates in a power generation mode, the voltage and the phase of the three-phase power are regulated by taking the bus voltage as a target (namely, a bus voltage target value) to be stabilized at a control value, so that current harmonics and power factors of the motor can be optimized, namely, the current sine of the motor is ensured, and the heat productivity of the motor and the like are controlled in a reasonable range. In the above description, the bus voltage target value may be determined according to the back electromotive force of the motor.

According to the control method of the frequency converter, through detection of the electrical parameters of the bus, when the electrical parameters of the bus are abnormal, the frequency converter can be switched to the power generation mode to operate, so that reasonable phase and pressure difference can be kept between the voltage and the phase of the output three-phase power and the counter electromotive force of the motor, current harmonics and power factors of the motor can be optimized, namely the current sine of the motor is ensured, the heating amount and the like of the motor are controlled within a reasonable range, and further the reliability of a unit is improved.

In an embodiment of the present application, a method for controlling a frequency converter further includes: judging whether the bus voltage rises to a second voltage threshold value and/or whether the bus current rises to a second current threshold value; if yes, switching to a deceleration stop mode or an aerodyne starting mode. Namely: when the frequency converter operates in the power generation mode, when the bus voltage recovers to the exit threshold (namely, the second voltage threshold), the frequency converter can enter a deceleration shutdown or runaway starting mode according to the control condition of the unit, so that the operation reliability of the unit is further improved. Wherein, the second voltage threshold value can be calibrated in advance,

in an embodiment of the present application, a method for controlling a frequency converter further includes: and detecting the electric parameters of the three-phase power output to the motor by the frequency converter, and obtaining a motor rotating speed signal according to the electric parameters of the three-phase power output to the motor by the frequency converter. As shown in fig. 3, the electrical parameters of the three-phase power output by the inverter to the motor may be detected by the second detection module 142, wherein the electrical parameters of the three-phase power output by the inverter to the motor are, but not limited to, the voltage and/or the current of the three-phase power output by the inverter to the motor.

Specifically, the voltage and/or current at the output side of the frequency converter (i.e., the three-phase power output to the motor) are detected, and then the current position of the rotor of the motor is calculated according to the voltage and/or current at the output side of the frequency converter (i.e., the three-phase power output to the motor), so that the motor speed signal can be calculated according to the current position of the rotor, and in a specific example, in combination with fig. 3, the motor speed signal can be provided to the magnetic bearing controller 150 for the magnetic bearing controller 150 to use. Therefore, an additional detection circuit is not required for detection, and the method has the advantages of simple and reliable detection and low cost.

Fig. 2 is a block diagram of a frequency converter according to an embodiment of the present application. As shown in fig. 2 in combination with fig. 3, the frequency converter 200 according to an embodiment of the present application includes not only the frequency converter including the rectifying module 110, the filtering module 120, the inverting module 130, and the controller 140 and the first detecting module 141.

The first detecting module 141 is configured to detect an electrical parameter of a bus of the frequency converter. The controller 140 is configured to switch the inverter to the power generation mode when the electrical parameter of the bus is abnormal, so as to adjust the voltage and phase of the three-phase power output by the inverter to the motor M according to the target value of the bus voltage.

In an embodiment of the present application, the electrical parameter of the bus includes a bus voltage and/or a bus current, and the controller 140 is configured to determine whether the bus voltage is less than a first voltage threshold and/or the bus current is less than a first current threshold, and if so, determine that the electrical parameter of the bus is abnormal.

In an embodiment of the present application, the controller 140 is further configured to determine whether the bus voltage rises to a second voltage threshold and/or the bus current rises to a second current threshold, and if so, switch to a deceleration shutdown mode or an aircraft start mode.

In one embodiment of the present application, the frequency converter 200 further includes: and the second detection module 142 is configured to detect an electrical parameter of the three-phase power output by the frequency converter to the motor, and the controller is further configured to obtain a motor rotation speed signal according to the electrical parameter of the three-phase power output by the frequency converter to the motor.

In one embodiment of the present application, the controller 140 is configured to determine the bus voltage target value according to a back electromotive force of the motor.

The frequency converter of this application embodiment, through the detection to the electrical parameter of generating line, can make the frequency converter switch to and generate electricity the mode and move down when the electrical parameter of generating line appears unusually to adjust the voltage and the phase place of the three-phase electricity of output and motor back electromotive force and keep reasonable phase place and pressure differential, thereby can optimize the current harmonic and the power factor of motor, ensure the electric current sine of motor promptly, make controls such as calorific capacity of motor in reasonable within range, and then, improve the reliability of unit.

It should be noted that a specific implementation manner of the frequency converter in the embodiment of the present application is similar to a specific implementation manner of the control method of the frequency converter in the embodiment of the present application, and please refer to the description of the method part specifically, which is not described herein again.

Further, an embodiment of the present application discloses a computer-readable storage medium on which a control program of a frequency converter is stored, which when executed by a processor implements the above-mentioned control method of the frequency converter.

The non-transitory computer readable storage medium described above may take any combination of one or more computer readable media. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM) or flash Memory, an optical fiber, a portable compact disc Read Only Memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of the present application may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C + +, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of Network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider).

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.