A single-phase asynchronous motor main and auxiliary winding identification method

Abstract

The application relates to a single-phase asynchronous motor main and auxiliary winding identification method, wherein the single-phase asynchronous motor main and auxiliary windings are connected in a V-shaped mode and are connected with U, V and W terminals of a frequency converter; the frequency converter inputs a direct-current detection voltage to the motor windings from a group of bridge arms; three-phase current values are measured and analyzed and processed to determine the winding middle point and the main and auxiliary winding end points; the application can identify the winding connection mode of the current single-phase motor without the aid of additional tools such as a universal meter or a bridge, can not only reduce the use difficulty of the single-phase asynchronous motor and simplify the operation process, but also effectively improve the motor control precision and operation efficiency, solves the problems that the single-phase asynchronous motor control in the prior art cannot be accurately speed-regulated and it is difficult to change the rotating direction by directly driving the motor with a power frequency power supply, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method for identifying the main and auxiliary windings of a single-phase asynchronous motor. Background Technology

[0002] Single-phase asynchronous motors are widely used in many fields due to their simple structure and low cost, such as refrigerators and washing machines in household appliances, as well as small fans and pumps in various industrial equipment. However, with the continuous development of automation control technology and the increasing requirements for motor control precision, traditional single-phase asynchronous motor control methods have gradually revealed many shortcomings.

[0003] Currently, most single-phase asynchronous motors are controlled by direct drive from industrial frequency power. This control method has obvious limitations: on the one hand, it cannot achieve precise control of motor speed, making it difficult for the motor to meet the requirements of some working scenarios with high speed accuracy during operation; on the other hand, it is difficult to change the direction of rotation of the motor, which requires adjustment of external mechanical structure or other complex operations, lacking flexibility. In order to overcome these difficulties, some frequency converter products for controlling single-phase asynchronous motors have gradually emerged, which can achieve speed control to a certain extent and improve the operating performance of the motor.

[0004] A single-phase asynchronous motor's windings consist of two sets of coils: a main winding (running winding) that provides the motor's operating torque, and a secondary winding (starting winding) that provides the motor's starting torque. The operating performance and control effect of a single-phase asynchronous motor largely depend on the accurate connection and control of the main and secondary windings. However, existing frequency converters controlling single-phase asynchronous motors all suffer from the inability to autonomously identify the main and secondary windings. To determine the motor's main and secondary windings, manual judgment using tools such as multimeters or bridges is usually required. This method is not only complex and requires experienced and skilled operators, but it is also easily affected by various factors during actual operation, such as the accuracy of the tools and the stability of the measurement environment, leading to inaccurate measurement results and affecting subsequent motor control and operation. Therefore, existing single-phase asynchronous motor control technology has significant shortcomings in winding identification, severely restricting the intelligent and efficient development of motor control. Summary of the Invention

[0005] In view of this, the present invention provides a method for identifying the main and auxiliary windings of a single-phase asynchronous motor. By applying a test voltage to the motor windings through a frequency converter, the main and auxiliary winding configuration of the current single-phase asynchronous motor can be identified. The method can determine the main and auxiliary windings without the need for manual operation of tools such as multimeters, greatly reducing the difficulty of use.

[0006] To achieve the above objectives, the present invention provides a method for identifying the main and auxiliary windings of a single-phase asynchronous motor, comprising the following steps:

[0007] S1. Connect the main winding and auxiliary winding of the single-phase asynchronous motor in a V-type manner, and connect the three terminals after the V-type connection to the output terminals U, V and W of the frequency converter respectively.

[0008] S2, Obtain the three bridge arms of the frequency converter , , Three-phase current values , , ;

[0009] S3, based on the three-phase current values , , Determine the midpoint of the motor windings, and denote the inverter bridge arm connected to the midpoint of the motor windings as... ;

[0010] S4, Obtain the three bridge arms of the frequency converter , , Three-phase current values , , ;

[0011] S5. Based on the three-phase current values , , Determine the endpoints of the primary winding and the secondary winding;

[0012] like and Then determine the three-phase current. Corresponding bridge arm The connection point is the terminal of the main winding, and the three-phase current... Corresponding bridge arm The connection point is the endpoint of the secondary winding;

[0013] like and , Then determine the three-phase current. Corresponding bridge arm The connection point is the terminal of the main winding, and the three-phase current... Corresponding bridge arm The connection point is the endpoint of the secondary winding.

[0014] Preferably, from any one of the three bridge arms of the frequency converter DC detection voltage is input to the winding of a single-phase asynchronous motor. Measure the three-phase current values ​​of the three bridge arms of the frequency converter respectively, and then connect the bridge arms. The corresponding current is denoted as The other two bridge arms , The corresponding currents are denoted as follows: , .

[0015] Preferably, determining the midpoint of the motor winding includes the following steps:

[0016] like Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding;

[0017] like and Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding;

[0018] like and Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding.

[0019] Preferably, from the bridge arm Re-input DC detection voltage to the single-phase asynchronous motor The three-phase current values ​​of the three bridge arms of the frequency converter were measured respectively, and the frequency converter bridge arms connected at the midpoint of the motor windings were also measured. The corresponding current is denoted as The other two bridge arms , The corresponding currents are denoted as follows: , .

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] This invention reduces operational complexity and human error by allowing the frequency converter to autonomously apply test voltage and analyze current. Simultaneously, it employs a precise current analysis algorithm, combined with multiple measurements and comprehensive analysis, ensuring the reliability of primary and secondary winding identification. Furthermore, it simplifies the control process, reduces the need for additional tools, optimizes system integration, and lowers operating costs. This enables the frequency converter to automatically identify and adapt to different motor winding connection methods, exhibiting broad versatility and adaptability. It further improves motor control accuracy and operating efficiency, meeting the needs of various application scenarios. Attached Figure Description

[0022] Figure 1 is a flowchart of the present invention;

[0023] Figure 2 This is a schematic diagram of the three bridge arms and main and auxiliary windings of the frequency converter of the present invention. Detailed Implementation

[0024] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0025] This embodiment provides a method for identifying the main and auxiliary windings of a single-phase asynchronous motor, including the following steps:

[0026] S1. Connect the main winding and auxiliary winding of the single-phase asynchronous motor in a V-type manner, and connect the three terminals after the V-type connection to the output terminals U, V and W of the frequency converter respectively.

[0027] S2, from any one of the three bridge arms of the frequency converter DC detection voltage is input to the winding of a single-phase asynchronous motor. Measure the three-phase current values ​​of the three bridge arms of the frequency converter respectively, and then connect the bridge arms. The corresponding current is denoted as The other two bridge arms , The corresponding currents are denoted as follows: , ;

[0028] S3, based on the three-phase current values , , Determine the midpoint of the motor windings, and denote the inverter bridge arm connected to the midpoint of the motor windings as... ;

[0029] like Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding;

[0030] like and Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding;

[0031] like and Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding;

[0032] S4, from the bridge arm Re-input DC detection voltage to the single-phase asynchronous motor The three-phase current values ​​of the three bridge arms of the frequency converter were measured respectively, and the frequency converter bridge arms connected at the midpoint of the motor windings were also measured. The corresponding current is denoted as The other two bridge arms , The corresponding currents are denoted as follows: , ;

[0033] S5. Based on the three-phase current values , , Determine the endpoints of the primary winding and the secondary winding;

[0034] like and Then determine the three-phase current. Corresponding bridge arm The connection point is the terminal of the main winding, and the three-phase current... Corresponding bridge arm The connection point is the endpoint of the secondary winding;

[0035] like and , Then determine the three-phase current. Corresponding bridge arm The connection point is the terminal of the main winding, and the three-phase current... Corresponding bridge arm The connection point is the endpoint of the secondary winding.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for identifying the main and auxiliary windings of a single-phase asynchronous motor, characterized in that, Includes the following steps: S1. Connect the main winding and auxiliary winding of the single-phase asynchronous motor in a V-type manner, and connect the three terminals after the V-type connection to the output terminals U, V and W of the frequency converter respectively. S2, Obtain the three bridge arms of the frequency converter , , Three-phase current values , , ; S3, based on the three-phase current values , , Determine the midpoint of the motor windings, and denote the inverter bridge arm connected to the midpoint of the motor windings as... ; Determining the midpoint of a motor winding includes the following steps: like Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding; like and Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding; like and Then determine the three-phase current. Corresponding bridge arm The connection point is the midpoint of the motor winding; S4, Obtain the three bridge arms of the frequency converter , , Three-phase current values , , ; S5. Based on the three-phase current values , , Determine the endpoints of the primary winding and the secondary winding; like and Then determine the three-phase current. Corresponding bridge arm The connection point is the terminal of the main winding, and the three-phase current... Corresponding bridge arm The connection point is the endpoint of the secondary winding; like and , Then determine the three-phase current. Corresponding bridge arm The connection point is the terminal of the main winding, and the three-phase current... Corresponding bridge arm The connection point is the endpoint of the secondary winding.

2. The method for identifying the main and auxiliary windings of a single-phase asynchronous motor according to claim 1, characterized in that, From any one of the three bridge arms of the frequency converter DC detection voltage is input to the winding of a single-phase asynchronous motor. The three-phase current values ​​of the three bridge arms of the frequency converter were measured respectively. The corresponding current is denoted as The other two bridge arms , The corresponding currents are denoted as follows: , .

3. The method for identifying the main and auxiliary windings of a single-phase asynchronous motor according to claim 1, characterized in that, From the bridge arm Re-input DC detection voltage to the single-phase asynchronous motor The three-phase current values ​​of the three bridge arms of the frequency converter were measured respectively, and the frequency converter bridge arms connected at the midpoint of the motor windings were also measured. The corresponding current is denoted as The other two bridge arms , The corresponding currents are denoted as follows: , .

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