Patent Description:
When operating in a high-speed area, a permanent magnet synchronous compressor is easy to enter a field weakening control area. During the field weakening control, the increase of Id current (Id: current that generates magnetic flux) is easy to cause the efficiency of a whole machine to become lower, meanwhile, the change of Id will cause problems such as position estimation, resulting in the unstable system. Therefore, if the time for the compressor to enter the field weakening control can be delayed, the efficiency of the compressor and the stability of the system will be improved.

<CIT> discloses a continuously variable transmission adapted to set a speed change ratio in accordance with a tilt angle of a rolling member mediating a torque being transmitted, and to transmit a torque among three elements. The transmission mechanism is provided with a rolling member having a smooth outer face and capable of tilting a rotational center axis thereof, and a rotary member arranged to be contacted with a predetermined portion of the outer face of the rolling member in a torque transmittable manner. Specifically, the continuously variable transmission mechanism is configured to vary a rotational speed of the rotary member by changing a rotation radius of a contact point between the rolling member and the rotary member by tilting the rotational center axis of the rolling member.

The present disclosure provides a device and a method for field weakening control of a compressor, an air conditioner and a storage medium, so as to solve the problem that the compressor is easy to enter a field weakening control area during high-speed operation. In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not a general comment, nor is it intended to identify key/important constituent elements or describe the scope of protection of these embodiments. The sole purpose thereof is to present some concepts in a simplified form as a preface to the following detailed description.

According to a first aspect of the present disclosure, there is provided a device for field weakening control of a compressor.

In some embodiments, the device for field weakening control of the compressor includes a main circuit unit and the compressor, the main circuit unit provides power for the compressor, and the device further includes:.

In some embodiments, the main circuit unit includes a rectifier, a power factor correction circuit, a smoothing circuit and an inverter, wherein an input end of the rectifier is an alternating current, an output end of the rectifier is electrically connected to an input end of the power factor correction circuit, the power factor correction circuit is connected to the inverter through the smoothing circuit, and an output end of the inverter is electrically connected to the compressor;
when the rotational speed ω of the compressor is less than ω1, an output voltage of the power factor correction circuit is controlled at the fixed value V0; and when the rotational speed ω of the compressor is greater than or equal to ω1, the compressor is controlled not to enter the field weakening control temporarily and the output voltage of the power factor correction circuit is controlled to rise, and the compressor is controlled to enter the field weakening control when the output voltage of the power factor correction circuit is unable to continue to rise.

In some embodiments, the smoothing circuit is a capacitor filter circuit.

According to a second aspect of the present disclosure, there is provided an air conditioner, including the aforementioned device for field weakening control of the compressor.

According to a third aspect of the present disclosure, there is provided a method for field weakening control of a compressor, including:.

In some embodiments, the main circuit unit includes a rectifier, a power factor correction circuit, a smoothing circuit and an inverter, wherein an input end of the rectifier is an alternating current, an output end of the rectifier is electrically connected to an input end of the power factor correction circuit, the power factor correction circuit is connected to the inverter through the smoothing circuit, and an output end of the inverter is electrically connected to the compressor;
when the rotational speed ω of the compressor is less than ω1, controlling an output voltage of the power factor correction circuit at the fixed value V0; and when the rotational speed ω of the compressor is greater than or equal to ω1, controlling the compressor not to enter the field weakening control temporarily and controlling the output voltage of the power factor correction circuit to rise, and controlling the compressor to enter the field weakening control when the output voltage of the power factor correction circuit is unable to continue to rise.

According to a fourth aspect of the present disclosure, there is provided a computer readable storage medium having a computer program stored thereon, when the computer program is executed by a processor, when the computer program is executed by a processor, the aforementioned method for field weakening control of the compressor is implemented.

Technical solutions provided by the present disclosure may include the following technical effects:
by setting the rotational speed threshold of the compressor, when the rotational speed of the compressor is greater than or equal to the threshold, the compressor is controlled not to enter the field weakening control temporarily and a drive voltage of the compressor is controlled to rise, and the compressor is controlled to enter the field weakening control until the drive voltage of the compressor is unable to continue to rise. In this way, the time for the compressor to enter the field weakening control can be delayed to the greatest extent, the compressor is controlled not to enter the field weakening control to the greatest extent, and the stability of the system is improved.

It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the present disclosure.

The accompanying drawings, which are incorporated in and constitute a part of this description, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

The following description and accompanying drawings fully illustrate the specific implementation solutions of the present disclosure so that a person skilled in the art can practice them. Parts and characteristics of some implementation solutions may be included in or replace parts and characteristics of other implementation solutions. The scope of the implementation solutions of the present disclosure includes the whole scope of the claims and all available equivalents of the claims. As used herein, terms such as "first" and "second" are merely for distinguishing one element from another element and do not require or imply any actual relationship or sequence among these elements. In fact, the first element may also be called the second element, and vice versa. Moreover, terms such as "comprise" and "include" or any other variants indicate a non-exclusive inclusion, so that a structure, apparatus, or device including a series of elements not only include these elements, but also include other elements not explicitly listed or also include elements inherent to such a structure, apparatus, or device. Without further restrictions, the element defined by the statement "includes a/an. " does not exclude the existence of other identical elements in the structure, apparatus, or device that includes the element. As used herein, each embodiment is described progressively, and contents focally described in each embodiment are different from those in other embodiments. The same or similar parts among each of the embodiments may be referred to each other.

Orientations or positional relationships indicated by terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like as used herein are based on orientations or positional relationships shown in the drawings, merely for facilitating describing the present disclosure and simplifying the description, rather than indicating or implying that indicated devices or elements have to be in a specific orientation or configured and operated in a specific orientation, therefore, they should not be construed as limiting the present disclosure. In the description herein, terms "mount", "join" and "connect" shall be construed in a broad sense, unless otherwise indicated and limited. For example, the connection may be mechanical connection or electrical connection, also may be internal communication between two elements, the connection may be direct connection or indirect connection through an intermediate medium. For a person of ordinary skill in the art, specific meanings of the above terms may be understood according to specific circumstances.

Herein, a term "a plurality of" as used herein refers to two or more than two, unless otherwise indicated.

Herein, a character "/" indicates that front and back objects are in an "or" relationship. For example, A/B means A or B.

Herein, a term "and/or" is used to describe an association relation between objects, and indicates that there may be three relationships. For example, A and/or B means A or B, or, A and B.

As shown in <FIG>, a device for field weakening control of a compressor includes a main circuit unit and the compressor, wherein the main circuit unit provides power for the compressor, and the device further includes:.

According to the present embodiment, by setting the rotational speed threshold of the compressor, when the rotational speed of the compressor is greater than or equal to the threshold, the compressor is controlled not to enter the field weakening control temporarily and a drive voltage of the compressor is controlled to rise, and the compressor is controlled to enter the field weakening control until the drive voltage of the compressor is unable to continue to rise. In this way, the time for the compressor to enter the field weakening control can be delayed to the greatest extent, the compressor is controlled not to enter the field weakening control to the greatest extent, and the stability of the system is improved.

Specifically, as shown in <FIG>, the main circuit unit includes a rectifier, a power factor correction circuit, a smoothing circuit and an inverter, wherein an input end of the rectifier is an alternating current, which performs full-wave rectification on an alternating current power; an output end of the rectifier is electrically connected to an input end of the power factor correction circuit, and the power factor correction circuit is used to control a duty ratio of PWM (Pulse Width Modulation), so as to improve the output voltage; the power factor correction circuit is connected to the inverter through the smoothing circuit, and the inverter is used to invert a direct current into the alternating current, so as to control the rotational speed of the compressor. As shown in <FIG>, the smoothing circuit is a capacitor filter circuit.

When the rotational speed ω of the compressor is less than ω1, an output voltage of the power factor correction circuit is controlled at the fixed value V0; and when the rotational speed ω of the compressor is greater than or equal to ω1, the compressor is controlled not to enter the field weakening control temporarily and the output voltage of the power factor correction circuit is controlled to rise, and the compressor is controlled to enter the field weakening control when the output voltage of the power factor correction circuit is unable to continue to rise.

Calculating the rotational speed of the compressor based on the current of the compressor belongs to the prior art. For example, the compressor rotational speed obtaining unit obtains currents Iu, Iv, Iw of the compressor (Iu, Iv, Iw respectively represent U, V, W phase currents of the compressor), and then converts coordinates into iα and iβ;.

Claim 1:
A device for field weakening control of a compressor, comprising the compressor and a main circuit unit providing power for the compressor, wherein the device further characterized by:
a compressor rotational speed obtaining unit used to obtain a current of the compressor, and calculate a rotational speed ω of the compressor; and
a control unit used to compare the rotational speed ω of the compressor with a rotational speed threshold ω1 of the compressor, and control the main circuit unit as follows according to comparison results:
when the rotational speed ω of the compressor is less than ω1, an output voltage of the main circuit unit is controlled at a fixed value V0; and when the rotational speed ω of the compressor is greater than or equal to ω1, the compressor is controlled not to enter the field weakening control temporarily and the output voltage of the main circuit unit is controlled to rise, and the compressor is controlled to enter the field weakening control when the output voltage of the main circuit unit is unable to continue to rise.