CROSS-REFERENCES TO RELATED APPLICATIONS

The present disclosure claims the priority of Chinese Patent Application No. 201810308108.5, filed with the Chinese Patent Office on Apr. 8, 2018 and entitled “COMPRESSOR AND REFRIGERATION DEVICE”, and the priority of Chinese Patent Application No. 201810005375.5, filed with the Chinese Patent Office on Jan. 3, 2018 and entitled “COMPRESSOR AND REFRIGERATION DEVICE”, and the priority of Chinese Patent Application No. 201820487751.4, filed with the Chinese Patent Office on Apr. 8, 2018 and entitled “COMPRESSOR AND REFRIGERATION DEVICE”, and the priority of Chinese Patent Application No. 201820007473.8, filed with the Chinese Patent Office on Jan. 3, 2018 and entitled “COMPRESSOR AND REFRIGERATION DEVICE”, the entire contents of which are herein incorporated by reference for all purposes. No new matter has been introduced.

FIELD

The present disclosure relates to the field of compressor manufacturing technology, and specifically to a compressor and a refrigeration device including the compressor.

BACKGROUND

Compressors are important and core components of refrigeration devices. The related technology proposed a winding switching scheme, that is, when the a compressor's motor is running at a low speed, the compressor's stator winding is in a star connection, and when the compressor's motor is running at a high speed, the compressor's stator winding is in a triangle connection. However, the related technology does not involve the design of related parameters of the compressor's motor. If the motor parameters are not properly designed, it will result in low comprehensive efficiency of the motor, a small expansion range, and poor user experience.

SUMMARY

The present disclosure aims to solve at least one of the technical problems existing in the prior art or related technologies.

To this end, the first aspect of the present disclosure proposes a compressor.

The second aspect of the present disclosure proposes a refrigeration device.

In view of this, the first aspect of the present disclosure proposes a compressor for a refrigeration device, the refrigeration device comprising a coupling assembly and a frequency converter connected to one end of the coupling assembly, wherein the compressor comprises: a first shell; and a permanent magnet motor being set in the first shell and connected to the other end of the coupling assembly; a critical rotation speed of the permanent magnet motor is n0; a number of poles of the permanent magnet motor is P; when a winding of the permanent magnet motor is a star connection, a busbar voltage of the frequency converter is Udc, a no-load back-EMF coefficient of the permanent magnet motor is E0, when a preset rotation speed of the permanent magnet motor is n1, a direct axis inductance of the permanent magnet motor is Ld, and an output current of the frequency converter is I1, a relationship between the E0, the P, the I1, the Ld, the n1, and the Udc satisfies (E0−P×I1×Ld)×n1≥0.6 Udc, wherein n1<n0, and n0−n1≤Ir/s, when the winding of the permanent magnet motor is in the star connection, a rotation speed of the permanent magnet motor is less than the n0.

The critical rotation speed of the permanent magnet motor of the compressor provided by the present disclosure is n0. When the winding of the permanent magnet motor is in the star connection, the rotation speed of the permanent magnet motor is less than n0. When the winding of the permanent magnet motor is in an angle connection, the rotation speed of the permanent magnet motor is greater than n0. Under the premise that the winding of the permanent magnet motor is in the angle connection, a relationship between E0, P, I1, Ld, n1 and Udc can be set reasonably to satisfy (E0−P×I1×Ld)×n1≥0.6 Udc, making the permanent magnet motor also have high efficiency performance at low speed and high speed, so as to achieve the purpose of higher performance of the product in the entire frequency band, further, by properly setting the preset rotation speed n1, the rotation speed n1<n0, and n0−n1≤Ir/s. When the rotation speed n1 is close to the critical rotation speed n0, the permanent magnet motor with winding in the star connection mode has a certain field weakening angle, and the performance of the permanent magnet motor decreases with increasing speed, when the rotation speed of permanent magnet motor is greater than the critical rotation speed n0, and is very close to the critical rotation speed n0, the permanent magnet motor with winding in the angle connection mode has a weak magnetic field. The performance of the permanent magnet motor increases with the increasing speed, so as to ensure that it has a certain field weakening depth, near the critical rotation speed n0 when in star connection, and it has a certain range of the permanent magnet motor's rotation speed increases without field weakening when in angle connection, so that if the connection mode of the winding of the permanent magnet motor is switched, the switching is smoother, the impact can be greatly reduced, the transition is more stable, the product's operating energy efficiency is improved, and the product's performance and market competitiveness are improved.

According to the compressor of the present disclosure, it may also have the following additional technical features.

In the above-mentioned technical solution, optionally, a value range of the n0 is n0≥40 r/s.

In the technical solution, by properly setting the value range of the critical rotation speed n0 to n0≥40 r/s, when the rotation speed of the permanent magnet motor is within the critical rotation speed n0, the efficiency of the star connection winding of permanent magnet motor is in a decline mode, and the efficiency of the angle connection winding of the permanent magnet motor is in rising mode, thereby ensuring that the product has higher performance in the entire frequency band. At the same time, if the winding connection method of the permanent magnet motor is switched in the above region, the switching is smoother, the impact can be greatly reduced, the transition is more stable, the product's operating energy efficiency is improved, and the product's performance and market competitiveness are improved.

In any of the above-mentioned technical solutions, optionally, the permanent magnet motor is a three-phase permanent magnet motor.

In the technical solution, the permanent magnet motor is not limited to three-phase permanent magnet motors, but may also be other multi-phase permanent magnet motors.

In any of the above mentioned technical solutions, optionally, the permanent magnet motor comprises: a stator being provided with a stator core and the winding being wound on the stator core; and a rotor being provided in a mounting chamber of the stator, and provided with a rotor core and a permanent magnet being located on the rotor core.

In the embodiment, the stator includes a stator core and a winding, by winding the winding on the stator core, the stator is stationary when the compressor is running, when the current passes through the winding, the stator generates a magnetic field, the rotor includes a rotor core and a permanent magnet, the magnetic pole of the permanent magnet does not change, by setting the permanent magnet on the rotor core, when the compressor is working, the rotor is set in the mounting chamber of the stator, the stator generates a rotating magnetic field, and the rotor is cut by the magnetic field lines in the rotating magnetic field to generate output current, which provides power for the operation of the compressor.

In any of the above-mentioned technical solutions, optionally, a winding of the stator is a three-phase stator winding, a winding of each phase of the stator comprises head joints and tail joints, all the head joints are connected to one terminal of the compressor, all the tail joints are connected to the other terminal of the compressor.

In the embodiment, a winding of each phase of the stator comprises head joints and tail joints, all the head joints of the three-phase stator winding are connected to one terminal of the compressor, all the tail joints of the three-phase stator winding are connected to the other terminal of the compressor, so that the coupling assembly is connected to the two terminals of the compressor respectively. In this way, through the different actions of the coupling assembly, different connection modes of the winding can be achieved, such as star connection and angle connection.

In any of the above-mentioned technical solutions, optionally, the permanent magnet is a rare earth permanent magnet, or the permanent magnet is a ferrite permanent magnet.

In any of the above-mentioned technical solutions, optionally, the rotor core includes slots, and the number of slots is at least one, all the slots are distributed at intervals along the circumferential direction of the rotor core, and the permanent magnets are arranged in the slots.

In the technical solution, a permanent magnet setting scheme of the rotor is specifically limited. By processing slots on the rotor core, it is possible to provide an installation position for the permanent magnet, which facilitates the positioning and assembly of the permanent magnet. At the same time, the structure has fewer processing steps and simple processing technology, low production cost and it is convenient to mass produce.

In any of the above-mentioned technical solutions, optionally, the permanent magnet is cylindrical, and the permanent magnet is sleeved on the outer wall of the rotor core.

In the technical solution, a permanent magnet setting scheme of the rotor is specifically limited. The permanent magnet is sleeved on the outer wall of the rotor core, and the rotor core plays a supporting role, which facilitates the positioning and assembly of the permanent magnet. At the same time, the structure has few processing steps, simple processing technology, low production cost, and it is convenient to mass produce.

The second aspect of the present disclosure provides a refrigeration device, comprising: a second shell; a frequency converter being set in the second shell; the compressor according to the first aspect being provided in the second shell; a coupling assembly being provided in the second shell and connected with the frequency converter and the compressor respectively; and a controller being set in the second shell and connected with the coupling assembly, the frequency converter and the compressor, and being used to control the frequency converter and the compressor, so that a relationship between the E0, the P, the I1, the Ld, the n1 and the Udc satisfies (E0−P×I1×Ld)×n1≥0.6 Udc.

The refrigeration device provided by the present disclosure includes: a second shell, frequency converter, a compressor, a coupling assembly and a controller. By setting the controller to make the winding of the permanent magnet motor in star connection, the controller controls the frequency converter and the compressor, so that a relationship between the E0, the P, the I1, the Ld, the n1 and the Udc satisfies (E0−P×I1×Ld)×n1≥0.6 Udc, thereby ensuring that when the rotation speed of the permanent magnet motor is very close to the critical rotation speed, the permanent magnet motor with star connection of the winding has a certain field weakening depth, and the permanent magnet motor with the angle connection of the winding does not enter the field weakening region, thereby ensuring that the product has high performance in the entire frequency band, and the switching of the winding connection mode of the permanent magnet motor has no stagnation, and the switching is smoother, ensuring the smoothness of the transition.

In the above-mentioned technical solution, optionally, when an input current of the frequency converter is AC, the frequency converter comprises: a rectifier; and an inverter being connected with the rectifier.

In the technical solution, the composition of the frequency converter is determined according to the characteristics of the input current of the frequency converter. When the input current of the frequency converter is AC, the frequency converter includes a rectifier and an inverter, after the input current of the frequency converter is filtered by the rectifier, so that the AC is converted into DC, and the DC is power supplied to the inverter.

In any of the above-mentioned technical solutions, optionally, when an input current of the frequency converter is DC, the frequency converter comprises an inverter.

In the technical solution, the composition of the frequency converter is determined according to the characteristics of the input current of the frequency converter. When the input current of the frequency converter is DC, the frequency converter includes an inverter, which uses the inverter to convert DC power to AC power.

In any of the above-mentioned technical solutions, optionally, the coupling assembly comprises: a selector switch being used to switch a winding of the permanent magnet motor between star connection and angle connection.

In the technical solution, by setting a selector switch, using the selector switch on or off to achieve the connection state of the winding of the permanent magnet motor and the frequency converter, and then achieve the winding of the permanent magnet motor in star connection and the winding of the permanent magnet motor in angle connection. At the same time, the structure setting is convenient for processing, installation and subsequent disassembly, replacement, and has strong interchangeability.

In any of the above-mentioned technical solutions, optionally, the refrigeration device further comprises: a detection device being provided in the second shell and connected with the controller and the compressor.

In the technical solution, by setting a detection device in the second shell and using the detection device to detect the rotation speed of the permanent magnet motor in real time, it provides real-time data for the controller to determine whether the rotation speed of the permanent magnet motor reaches the preset rotation speed n1, which is convenient for the controller to accurately and timely control the movement of other components, thereby ensuring the reliability and accuracy of product use.

Additional aspects and advantages of the present disclosure will become apparent in the following description, or are understood by the practice of the present disclosure.

