CN-122026670-A - Permanent magnet variable frequency all-in-one machine with multi-loop flow self-adaptive distribution function and cooling system thereof

CN122026670ACN 122026670 ACN122026670 ACN 122026670ACN-122026670-A

Abstract

The application provides a permanent magnet variable frequency all-in-one machine with a multi-loop flow self-adaptive distribution function and a cooling system thereof, and relates to the technical field of permanent magnet synchronous motor driving and thermal management, and the permanent magnet variable frequency all-in-one machine comprises a motor cavity, a frequency converter cavity, a heat insulation plate, a motor cooling unit, a frequency converter cooling unit and an electric control three-way proportional control valve, wherein the motor cavity is fixedly connected with the frequency converter cavity, and the heat insulation plate is arranged at the connection position of the motor cavity and the frequency converter cavity; the motor cavity is provided with the motor cooling unit, and the converter cavity is provided with the converter cooling unit, and the output of automatically controlled tee bend proportional control valve is connected respectively to motor cooling unit and converter cooling unit, automatically controlled tee bend proportional control valve can adjust the output proportion of coolant liquid. The scheme is applied to a heat dissipation framework of deep integration of the frequency converter and the motor, and independent control of a high heat flux density region of the frequency converter and a high heat capacity heat dissipation region of the motor is realized by taking an electric control three-way proportional control valve as a cold source distribution core.

Inventors

LI NA
JI SHIZHONG
MENG QINGYUE
FANG YUCHAO
WANG SHUANG
WU YUHANG

Assignees

天津电气科学研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (10)

1. A permanent magnet variable frequency all-in-one machine with a multi-loop flow self-adaptive distribution function is characterized by comprising a motor cavity, a frequency converter cavity, a heat insulation plate, a motor cooling unit, a frequency converter cooling unit and a proportional control valve, wherein the motor cavity is fixedly connected with the frequency converter cavity, the heat insulation plate is arranged at the connection position of the motor cavity and the frequency converter cavity, the motor cavity is provided with the motor cooling unit, the frequency converter cavity is provided with the frequency converter cooling unit, the motor cooling unit and the frequency converter cooling unit are respectively connected with the output end of the proportional control valve, and the proportional control valve can adjust the output proportion of cooling liquid.
2. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 1, wherein the motor cavity is formed by enclosing a motor shell and a motor end cover, the frequency converter cavity is formed by enclosing a frequency converter shell and a frequency converter end cover, the motor is arranged in the motor cavity, the frequency converter is arranged in the frequency converter cavity, and the motor shell is fixedly connected with the frequency converter shell.
3. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 2, wherein the motor cooling unit comprises a cooling water channel, the cooling water channel is arranged in a motor shell, the cooling water channel is in a double-spiral water channel structure, two ends of the two spiral water channels are respectively connected with a water inlet and a water outlet, the two spiral water channels are arranged at intervals in parallel, the thread pitches are consistent, the directions are the same, and the flowing directions of cooling liquid in the water channels are opposite.
4. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 2, wherein the frequency converter cooling unit comprises a zigzag water channel, the zigzag water channel is arranged in an end cover of the frequency converter, the water channel spacing of the zigzag water channel is equal, the water flow turning part is a semicircular water channel, two ends of the zigzag water channel are respectively connected with an end cover water inlet and an end cover water outlet, and the end cover water inlet is connected with one output end of the electric control three-way proportional control valve.
5. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 4, wherein a plurality of layers of pin fin structure cooling fins are arranged on the outer side surface of the end cover of the frequency converter.
6. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 2, wherein the motor shell, the motor end cover, the frequency converter shell and the frequency converter end cover are made of aluminum or iron materials.
7. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 1, wherein the whole heat insulation plate adopts a multi-layer composite structure, comprises a central mechanical support layer positioned at the center and a heat insulation coating composited on one side of the central mechanical support layer, a plurality of heat insulation grooves are formed in the other side of the heat insulation plate, and low-heat-conductivity heat insulation materials are filled in the heat insulation grooves.
8. The permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function, which is disclosed in claim 7, is characterized in that the central mechanical supporting layer is made of a high-strength high-temperature-resistant nonmetallic material, the thermal insulation coating is made of ceramic-based thermal insulation paint or organic silicon modified thermal insulation material, the depth of a thermal insulation groove is 3mm-8mm, and the thermal conductivity coefficient of the low-thermal-conductivity thermal insulation material is lower than 0.1W/(mK).
9. The utility model provides a cooling system of permanent magnetism frequency conversion all-in-one with multiloop flow self-adaptation distribution function which characterized in that includes: The temperature sensor is divided into a first sensor pre-embedded in the base plate of the frequency converter and a second sensor pre-embedded in the stator winding of the motor, The controller reads the first sensor data and the second sensor data in real time, compares the measured temperature with a preset target temperature interval, calculates the heat load of the frequency converter side and the heat load of the motor side, further calculates the target opening of the proportional control valve, and sends driving pulses to the proportional control valve; the proportional control valve receives a driving pulse control instruction of the controller, changes the position of a piston or a valve core in the proportional control valve, and completes flow redistribution.
10. The cooling system of the permanent magnet variable frequency all-in-one machine with the multi-loop flow self-adaptive distribution function according to claim 9, wherein the control method of the controller comprises the following specific steps: Step 1, data acquisition and deviation preprocessing The system is according to the preset sampling period Synchronously reading measured temperature of first temperature sensor And the measured temperature of the second temperature sensor The measured temperature and the preset target temperature Comparing, calculating the temperature deviation value of each controlled object : Motor side bias: , Frequency converter side offset: , Step 2, double-channel parallel PI operation, wherein two groups of control amounts are calculated respectively due to different thermal characteristics of the motor and the frequency converter: Frequency converter side heat load control quantity : , Motor side heat load control amount : , Wherein, the Is the proportional gain of the frequency converter side thermal load PI controller, Is the integral gain of a frequency converter side thermal load PI controller, Is the proportional gain of a motor side thermal load PI controller, Is the integral gain of the motor side thermal load PI controller; step 3, synthesizing and dynamically adjusting the target opening, and calculating the target opening of the proportional regulating valve by the system through a weighted fusion algorithm according to the two-path heat load requirements calculated in the step 2 The specific formula is as follows: , Wherein, the Is a dynamic coupling factor, the value range is [ 0.6-0.9 ], Step 4, amplitude limiting processing and execution, in order to prevent frequent valve jitter, to Dead zone processing and rate of change limiting if The valve opening is kept unchanged, and when the target opening is reached When the three-way proportional regulating valve is increased, the flow share of the cooling fluid flowing to the cooling unit of the frequency converter is increased, and the flow share of the cooling unit of the motor is correspondingly reduced, so that dynamic balance adjustment of heat loads on the motor and the side of the frequency converter is realized.

Description

Permanent magnet variable frequency all-in-one machine with multi-loop flow self-adaptive distribution function and cooling system thereof Technical Field The application relates to the technical field of permanent magnet synchronous motor driving and thermal management, in particular to a permanent magnet variable frequency all-in-one machine with a multi-loop flow self-adaptive distribution function and a cooling system thereof. Background With the development of power electronic technology and motor manufacturing process, the frequency converter and the permanent magnet synchronous motor are designed into a physical integrated design (namely a permanent magnet frequency conversion integrated machine), so that the frequency converter has the remarkable advantages of compact structure, no need of external cables, high power density and the like, and is widely applied to the fields of new energy automobiles, mining industry, metallurgy and the like. However, the compact design of the permanent magnet variable frequency all-in-one machine presents a significant challenge for the heat dissipation system. The frequency converter and the motor are integrated in the same shell, and a serious thermal coupling effect exists between the frequency converter and the motor. In actual operation, the heating characteristics of the frequency converter and the motor are obviously different (1) the heating characteristics are different, namely, a power device (such as an IGBT or an SiC module) in the frequency converter generates heat by a typical point source, extremely high local heat exchange efficiency is required, and the motor stator generates heat with large distribution area, belongs to non-point source heating, and emphasizes the uniformity of a temperature field. (2) Temperature difference resistance electronic components in the frequency converter are usually resistant to lower temperatures, while the motor windings and permanent magnets are relatively resistant to higher temperatures. Conventional series cooling results in the downstream components absorbing the heated coolant, which reduces the heat dissipation. (3) The working condition is dynamically changed, namely the ratio of the loss of the frequency converter to the loss of the motor is dynamically changed under different load working conditions. For example, under the working condition of low speed and heavy load, the heat generated by the motor is dominant, and under the working condition of high speed and light load but high switching frequency, the heat generated by the frequency converter is dominant. The existing permanent magnet frequency conversion all-in-one machine cooling scheme mostly adopts a single water channel structure to synchronously cool the permanent magnet frequency conversion all-in-one machine cooling scheme or adopts a fixed parallel branch. The flow rate ratio of the cooling liquid cannot be dynamically adjusted according to the real-time heat load of the frequency converter and the motor, the same water channel structure is difficult to simultaneously consider the high-strength local enhanced heat exchange required by the frequency converter and the large-area global uniform heat exchange required by the motor, and the real-time feedback and independent adjustment means are lacked. Therefore, developing a permanent magnet variable frequency integrated machine and a cooling system thereof, which can design a differential water channel aiming at the heterogeneous heating characteristics of a frequency converter and a motor and can adaptively adjust multi-loop flow distribution according to real-time heat load, has become a key technical problem of improving the power density of the system, ensuring the operation reliability and optimizing the energy efficiency ratio. Disclosure of Invention Based on the defects of the prior art, the application provides a permanent magnet variable frequency all-in-one machine with a multi-loop flow self-adaptive distribution function and a cooling system thereof. The method is realized by adopting the following technical scheme: A permanent magnet variable frequency all-in-one machine with a multi-loop flow self-adaptive distribution function comprises a motor cavity, a frequency converter cavity, a heat insulation plate, a motor cooling unit, a frequency converter cooling unit and a proportional regulating valve, wherein the motor cavity is fixedly connected with the frequency converter cavity, the heat insulation plate is arranged at the connection position of the motor cavity and the frequency converter cavity, the motor cavity is provided with the motor cooling unit, the frequency converter cavity is provided with the frequency converter cooling unit, the motor cooling unit and the frequency converter cooling unit are respectively connected with the output end of the proportional regulating valve, and the proportional regulating valve can regulate the output proportion of cooling liquid. Fur