Permanent magnet motor, compressor and refrigeration system

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Solution Overview

Problem

Conventional stators with thick windings in high-power or low-voltage permanent magnet motors result in poor manufacturability and degraded performance, particularly in compressors with triangular winding structures.

Innovation Solution

A permanent magnet motor with a stator and rotor design that includes specific parameter ranges for the diameter, rotor length, flux density, and winding turns, connected in a triangular winding structure to improve energy efficiency and manufacturability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If thick windings are used in high-power or low-voltage permanent magnet motors, then the motor can deliver sufficient power, but the manufacturability deteriorates and performance is degraded

Engineering Contradiction:
Improvemotor powerVSAvoidmanufacturability
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent changes the winding connection configuration from traditional star or delta to a specific triangular winding structure with optimized parameter ranges. The key parameter (D+d)×L×Bm1×Ns is optimized to fall within 0.003Udc≤(D+d)×L×Bm1×Ns≤0.008Udc, where D is stator inner diameter, d is rotor outer diameter, L is rotor axial length, Bm1 is air-gap flux density fundamental wave amplitude, Ns is series turns per phase, and Udc is bus DC voltage. This parameter optimization allows the motor to achieve high power output while using thinner, more manufacturable windings.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If traditional parameter ranges are applied to triangular winding structure, then the winding structure can be implemented, but the energy efficiency of the compressor is reduced

Engineering Contradiction:
Improvewinding structure implementationVSAvoidcompressor energy efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent establishes optimized parameter ranges specifically for triangular winding structures in compressor applications. By setting the parameter (D+d)×L×Bm1×Ns within 0.003Udc≤(D+d)×L×Bm1×Ns≤0.008Udc, the invention achieves both manufacturability of the triangular winding structure and high energy efficiency for the compressor system, resolving the contradiction between implementation ease and energy performance.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The new design enhances energy efficiency and manufacturability of compressors by optimizing the parameter ranges, ensuring high performance across various speed ranges.

Implementation Method 1

the rotor has a rotor core and a permanent magnet provided on the rotor core

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a second group of connectors of the A-phase winding and a first group of connectors of the B-phase winding are connected to a common lead-out wire

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentEP3648319B1Permanent magnet motor, compressor and refrigeration system
Publication Date: 2025.11.26 GUANGDONG MEIZHI COMPRESSOR
  • EP3648319B1 patent drawingFigure 1
  • EP3648319B1 patent drawingFigure 2
  • EP3648319B1 patent drawingFigure 3~4

AI summary

Disclosed are a permanent magnet motor, a compressor and a refrigeration system. In the permanent magnet motor (1), the diameter D (m) of a contour circle of the smallest inner periphery of a stator (11), the diameter d (m) of a contour circle of the largest outer periphery of a rotor (12), the fundamental wave amplitude Bm1 (T) of an air-gap flux density at an average gap between the stator and the rotor, the axial length L (m) of the rotor (12), the total number of serially connected turns Ns of each phase winding, and a bus DC voltage Udc (V), before inversion, of a frequency converter supplying power to the permanent magnet motor are set as: 0.003Udc ≤ (D + d) × L × Bm1 × Ns ≤ 0.008Udc, wherein D, d, Bml, L, and Udc are values without units.