# US 2021/0340975 A1 · Method for increasing the efficiency of hermetic compressors used in refrigeration and air conditioning

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0340975 A1
- Document ID: US20210340975A1
- Status: Published application
- Kind: A1
- Application number: 17/286,579
- Filed: 2019-10-18
- Published: 2021-11-04
- Earliest claimed: 2018-10-19
- Assignees: Tecumseh do Brasil LTDA.
- Applicants: Tecumseh Do Brasil Ltda.
- Inventors: Mario Luis Botega, JR.; William Cesar De Andrade Pereira
- Web page: https://patentgrep.com/patent/US20210340975A1

## CPC

- F04B 49/065: {and making use of computers}
- F04B 35/04: the means being electric
- F04B 49/20: by changing the driving speed
- F04C 28/08: characterised by varying the rotational speed
- H02P 21/02: specially adapted for optimising the efficiency at low load
- H02P 21/18: Estimation of position or speed
- H02P 21/20: Estimation of torque
- H02P 21/22: Current control, e.g. using a current control loop
- F04B 2203/0201: Current
- F04B 2203/0202: Voltage
- F04B 2203/0209: Rotational speed
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)
- F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS

## Abstract

The present invention relates to a speed control system for hermetic compressors of the variable speed type, which uses a PMSM motor, containing a strategy for optimization, or minimization, of the electric current. Once the minimum current has been defined to meet a given demand for torque, it is applied to the hermetic compressor motor, which will operate at the maximum efficiency point for each load point.

## Claims

### Claim 1

A method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioning, characterized by having an electronic converter, which executes at least one control algorithm to conveniently drive a variable speed hermetic compressor, said compressor being an integral part of a plurality of refrigeration systems, such as refrigerators and freezers for residential or commercial use, window-type or split-type air conditioners.

### Claim 2 (depends on 1)

The method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 1, wherein at least one electronic converter, consisting of a power circuit containing at least one rectifier circuit, a DC filter, an inverter circuit and a digital signal processor, which can be implemented by a multiplicity of digital processors.

### Claim 3 (depends on 2)

The method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 2, characterized by having a current sensor and a voltage sensor on the DC bus.

### Claim 4 (depends on 2)

The method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 2, characterized by having at least one electric motor control algorithm that is performed by the digital signal processor.

### Claim 5 (depends on 4)

The method to increase the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 4, characterized by having an algorithm for controlling the speed of the hermetic compressor's electric motor, being this vector-type algorithm (FOC).

### Claim 6 (depends on 5)

The method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 5, characterized by having a second algorithm of the MTPA type, which is responsible for defining the lowest operating current for the compressor hermetic, to supply to a certain conjugate.

### Claim 7 (depends on 6)

The method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 6, characterized by having a curve with the trajectory of the best combinations of currents id and iq to meet a given demand for conjugate.

### Claim 8 (depends on 7)

The method for increasing the efficiency of hermetic compressors applied in refrigeration and air conditioners of claim 7, characterized by having a multiplicity of curves of the same conjugate that, when intercepted by the MTPA curve, define the lowest currents id and iq to operate the hermetic compressor and thus consume the lowest power, maximizing its efficiency over the entire operating speed range and at all load points within the operating envelope delimited by.