# US 12,009,740 B2 · Power conversion system with enhanced protection for gaseous corrosive atmospheres

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- Number: US 12,009,740 B2
- Document ID: US12009740B2
- Status: Granted
- Kind: B2
- Application number: 18/303,259
- Filed: 2023-04-19
- Published: 2024-04-25
- Granted: 2024-06-11
- Earliest claimed: 2020-09-14
- Assignees: Rockwell Automation Technologies, Inc.
- Applicants: Rockwell Automation Technologies, Inc.
- Inventors: Garron Morris; Garrett Wolff; Craig Devroy; James Carter; Christopher Genthe
- Web page: https://patentgrep.com/patent/US12009740B2

## CPC

- H05K 5/064: {sealed by potting, e.g. waterproof resin poured in a rigid casing}
- C09D 5/08: Anti-corrosive paints
- C09D 127/12: containing fluorine atoms
- H02M 1/32: Means for protecting converters other than automatic disconnection
- H02M 7/217: using semiconductor devices only
- H05K 5/0095: {hermetically-sealed}
- H05K 7/1432: {specially adapted for power drive units or power converters}
- H05K 7/14322: {wherein the control and power circuits of a power converter are arranged within the same casing}
- H10W 42/00: Arrangements for protection of devices (arrangements for thermal protection H10W40/00)
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A motor drive or bus supply power conversion system includes a rectifier with at least one rectifier switch module for rectifying AC input power. A DC bus is connected to the rectifier and supplies DC output power. An optional inverter is connected to the DC bus and includes at least one inverter switch module for inverting the DC bus voltage to an AC output power. The at least one rectifier switch module and the at least one inverter switch module each include a base plate and a housing connected to the base plate. The housing defines an interior space that contains at least one semiconductor switch. Anti-corrosion features are provided including a conformal coating on printed circuit board assemblies, removable connector covers, dielectric grease coated connections, nano-coated fiber optic transceivers, and an exterior protective film wrap.

## Claims

### Claim 1

A power conversion system comprising:
a rectifier comprising at least one rectifier switch module for rectifying AC input power;
a DC bus connected to the rectifier;
wherein said at least one rectifier switch module comprises:
a base plate;
a housing connected to the base plate and defining an interior space that contains at least one semiconductor switch; and
at least one printed circuit board assembly including a plurality of electronic components, a plurality of vias, and a plurality of test points, wherein said at least one printed circuit board comprises a protective coating comprising at least one of: (i) a conformal coating that covers at least said electronic components, said plurality of vias, and said plurality of test points; and (ii) a nanocoating that covers at least said electronic components, said plurality of vias, and said plurality of test points.

### Claim 2 (depends on 1)

The system as set forth in claim 1, wherein said at least one printed circuit board comprises a plurality of unused connectors, wherein each of said unused connectors comprises a removable connector cover mated therewith to protect metal contacts of the unused connector from contact with a corrosive atmosphere.

### Claim 3 (depends on 2)

The system as set forth in claim 2, wherein said at least one printed circuit board comprises a plurality of active connectors that are respectively connected to a corresponding mating connector, wherein each active connector comprises one or more metal contacts that are abutted with corresponding metal contacts of the corresponding mating connector, wherein the metal contacts and the corresponding metal contacts are protected from corrosion by a layer of dielectric grease.

### Claim 4 (depends on 3)

The system as set forth in claim 3, wherein the dielectric grease comprises a UV tracer material.

### Claim 5 (depends on 1)

The system as set forth in claim 1, wherein said at least one printed circuit board comprises a plurality of active connectors that are respectively connected to a corresponding mating connector, wherein each active connector comprises one or more metal contacts that are abutted with corresponding metal contacts of the corresponding mating connector, wherein the metal contacts and the corresponding metal contacts are protected from corrosion by a layer of dielectric grease.

### Claim 6 (depends on 5)

The system as set forth in claim 5, wherein the dielectric grease comprises a UV tracer material.

### Claim 7 (depends on 1)

The system as set forth in claim 1, further comprising at least one fan that comprises a fan printed circuit board assembly including a plurality of fan electronic devices, wherein said fan printed circuit board assembly comprises the conformal coating that covers at least said fan electronic devices.

### Claim 8 (depends on 7)

The system as set forth in claim 7, wherein the conformal coating is a parylene protective coating.

### Claim 9 (depends on 1)

The system as set forth in claim 1, wherein said at least one printed circuit board further comprises a fiber optic transceiver, wherein said fiber optic transceiver is coated with the nanocoating that is a protective anti-corrosive nanocoating.

### Claim 10 (depends on 9)

The system as set forth in claim 9, wherein the nanocoating comprises a fluorocarbon nanocoating.

### Claim 11 (depends on 1)

The system as set forth in claim 1, wherein the conformal coating comprises an ultra-violet light cured polymer.

### Claim 12 (depends on 1)

The system as set forth in claim 1, wherein the conformal coating is spray applied and cured on to said electronic components.

### Claim 13 (depends on 1)

The system as set forth in claim 1, wherein the protective coating comprises both the conformal coating and the nanocoating.

### Claim 14 (depends on 13)

The system as set forth in claim 13, wherein the nanocoating forms an outer layer.

### Claim 15 (depends on 1)

The system as set forth in claim 1, further comprising an enclosure that houses said rectifier and said DC bus, wherein said system further comprises a protective film that completely encases said enclosure such that said protective film defines a sealed internal space including said enclosure.

### Claim 16 (depends on 15)

The system as set forth in claim 15, wherein said protective film comprises a flexible polymeric substrate and metallic particles contained in said polymeric substrate.

### Claim 17 (depends on 15)

The system as set forth in claim 15, further comprising:
a desiccant and a volatile corrosion inhibitor (VCI) emission device located in the internal space defined by the protective film.

### Claim 18 (depends on 1)

The system as set forth in claim 1, further comprising:
a protective cover layer comprising a corrosion protection material, said protective cover layer dividing the interior space into an inner sub-space located between the base plate and the protective cover layer and an outer sub-space located between the protective cover layer and the housing;
wherein said at least one semiconductor switch is located in said inner sub-space such that an atmosphere in said outer sub-space passes through the protective cover layer of corrosion protection material before entering said inner sub-space, wherein said corrosion protection material comprises a sacrificial corrosion protection material.

### Claim 19 (depends on 18)

The system as set forth in claim 18, wherein the sacrificial corrosion protection material comprises a polymeric substrate including a plurality of reactive metallic particles dispersed throughout said substrate.

### Claim 20 (depends on 19)

The system as set forth in claim 19, further comprising:
an inverter connected to the DC bus and comprising at least one inverter switch module for inverting the DC bus voltage to an AC output power, wherein said at least one inverter switch module comprises:
an inverter switch module base plate;
an inverter switch module housing connected to the inverter switch module base plate and defining an inverter switch module interior space that contains at least one inverter semiconductor switch;
an inverter switch module protective cover layer comprising said corrosion protection material, said inverter switch module protective cover layer dividing the interior space of said inverter switch module housing into an inverter switch module inner sub-space located between the inverter switch module base plate and the inverter switch module protective cover layer and an inverter switch module outer sub-space located between the inverter switch module protective cover layer and the inverter switch module housing;
wherein said at least one inverter semiconductor switch is located in said inverter switch module inner sub-space such that an atmosphere in said inverter switch module outer sub-space passes through the inverter switch module protective cover layer of corrosion protection material before entering said inverter switch module inner sub-space;
and wherein said at least one semiconductor switch of said at least one rectifier switch module and said at least one inverter semiconductor switch of said at least one inverter module each comprise an insulated gate bipolar transistor (IGBT).