Difference between revisions of "Lexus GS450h Inverter"

From openinverter.org wiki
Jump to navigation Jump to search
(initial page)
(2 intermediate revisions by the same user not shown)
Line 6: Line 6:
  
 
The Lexus GS450h is a hybrid vehicle. Their inverters are suitable and attractive for DIY EVs because of:
 
The Lexus GS450h is a hybrid vehicle. Their inverters are suitable and attractive for DIY EVs because of:
* things
+
* Good availability and price - an inverter and "transmission" can generally be purchased for less than £/€1000.
 +
* Durability. Toyota engineers appear to have made the inverters foolproof, many inputs and outputs gracefully handle fault conditions.
 +
 
 +
* Respectable performance. Rated for a combined 250kW output.
 +
* Ease of repurposing. Emulating the original ECU seems reasonably feasible. The transmission is a similar size and layout to many RWD transmissions.
 
The Lexus GS450h (2006-2012 model years) has a variety of useful components inside the inverter package:
 
The Lexus GS450h (2006-2012 model years) has a variety of useful components inside the inverter package:
 
* 2 high power inverters, for the 2 motors MG1 capable of handling X(?) amps, and MG2 capable of handling Y(?) amps.
 
* 2 high power inverters, for the 2 motors MG1 capable of handling X(?) amps, and MG2 capable of handling Y(?) amps.
Line 12: Line 16:
  
 
== GS450h Converter ==
 
== GS450h Converter ==
converter
+
A buck/boost converter lives within the inverter housing, originally this is used to step up the 288V battery pack in the GS450h to the 650V for use in the inverter. For those using a 600+V battery pack, this converter can be used to step the voltage down to a more reasonable level to interface with charfgers, DCDC converters, heaters, AC compressors, and other components which can be found in "regular" EV's (Tesla, Leaf, Volt, etc).
 +
 
 +
This unit is rated at 30kW, making it unsuitable for traction power, but good for auxiliary devices.
 +
 
 +
== GS450h Transmission ==
 +
[[File:Inverter.png|thumb|213x213px|GS450h inverter]]
 +
The transmission contains two "Motor-Generator" units. MG1 sits at the front of the transmission, and interfaces with the internal combustion engine through a planetary gear set. For this reason, to obtain torque from MG1, the input shaft of the transmission must be locked in place. This is usually done using a splined coupler, which is then welded onto the transmission front mount.
 +
 
 +
The input shaft on the transmission has 21 splines, with a 28mm major diameter. It is believed that there are several Toyota clutches which will have this in their centre. The original GS450h flywheel and coupler also contains the appropriate slined centre, of course.
 +
 
 +
The fluid fill port is the banjo bolt for the upper transmission cooler hose. The specified fluid is "Toyota WS" ATF.
 +
 
 +
It is a good idea to replace the two bearings in the electric oil pump before fitting a used transmission. There is a guide [http://carlthomas66.blogspot.com/2016/03/lexus-gs450h-transmission-oil-pump.html here]. Bearing part numbers are 61900-2Z and 608-2Z, you will need one of each.
 +
 
 +
The shift position lever on the right-hand side of the transmission engages the parking pawl when in the "all-the-way-back" position. All other positions disengage this pawl. The R, N, D, M positions only affect the output of the shift position sensor.
 +
 
 +
Note the following when purchasing the transmission:
 +
[[File:Shift position.png|thumb|154x154px|GS450h shift position sensor]]
 +
* It is recommended to purchase one which has the electric oil pump fitted - these are a costly item as the bearings in them often fail, in some cases they cost more than the transmission.
 +
* It is recommended to purchase a transmission which includes the wiring harness, or at least off-cuts of the connectors. Some connectors may be unavailable for purchase. There is a thread [https://openinverter.org/forum/viewtopic.php?f=14&t=271 here] which covers the connectors on this transmission.
 +
 
 +
==Control Board==
 +
An open-source VCU, designed by Damien Maguire, can be purchased as both partially populated and fully populated and tested boards on his website:
 +
 
 +
[https://www.evbmw.com/index.php/evbmw-webshop/toyota-partially-built-boards-copy/lexus-gs450h-vcm-partial Lexus GS450H VCM Partially Built]
 +
[[File:Transmission.png|thumb|147x147px|GS450h transmission and oil pump temperature sensor]]
 +
[https://www.evbmw.com/index.php/evbmw-webshop/toyota-built-and-tested-boards/gs450h-vcm-fully-built-and-tested Lexus GS450H VCM Fully Built and Tested]
 +
 
 +
The VCU is an external unit that will not fit within the GS450h inverter housing. It does not replace the GS450h inverter control board, instead it interfaces with it over USART.
 +
 
 +
For those who have purchased the fully built board, the mating connectors for the VC are Molex parts:
 +
[[File:Speed sensor.png|thumb|224x224px|GS450h transmission speed sensor]]
 +
* 33472-2002 (Left side, grey in colour)
 +
 
 +
* 33472-2001 (Right side, black in colour)
 +
* 33012-2002 (Crimp terminals)
 +
These parts are available from many electronics distributors.
 +
 
 +
==Development History==
 +
V1 - This board was sold tested but also as a bare logic board requiring purchase of your own components and SMD placement and soldering skills. https://www.evbmw.com/index.php/evbmw-webshop/toyota-bare-boards/prius-gen-3-inverter-bare-logic-board
 +
 
 +
V2 - A new board source was found to be both high quality and low cost. The boards were redesigned around the inventory of parts available from this supplier. In particular the high cost of populated and soldered boards (10x the price) from the source used to make the v1 boards is so significantly lower on the v2 that there are likely no savings by building and soldering the board yourself. Software is still in development.
 +
==Vendors==
 +
- ?? List of known vendors with support?
 +
==Support==
 +
Community support is available on the [https://openinverter.org/forum/viewtopic.php?f=14&t=396 Lexus GS450H VCU Support Thread]

Revision as of 19:00, 9 February 2020

GS450h inverter external connector
GS450h internal inverter connections

The Lexus GS450h VCU is an open source project to repurpose 2006-2012 Lexus GS450h inverters for DIY EV use. It consists of a circuit board and programming that replaces the original logic board in the inverter and allows independent control of it without communicating with a GS450h ECU.

GS450h Inverter

The Lexus GS450h is a hybrid vehicle. Their inverters are suitable and attractive for DIY EVs because of:

  • Good availability and price - an inverter and "transmission" can generally be purchased for less than £/€1000.
  • Durability. Toyota engineers appear to have made the inverters foolproof, many inputs and outputs gracefully handle fault conditions.
  • Respectable performance. Rated for a combined 250kW output.
  • Ease of repurposing. Emulating the original ECU seems reasonably feasible. The transmission is a similar size and layout to many RWD transmissions.

The Lexus GS450h (2006-2012 model years) has a variety of useful components inside the inverter package:

  • 2 high power inverters, for the 2 motors MG1 capable of handling X(?) amps, and MG2 capable of handling Y(?) amps.
  • A boost module to boost the 288v battery pack up to 650v

GS450h Converter

A buck/boost converter lives within the inverter housing, originally this is used to step up the 288V battery pack in the GS450h to the 650V for use in the inverter. For those using a 600+V battery pack, this converter can be used to step the voltage down to a more reasonable level to interface with charfgers, DCDC converters, heaters, AC compressors, and other components which can be found in "regular" EV's (Tesla, Leaf, Volt, etc).

This unit is rated at 30kW, making it unsuitable for traction power, but good for auxiliary devices.

GS450h Transmission

GS450h inverter

The transmission contains two "Motor-Generator" units. MG1 sits at the front of the transmission, and interfaces with the internal combustion engine through a planetary gear set. For this reason, to obtain torque from MG1, the input shaft of the transmission must be locked in place. This is usually done using a splined coupler, which is then welded onto the transmission front mount.

The input shaft on the transmission has 21 splines, with a 28mm major diameter. It is believed that there are several Toyota clutches which will have this in their centre. The original GS450h flywheel and coupler also contains the appropriate slined centre, of course.

The fluid fill port is the banjo bolt for the upper transmission cooler hose. The specified fluid is "Toyota WS" ATF.

It is a good idea to replace the two bearings in the electric oil pump before fitting a used transmission. There is a guide here. Bearing part numbers are 61900-2Z and 608-2Z, you will need one of each.

The shift position lever on the right-hand side of the transmission engages the parking pawl when in the "all-the-way-back" position. All other positions disengage this pawl. The R, N, D, M positions only affect the output of the shift position sensor.

Note the following when purchasing the transmission:

GS450h shift position sensor
  • It is recommended to purchase one which has the electric oil pump fitted - these are a costly item as the bearings in them often fail, in some cases they cost more than the transmission.
  • It is recommended to purchase a transmission which includes the wiring harness, or at least off-cuts of the connectors. Some connectors may be unavailable for purchase. There is a thread here which covers the connectors on this transmission.

Control Board

An open-source VCU, designed by Damien Maguire, can be purchased as both partially populated and fully populated and tested boards on his website:

Lexus GS450H VCM Partially Built

GS450h transmission and oil pump temperature sensor

Lexus GS450H VCM Fully Built and Tested

The VCU is an external unit that will not fit within the GS450h inverter housing. It does not replace the GS450h inverter control board, instead it interfaces with it over USART.

For those who have purchased the fully built board, the mating connectors for the VC are Molex parts:

GS450h transmission speed sensor
  • 33472-2002 (Left side, grey in colour)
  • 33472-2001 (Right side, black in colour)
  • 33012-2002 (Crimp terminals)

These parts are available from many electronics distributors.

Development History

V1 - This board was sold tested but also as a bare logic board requiring purchase of your own components and SMD placement and soldering skills. https://www.evbmw.com/index.php/evbmw-webshop/toyota-bare-boards/prius-gen-3-inverter-bare-logic-board

V2 - A new board source was found to be both high quality and low cost. The boards were redesigned around the inventory of parts available from this supplier. In particular the high cost of populated and soldered boards (10x the price) from the source used to make the v1 boards is so significantly lower on the v2 that there are likely no savings by building and soldering the board yourself. Software is still in development.

Vendors

- ?? List of known vendors with support?

Support

Community support is available on the Lexus GS450H VCU Support Thread