Axiom can be said to be the first in history, which provides a clear and open channel for the exact control of large three-phase motors. It is not more conjunctive than currently, with billions of dollars used to accelerate electric vehicles enter new energy era. With a huge EV team, many semiconductor companies have begun to compete for a new round.
Axiom includes not only a highly functional high-performance controller, but also power-intensive packages. Of course, the best part is that hardware and firmware are open source! Make the schematic, BOM, and code for all people to experiment and improve, is an ideal platform for vehicles, research and industries.
What is AXIOM?
Axiom is a three-phase motor controller. It requires a DC voltage and generates 3 sine waves to drive the motor, which is conceptually similar to a small ESC for drone and bicycles. The difference is that this particular setting can safely use 400V batteries.
Our work is concentrated on the control board, which can be driven by current drives greater than 400V and greater than 300A, which are defined by the power level rating.
We choose the EconoDual IGBT module because it uses popular packages, which have many voltage and current level (from 600V to 1700V, from 100A to 1000A), from many brands, IGBT and SIC technology, and are ready-made Gate drivers work together.
Why design Axiom?
Because we want to develop a maximum, most spectacular product, there is no other open platform to drive 100KW electric motors, that is because the matches you can get are all high-priced proprietary controllers, can't According to your needs, the most important thing is that you can't see the internal working principle to assess whether the quality of software and hardware meets the standard.
Some new programs of electric vehicles have been bundled with specific motor drivers. We provide customers with opportunities to integrate motor drivers into their system, providing a unique vertical opportunity for their products, which saves costs. And improve the quality and integration of the vehicle.
Open Axiom can also show our strength, in the world, there is not much person with a set of skills and knowledge that can produce high-performance drives.
Axiom can also become a comprehensive EV technology with the stable development of the VESC basic platform.
Who is using AXIOM?
Since AXIOM has publicly launched this year, some individuals and engineering teams around the world have signed orders for Axiom. We are currently in the BETA test phase, only choose to provide us with valuable feedback to ensure we offer the best engineering team with reliable products. The following figure is some teams that are testing the Axiom controller from all over the world.
What can you do with AXIOM?
Almost involving all powerful three-phase electric motors, including:
Electric car conversion
Electric racing
Mining
OEM EV, such as bicycle and ATV
Underwater robot
Aircraft system
Glider transmitter
Wind turbine
R & D department
Do you think this can be used to transmit a glider? But the fact is that these applications come from our customers.
Why choose us?
The performance and user experience of the VESC system is first-class, users need an interface to configure motor parameters, which will be the main tool for debugging issues and understanding of the machine.
With proper software and firmware, high-power applications will require some very special hardware:
This is our view:
Mechanically matched with the ECONODUAL / 17MM IGBT module. More compact, fewer assembly steps, fewer wiring and crimping, no adapter parts.
The board is integrated with an isolated HVDC and phase voltage monitor, which can be directly connected to the IGBT to obtain a clearer signal and speed assembly speed.
DC bus capacitor discharge resistor on the board. Safety requirements, discharge it when power is powered on the board.
RF connector for measuring analog signals. This provides a signal quality similar to the simulation, which is ideal for development.
Separate IGBT troubleshooting. You can judge which IGBT fault.
Individual failures cause overpressure, overcurrent, and overheating.
Separate IGBT temperature monitoring.
Ledith ICE40 FPGA, using an open source tool chain to develop and HDL development.
This FPGA constantly monitors all fault inputs. If you assert any fault, all PWM activities will be closed.
The FPGA monitors the PWM generated by the MCU. If the direct command is detected, turn off the PWM.
We are implementing this outstanding motor control technique in FPGA
RJ45 port. These are not Ethernet, but to provide shield twisted pairs in a ready-made standard manner.
Dual simulation accelerator input.
Double isolated CANBus interface.
The parser support.
BISS absolute encoder support (firmware under DEV).
Strove / cosine encoder support.
A stable 15VDC is supplied to the gate driver and monitors the voltage.
Two DAC outputs with RF connector can peek inside the control algorithm.
2 Open drain output for driving small loads or relays, such as pumps.
More fuses, more TVS, more EMI filtering.
Here are some high-resolution pictures for reference:
In the school, you must use the RF connector to poke your key analog signals:
The oldrant type of the isolation gap can be displayed. For newer board, you can't see thicker solder resist.
The all-speed reverse of the IGBT-based power level: (yellow trace is the observer phase output to the DAC channel), this waveform is simply, you will not see this waveform.
Of course, on the AXIOM, what kind of waveform will not be amazing.
This is an exercise for the quality of the board, in practice, we strongly recommend using an absolute encoder on high-power components.
The clear signal is measured at the ADC pin, and the motor angle is sent to the oscilloscope through the DAC. Please note how you can track the motor angle in a non-drive -> Drive transition.
Clear the fault report.
Principle Top:
How to operate?
It requires your battery voltage (DC high pressure), using PWM generates 3 sine waves, and its propagation angle is 120 ° to drive the motor. In fact, it uses spatial vector modulation (SVM) to reduce the required switch, thereby reducing switching loss.
Although VESC supports drive motors in trapezoidal and magnetic field directional control control mode, our board is only available for FOC. It is just suitable for the application.
The purpose of the FOC is to align the sine wave and the actual magnetic field inside the motor, and the vector signal is controlled by the vector signal, the vector signal is composed of a torque orthogonal to the magnetic flux (IQ), and the magnetic flux generating current (ID) is composed.
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This is a great research platform that can be used for high power construction, we have already conducted a long way, no external feedback, so I really want to hear your ideas. Axiom is not an inexpensive controller, but to drive very expensive and dangerous equipment, so it must be a safe and reliable hardware.
Finally, I will see the video introduction of Axiom:
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Copyright Notice: Circuit City Original compilation, translation from HackADAY, please indicate the source!
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