top of page


Visiting our FAQ page is the first recommended step for customers as it significantly increases the likelihood of finding the answers they seek. Take advantage of this valuable resource to save time, get immediate assistance, and gain clarity on common inquiries.

  • Why is the inverter not controlling?
    The first task is to review the settings of the inverter motor and power source. Let's set these for the current application. The motor position sensor must be calibrated using an automatic calibration function. The software contains many protection functions so that all limiting factors can be monitored. These values can be seen by clicking on the LMIMTS tab within the graphic interface. As long as we see a limiting factor, the system limits performance. Most common errors: -Motor Temp Limit: If the motor temperature sensor is not connected. -DRV error: When the low voltage system of the inverter has a weak or insufficient power supply. -ABS over current: If the position sensor is not calibrated. -Under voltage: High voltage power supply is weak or the voltage is configured incorrectly
  • Why does it oscillate during operation?
    You may need to adjust the current regulator settings to get maximum performance. Also, if the wrong motor parameters are specified, this may be the cause of the oscillation. If the motor parameters are good, it is possible to set the controller in the "PI Current Control" menu. Only who have experience in setting up such a controller should change the parameters! It is necessary to achieve that the "FOC iq" meets the "FOC iq target" as close as possible. Trial and error is the fastest way to achieve results. Try to double the "I" and "P" values per attempt for this purpose. It is not realistic to use more than 10 time biger values for the current motor. After each attempt, try to make bug steps in the "iq target".
  • How can I use two inverters for one motor?
    With the DTI system, it is possible to put two inverters on one motor and increase torque and power. This option is only available for special double winding motors. The motor has one position sensor, but an encoder splitter is needed to divide the signal between the two inverters. The electric schematic does not change.
  • What motors is compatible with the inverter?
    Our inverters are currently compatible with all Permament Marnet Surface Mount synchronous motors. Compatibility with Internal Magnet is also under development, but it is not currently available. You will find the parameters of all EMRAX motors as predefined parameters. If you use a motor from another manufacturer, the following parameters must be entered on the graphical interface: -Motor resistance -Motor inductance -KV (RPM/Voltage) -Poles (EMRAX 10 pole pairs means 20 poles)
  • What liquid can I use for liquid-cooled inverters?
    Glycol – Distillate water mixture that we recommend. The cooling system must include a radiator, water pump and an expansion tank. As an electric water pump, we recommend one of the Pierburg pumps. CWA150 for one or two inverter drives. CWA400 for larger system. Choose a medium compatible with the aluminum system. Connect the water cooling of the individual units in parallel in order to take advantage of the high water flow capacity of the pumps.
  • Is there a possibility for sensorless control?
    In the current phase, there is no development and there are no plans for it. This would not be beneficial for the majority of customers, so this feature has a very low priority.
  • Can HALL effect sensor position detection be used?
    Yes, it can be used. Thanks to a special algorithm, we minimized the pulsation of the motor torque caused by the HALL sensor position detection. So it can be used almost problem-free. It must be taken into account that this is a much more imprecise detection method than encoder detection. Because of this, a performance reduction of roughly 80% must be expected.
  • As the first step of implementation, I would use the inverter on a labor table. Can I use it without cooling system?
    The inverter protects itself from overheating. No need to worry about the inverter destroying itself. With the default settings, it can be used safely in the initial phase of development. However, sustained high temperatures reduce the lifetime, so as soon as the inverter receives a load, it is recommended to build a cooling system.
  • Does the inverter comply with the FSAE safety regulations?
    The rules change from year to year and we try to respond to the new rule changes with our developments. At the moment, yes, it complies with the regulations. The inverter supports the connection and processing of the double redundant analog accelerator pedal according to the regulations. It has the HVIL interlock system, which is mandatory when using the quick connectors.
  • What control modes does the inverter support?
    At the moment, there are 3 main control modes supported by the inverter. -AC current control corresponding to torque control -Motor speed control mode, which is close to to AC voltage control. -Position holding. This is mainly used for gliders and VTOLs to minimize air resistance.
  • What is needed to be able to put two inverters on one motor?
    The DTi system is capable of synchronously operating two inverters even on one motor. Double current / torque is achieved with this solution. The motor must be a special double winding or insulated two winding. The position encoder signal must be split in two with an encoder splitter unit so that both inverters can process the signal. In addition, everything must be done as if there were two independent systems.
  • Can two motors be controlled with one inverter?
    This cannot be solved. The two independent motors require two independent inverters.
  • What happens if the voltage drops down on the low voltage system?
    It should be taken into account that if the inverter is controlling, the consumption of the low voltage part will increase. In this case, it is usually found that the power supply is too weak or the voltage in the low-voltage battery is low. The internal protection of the inverter protects the transistors and disables the control. We get a DRV error message.
  • I calibrated the motor and it still doesn't work. What could be the problem?
    One of the most important factors is that the motor is not under load. It must be calibrated in free rotation. Before calibration, check that the position sensor is properly connected. We can do this by clicking on the "ENCODER" button within the "Optional Data" menu item. Turn the motor by hand (It is very important that the high voltage system is switched off at this time) and the graph should show the same rotation as in reality. After calibration, we should see the actual number of motor pole pairs in the "Encoder Ratio" value. For EMRAX motors it is 10
  • I would like to use a double redundant analog input. Is the inverter compatible with this?
    Yes, the inverter supports double redundant analog inputs. The HV-850 and HV-550 have 3 analog inputs. You can use any two of these. It is also compatible with "offset" and "inverse" operation redundancy. The voltage levels are freely configurable and an error limit can be specified, above which the control is disabled with an error message.
  • Can the inverter be used with a different battery voltage?
    The inverter can be used at any voltage within the "High voltage input range" which specified in the data sheet. This value is between 30V and 800V for the HV-850 controller. If the motor winding is the same, then as the voltage decreases, the maximum speed that can be achieved will decrease in direct proportion, and thus the power as well.
  • How does the HVIL system work?
    This is a safety regulation when we use quick connectors or other easily removable high voltage protection elements in the high voltage system. There is an additional switch on the high-voltage connectors of the inverter that detects whether the connectors are connected. They are connected in series and when all connectors are in place, they close the HVIL circuit. This circuit is isolated from the high voltage system and is available on the harness connector of the inverter. The battery management system or a additional control unit must detect this circuit and if there is a break in the system, it must disconnect the high voltage power supply.
  • Can I use a power supply to power the inverter?
    DC power supply is not permitted or only in special cases with adequate precautions. The power supply is unable to withstand back-acting transients, which can also result in the failure of the inverter. We have to take care of this separately if we want to use it from a power supply.
  • What causes the DRV error message?
    This error code is generated by the driver of the high power transistors. One of the most common mistakes is when the voltage of the low-voltage power supply voltage level is adequate but not strong enough to handle the operation of the transistors. For example if it is 12V, and it can only handle 1A current. In this case, when the inverter starts controlling, the voltage drops below 9V and the inverter is enters error mode due to insufficient drive voltage. The other reason is if, due to some technical fault, the phases of the inverter are short-circuited and one of the drive is destroyed. In such cases, the inverter protects the system with this error phenomenon.
  • The motor calibration stops during the journey and a SENSOR_FAULT error message pops up.
    If the motor fails to calibrate, this error message appears. One of the most common problems is when the motor is under load and cannot rotate freely. The second most common error is if the position sensor is not properly connected to the sensor connector. Look it up in the data sheet and check it several times. It is important to connect the shielding as well.
  • I am trying to upload a configuration to the inverter and I get an error message Error 34.
    This happens when one of the parameters is too large or too small and exceeds the limits. It happens when we try to upload a bad configuration. In such cases, we have to search for the wrong parameter, or in drastic cases, we have to start the setting again with a default configuration.
bottom of page