Motor Control
Universal Motors
DC Motors
Three-phase Synchronous
Three-phase Asynchronous
Functions and protection
Testing
One of our basic development and production programs is the development of electronics for commutator, direct current, BLDC, and asynchronous motors used in electric and battery tools. Electronics are produced as modules embedded in plastic trays and inserted into a variety of electrical tools such as angle and straight grinders, drills, circular and oscillating saws, planers, slotting machines, and drilling and demolition hammers.
The vast majority of electronics use a microprocessor to control the required functions of the electronics, which programmers create software for according to the customer's requirements. The basic functions of the modules we produce include soft start, no-load speed limit, speed regulation, motor winding temperature monitoring with a PTC/NTC sensor, motor shutdown in case of overcurrent, switching to cooling speed, monitoring of supply voltage failure, network undervoltage monitoring, LED signaling of functional states, etc.
WHAT ENGINES CAN WE DRIVE?
Universal motors with triac regulation
Used in most small plug-in power tools
compact dimensions and ease of regulation, relatively cheap
lower efficiency of the drive and commutator (carbons need replacing)
DC motors for cordless tools
This is a design that has already been replaced, but it is still used in applications where higher engine torque is needed when the rotor is stationary. Such a start-up is often difficult for drives with a synchronous motor.
ease of regulation where the motor rotates in one direction
lower efficiency of the drive and commutator (carbons need replacing)
Three-phase synchronous motors with permanent magnets for battery-powered and mains-powered tools / BLDC, PMSM
These motors are called BLDC or PMSM. The BLDC motor has a trapezoidal voltage waveform and its control is simpler (6-step). A PMSM motor has a sinusoidal voltage waveform and is regulated by a vector control method based on the mathematical model of the motor. It is more efficient than BLDC with an efficiency reaching over 90% in our applications; with large drives, efficiency over 95% can be achieved.
unlike DC motors, they have no brushes. If the engine is well constructed, it has a very long life. Thanks to the lower voltage, it is possible to achieve very compact dimensions of the control electronics (typically 50 x 50 mm)
problematic start-up when starting up to a heavy load, relative complexity of control electronics, more expensive compared to other types of regulation
Despite these disadvantages, BLDC and PMSM motors are among the most efficient and are currently widely used in high-quality battery tools due to their long service life and low consumption.
Three-phase asynchronous motors
This is another type of brushless motor. Unlike the PMSM motor, it does not have magnets installed in the rotor, but the cage is short-circuited. Thanks to this constructional design, this motor is cheaper.
longer service life than PMSM due to the absence of permanent magnets which risk demagnetization if improperly controlled. Thanks to its design, it has a high torque even when the rotor is stationary. This is one of the most used drives in households and industry for three-phase machines, as it enables start-up without control electronics
lower efficiency compared to PMSM motors. Larger electronics that have the same properties as electronics for PMSM motors powered from the mains
Our priority is to find a fast and quality solution.
The architecture of the control processors and the circuit design is central to our developers and allows them to adapt to your requirements.
FUNCTIONS AND PROTECTION OF TESLA CONTROL ELECTRONICS
Slow start - It serves to limit the currents through the motor during start-up, which increases its service life. The ramp speed can be varied depending on the current flowing through the motor.
Setting the speed with a potentiometer
Regulation depending on the motor speed sensor
Regulation using a virtual speed sensor - such a sensor is usually sensorless algorithms, but it can also be e.g. a motor load map.
Motor cooling mode - in this special mode, the motor reduces the speed so that the winding can be cooled by the integrated propeller on the motor.
Status signaling - we use operational or service signaling. Operational signaling uses LEDs, when the current state of the electronics is displayed. Service signaling informs of a possible HW error. An LCD or OLED display can be used for both types.
Customer-defined actions - the action that occurs is the result of the reaction of one of the protections. This is usually stopping the motor, going into cooling mode, or stopping and restarting.
Communication - using communication protocols, it is possible to read and set motor parameters. A common protocol is e.g. MODBUS.
Dust protection - electronics are normally potted to protect against conductive dust and external environmental influences.
Overcurrent protection - protects electronics from instant overload.
Short circuit protection - quick evaluation of the high current flowing through the motor. The response of electronics is usually in microseconds.
Long-term overload protection - the electronics allow a defined short-term overload, but if it lasts for a certain time, the electronics will react to the overload according to the settings.
Thermal protection of electronics - the temperature of semiconductors is monitored using a thermistor. If the value exceeds the limit, the electronics will react in such a way that it is not destroyed by thermal overload.
Motor thermal protection - a temperature sensor is placed in the motor winding. If the given sensor allows temperature monitoring, the electronics can detect it, and this can be used to define other advanced functions. More often, however, information is only available if the temperature determined by the sensor's properties has been reached. As soon as the motor overheats, the electronics react accordingly and protect the motor from destruction.
TESTING
We take thorough testing seriously. All our electronics undergo a three-phase testing process during production.
1.
Test in the un-soldered state, when the voltage state in the electronics is checked and programming is carried out with the final SW.
2.
Test after filling with insulating PU material at the mains voltage.
3.
Statistical selection of electronics and their control through the Quality Control Department.
