In daily life, we often hear the term "DC inverter," such as in DC motor fans, air conditioners, etc. So, does a DC motor have a frequency?
Some people refer to the self-controlled variable frequency speed regulation system of brushless DC motors as "DC inverter," but direct current does not have a frequency. However, the term "DC inverter" has become widely used. This is where the so-called DC inverter comes from.
In DC motors, speed regulation appears to only control the input voltage. However, the automatic frequency conversion speed control system of a DC motor automatically controls the frequency based on the voltage. For DC motors using excitation windings, the excitation can be controlled independently, increasing the speed range. However, for DC motors using permanent magnets, excitation control is more complicated and prone to demagnetization, making it impossible to match the speed range of DC motors with excitation windings. However, with the addition of permanent magnets, such as rare-earth permanent magnets, the magnetic properties are extremely strong, eliminating the need for a dedicated excitation winding. This results in smaller, lighter, and more efficient DC motors.
DC inverters can be understood from another perspective as converting DC voltage into AC voltage with a variable frequency. In the field of residential air conditioning, many people are familiar with the concept of DC inverters.
