The generation of three-phase low-frequency waves in the inverter is a very important link because the output waveform frequency of the inverter is low.
According to different occasions, the frequency can be several Hz to 20Hz. The quality and stability of the low frequency waveform directly affect the operating condition of the driven motor, including whether the torque is balanced, whether there is a partial magnetic phenomenon, etc, these can affect the quality of the product and the safe operation of the equipment.
The application example shows that the circuit is simple, practical and convenient, easy to control, conforms to the development trend of integration and modularization, and has achieved good results in practical application, therefore, the circuit has broad development and application prospects.
In recent years, four power supply lines have been laid on frequency conversion cranes, one power supply line other than three phases has been used for zero-connection protection lines, and the track has also been wired according to the specified zero-connection protection method, the lighting and maintenance power supply still takes power from the lighting transformer and maintenance transformer.
The user aims to 'strengthen' the anti-interference ability of the system: However, this makes it difficult to control the system that was still stable.
Usually, multiple components that need to be grounded in the inverter crane cabinet and screen (
For example, frequency converter, PLC, reactor, transformer, man-machine interface, etc)
The ground wire is directly connected to the thick grounding copper bar on the control cabinet and screen.
The grounding resistance of the crane track shall not be greater than 10Q, the ground wire must be selected according to the specified wire specifications, and the length of the grounding wire must be shortened as much as possible;
Because the inverter generates induced voltage and leakage current, the grounding point is too far, and the grounding wire is too long, which will cause instability of the potential.