3results about How to "Avoid harmonics" patented technology

The application provides a dynamic equalization method and circuit, which comprises the following steps: calculating a maximum gain coefficient and a minimum gain coefficient according to an input signal and preset processing parameters; multiplying the filtered input signal and one of the maximum gain coefficient and the minimum gain coefficient to obtain a first output signal; multiplying the input signal directly or after filtering or delaying and the other of the maximum gain coefficient and the minimum gain coefficient to obtain a second output signal; and superimposing the first output signal and the second output signal to obtain a final output signal; and adjusting the proportional relationship between the two input signals to achieve the purpose of adjusting the final output signal in real time. This method simplifies the required calculation amount and storage space of the dynamic filter, avoids the problem of harmonic and noise caused by the sudden change of the filter coefficient, and is effective in optimizing the calculation amount.

The invention discloses a pre-synchronization method, a pre-synchronization device and a medium, relates to the technical field of grid-connected converter control, and provides the pre-synchronization method for solving the problems of relatively high threshold and insufficient efficiency of parameter pre-synchronization through a phase-locked loop method at present. Synchronization of amplitude, frequency and phase can be completed only by processing alternating current bus voltage and inverter output voltage through a simple mathematical method. Parameter difference before grid connection of a grid-forming system can be eliminated without depending on a phase-locked loop or a control link needing parameter setting, and the purposes of suppressing grid-connected impact current, avoiding current distortion and harmonic problems and ensuring smooth transition of grid-connected and off-grid mode switching are achieved. Therefore, compared with a common pre-synchronization scheme based on a phase-locked loop, the method occupies less computing resources, has a lower threshold and is easy to realize in an engineering manner. And moreover, the synchronization efficiency is higher, and the switching efficiency of the grid-connected and off-grid modes of the network construction type system is improved.

The utility model discloses a test module for a high-power tuning antenna switch. The test module comprises a transmitting link (101) and a receiving link (102), each of the transmitting link (101) and the receiving link (102) is provided with a switch array. According to the test module for the high-power tuning antenna switch disclosed by the utility model, through the switch array, the normalization test of low-power signals and high-power signals is realized, and the test efficiency of test equipment is greatly improved.