Delta Electronics (Shanghai) Co., Ltd

Xi'an Jiaotong University

Virginia Tech Intellectual Properties Inc

Jinjun Liu

Baojin Liu

Zeng Liu

Teng Wu

Shike Wang

Dushan Boroyevich

Jin Li

Yong Tao

Zipeng Liu

The present disclosure discloses a two-point sampling optimized method and system for sinusoidal excitation-based frequency response measurement. A plurality of points are sampled at equal intervals within the starting frequency and ending frequency range as initial information, the interpolation error of each sub-frequency band is estimated according to existing sampling information, the sub-frequency band with the largest interpolation error is selected, two new sampling points are added within the sub-frequency band, and the above steps are repeated until the quantity of sampling points reaches the total quantity set by a user; and the user is asked whether new sampling points need to be added, if so, after the user specifies a new quantity of sampling points, the interpolation error of each sub-frequency band is estimated again and sampling continues, otherwise, the sampling ends. The present improves the practicality of a sinusoidal excitation-based frequency response measurement method.

Two-point sampling optimization method and system for sinusoidal excitation-based frequency response measurement

A method and an apparatus for decoupling output power of an inverter are provided. The method comprises: obtaining voltage amplitude instruction E* and voltage phase instruction &#x3b8;* according to an output voltage and an output current of the inverter; obtaining an amplitude feedforward amount Eand a phase feedforward amount &#x3b4;according to an amplitude U of a grid voltage of the power grid, an amplitude E of the output voltage of the inverter, and a phase difference &#x3b4; between the output voltage of the inverterand the grid voltage; obtaining a reference voltage amplitude Eaccording to the voltage amplitude instruction E* and the amplitude feedforward amount E, and obtaining a reference voltage phase &#x3b8;according to the voltage phase instruction &#x3b8;* and the phase feedforward amount &#x3b4;; and regulating the output power of the inverter using the reference voltage amplitude Eand the reference voltage phase &#x3b8;.

Method and apparatus for decoupling the power of grid-connected inverter

The present invention discloses a secondary control method and apparatus of parallel inverters in a micro grid, comprising: generating frequency and amplitude of fundamental voltage in the voltage instruction of inverter by droop control according to output voltage and output current of inverter to obtain a fundamental voltage instruction value; extracting voltage values and current values of a first and second AC signals from output voltage and output current of inverter, generating frequency instruction values of the first and second AC signals by droop control to obtain voltage instruction values of the first and second AC signals; regulating the output voltage of inverter according to the voltage instruction value of the first AC signal, the voltage instruction value of the second AC signal and the fundamental voltage instruction value.

Secondary control method and apparatus of parallel inverters in micro grid

A main circuit of a three-level active neutral point clamped voltage source converter having a pair of additional main switches provides two paths between an output node and a neutral point in which one of the paths involves only switches of an inner pair of switches that are operated at a high frequency. An auxiliary circuit operating at a high frequency for only a brief period during each high frequency switching cycle selects the path involving only the inner switches and provides operation with zero voltage switching and avoids reverse recovery of diodes connected antiparallel with the main and additional main switches. Accordingly, turn-on switching losses in the main switches is avoided and the voltage source converter can be operated at increased frequency to allow reduction in size of magnetic components and full potential power transfer to be achieved.

Three-level active neutral point clamped zero voltage switching converter

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Shaanxi, China

Jinjun Liu