3 results about "Three phase system" patented technology

The application belongs to the technical field of electric power, and relates to a constant-voltage three-phase capacitor wireless power transmission circuit and a parameter design method. The three-phase capacitor wireless power transmission circuit comprises a high-frequency three-phase inverter, three LCL input resonance compensation networks, three compensation inductance and capacitor plates, three CLC output resonance compensation networks and a three-phase uncontrolled rectifier. In the parameter design method, firstly, actual requirements and circuit structure parameters are determined; secondly, compensation network constraints and gains are determined; and finally, considering parameter robustness and operation efficiency, the parameters are designed. Compared with a traditional single-phase CPT structure, the three-phase CPT structure has higher power transmission capacity, and the parameter design method effectively improves the robustness of the three-phase CPT system to parameter deviation, ensures constant voltage output in the entire load power range, and controls the output voltage deviation within ±5%.

The application discloses a zero sequence injection modulation method of a modular multilevel matrix converter and relates to the technical field of power electronic control. The modular multilevel matrix converter is connected with two AC systems with different frequencies; the method comprises the following steps: obtaining modulation wave components of three-phase systems on input and output sides respectively through capacitor voltage outer loop control and input current inner loop control of a sub-converter and overall output current control; for each bridge arm, corresponding modulation waves are calculated based on the two modulation wave components; a zero sequence modulation voltage is calculated based on the modulation wave components of the three-phase system on the input side; the zero sequence modulation voltage is injected into each modulation wave to obtain a zero sequence modulation wave; all the zero sequence modulation waves are modulated by using a carrier wave to generate trigger pulses which are distributed to switch devices of corresponding bridge arms. The method can expand the linear modulation range and operation range of the modular multilevel matrix converter and improve the utilization rate of capacitor voltages of sub-modules by injecting zero sequence components into modulation waves.

The invention relates to a method for operating a drive unit (1000) comprising an electric machine (1) and a power converter arrangement (100) for supplying the electric machine with electrical power. The power converter arrangement comprises a first DC voltage terminal (101) and a second DC voltage terminal (102) and at least two half-bridges (110, 120, 130). In each half-bridge, a first and a second semiconductor switch (111, 121, 131, 112, 122, 132) are arranged between the first or second DC voltage terminal (101) and a center terminal (113, 123, 133) of the half-bridge (110, 120, 130). Furthermore, at least two half-bridges comprise a current sensor (114, 124) configured to measure the current flowing through the center terminal.In this method, a symmetrical three-phase system is produced, and the current intensity profile of the flowing current is recorded by each current sensor for a first time interval. Subsequently, a correction factor for the current intensity is determined for at least one of the at least two half-bridges as a function of a characteristic parameter of the recorded current intensity profiles, and the drive unit is operated using the determined correction factor. The invention further relates to a drive unit.