Delta Electronics (Shanghai) Co., Ltd

Jianfei Zheng

Jianping Ying

Jun Wei Zhang

Zhiming Hu

Lan Wei

Dingkun Shen

Wei Xie

Wei Tian

Yang Liu

Zhi Bin Li

Fei Lu

Aibin Qiu

Bingjie Liu

Binbin Dong

Wei Xu

A hybrid compensation system is electrically connected between a power grid and a load. The hybrid compensation system includes an active filter, a passive filter and a control unit. The active filter generates an output current. The active filter includes a switching circuit, a DC bus capacitor and a filtering inductor. The control unit includes a voltage controller, a first reactive current detector, a harmonic current compensator, a current loop controller and a modulator. The voltage controller generates a first current given signal according to a bus voltage of the DC bus capacitor and a reference voltage. The first reactive current detector generates a second current given signal. The harmonic current compensator generates a third current given signal. The current loop controller generates a control signal. The modulator generates a driving signal according to the control signal.

Hybrid compensation system and control method thereof

A control method of a multilevel converter includes: classifying power modules that start working, need to update an output state or stop working to form m power module groups; and controlling power modules in a same one of the power module groups to start working, update the output state or stop working at the same time, and sequentially controlling the m power module groups to start working, or update the output state or stop working, according to a preset time interval. The number of power modules in each power module group is less than or equal to a preset value, causing a change value of an output level of the each power module group to be less than or equal to a preset voltage value.

Control method of multilevel converter and the multilevel converter

A driving method for power semiconductor switches in an H-bridge circuit is provided. The method includes: calculating a start time and an end time of a zero level of an output voltage and determining a zero level section based on the start time and end time of the zero level; and driving an upper power semiconductor switch of a first bridge arm and an upper power semiconductor switch of a second bridge arm to be on simultaneously or driving a lower power semiconductor switch of the first bridge arm and a lower power semiconductor switch of the second bridge arm to be on simultaneously in the zero level section.

Driving method for power semiconductor switches in H-bridge circuit

A topology of composite cascaded high-voltage and low-voltage modules is provided. It includes at least one high-voltage module, at least one low-voltage module, at least one local control circuit and at least one DC-to-DC module. At least one high-voltage module is connected with at least one low-voltage module in cascade manner. At least one local control circuit outputs at least one signal to at least one high-voltage driving circuit and at least one low-voltage driving circuit. An input of at least one DC-to-DC module is connected with two ends of a low-voltage bus capacitor, for receiving a low-voltage DC bus voltage and converting the low-voltage DC bus voltage into a DC output voltage, so as to provide one or more of at least one high-voltage driving circuit, at least one low-voltage driving circuit and at least one local control circuit with a power supply.

Topology of composite cascaded high-voltage and low-voltage modules

A hybrid topology power converter includes a three-level circuit module and a cascaded H-bridge circuit module. A control method includes the following steps. Firstly, a zero sequence component is injected into a total modulation wave, thereby generating a compensated total modulation wave. Then, a first voltage signal is generated according to the compensated total modulation wave. An H-bridge modulation wave is generated according to the compensated total modulation wave and the first voltage signal. A three-level driving signal is generated according to the first voltage signal, and an H-bridge driving signal is generated according to the H-bridge modulation wave. A duty cycle of at least one switch element of the three-level circuit module is adjusted according to the three-level driving signal. A duty cycle of at least one switch elements of the cascaded H-bridge circuit module is adjusted according to the H-bridge driving signal.

Hybrid topology power converter and control method thereof

A pre-charge control method for a hybrid multilevel power converter comprises steps of: (a) controlling access of the current-limiting resistor unit, limiting current from the AC power via the current-limiting resistor unit, and outputting the current; (b) controlling the second capacitor unit to bypass, and charging the first capacitor unit; (c) controlling the access of the second capacitor unit when the first capacitor unit is charged to a third preset voltage, and charging the first and second capacitor units at the same time; (d) controlling the first capacitor unit to bypass when the second capacitor unit is charged to a fourth preset voltage, or the first capacitor unit is charged to a first preset voltage, and charging the second capacitor unit; and (e) controlling the access of the first capacitor units and the current-limiting resistor unit to bypass when the second capacitor unit is charged to a second preset voltage.

Pre-charge control method

Provided is a doubly-fed induction generator system and a self-test method for the active crowbar circuit of the doubly-fed induction generator system. The invention is featured by using the controller of the doubly-fed induction generator system to carry out a self-test procedure to detect the loop current of the active crowbar circuit for determining if the active crowbar circuit can be turned on and off normally. Also, the rotor-side converter and the active crowbar circuit of the doubly-fed induction generator system are forbidden to turn on simultaneously during the execution of the self-test procedure.

Growing community of inventors

Shanghai, China

Jianfei Zheng