48results about How to "Reduce switch stress" patented technology

The present invention provides an electrical isolation apparatus having independently controllable contactors. The isolation apparatus includes a contactor for each phase or pole of an electrical device as well as each phase or pole of a load. Each contactor is constructed so that each includes multiple contact assemblies that may be independently controlled to open and close. Moreover, the contactors within a single contactor assembly or housing can be independently controlled so that the contacts of one contactor can be opened without opening the contacts of the other contactors in the contactor assembly. Additionally, the contactors are constructed and controlled such that a single line side contactor and a single load contactor open simultaneously when an open circuit condition is desired.

A method of and apparatus for protecting a MEMS switch is provided. The method and apparatus improve the integrity of MEMS switches by reducing their vulnerability to current flow through them during switching of the MEMS switch between on and off or vice versa. The protection circuit provides for a parallel path, known as a shunt, around the MEMS component. However, components within the shunt circuit can themselves be removed from the shunt when they are not required. This improves the electrical performance of the shunt when the switch is supposed to be in an off state.

The invention discloses a PWM plus double phase shift control method for a bidirectional DC / DC converter, comprising: collecting the port voltage of the bidirectional DC / DC in real time, and calculating the duty ratio of the control signal when the leakage inductance voltage is re-matched ; Obtain the external phase angle j output by the closed-loop controller of the circuit; calculate the internal phase angle acting on the second bridge arm of the improved H bridge when the circuit power circulation is completely eliminated according to the obtained duty cycle and the external phase angle j 0 ; The three parameters of external phase angle, duty cycle and internal phase angle are used to generate the control signal of the circuit. The beneficial effects of the present invention are: the present invention is applicable to a bidirectional DC / DC topology structure in which one side of the converter is an improved H-bridge, and the other side is a buck, boost or its derivative circuit, which can reduce the current stress of the circuit switching device , expand the soft switching range of the circuit, and can completely eliminate the circulating power in the circuit when the circuit works in different working conditions such as light load or heavy load, and improve the working efficiency of the circuit.

The invention discloses an active clamp non-electrolytic capacitor LED driving power supply, comprising an AC input power supply, an input filter part, a rectifier part, a clamp circuit, a flyback converter, an output filter capacitor Co, a parallel absorption circuit and an LED load; The input filter part is composed of input filter inductor and input filter capacitor; the rectifier part is composed of four switch tubes; the clamping circuit is composed of switch tubes S 2 and the clamping capacitor C aux The flyback converter consists of a flyback transformer, a switch tube S 1 and diode D s Composition; the flyback transformer includes the primary winding and the secondary winding, and the primary winding includes the main inductance L m and leakage inductance L r , the primary winding is connected to the input, and the secondary winding is connected to the output; the parallel absorption loop includes the boost inductor L b , switch tube S 3 , switch tube S 4 and storage capacitor C ds . The present invention introduces an active clamp circuit to reduce the switch tube S 1 switch stress; switch tube S 1 and switch tube S 2 Both realize soft switching, reducing switching loss; at the same time, leakage inductance energy can be fed back.

The invention discloses a non-transformer isolated DC-DC converter with a large step-down ratio. The positive pole of the input power supply is connected to the positive pole of the first capacitor and one end of the first switch tube, and the other end of the first switch tube is connected to the first switch tube. One end of the second switch tube is connected to the positive pole of the third capacitor, the negative pole of the third capacitor is connected to one end of the first inductor and one end of the fourth switch tube, the other end of the first inductor is connected to one end of the load resistor and the second inductor One end of the first capacitor is connected, the negative pole of the first capacitor is connected with the positive pole of the second capacitor, the other end of the second switch tube, the other end of the second inductor and one end of the fifth switch tube, the negative pole of the second capacitor, the input power supply Both the negative pole and one end of the third switching tube are grounded, and the other end of the third switching tube is connected to the other end of the fifth switching tube, the other end of the fourth switching tube and the other end of the load resistor, and the converter has low loss. At the same time, it has the characteristics of high efficiency, small size, light weight, and large voltage change ratio.

The invention relates to a Z source inverter double loop grid-connected control method based on repetitive proportional resonant control. The method is used for an LC type Z source inverter grid-connected system. The method comprises the steps of 1, obtaining circuit reference values at an alpha and beta axis according to acquired capacitor and voltage in a Z source inverter; 2, obtaining circuit feedback values at the alpha and beta axis according to acquired grid side inductive current; 3, adding difference values of the circuit reference values and the circuit values after the circuit reference values and the circuit values pass through a repetitive controller and a proportional resonant controller respectively to obtain circuit values of repetitive proportional resonant control, and inputting the obtained circuit values into an SPWM module. Compared with the prior art, waveform quality of grid-connected circuit and voltage under the LC type filter is improved, harmonic distortion rate is reduced, pressure raising effect is drastically improved, system structure is simplified, and use of related materials is saved.

The invention discloses a control circuit for a three-phase high power factor rectifier, and belongs to the field of electrical control. The control circuit comprises an input high-frequency filter circuit, a three-phase input inductor, a three-phase rectifier circuit, a switch tube power circuit, an output rectifier filter circuit, a voltage-dividing detection circuit, an input current detection unit, a single cycle controller and a switch tube driving circuit. A three-phase high power factor can be rectified, high-precision stable output voltage can be obtained, and interference resistance is high.