48results about How to "Reduce the number of capacitors" patented technology

The invention discloses a modular multilevel dynamic switching DC-DC transformer which is composed of N DC-DC sub modules connected in series. Each DC-DC sub module is a symmetric structure which is composed of two half-bridge sub modules and isolating switches S1 and S2 arranged between the two sub modules and can realize bidirectional power flow. Capacitors C1 and C2 are arranged in parallel between the half-bridge sub modules and the isolating switches. The power input end is used as the primary side of the DC-DC transformer, and the power output end is used as the secondary side of the DC-DC transformer. The half-bridge sub modules are primary sub modules when on the primary side of the DC-DC transformer, and are secondary sub modules when on the secondary side of the DC-DC transformer. The primary and secondary sub modules are switched on or off by turning on or off a switching device. Compared with the prior art, the switching ratio of primary to secondary sub modules can be changed dynamically; the transmission power can be controlled flexibly, and the DC-DC transformer has DC power flow control ability; and the number of sub modules is greatly reduced, the advantage of economical performance is significant, the size of the DC-DC transformer is reduced, and the DC-DC transformer can be easily promoted and applied.

The invention discloses a resonant double power supply aviation electromagnetic launching device. The high-power main circuit module includes an AC generator set, a DC airborne power supply, a power conversion main circuit, a resonant main circuit and a transmitting circuit; the AC generator set and the DC airborne The power supply is connected in parallel to the main circuit of the power conversion, and the main circuit of the power conversion converts the direct current of the airborne power supply or the alternating current of the generator set into high-frequency alternating current through the high-frequency inverter bridge or controllable rectifier bridge-high-frequency inverter bridge, and the high-frequency alternating current is passed through The high-frequency uncontrolled rectifier bridge is converted into direct current, and the direct current is converted into an AC square wave by the half bridge; the power conversion main circuit is connected with the resonant main circuit, and the resonant main circuit converts the AC square wave into a sine wave with a fixed resonant frequency; the resonant main circuit It is connected with the transmitting circuit, and the electromagnetic wave of the required transmitting frequency and waveform is transmitted through the transmitting circuit. The invention adopts the mode of parallel power supply to reduce the capacity, weight and volume of the hoisting alternator.

The invention discloses an energy feedback type three-phase high-voltage frequency converter, comprising a main transformer, three-phase reactors, three-phase low-voltage frequency converters with energy feedback functions, and three-phase output transformers. Secondary windings of the main transformer comprise M lines of symmetrical three-phase outputs which are separated from each other and are equal in phase and voltage; and one secondary winding is connected to an input end of each three-phase low-voltage frequency converter through a three-phase reactor. Output ends of the three-phase low-voltage frequency converters are connected to a load or to windings of the output transformers; and three output phases of each low-voltage frequency converter are connected to corresponding output phases of the high-voltage frequency converter in direct series connection or in series connection through coupling of the output transformers.. For three low-voltage frequency converters whose two phases among three output phases are directly connected in series to corresponding high-voltage ac output phases, public output ends of the two phases are used as output ends of the high-voltage frequency converter. According to the invention, input / output ripple current of the low-voltage frequency converters is decreased, driving performance of the load is improved, and cost of the high-voltage frequency converter is declined.

The invention provides a PECVD (Plasma Enhanced Vapor Deposition) reaction chamber and a support pin for the PECVD reaction chamber, which belong to the technical field of semiconductors. The supportpin for the PECVD reaction chamber comprises a pin core , a pin sleeve coating outside the pin core, and at least one layer of spacer arranged on the bottom parts of the pin core and the pin sleeve, wherein the pin core and parts, corresponding to the pin core and the pin sleeve, of the gaskets are made of conductive materials; and the pin sleeve is made of a non-conductive material. According tothe support pin, the pin core is made of the conductive material, and the pin core and the gaskets are grounded, so that the whole support pin is grounded, the number of serially connected capacitorsof a Pin area can be reduced, the plasma density of the Pin area is improved, and a capacitor difference between the Pin area and a non-Pin area is reduced.

The invention provides a half-bridge modular multi-level single-phase inverter and a modulation method, comprising: a capacitor bridge arm and a modular multi-level bridge arm; the modular multi-level bridge arm includes: two ports sub-module; the capacitor bridge arm and the modular multilevel bridge arm each include a DC positive terminal, a DC negative terminal and an AC terminal; the DC positive terminal of the capacitor bridge arm and the modular multilevel terminal The DC positive terminal of the bridge arm is connected to the positive terminal of the DC power supply; the DC negative terminal of the capacitor bridge arm is connected to the DC negative terminal of the modular multi-level bridge arm and is connected to the negative terminal of the DC power supply The AC terminal of the bridge arm of the capacitor and the AC terminal of the modular multi-level bridge arm together constitute the AC output port of the single-phase inverter. The novel nearest-level approximation modulation strategy proposed by the present invention for the topology can realize accurate topology output and maintain the effective operation of the system.

The invention discloses a bidirectional DC-DC converter and a control method. The bidirectional DC-DC converter comprises a first switch network and a second switch network, wherein a first port of the first switch network is connected with a first power supply, a second port of the second switch network is connected with a second power supply, the voltage of the first power supply is smaller than the voltage of the second power supply, the bidirectional DC-DC converter also comprises a transformer, the transformer is used for mutually transferring energy between a first side and a second side, the first side of the transformer is connected with the first switch network by an inductor, and the second side of the transformer is connected with the second switch network by a capacitor and an inductor. By arranging the capacitor at the second side of the transformer, the requirement for a voltage resistant range of the capacitor can be reduced, the number of capacitors in parallel is reduced, and thus, the cost of the bidirectional DC-DC converter is reduced. The bidirectional DC-DC converter is simple in structure and is convenient to detect and maintain.