34results about How to "Simple circuit topology" patented technology

An A / A inverter in high frequency AC link belongs to eletric power and electronic inverting technique which includes input cycle inverter, high frequency transformer or high frequency energy accumulation transformer, output cycle inverter as well as input and output filtering circuits. It can invert one kind frequency of AC electricity to another kind current electricity with the same frequency (or diffeent frequency) so that it has the advantages of circuit topology in simple power invertion in two stages, power circuit in double direction, modification of current wave shape at net side and power factor as well as the critical technique established for electronic transformer, sine AC stabilizer and variable frequency power source.

The invention provides a multi-spacecraft series connection state detection circuit and an implementation method. When the contacts of a spacecraft 1 and a spacecraft 2 are not connected, a resistor R1 and a resistor R2 are connected in parallel and thereafter are connected in series with a resistor R3; when the contacts of the spacecraft 1 and the spacecraft 2 are connected, the resistor R1 is disconnected, the resistor R2 is connected in series with the resistor R3, and the resistor R3 is grounded; and the series connection state of the spacecraft 1 and the spacecraft 2 can be judged throughdetecting a state output voltage P at the resistor R3. The implementation principle topology of the multi-spacecraft series connection state detection circuit is simple and easy to understand; the engineering implementation of the multi-spacecraft series connection state detection circuit is easy; and the multi-spacecraft series connection state detection circuit has an important engineering application value for multi-spacecraft series use.

The invention discloses a dual-motor driving system of a nine-switch inverter and a control method thereof. The system comprises two three-phase permanent magnet synchronous motors, a three-phase nine-switch inverter, a PI controller, a reference current generator, a hysteresis controller, a PWM pulse generating unit, a permanent magnet synchronous motor current detecting sensor, a Hall sensor anda direct current ( DC) power supply, wherein one end of the PI controller is connected with the DC power supply, and the other end is connected with the two three-phase permanent magnet synchronous motors through the reference current generator, the hysteresis controller, the PWM pulse generating unit and the three-phase nine-switch inverter in turn, and the permanent magnet synchronous motor current detecting sensor and the Hall sensor are respectively connected with a position and speed comparator and the reference current generator. The invention enables two permanent magnet synchronous motors to operate synchronously. According to the control topology structure and its control method, the power loss of the nine-switch inverter driven dual-permanent magnet synchronous motor is reducedby declining the number of the power switching tubes.

The invention relates to a nonlinear pulse width modulation control device of a single-phase current source grid-connected inverter. The device can be used for adjusting duty ratio in time and outputting high quality power grid current by feedback of modulation current, so as to effectively overcome the native defect of serious aberration of power grid current wave form when the traditional linear PWM control strategy is adopted; a control circuit of the device comprises an integrating circuit having high frequency resetting function, an absolute-value circuit I, a comparison circuit, a RS trigger, a combinational logic circuit as well as a reference sinusoidal current circuit, an absolute-value circuit II, a zero-crossing comparison circuit and a constant frequency clock circuit that have fixed phase relationship with the power grid voltage. The nonlinear pulse width modulation control device can lead unstable DC voltage to be converted into stable grid-connected current with the needed magnitude and high quality, and has the advantages of single stage power conversion, high conversion efficiency, small harmonic wave of the grid-connected current, rapid dynamic response, high reliability when in overloading, low cost and the like, so as to establish key technology for a renewable energy source grid-connected power generation system.