34results about How to "Small output capacity" patented technology

The invention provides an integrated standard device for field calibration of an extra / ultra high voltage capacitor voltage transformer (CVT). The device comprises a test power supply, a test lifting platform, a standard appliance, a measuring instrument and a vehicle platform, wherein the test power supply comprises cascade upper and lower level test transformers, a secondary compensating reactor and a voltage regulator; the standard appliance comprises cascade upper and lower level standard voltage transformers and a high voltage isolated transformer; the test lifting platform comprises a base, transmission mechanisms and insulating support members; the measuring instrument comprises a transformer calibrator and load boxes; all the equipment is fixedly installed on the vehicle platform;and the test lifting platform can lift in the vertical direction. The upper and lower level standard voltage transformers in the standard device can troubleshoot the standard device by way of mutual calibration in the field and complete field calibration of the extra / ultra high voltage CVT, without unloading.

The invention discloses a switched reluctance motor direct instantaneous torque control method based on voltage vectors. The switched reluctance motor direct instantaneous torque control method is characterized in that sectors can be divided according to a torque characteristic curve of a switched reluctance motor, and a size of a hysteresis region can be determined in a self-adapted manner according to a torque pulsation coefficient and an expected torque; by considering a torque output capability of a conducted phase of a commutation region, real-time adjustment of a duty ratio of a voltage of every phase can be carried out according to an operation condition and a conduction rule, and the voltage vectors of the direct instantaneous torque control can be refined. The method provided by the invention is advantageous in that the realization costs are low, the sampling period can be expanded, the current pulsation and the torque pulsation can be reduced, the winding copper loss is low, and the practicability is strong.

The invention relates to a single-stage multi-input inverter with simultaneous power supply in series and isolated flyback DC chopper. The filter is connected with a shared output filter circuit. Each input terminal of the multi-input and single-output combined isolation bidirectional flyback DC chopper is connected with the output terminal of each input filter in one-to-one correspondence, and the combined isolation of multiple input and single output The output terminal of the bidirectional flyback DC chopper is connected with the output filter circuit. This kind of inverter has the advantages of multiple input sources with different ground, time-sharing or simultaneous power supply, electrical isolation between output and input, simple circuit topology, single-stage power conversion, high power density, high conversion efficiency, high reliability when the load is short-circuited, and output The characteristics of small capacity and wide application prospects have laid a key technology for realizing the small-capacity distributed power supply system of multiple new energy joint power supply.

The invention discloses a three-phase integrated power transformer low-frequency heating power supply system and its operating method. The system includes: an incoming line circuit breaker, which is used to realize input and cut-off operations of the input power supply; an incoming line contactor and an outgoing line contactor, It is used to realize the remote switching operation of the power supply of the whole machine; the phase-shifting transformer is used to realize the input power boost and the multi-pulse rectification input power formation; the low-frequency inverter includes multiple sets of power units for Realize three-phase low-frequency output; automatic power-off system is used to realize automatic power-off when the temperature is too high or the circuit connection line fails, and protect the entire low-frequency heating power system; control system is used to realize the control of the incoming circuit breaker, On-off control of incoming line contactor, outgoing line contactor, phase-shifting transformer and low-frequency inverter. The invention can greatly reduce the power consumption of the heating capacity of the power supply, and can improve the heat dissipation efficiency.

The invention discloses an electrowelding method of touch spark-free steel electroslag pressure welding. In the whole welding process, virtual voltage is output to a welding output end, and the virtual voltage is reduced to 0 volt when an output circuit is short-circuited. According to the scheme, touch arc-spark is avoided in the process of connecting and disconnecting a power supply, and the touch spark-free steel electroslag pressure welding is realized.

The invention relates to an optimization method of an automatic balance adjusting parameter of a three-phase load. The method is characterized in that capacitance or inductance elements with different capacities are connected between a three-phase line and a neutral line and between phase lines; current active powers and reactive powers of all phases are measured and then numerical values of the capacitance or inductance elements with different capacities are calculated, wherein the elements are connected between the three-phase line and the neutral line and between phase lines. In the prior art, when an unbalancing phenomenon occurs at a three-phase load, currents of all phases are not identical and the mutual deviation of the phases of the three-phase currents is not 120 degrees and phases of the three-phase currents and voltages are not identical, so that the unbalancing phenomenon occurs at the three-phase currents; the current of the neutral line is not zero due to the unbalancing phenomenon of the three-phase currents, so that the reactive losses are increased, the wire losses and additional losses of the transformer are increased, and the output capacity of the transformer is reduced; and the certain phase of voltage or the certain two phases of voltages at the tail end is or are low severely. Therefore, the electrical energy quality is affected. However, with the provided optimization method, the defects can be overcome.

The invention discloses a power monitoring and energy saving system which comprises a discharging circuit module and a grid-connected inverting circuit module, wherein the grid-connected inverting circuit module comprises a high-performance DSP (Digital Signal Processing) main board; the input end of the discharging circuit module is connected into the input end of the grid-connected inverting circuit module, and the output end of the grid-connected inverting circuit module is connected into a power grid; the discharging circuit module comprises an LC filtering circuit consisting an inductor L1 and a capacitor C1 and a power pipe Q1; and the power pipe Q1 and an inverting circuit are both controlled by the high-performance DSP main board. The LC filtering circuit is adopted in the discharging module and can obtain constant current and voltage; and when in use, the system can run in a constant current, resistance and power state just by setting the power supply ageing condition of the system and the current, resistance and power of a storage battery in a charging and discharging test, calculating and analyzing a set parameter by the high-performance DSP main board and outputting a corresponding parameter value for controlling conduction or interruption of the power pipe.

The invention discloses a control method for frequency-conversion starting of a diesel engine by utilizing a synchronous generator in an alternating-current diesel locomotive. The control method comprises the following steps of carrying out no-load pre-excitation according to a calculated no-load exciting current ifb; judging whether an exciting current reaches ifb, if the exciting current does not reach ifb, returning and continuously carrying out the pre-excitation; otherwise, carrying out initial positioning according to a preset initial position angle; judging whether the initial positioning is finished, if the initial positioning is finished, selecting a torque command curve according to a preset starting time; otherwise, returning and continuously positioning; carrying out torque loop control according to the torque command curve; judging whether the rotating speed of a motor reaches a preset ignition speed, if the rotating speed of the motor reaches the preset ignition speed, stopping the motor; otherwise, returning and continuously controlling. According to the control method, an air-gap field control strategy, in which the power factor is accurate to 1, of the synchronous generator is realized, and meanwhile, by designing an off-line calculation method for planning the torque command curve according to a preset starting finishing time, the output current of the motor required in a starting system is better optimized.