1279 results about "Current wave" patented technology

A combined power supply and driver control module includes rectifier circuitry, switching circuitry, and driver circuitry for providing output power to a load. Rectified output from an input power source is used to produce a DC power. The switching circuitry receives the DC power and modulates the input current drawn from the power source. An intelligent control module includes control circuitry, such as a digital processor, for controlling the switching circuitry. Power factor is improved by modulating the input current to be closer in phase with the voltage of the power source. Also disclosed is a power factor correction circuit in which a digital processor reads waveform values from a lookup table and modulates the input current waveform based on the values. A zero crossing detector connected to the input power source may direct the digital processor when to commence reading values from the lookup table.

An electrical waveform generator for driving an electromechanical load includes a digital signal processor connected to a waveform generator component in turn connected to an amplifier section with a filter network, the latter being connected to sensing and conditioning circuit componentry that is in turn connected to analog-to-digital converter circuitry. A digital memory stores digitized voltage and current waveform information. The processor determines a phase difference between voltage and current waveforms, compares the determined phase difference to a phase difference command and generates a phase error or correction signal. The processor also generates an amplitude error signal for inducing the amplifier section to change its output amplitude to result in a predetermined amplitude error level for a respective one of the voltage and current waveforms.

Disclosed are a grid-connected converter device of a direct-drive wind power system and a corresponding power coordination control method. The converter device is composed of basic converter units of a Boost circuit based on ac-side energy storage; the structure sufficiently utilizes the equivalent inductance of a power generator stator winding, avoids an external inductor in traditional dc voltage booster circuit, and reduces power loss and equipment cost. Two converter proposals, including a diode rectification mode and a PWM rectification mode are designed; converter topologies with two capacity grades, including medium and small power converter topology, megawatt grade high power converter topology, and relative extension structures are designed, such as a parallel connection converter and an H bridge cascade structure converter; wherein, the converter with the H bridge cascade structure is applicable to grids with high capacity and high voltage, and can obviously reduce the harmonic content in grid-connected current; meanwhile, the control method performing feedback through three closed loops is designed, so the input power and output power of the converter are balanced instantaneously, the dc bus voltage maintains stable, and the grid-connected current wave is sine.

The invention relates to an active damping method of an LCL grid-connected inverter system. The active damping method is realized through the following steps of: setting conjugated zero points or independent zero points to set off conjugated resonance limit points generated by an LCL filter in the grid-connected inverter system or to draw the conjugated resonance limit points to a stable area, and adopting grid-side inductive current to feed back and introduce a state variable in the LCL filter to conduct feedback compensation. By conducting feedback compensation on grid-side inductive voltage, the resonance damping of the LCL filter is controlled, the waveform and the amplitude of grid current of the grid-connected inverter system are controlled and the influence of grid voltage harmonic wave on the grid current can be effectively suppressed. The active damping method is a simple and effective realization method. A realization circuit comprises parallel and series active damping circuits.

The invention aims to provide a driving system and a control method thereof for a four-wheel-drive hybrid vehicle which has high horsepower and higher fuel economical efficiency. The driving system comprises a power battery, a front driving unit, a rear driving unit and an entire vehicle controller for controlling the front driving unit and the rear driving unit to work, wherein the key points are that the front driving unit comprises an engine arranged on a front driving axle and a front axle ISG motor and a front speed reducer connected with the engine through a driving device, the rear driving unit comprises a rear axle ISG motor arranged on a rear driving axle and a rear speed reducer connected with the rear axle ISG motor through the driving device, the front axle ISG motor and the rear axle ISG motor are electrically connected with the power battery through an inverter respectively, and the ratio of the peak power of the front axle ISG motor to the rated power of the engine is over 40 percent. The driving system has a simple mechanical structure and less power loss, can improve the fuel economical efficiency of the vehicle while ensuring the dynamic property, and accord with the modern energy saving and environmental protection trend.

The invention relates to detection of fault arc, wherein, fault arc cycle is recognized through at least two wave characters by gathering current waveform of each cycle; the fault arc is verified through judging whether a plurality of continuous fault arc cycles exist; if the waveform not only meets the condition that the amplitude is smaller than that of normal current or phenomenon of flat shoulder exists on a zero crossing point but also meets the condition that the waveform of positive and negative half cycles is asymmetric or di/dt is overlarge at a certain moment, then the cycle is estimated as a fault arc cycle; if a plurality of cycles continuously are estimated as fault arc cycle, then the fault arc is verified. Compared with the prior art, the technical proposal of the invention has the advantages that the fault arc can be detected during the process of normal power supply; the power can be automatically cut off within very short period, and simultaneously the fault arc current and the starting impulse current can be distinguished; the spurious trip rate is reduced.

The invention provides a three-phase network jointing AC generation circuit and an attached controlling method thereof, which comprises a three level voltage increasing circuit and a three level inverting circuit, wherein, the three level voltage increasing circuit is connected with an input power and comprises a positive voltage increasing part and a negative voltage increasing part, the three level inverting circuit is connected with the three level voltage increasing circuit and comprises a positive inverting part and a negative inverting part; wherein, when the input power is on low voltage state, the low voltage can increase the voltage through the three level voltage increasing circuit and output through the inverting process by the three level inverting circuit; when the input power in on high voltage state, the high voltage can directly output through the inverting process by the three level inverting circuit; and the positive voltage increasing part and the positive inverting part can form a first voltage increasing-decreasing circuit used for outputting a positive semi-circle current wave shape, and the negative voltage increasing part and the negative inverting part can form a second voltage increasing-decreasing circuit used for outputting a negative semi-circle current wave shape. The invention can increase the efficiency of the inverting circuit.

The invention relates to a worm-type plastic corrugated pipe grooving machine. Function of conveying plastic corrugated pipes is completed by a worm curve fixed on a cutter bar of a grooving cutter; the functions of cutting and grooving are realized by one alloy cutter head arranged at the terminal of the worm curve, the worm curve is meshed with wave crests of the plastic corrugated pipes, the plastic corrugated pipes advance for one pitch when being pushed by the worm curve once the cutter bar rotates for a circle, namely the plastic corrugated pipes advance to the next wave crest from the current wave crest, the alloy cutter head arranged at the terminal of the worm curve carries out grooving on the current wave crest for once, the alloy cutter head arranged at the terminal of the worm curve is vertical to axes of the plastic corrugated pipes to ensure that a blade is in a cutting interval while the plastic corrugated pipes do not axially move, the plastic corrugated pipes continuously axially move along with rotation of the cutter bar, and the blade carries out grooving on the wave crest one by one. The grooving machine provided by the invention has simple mechanical structure, no independent pipe conveying device or electronic and electrical inductive control system is required, grooving position is accurate, grooving quality is greatly improved, and rejection rate is greatly reduced while grooving efficiency is greatly improved.

The invention discloses a polyphase permanent magnet synchronous motor current waveform optimal control method, comprising the following steps of A, current reference value coordinate transformation; B, current multiple proportion resonance regulation; and C, coupling compensation. In the control method, based on polyphase permanent magnet synchronous motor vector control, a polyphase synchronous rotating coordinate system current reference value is transformed to a current reference value of each phase in a polyphase static coordinate system through polyphase coordinate transformation, the current reference value of each phase and a current feedback value of each phase of a motor are respectively subjected to improved multiple superposition proportion resonance regulation, and a resonance separation method is introduced, decoupling is realized by feed-forward compensation, and floating tracking and harmful subharmonic restraining for highly dynamic property fundamental waves and usable subharmonic are realized. The method can restrain the adverse impacts, such as motor loss, torque ripple and vibration noise, caused by a harmful harmonic current of the polyphase motor, can explore the positive effects of the usable harmonic current, gives full play to the advantages of the polyphase motor and improves the system performance.

The invention relates to a diagnosis and detection method and a device for an electromagnetic valve used for an electrically controlled common rail fuel feed pump. The method is characterized in that control parameters predetermined by test is input by a monitor program, current waveform during the drive of the electromagnetic valve is detected in real time and curve fitting is conducted; accordingly, the characteristics of the electromagnetic valve are judged, the movement circumstances when turning-on and shutting-down of the electromagnetic valve delays are measured and then whether the electromagnetic valve has the fault of deadlocking or open circuit can be analyzed. When the electromagnetic valve diagnosis and detection device is in use, no fuel injection pump test stand is needed; the use of the device can improve the consistence of the performance of the fuel feed pump electromagnetic valve, thereby greatly improving the performance and reliability of a common rail fuel injection system. The electromagnetic valve detection device has the advantages of low manufacture cost, convenient use, good self-diagnostic function and easy implementation in mass production.

The invention discloses a new energy air force station sending out circuit pilot protection method based on current wave form similarity. The method comprises the steps that same relay protection devices are installed at the M and N sides of a new energy air force station sending out circuit, wherein each suit of the protection devices independently measures a three-phase current at the side each suit of the protection devices is installed and obtains the three-phase current of the opposite side through a communication channel; each suit of the relay protection devices conducts relevant coefficient calculation according to same name phase current sampling values which correspond to the same moment in a same time window length of the side each of the protection devices is installed and the opposite side; each suit of the relay protection devices judges whether or not default occurs in the inner part of the new energy air force station sending out circuit according to the size relationship between the calculated relevant coefficient of each phase current and a setting value so as to start corresponding protection measures according to the types of the default. The method can provide new principle pilot protection of which the reliability and sensitivity are high and the power sing is good for the new energy air force station sending out circuit of different types and different capacity sizes.

The invention discloses a method for generating a remote sensing image quick view under Linux environment and belongs to the technical field of remote sensing image processing. The method comprises that (1) an image of a band sequence (BSQ) format is generated to an image of a tagged image file (TIF) format and (2) a quick view file of a joint photographic experts group (JPEG) format is generated, wherein the step (1) comprises of a, linear mapping, b, pretreatment of decimal part of image data, c, cutting of image data in accordance with a threshold, d, histogram equalization and e, generation of an image file of the TIF format. The method has the advantages of being simple and easy to operate. The generated quick view can describe data information of a current wave band of a hyperspectral image accurately, the method is used for processing 8-position unsigned char type data converted from 32-position single precision floating point type data, and the quantification method has low noise.

The invention discloses a double three-phase permanent magnet motor vector control method based on a proportional resonance regulator. The double three-phase permanent magnet motor vector control method aims at weakening and eliminating (6m+/-1)th power of motor harmonic components under double three-phase permanent magnet motor vector control, wherein m=1,3,5.... The double three-phase permanent magnet motor vector control method is characterized in that on the basis of vector space decoupling vector control, a proportional-resonant regulator is adopted to carry out tracking control on the components (isz1 and isz2) on z1-z2 harmonic sub planes after static coordinate transformation is carried out on six-phase electric currents. By the adoption of the double three-phase permanent magnet motor vector control method, optimal control of a double three-phase permanent magnet synchronous motor can be achieved. Compared with traditional double three-phase motor vector control, the double three-phase permanent magnet motor vector control method has the advantages that current wave forms are more sinusoidal, the harmonic content is greatly reduced, especially the (6m+/-1)th power of the current harmonic components is reduced, system loss is low, and good steady-state performance is achieved.

The invention discloses a borehole time domain pulse electromagnetic method for detecting the electrical resistivity of the stratum out of a metal bushing, comprising the following steps of: 1) building a large-power pulse emitting source underground; receiving the time variable data of induced electromotive force e produced by a magnetic field vertical component Bz recorded in the recording system; and simultaneously recording emitting wave type and receiving signal; 2) emitting and receiving several times, and overlapping signals to improve the signal to noise ratio; 3) calculating bushing response according to the bushing parameter and the recorded emitting source current wave type to obtain the induced electromotive force delta epsilon f relative to the stratum out of metal bushing; 4) correcting the relative induced electromotive force; 5) one-dimensionally reversing and transforming the time variable observed signal into the radial variation information of the electrical resistivity of the stratum around the well; 6) obtaining the longitudinal and radial two-dimensional images of the electrical resistivity of the stratum out of the borehole bushing through the reversed electrical resistivity; 7) confirming the distributing situation of the surplus oil in the storage layer through the distribution of the electrical resistivity of the storage layer out of the bushing according to the survey data and the explained result when well completion.

The invention relates to the field of pulse power technology applications and energy exploitation technology, in particular to a method of electrically exploding wires to generate shock waves in waterby driving energy containing mixtures. The method of the electrically exploding wires to generate the shock waves in water by driving the energy containing mixtures comprises the following steps thata specific pulse power drive source is used to drive the wires of different materials, different diameters, and different lengths to cause an electrical explosion, the phase transition time, discharge current waveform and emission spectrum intensity of the corresponding wires are recorded; shock wave loads of different formulations are made and underwater shock wave experiments are correspondingly performed; shock wave probes are used to measure shock wave waveform and compared with the required waveform to determine the corresponding relationship between shock wave specific impulse and the shock wave loads; and according to the required shock wave parameters and the corresponding relationship between the shock wave specific impulse and the shock wave loads, a corresponding shock wave load is selected to be placed between the high and low voltage electrodes at the output end of the pulse power drive source and is driven under water to generate a controlled shock wave.

The invention discloses an output current wave shape control method for a triphase Active Power Filter (APF). A T-shaped filter and a current wave shape controller are adopted to control the output current wave shape of the triphase AFT. The output filter for each phrase bridge arm of an inverter is a capacity connected to the middle point of two inductances connected with each other in series, and form a T-shaped structure, namely T-shaped filter; the calculation method for wave shape controlling is conducting Alfa, Beta, Omicron transformations to instruction current of the triphase APF, actual output current and the voltage of the power network, so as to realize decoupling of the wave shape controlling of the abc triphase output current; and respectively conducting pole assignment to the single-phrase system under decoupled Alfa, Beta, Omicron axis system, and correcting the error between the APF actual output current an the instruction current, so as to get instruction voltage of each phrase under the alfa, beta, Omicron axis system; and at last sending the instruction voltage to a space vector modulating module, so as to confirm the on-off signal of each bridge arm switch tube, thereby causing the actual output current of the PFA to accurately track the instruction current.

The electrosurgical systems and associated methods of the present disclosure perform narrowband real impedance control for precise treatment of tissue in electrosurgery. The electrosurgical systems include an electrosurgical generator that includes an output stage configured to generate electrosurgical energy to treat tissue, a plurality of sensors configured to sense voltage and current waveforms of the electrosurgical energy, and a controller coupled to the output stage to control the generated electrosurgical energy. The controller includes a signal processor that (1) determines a complex-valued voltage and a complex-valued current based on the voltage waveform and the current waveform sensed by the plurality of sensors using a plurality narrowband filters, and (2) calculates a real part of an impedance of the tissue using the complex-valued voltage and the complex-valued current. The controller also includes an output controller that controls the output stage based on the calculated real part of the impedance of the tissue.

The invention discloses a residual voltage test circuit of a controllable metal oxide arrester and a method thereof. The test circuit comprises an impulse current generation device, an impulse modulation capacitor, a voltage divider, a Rogowski coil and a wave form recorder; wherein the impulse current generation device generates operation impulse current and/or lightning impulse current, and is provided with a high voltage output end and a low voltage output end; the impulse modulation capacitor is connected in parallel with a controllable arrester sample between the high voltage output end and the low voltage output end; one end of the voltage divider is connected with the high voltage output end of the impulse current generation device, while the other end is earthed; the Rogowski coil is directly sleeved on a conductor on a branch circuit of the controllable arrester sample; the wave form recorder is connected with the voltage divider and the output end of the Rogowski coil respectively, and is used for recording voltage and current wave form of the controllable arrester sample. The residual voltage test circuit for the controllable arrester and the method thereof prolong wave head time of the residual voltage on the controllable arrester sample by using the impulse modulation capacitor without changing parameters of the test circuit or the wave form of the lightning impulse current, so that tests have better system equivalence.

The invention belongs to the technical field of power load identification, and particularly relates to a non-intrusive household appliance load identification method. Firstly, a household appliance load is regarded as an independent system, steady-state voltage and steady-state current data in the case of independent operation of each household appliance load are acquired, and according to steady-state current wave crest coefficients, loads are divided into a type of approximately linear loads and a type of nonlinear loads; the steady-state voltage then serves as input data, the steady-state current serves as output data, a system identification method is used for building models for the two types of loads, and a model library is formed; and finally, the steady-state voltage and the steady-state current of a to-be-identified load are acquired, a model library type is determined through pre-selection, and the load is identified according to a model matching principle. The actually-measured data can be used for effectively identifying the linear loads and the nonlinear loads, the algorithm is simple, the operational efficiency is quick, the method can be applied to a condition with increased loads in a home network, large-scale training is not needed when a new load is added to a power consumption network, and a model only needs to be built for the load, and the model is added to the corresponding model library.

The invention discloses a digital ultrasonic generator for measuring current wave forms and voltage wave forms at two ends of a transducer load in an isolation manner, acquiring current signals and voltage signals under effective power and automatically tracking frequencies through the signals to accurately find out resonant frequencies. The voltage wave forms and the current wave forms are calculated by multiplication; phase differences delta phi of the voltage and current wave forms are directly reflected through the obtained direct-current wave forms; and when delta phi is lower, a transducer is nearer a pure resistor, the conversion frequency of the transducer is higher, and the oscillation frequency thereof is nearer an optimal resonant point, so that the transducer load works in a resonant state, the conversion frequency of the ultrasonic transducer is improved, the heating capacity of an inductor and a transformer is reduced, and the current stability and efficiency are improved.

The invention relates to a power network model-based wind power field automatic voltage control method which comprises the following steps of: 1, reading original data and building a wind power field power network mathematical model; 2, reading a wind power field real-time running working condition and a voltage target value released by the power grid dispatching; 3, carrying out load flow calculation to obtain initial load flow distribution on the basis of the former two steps; 4, distributing and releasing the reactive power reference value of a wind driven generator according to a sensitivity ordering strategy; 5, distributing and issuing the reactive power reference value of a dynamic reactive compensation device according to the sequence; and 6, confirming and releasing the tapping point gear reference value of an on-load tap changing transformer according to a step-by step adjustment strategy. According to the power network model-based wind power field automatic voltage control method, the unified coordination control among the reactive power of the wind power field wind driven generator, the reactive power of the dynamic reactive compensation device and the tapping joint of the on load tap changing transformer can be realized.

The invention aims to provide a new method for on-line monitoring of an insulation damping defect of a transformer bushing. Transient voltage waves u(t) and current waves i(t) that occur on the bushing are utilized, and through inversion of a changing characteristic of bushing oil paper insulation dielectric constant [epsilon]r with frequency, the purpose of diagnosing whether the bushing is affected with damp is achieved.