31results about How to "Control output current" patented technology

The invention concerns a load pump device able to provide a constant current, respectively positive or negative, over an extremely wide output voltage range. A symmetrical switching system activates a first operational amplifier (AOP1) associated with the positive current source or a second amplifier (AOP2) associated with the negative current source according to predetermined threshold values (Vref), the first amplifier being provided so as to restore the behavior of the current mirror (M2, M1) generating a positive current when the output voltage of the device approaches the feed voltage (VDD) and the second amplifier being provided so as to restore the behavior of the current mirror (M4, M3) generating a negative current when the output voltage of the device approaches the earth (GND), thus allowing the output current of the device to be always constant and equal to a reference value (Iref).

The invention relates to a method for controlling an alternator or alternator-starter of a motor vehicle, the electric machine being capable of providing an electric current, the strength of which varies on the basis of the excitation signal (EXC), a duty cycle being associated with each excitation signal, the method comprising the following steps: comparing the difference between the duty cycle values of two consecutive excitation signals at a predetermined threshold; if said difference is greater than the predetermined threshold, releasing a gradual response phase, during which the duty cycle of the excitation signals is gradually increased, particularly in a substantially linear manner; at the start of said gradual response phase, increasing the duty cycle of the consecutive excitation signals by a predetermined jump (D_B), then gradually increasing the duty cycle, the duty cycle jump at the start of the gradual response phase being less than or equal to the release threshold of the gradual response phase.

An embodiment of the present invention provides a current inverter, including a current controller of the inverter; it is characterized in that the current controller includes a simple proportional-integral control part and a proportional resonance control part. The simple proportional-integral control part and proportional resonance control part designed according to the method of the embodiment of the present invention can well control the output current of the inverter.

The invention discloses a supply switching circuit, composed of a power switching portion, a power protecting portion and a charging portion. The circuit is capable of realizing continuous power supply to external equipment to cause the external power demand equipment to be not restarted or to abnormally work, and capable of detecting the battery voltage in real time to carry out protection duringa low voltage of the battery and improve the service life of the battery. While such type of integrated circuit adopted by battery management in the market has a cost about three times higher than that of the invention, the supply switching circuit provided by the invention greatly reduces the production cost.

The invention discloses a primary side feedback flyback LED constant current driver based on power tube drain detection technology, which consists of an EMI filter, a rectifier, a large capacitor Cin, an RCD absorption circuit, a flyback transformer, a power MOS tube, a primary side It consists of sampling resistor Rcs, secondary diode D0, output capacitor Co, LED, secondary on-time acquisition module, LED output current estimation module and PWM controller. Compared with the prior art, the present invention does not need an optocoupler device and an auxiliary winding, and obtains the conduction time information of the secondary diode by detecting the drain of the power switch tube, and the peak current information of the primary side obtained by sampling the source of the power MOSFET, and inputs them together To the PWM controller, the PWM controller obtains the output current information through calculation, so as to control the LED output current to be constant.

The invention discloses an excitation state analysis-based low-voltage ride-through control method of a virtual synchronous power generator. The method comprises the steps of improving designs of droop characteristic, a reactive power ring and an active power ring by means of a reactive power adjustment principle of the synchronous power generator and a power grid which are connected in parallel,and the problems of excessive large reactive power increment, difficulty in preventing impact current and loop coupling reinforcement are effectively dealt with; and on the basis of no change on characteristic of the state analysis-based low-voltage ride-through control method of virtual synchronous power generator (VSG) system, an additional current ring is designed again, the under-excitation state running of an auxiliary system can be assisted during power grid fault period, an output current is adjusted, and a reactive power support is given out. A new directional method is employed, the transient process is accelerated, a control algorithm is not needed to be switched during the power grid fault period, a smooth switching strategy among states is also not needed to be added, and the low-voltage ride-through problem and the asymmetric drop of the power grid can be simultaneously dealt with.

The present invention provides switching type controller, used in power supply delivery unit primary side for controlling current output. It includes waveform detector, discharge time detector, oscillator, integrator, error amplifier pulsewidth comparer. The current output of power supply delivery unit can be stable adjusted on primary side.

The invention discloses a control gain adjustment method and device of a reactive power compensation device and a system. The method comprises a step of calculating a deviation value of control pointbus voltage according to a sampling value of the control point bus voltage and a target value of the control point bus voltage, a step of obtaining a control point operation short-circuit capacity ofan SVC, and a step of calculating an adjustment step number of the control gain of the SVC based on the deviation value of control point bus voltage and the control point operation short-circuit capacity. According to the method provided in the embodiment of the present invention, the adjustment step number of the control gain can be adjusted according to an actual value of the control point operation short-circuit capacity such that SVC controller gain parameters are matched with a short-circuit capacity of a power grid.

The invention discloses a control device for parallel connection of multiple LED power supplies for light control and dimming, including: a master-slave power supply determination module, a master power supply module and a slave power supply module; the master-slave power supply determination module is used for detecting results according to environmental conditions Set the main power module and the slave power module; the main power module converts the collected environmental state detection information into a synchronous signal, sends it to the synchronous signal receiving circuit through the synchronous signal sending circuit, reads the synchronous signal from the power module, and according to the synchronous The signal reading result determines whether the output is turned on and the dimming is enabled or the output is turned off and the dimming function is turned off. The invention also discloses a control method corresponding to the device. The device and method enhance the control precision, improve the overall control performance and reduce the cost.