33results about How to "Guaranteed power factor" patented technology

The invention discloses an LED linear constant current drive circuit. The invention can form a first working interval, a second working interval and a third working interval in one power frequency cycle, and the current in the first working interval and the third working interval is greater than In the second working area, a current curve with small two ends is formed in the middle, and the average current value is kept unchanged to realize linear constant current drive control. This solution can improve the efficiency of the linear constant current drive, and also ensure the power factor. At the same time, a temperature feedback is set to control the temperature rise, and the voltage feedforward is introduced as a reference value, which can further improve the efficiency and power factor.

The invention discloses a power factor correction control circuit for reducing EMI (electro magnetic interference), which comprises an inductive current threshold value, wherein when an inductive current is less than the inductive current threshold value, a peak value of the inductive current is controlled to be changed along with an input voltage; and when the inductive current reaches the inductive current threshold value, the inductive current is limited to be the inductive current threshold value. In such a way, the maximum peak of the inductive current is reduced, so that an inductive ripple current is reduced; the power factor is ensured, and the EMI of the circuit is reduced simultaneously, so that circuit filtering can be carried out simply and easily; and the power factor correction control circuit is extremely suitable for occasions with middle or low power. In addition, the peak current stress of the circuit is low, so that a switch tube and other components have small loss, and the utilization ratio of a power supply is further improved. The power factor correction control circuit for reducing the EMI disclosed by the invention meets the requirements of high-power factor and IEC61000-3-2 on the harmonic of the power supply, and has low cost and a small size.

The invention discloses a harmonic wave reactive compensation control method based on a high-voltage inverter bypass. A high-voltage inverter failure bypass reactive compensation circuit comprises an inverter, wherein the inverter is connected with a power grid through an wire inlet switch; a wire outlet end of the inverter is connected to a motor through a three-phase reactor and a wire outlet switch sequentially; a wire inlet end of a bypass switch is connected with a wire inlet end of an inverter wire inlet switch; and a wire outlet end of the bypass switch is connected with a wire outlet end of an inverter wire outlet switch. By the harmonic wave reactive compensation control method based on the high-voltage inverter bypass, a high-voltage inverter device can perform reactive compensation in real time according to motor load after the high-voltage inverter automatically switches the failure into the power frequency to operate, the network side power factor is increased, and the quality of electric energy is improved, so that the utilization ratio of the inverter is increased to the maximum degree and the benefit maximization of users is guaranteed.

The invention relates to a power supply system without passing neutral phases in the whole journey of a high-speed passenger transport line electric multiple units (EMU), and belongs to the field of power supply of high-speed EMU. A cantilever at the upper end of an anchoring section pillar is provided with two catenary wires, the catenary wires are connected with droppers, the droppers are connected with a single-phase alpha contact line and a single-phase beta contact line which are output from the secondary side of a traction transformer, the single-phase alpha and the single-phase beta are parallel, are insulated with each other, are input into the internal power supply system of the EMU through double-phase pantographs and are connected with a basic power supply unit TUB1 and a basic power supply unit TUB2 respectively, and the basic power supply unit TUB1 and the basic power supply unit TUB2 are separate with each other. No circuit breaker switch or neutral insulating section is needed to be arranged on the single-phase alpha and the single-phase beta, and no negative-sequence current generates in a three-phase high-voltage supply network. The invention further provides a circuit structure used for improving a CRH1-model 8-compartment EMU and a CRH5-model 8-compartment EMU into a 6-compartment EMU, a 10-compartment EMU, a 12-compartment EMU and a 16-compartment EMU recombined by two 8-compartment EMUs and for brake regenerative braking.

The invention relates to a voltage reactive compensation control device of a low-voltage circuit. The voltage reactive compensation control device comprises a shell and a low-voltage circuit phase-division automatic voltage-regulation device, wherein the shell is fixedly connected with an installation support, the low-voltage circuit phase-division automatic voltage-regulation device is arranged in the shell and comprises an A-phase voltage-regulation compensation module, a B-phase voltage-regulation compensation module and a C-phase voltage-regulation compensation module, the A-phase voltage-regulation compensation module is arranged between an A-phase line and a null line, the B-phase voltage-regulation compensation module is arranged between a B-phase line and the null line, the C-phasevoltage-regulation compensation module is arranged between a C-phase line and the null line, the A-phase voltage-regulation compensation module, the B-phase voltage-regulation compensation module andthe C-phase voltage-regulation compensation module are controlled by a controller, the controller comprises a GPRS communication module, and the control of a remote controller is accepted by the controller through the GPRS communication module. By the voltage reactive compensation control device, the problems of large current and difficulty in matching of an automatic control switch can be effectively solved, and the load balance can be achieved.

The invention discloses a reactive compensation control method for a distributed photovoltaic power station, and belongs to the field of photovoltaic power generation. The method comprises the steps:determining the actual reactive demand quantity of a property right boundary metering point of an enterprise power grid; determining a static reactive demand quantity of the distributed photovoltaic power station; determining a dynamic reactive compensation quantity according to an instantaneous fluctuation value of an enterprise load voltage and an instantaneous fluctuation value of a voltage ofthe distributed photovoltaic power station; calculating an inductive reactive demand quantity according to the charging power; determining the dynamic reactive demand quantity of the distributed photovoltaic power station according to the dynamic reactive compensation quantity and the inductive reactive demand quantity; determining the configuration information of dynamic compensation equipment and static compensation equipment according to the dynamic reactive compensation quantity and the inductive reactive demand quantity; and controlling the operation of the dynamic compensation equipmentand static compensation equipment according to the configuration information. The method solves a problem that the actual power factor does not meet the requirements after the distributed photovoltaicpower station is added. The method achieves the compensation for the reactive consumption of the distributed photovoltaic power station, and guarantees that the power factor of the property right boundary metering point of the enterprise power grid reaches the standard.

The invention discloses an active filter rectification circuit, which includes a rectification link circuit and a DC link circuit. The rectification link circuit includes an input reactance L1, a main power circuit composed of several power elements, a control circuit, and a sampling circuit. The sampling circuit The collected voltage and current data are sent to the control circuit, the control circuit outputs control signals to the main power circuit, and the alternating current is sent to the main power circuit through the input reactance L1, and the main power circuit converts the alternating current into direct current and sends it to Into the DC conversion link circuit, and output after the DC conversion link. The invention has the advantages that the topological structure design is simple, the input power factor requirement can be met, and the output voltage can be adjusted. The system is equivalent to the traditional two-stage structure, which reduces the number of components, improves the conversion efficiency, and does not require an external low-frequency isolation transformer.

A motor noise reduction control circuit applied to an intelligent laundry machine, including an MCU controller, a phase voltage phase detection module, a current phase detection module, a first and a second drive circuit and a first and a second thyristor; the first , The second thyristor is respectively connected between the AC power supply of the motor and the forward and reverse voltage input terminals of the motor; the MCU controller inputs the phase voltage phase detection signal output by the phase voltage phase detection module and the phase voltage phase detection signal output by the current phase detection module The current phase detects and processes the signal, outputs the first control signal to the first drive circuit, controls the conduction angle of the first thyristor, thereby controls the input voltage of the forward rotation of the motor, or outputs the second control signal to the second drive circuit , to control the conduction angle of the second thyristor, thereby controlling the input voltage for motor reversal. The invention also proposes a motor noise reduction control method applied to the intelligent laundry machine. Even if the motor runs under light load, the present invention does not increase the torque and running speed of the motor, and has low noise.