5results about How to "Improve current quality" patented technology

The invention discloses an active damping control system for improving the output impedance of a current source type inverter, which comprises a current loop control loop, an active damping branch and an improved phase-locked loop, and is characterized in that the difference value of reference current and feedback network access current passes through a current controller to form the current loop control loop; the voltage of the grid-side inductor is fed back to the output of the current loop through the virtual resistor link to form a damping branch, and the voltage of the common coupling point enters the traditional phase-locked loop link through the low-pass filter and forms an improved phase-locked loop through phase compensation. The optimal feedback coefficient of the damping branch is designed according to the optimal damping ratio, the low-pass filter parameters are designed according to the phase at the maximum resonant frequency, the reasonable proportional gain link is designed according to the improvement of the output impedance amplitude, the resonance of the current source type inverter can be effectively inhibited, the output impedance of the inverter is increased, and the output impedance of the inverter is improved. And the quality of the network access current of the current source type inverter and the stability margin of the current source type inverter in a weak power grid are improved, and the stability of the system is improved.

The invention discloses an interleaved parallel flyback micro inverter control method and device, and a readable medium. The method comprises the steps of obtaining a direct current voltage and a direct current of a photovoltaic module at an input end of a micro inverter, and performing maximum power point tracking calculation to obtain a reference output power; obtaining a power grid voltage instantaneous value and carrying out effective value calculation to obtain a power grid voltage effective value; calculating a grid-connected reference current effective value according to the reference output power and the grid voltage effective value; by setting a secondary side current overlapping factor and calculating and adjusting the switching frequency and the duty ratio, a secondary side current overlapping area is reduced to the greatest extent, and the peak value of the secondary side current can be reduced as far as possible, so that the current stress of a flyback diode and a power frequency flip circuit switching tube is reduced, and the grid-connected current quality is improved.

This invention discloses a hybrid model predictive control method and device for a three-level energy storage converter. The method determines candidate voltage vectors based on voltage vector transformation rules; calculates the cost function value of each candidate voltage vector using a cost function; and selects the voltage vector corresponding to the minimum cost function value as the first... k The pre-optimal voltage vector for the first control cycle; based on the first... k The preliminary optimal voltage vector and midpoint voltage of the first control cycle are combined to determine the first control cycle. k The optimal voltage vector in the first control cycle; in the second... k Calculate the control cycle. k -1 and k The duty cycle of the optimal voltage vector is determined; the gate drive signal corresponding to the optimal voltage vector and its duration is applied to the power electronic semiconductor devices of the T-type three-level energy storage converter. This invention combines the advantages of intuitive and simple finite set model predictive control and high current quality of continuous set model predictive control, enabling current ripple attenuation and current quality optimization of the T-type three-level energy storage converter.

The invention discloses a multi-mode frequency conversion control method of a three-phase four-wire system Vienna rectifier. A carrier reset pulse generation unit and a modulation unit are included. The carrier reset pulse generation unit comprises an AND gate, a first integrator and a first RS trigger; the modulation unit comprises an OR gate, a second integrator and a second RS trigger. The output of the OR gate is used as the input of the first input port of the OR gate. According to the invention, CCM-CRM-DCM multi-mode frequency conversion control is realized by using the logic circuit, and the input current quality during light load is improved; gain compensation is added to modulation signal voltage in a control loop, so that control loop gain change caused by frequency conversion control is offset, uniform control of average current in different working modes is realized, zero-crossing distortion of current in a DCM mode is reduced, oscillation and impact caused by control switching of different modes are avoided, and the reliability of the control loop is improved. The current quality is further improved, and the performance of the rectifier is improved.

The present application relates to the technical field of light storage hybrid power generation control, and particularly to a multi-port light storage hybrid power generation modulation method and system based on current ripple suppression. The method comprises obtaining grid-side voltage and current data; determining a space vector sector according to a reference voltage vector of the grid-side voltage and current data; constructing a clamping sequence based on a reference sector of the space vector sector; establishing a current ripple model according to the clamping sequence and selecting a minimum ripple clamping sequence; deriving a double modulation wave of the minimum ripple clamping sequence based on a volt-second balance; and performing carrier comparison and driving output based on the double modulation wave. The present application systematically gives all clamping switch sequences and determines the influence type of the clamping switch sequences on system power, so that dynamic power regulation among photovoltaic units, energy storage units and loads of a multi-port light storage hybrid power generation system can be realized on the basis of reducing switch loss and improving system efficiency.