Single-phase device-multiplexing active power decoupling cascaded rectifier and control method thereof

A control system of a multi-module single-phase device-multiplexing active power decoupling cascaded rectifier,

• the rectifier comprising:
• n device-multiplexing active power decoupling H-bridge units that are cascaded, n≥2;
• each device-multiplexing active power decoupling H-bridge unit comprising:
• a bridge arm H1 and a bridge arm H2 connected in parallel, a decoupling capacitor branch formed by two capacitors connected in series, and a resistive load;
• a decoupling inductor being connected in series between a midpoint of the decoupling capacitor branch and a midpoint of the bridge arm H2;
• and a midpoint of an bridge arm H1 of a first device-multiplexing active power decoupling H-bridge unit being sequentially connected in series to an inductor Ls, a resistor Rs, and a power supply Us, and then connected to a midpoint of a bridge arm H2 of a last device-multiplexing active power decoupling H-bridge unit,
• the control system comprising:
• a second direct current (DC) bus voltage control module, configured to add up instantaneous voltages outputted by a controller as a total system voltage through DC-side voltage closed-loop control;
• a voltage balance control module, configured to generate, according to a deviation between an instantaneous voltage Pvi of each cascaded H-bridge unit and an average voltage, a DC bus voltage deviation modulation signal factor of each cascaded H-bridge unit;
• a second unit power factor rectification module, configured to generate a grid-side current reference value according to the total system voltage, calculate a difference between a grid-side inductor current and the grid-side current reference value, and generate a first modulation signal through a proportional resonance (PR) controller;
• a second active power decoupling control module, configured to generate a reference value of a decoupling inductor current according to an instantaneous power Pn of each cascaded H-bridge unit, calculate a difference between the decoupling inductor current and the reference value of the decoupling inductor current, and generate a modulated wave signal of a bridge arm H2 of each cascaded H-bridge unit through the PR controller;
• a rectification bridge arm modulation signal generation module, configured to superimpose the modulated wave signal of the bridge arm H2 of each cascaded H-bridge unit onto the first modulation signal and then onto a respective DC bus voltage deviation modulation signal factor, to generate a modulated wave signal of a bridge arm H1 of each cascaded H-bridge unit;
• a rectification bridge arm drive signal generation module, configured to generate a drive signal of the bridge arm H1 of each cascaded H-bridge unit based on the modulated wave signal of the bridge arm H1 of each cascaded H-bridge unit through a carrier phase-shifted modulation technology;
• and
• a decoupling bridge arm drive signal generation module, configured to generate a drive signal of the bridge arm H2 of each cascaded H-bridge unit after comparing the modulated wave signal of the bridge arm H2 of each cascaded H-bridge unit with a carrier signal.

A control method of a single-phase device-multiplexing active power decoupling cascaded rectifier,

• the rectifier comprising:
• a bridge arm H1 and a bridge arm H2 connected in parallel, a decoupling capacitor branch formed by two capacitors connected in series, and a resistive load;
• a decoupling inductor being connected in series between a midpoint of the decoupling capacitor branch and a midpoint of the bridge arm H2;
• and a midpoint of the bridge arm H1 being sequentially connected in series to an inductor Ls, a resistor Rs, and a power supply Us, and then connected to the midpoint of the bridge arm H2,
• the control method comprising:
• generating a system voltage P in a circuit operation through direct current (DC) bus voltage closed loop control;
• respectively generating a grid-side current reference value and a reference value of a decoupling inductor current according to the system voltage P;
• calculating a difference between a grid-side inductor current and the grid-side current reference value, and generating a first modulation wave through a proportional resonance (PR) controller;
• comparing the decoupling inductor current and the reference value of the decoupling inductor current, and generating a second modulation wave through the PR controller;
• superimposing the first modulation wave onto the second modulation wave for comparison with a carrier, and generating a first drive signal of a bridge arm H1 switching transistor that is used to drive rectification;
• and
• generating a second drive signal of a bridge arm H2 switching transistor that is used to drive decoupling and rectification after comparing the second modulation wave with the carrier.

A control system of a single-phase device-multiplexing active power decoupling cascaded rectifier,

• the rectifier comprising:
• a bridge arm H1 and a bridge arm H2 connected in parallel, a decoupling capacitor branch formed by two capacitors connected in series, and a resistive load;
• a decoupling inductor being connected in series between a midpoint of the decoupling capacitor branch and a midpoint of the bridge arm H2;
• and a midpoint of the bridge arm H1 being sequentially connected in series to an inductor Ls, a resistor Rs, and a power supply Us, and then connected to the midpoint of the bridge arm H2,
• the control system comprising:
• a first direct current (DC) bus voltage control module, configured to generate a system voltage P in a circuit operation through DC bus voltage closed loop control;
• a first unit power factor rectification control module, configured to generate a grid-side current reference value according to the system voltage P, compare a grid-side inductor current with the grid-side current reference value, and generate a first modulation wave through a proportional resonance (PR) controller;
• a first active power decoupling control module, configured to generate a reference value of a decoupling inductor current according to the system voltage P, compare the decoupling inductor current with the reference value of the decoupling inductor current, and generate a second modulation wave through the PR controller;
• and
• a first drive signal generation module, configured to superimpose the first modulation wave onto the second modulation wave for comparison with a carrier, generate a first drive signal of a bridge arm H1 switching transistor that is used to drive rectification, and generate a second drive signal of a bridge arm H2 switching transistor that is used to drive decoupling and rectification after comparing the second modulation wave with the carrier.