Hybrid direct current energy dissipation device and hybrid direct current energy dissipation control method

Abstract

The present application relates to the field of wind power technology, and particularly relates to a hybrid DC energy dissipation device and a hybrid DC energy dissipation control method. The energy dissipation device comprises a plurality of energy dissipation modules and a centralized energy dissipation resistor connected in series with the energy dissipation modules. The incoming line end of the energy dissipation module is connected to the positive DC direction, and the outgoing line end of the energy dissipation module is connected to the negative DC direction. The energy dissipation module comprises a charging voltage equalization unit, a bypass unit, a capacitor unit and an energy dissipation branch. The charging voltage equalization unit and the bypass unit are connected in series to form a dynamic voltage equalization branch, and the dynamic voltage equalization branch is connected in parallel with the capacitor unit and the energy dissipation branch. The present application decouples the control of the bypass unit and the energy dissipation module. Through the separate sorting of the virtual energy consumption and the capacitor voltage of the energy dissipation module, the capacitor voltage and the dissipated energy are balanced. Based on the energy dissipation module design method, the resistance value of the energy dissipation resistor of the energy dissipation branch is improved, the current stress of the switch tube of the energy dissipation branch is reduced, and the device cost is reduced.

Claims

1. A hybrid DC energy-consuming device, characterized in that, The energy-consuming device includes multiple energy-consuming modules and a centralized energy-consuming resistor connected in series with the energy-consuming modules. The input terminal of each energy-consuming module is connected to the positive DC direction, and the output terminal of each energy-consuming module is connected to the negative DC direction. Each energy-consuming module includes a charging voltage equalization unit, a bypass unit, a capacitor unit, and an energy-consuming branch. The charging voltage equalization unit includes a dynamic voltage equalization resistor and a first diode connected in parallel with the dynamic voltage equalization resistor. The anode of the first diode is connected to the input terminal of the energy-consuming module, and the cathode of the first diode is connected to the high-voltage terminal of the capacitor unit. The bypass unit includes... A first fully controlled power electronic switch and a second diode connected in reverse parallel to the first fully controlled power electronic switch, wherein the anode of the second diode is connected to the output terminal of the energy-consuming device. When the first fully controlled power electronic switch is turned on, the capacitor unit discharges through the dynamic voltage equalization resistor and the first fully controlled power electronic switch to achieve dynamic voltage equalization, accelerate the discharge of the capacitor unit, increase the resistance value of the static voltage equalization resistor, and reduce the loss of the energy-consuming device. The charging voltage equalization unit and the bypass unit are connected in series to form a dynamic voltage equalization branch, and the dynamic voltage equalization branch is connected in parallel with the capacitor unit and the energy-consuming branch.

2. The hybrid DC energy-consuming device according to claim 1, characterized in that, The energy-consuming device further includes a static voltage equalization branch connected in parallel with the capacitor unit, and the static voltage equalization branch includes a static voltage equalization resistor.

3. The hybrid DC energy-consuming device according to claim 2, characterized in that, The capacitor unit includes a capacitor. The low-voltage end of the capacitor unit is connected to the output terminal of the energy-consuming module, and the high-voltage end of the capacitor unit is connected to the cathode of the first diode of the charging equalization unit.

4. The hybrid DC energy-consuming device according to claim 3, characterized in that, The energy-consuming branch includes a second fully controlled power electronic switch and an energy-consuming resistor connected in series with the second fully controlled power electronic switch.

5. The hybrid DC energy-consuming device according to claim 4, characterized in that, The energy-consuming branch further includes a third diode connected in reverse parallel with the second fully controlled power electronic switch, the anode of the third diode facing the low-voltage end of the capacitor unit, and the cathode of the third diode facing the high-voltage end of the capacitor unit.

6. The hybrid DC energy-consuming device according to claim 5, characterized in that, The energy-consuming branch further includes a fourth diode connected in reverse parallel with the energy-consuming resistor, the anode of the fourth diode facing the low-voltage end of the capacitor unit, and the cathode of the fourth diode facing the high-voltage end of the capacitor unit.

7. The hybrid DC energy-consuming device according to claim 6, characterized in that, The capacitor unit is in a charging state when the current of the energy-consuming device is greater than the current of the energy-consuming branch; the capacitor unit is in a discharging state when the energy-consuming current of the energy-consuming device is less than the current of the energy-consuming branch.

8. The hybrid DC energy-consuming device according to claim 6, characterized in that, The power consumption module has multiple operating modes, including no-pulse mode, bypass mode, power consumption mode, and bypass power consumption mode: When both the first fully controlled power electronic switch and the second fully controlled power electronic switch are in the off state, the energy consumption module is in the no-pulse mode; When the first fully controlled power electronic switch is in the on state and the second fully controlled power electronic switch is in the off state, the energy consumption module is in bypass mode; When the first fully controlled power electronic switch is in the off state and the second fully controlled power electronic switch is in the on state, the energy consumption module is in the energy consumption mode; When both the first fully controlled power electronic switch and the second fully controlled power electronic switch are in the on state, the energy consumption module is in the bypass energy consumption mode.

9. A hybrid DC energy consumption control method, characterized in that, The method is applied to the hybrid DC power consumption device according to any one of claims 1 to 8, and the method includes: When the hybrid DC energy-consuming device is in the input mode, the DC voltage value or DC power value of the energy-consuming device, as well as the capacitor voltage value and virtual energy consumption of each energy-consuming module in the hybrid DC energy-consuming device are obtained. By controlling the DC voltage or DC power value of the hybrid DC energy-consuming device and the capacitor voltage sorting of each energy-consuming module in the hybrid DC energy-consuming device, the number and target of the bypass units of the energy-consuming modules in the hybrid DC energy-consuming device are controlled. By controlling the sum of the capacitor voltage values ​​of each energy-consuming module in the hybrid DC energy-consuming device and the virtual energy consumption ranking of each energy-consuming module in the hybrid DC energy-consuming device, the number of energy-consuming branches and the objects of energy consumption in the hybrid DC energy-consuming device are controlled.

10. The hybrid DC energy consumption control method according to claim 9, characterized in that, The method includes: When the hybrid DC power consumption device is in standby mode, the capacitor voltage value of each power consumption module in the power consumption device is obtained; Based on the capacitor voltage ranking of each energy-consuming module in the hybrid DC energy-consuming device, several energy-consuming modules with high capacitor voltages are placed in bypass mode to achieve dynamic voltage equalization of the energy-consuming device. When the hybrid DC energy-consuming device is in both on-state and standby modes, the bypass unit is controlled by the capacitor voltage ranking result, effectively avoiding the switching between different ranking control quantities when switching between standby and on-state.

11. The hybrid DC energy consumption control method according to claim 9, characterized in that, The method includes: Based on the rated DC operating voltage of each energy-consuming module in the energy-consuming device, the resistance value of the energy-consuming resistor, and the conduction time of the second fully controlled power electronic switch in the energy-consuming branch, determine the virtual energy consumption of each energy-consuming branch: , Where: Er represents virtual energy consumption; This refers to the rated DC operating voltage of each power-consuming module; This is the resistance value of the energy-consuming resistor; This refers to the operating state of the second fully controlled power electronic switch. When the second fully controlled power electronic switch is turned on... The value is 1 when the second fully controlled power electronic switch is turned off. The value is 0.

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