Pre-charge control method

A pre-charge control method for a hybrid multilevel power converter, wherein the hybrid multilevel power converter comprises a first converter, a second converter and a current-limiting resistor unit, the first converter comprises three H-bridge modules, each of the three H-bridge modules comprises at least one H-bridge circuit, each H-bridge circuit comprises a first capacitor unit, and the second converter comprises a second capacitor unit, wherein the three H-bridge modules are electrically connected with the second converter, and the three H-bridge modules are connected with the AC power by the current-limiting resistor unit, the pre-charge control method comprising steps of:

• (a) controlling the access of the current-limiting resistor unit, and limiting a current outputted from the AC power via the current-limiting resistor unit, and outputting the current;
• (b) controlling the second capacitor unit to bypass, and charging the first capacitor unit using the current;
• (c) controlling the access of the second capacitor unit when the first capacitor unit is charged to a fifth preset voltage, and allowing the current to charge the first capacitor unit and the second capacitor unit at the same time;
• (d) controlling the first capacitor unit to bypass periodically when the second capacitor unit is charged to a sixth preset voltage or the first capacitor unit is charged to a seventh preset voltage, and allowing the current to charge the first capacitor unit and the second capacitor unit;
• and
• (e) controlling the access of the first capacitor unit and the current-limiting resistor unit to bypass when the second capacitor unit is charged to a second preset voltage or the first capacitor unit is charged to a first preset voltage.

A pre-charge control method for a hybrid multilevel power converter, wherein the hybrid multilevel power converter comprises a first converter, a second converter and a current-limiting resistor unit, the first converter comprises three H-bridge modules, each of the three H-bridge modules comprises at least one H-bridge circuit, each H-bridge circuit comprises a first capacitor unit, and the second converter comprises a second capacitor unit, wherein the three H-bridge modules are electrically connected with the second converter, and the three H-bridge modules are connected with the AC power by the current-limiting resistor unit, the pre-charge control method comprising steps of:

• (a) controlling the access of the current-limiting resistor unit, and limiting a current outputted from the AC power via the current-limiting resistor unit, and outputting the current;
• (b) controlling the first capacitor unit to bypass, and charging the second capacitor unit using the current;
• (c) controlling the access of the first capacitor unit when the second capacitor unit is charged to an eighth preset voltage, and allowing the current to charge the first capacitor unit and the second capacitor unit at the same time;
• (d) controlling the second capacitor unit to bypass when the first capacitor unit is charged to a ninth preset voltage or the second capacitor unit is charged to a second preset voltage, and charging the first capacitor unit using the current;
• and
• (e) controlling the access of the second capacitor unit and the current-limiting resistor unit to bypass when the first capacitor unit is charged to a first preset voltage.

A pre-charge control method for a hybrid multilevel power converter, wherein the hybrid multilevel power converter comprises a first converter, a second converter and a current-limiting resistor unit, the first converter comprises three H-bridge modules, each of the three H-bridge modules comprises at least one H-bridge circuit, each H-bridge circuit comprises a first capacitor unit, and the second converter comprises a second capacitor unit, wherein the three H-bridge modules are electrically connected with the second converter, and the three H-bridge modules are connected with the AC power by the current-limiting resistor unit, the pre-charge control method comprising steps of:

• (a) controlling the access of the current-limiting resistor unit, and limiting a current outputted from the AC power via the current-limiting resistor unit, and outputting the current;
• (b) controlling the first capacitor unit to bypass periodically, and charging the first capacitor unit and the second capacitor unit using the current;
• (c) controlling the access of the first capacitor unit when the second capacitor unit is charged to a tenth preset voltage or the first capacitor unit is charged to an eleventh preset voltage, and allowing the current to charge the first capacitor unit and the second capacitor unit;
• (d) controlling the second capacitor unit to bypass and charging the first capacitor unit using current when the first capacitor unit is charged to a twelfth preset voltage or the second capacitor unit is charged to a second preset voltage;
• and
• (e) controlling the access of the second capacitor unit and the current-limiting resistor unit to bypass when the first capacitor unit is charged to a first preset voltage.