Power electronic converter with a ground fault detection unit that shares a common ground with both DC ports and AC ports

• Main Author: Qingchang Zhong
• Format: Patent
• Language: English
• Published: 17.02.2021
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

Converter with a DC leg, an AC leg, a DC bus capacitor C0, and a ground-fault detection unit, all connected to a common ground - in particular a neutral line N of the AC port. The DC leg has a DC port and a first DC bus; the AC leg has an AC port and a second DC bus. There may be multiple DC legs, AC legs and DC bus capacitors. The DC leg may have semiconductor/switch devices Q1, Q2 connected in series; the AC leg may have switches Q3, Q4 connected in series. The first and second DC buses are connected to form a converter DC bus. The ground-fault detection unit is connected between the neutral line N and a protective earth. The ground-fault detection unit has a current sensor and a neutral ground resistor in series, and a voltage sensor to measure the voltage across it. A value of neutral ground resistor is selected to limit the current though it when there is a ground fault. A residual current circuit breaker or a ground-fault circuit breaker is connected to the AC port.