Abstract: A charging pile, a power module, and a method for controlling the same. In response to receiving a signal of operation, samples of an input voltage of three relays corresponding to three phases, respectively, at an input of a power module are acquired to determine whether a line voltage between inputs of two of the three relays is within a predetermined voltage range. The two relays are closed to pre-charge a bus capacitor in a converting circuitry of the power module, in response to determining that the line voltage is within the predetermined voltage range. The predetermined voltage range comprises zero voltage, such that each relay can be closed when a voltage at its input is close to zero. An impulse current is decreased without help of an arc quenching device, thereby saving an internal space of the charging pile.

Abstract: Provided are a bypass type 220V grid voltage sag prevention device and a control method therefor. The bypass type 220V grid voltage sag prevention device comprises an AC-to-DC energy storage unit, a Single Chip Microcomputer (SCM) control and display unit, and an inverter output unit. The AC-to-DC energy storage unit comprises a rectifier circuit, an energy storage control circuit and a quick tank circuit; the SCM control and display unit comprises an SCM, a DC step-down module circuit and an energy storage voltage detecting circuit; and the inverter output unit comprises a high-frequency PWM generating circuit, a high-frequency transformer output circuit, a transformer output full-bridge rectifier circuit, a PWM generating circuit, a PWM driving and full-bridge inverter circuit, a 220V grid zero-cross point detecting circuit, a 220V grid voltage detecting circuit, a 220V grid and inversion AC converting circuit, and a signal interface circuit.

Abstract: Provided are a bypass type 220V grid voltage sag prevention device and a control method therefor. The bypass type 220V grid voltage sag prevention device comprises an AC-to-DC energy storage unit, a Single Chip Microcomputer (SCM) control and display unit, and an inverter output unit. The AC-to-DC energy storage unit comprises a rectifier circuit, an energy storage control circuit and a quick tank circuit; the SCM control and display unit comprises an SCM, a DC step-down module circuit and an energy storage voltage detecting circuit; and the inverter output unit comprises a high-frequency PWM generating circuit, a high-frequency transformer output circuit, a transformer output full-bridge rectifier circuit, a PWM generating circuit, a PWM driving and full-bridge inverter circuit, a 220V grid zero-cross point detecting circuit, a 220V grid voltage detecting circuit, a 220V grid and inversion AC converting circuit, and a signal interface circuit.