A locus of integrals, in terms of time, of unit voltage vectors forms a loop within a period shorter than a reciprocal of a maximum value of an operating frequency, in terms of electrical angle, of a compressor motor, the unit voltage vectors being voltage vectors that are units composing an instantaneous space vector indicating voltage which an inverter for driving the compressor motor outputs except in a dead time period.

A locus of integrals, in terms of time, of unit voltage vectors forms a loop within a period shorter than a reciprocal of a maximum value of an operating frequency, in terms of electrical angle, of a compressor motor, the unit voltage vectors being voltage vectors that are units composing an instantaneous space vector indicating voltage which an inverter for driving the compressor motor outputs except in a dead time period.

Systems and methods of this disclosure use low voltage energy storage devices to supply power at a medium voltage from an uninterruptible power supply (UPS) to a data center load. The UPS includes a low voltage energy storage device (ultracapacitor/battery), a high frequency (HF) bidirectional DC-DC converter, and a multi-level (ML) inverter. The HF DC-DC converter uses a plurality of HF planar transformers, multiple H-bridge circuits, and gate drivers for driving IGBT devices to generate a medium DC voltage from the ultracapacitor/battery energy storage. The gate drivers are controlled by a zero voltage switching (ZVS) controller, which introduces a phase shift between the voltage on the primary and secondary sides of the transformers. When the primary side leads the secondary side, the ultracapacitor/battery discharges and causes the UPS to supply power to the data center, and when the secondary side leads the primary side, power flows from the grid back to the UPS, thereby recharging the ultracapacitor/battery.

Systems and methods of this disclosure use low voltage energy storage devices to supply power at a medium voltage from an uninterruptible power supply (UPS) to a data center load. The UPS includes a low voltage energy storage device (ultracapacitor/battery), a high frequency (HF) bidirectional DC-DC converter, and a multi-level (ML) inverter. The HF DC-DC converter uses a plurality of HF planar transformers, multiple H-bridge circuits, and gate drivers for driving IGBT devices to generate a medium DC voltage from the ultracapacitor/battery energy storage. The gate drivers are controlled by a zero voltage switching (ZVS) controller, which introduces a phase shift between the voltage on the primary and secondary sides of the transformers. When the primary side leads the secondary side, the ultracapacitor/battery discharges and causes the UPS to supply power to the data center, and when the secondary side leads the primary side, power flows from the grid back to the UPS, thereby recharging the ultracapacitor/battery.

A locus of integrals, in terms of time, of unit voltage vectors forms a loop within a period shorter than a reciprocal of a maximum value of an operating frequency, in terms of electrical angle, of a compressor motor, the unit voltage vectors being voltage vectors that are units composing an instantaneous space vector indicating voltage which an inverter for driving the compressor motor outputs except in a dead time period.

A locus of integrals, in terms of time, of unit voltage vectors forms a loop within a period shorter than a reciprocal of a maximum value of an operating frequency, in terms of electrical angle, of a compressor motor, the unit voltage vectors being voltage vectors that are units composing an instantaneous space vector indicating voltage which an inverter for driving the compressor motor outputs except in a dead time period.

The purpose of the present disclosure is to protect a power circuit of a base station in a wireless communication system, the base station comprising: at least one module for processing a signal; and the power circuit for supplying power to the at least one module. The power circuit comprises a transformer, a rectifier circuit and a smoothing circuit, and the power circuit reduces the ratio of an on-section of the rectifier circuit if a reverse current from the at least one module is detected.

The purpose of the present disclosure is to protect a power circuit of a base station in a wireless communication system, the base station comprising: at least one module for processing a signal; and the power circuit for supplying power to the at least one module. The power circuit comprises a transformer, a rectifier circuit and a smoothing circuit, and the power circuit reduces the ratio of an on-section of the rectifier circuit if a reverse current from the at least one module is detected.

Systems and methods of this disclosure use low voltage energy storage devices to supply power at a medium voltage from an uninterruptible power supply (UPS) to a data center load. The UPS includes a low voltage energy storage device (ultracapacitor/battery), a high frequency (HF) bidirectional DC-DC converter, and a multi-level (ML) inverter. The HF DC-DC converter uses a plurality of HF planar transformers, multiple H-bridge circuits, and gate drivers for driving IGBT devices to generate a medium DC voltage from the ultracapacitor/battery energy storage. The gate drivers are controlled by a zero voltage switching (ZVS) controller, which introduces a phase shift between the voltage on the primary and secondary sides of the transformers. When the primary side leads the secondary side, the ultracapacitor/battery discharges and causes the UPS to supply power to the data center, and when the secondary side leads the primary side, power flows from the grid back to the UPS, thereby recharging the ultracapacitor/battery.

Systems and methods of this disclosure use low voltage energy storage devices to supply power at a medium voltage from an uninterruptible power supply (UPS) to a data center load. The UPS includes a low voltage energy storage device (ultracapacitor/battery), a high frequency (HF) bidirectional DC-DC converter, and a multi-level (ML) inverter. The HF DC-DC converter uses a plurality of HF planar transformers, multiple H-bridge circuits, and gate drivers for driving IGBT devices to generate a medium DC voltage from the ultracapacitor/battery energy storage. The gate drivers are controlled by a zero voltage switching (ZVS) controller, which introduces a phase shift between the voltage on the primary and secondary sides of the transformers. When the primary side leads the secondary side, the ultracapacitor/battery discharges and causes the UPS to supply power to the data center, and when the secondary side leads the primary side, power flows from the grid back to the UPS, thereby recharging the ultracapacitor/battery.