To share, i.e., to use, a common submarine DCDC converter for both a submarine DCDC converter for positive outputting and one for negative outputting. A submarine DCDC converter according to the present disclosure includes: a DCDC conversion circuit configured to supply a first constant current input to an input terminal from a land feeding apparatus through a first submarine cable to a first output terminal, generate a second constant current using the first constant current, and supply the generated second constant current to a second output terminal; a control circuit configured to switch a polarity of the second constant current output from the second output terminal; a first switch; and a second switch.

The present subject matter relates to an electronic system including multiple power supply circuits connected in parallel. A first power supply circuit includes a current sensing circuit configured to measure current to the first power supply circuit and total current drawn by the multiple power supply circuits. A second power supply circuit is connected in parallel to the first power supply circuit and includes a current sensing circuit configured to measure current to the second power supply circuit and the total current drawn by the multiple power supply circuits. Each of the first and second power supply circuits are configured to change operation of the power supply circuit to reduce current drawn by the power supply circuit when either the current to the power supply circuit or the total current drawn by the multiple power supply circuits exceeds a specified current limit level.

A power supply circuit for a magnetic bearing system comprises a power convertor configured to be electrically connected to an alternating current (AC) power source, an inverter configured to be electrically connected between the power convertor and a motor associated with the HVAC system, and a battery, an input side of the battery electrically connected to a direct current (DC) bus configured between the power convertor and the inverter, and an output side of the battery electrically connected to one or more electromagnetic bearings and a magnetic bearing control drive associated with the motor or the magnetic bearing system, wherein the battery is configured to receive and store a portion of the DC electrical power. The battery is configured to supply the stored electrical power to the electromagnetic bearings and the magnetic bearing control drive in an event of failure of supply of electrical power to the motor.

A charge pump includes a first transistor, a first switch coupled between the first transistor and an output of the charge pump, a second transistor, and a second switch coupled between the output of the charge pump and the second transistor. The charge pump also includes a third transistor, wherein a gate of the third transistor is coupled to a gate of the first transistor, a fourth transistor, wherein a drain of the fourth transistor is coupled to a drain of the third transistor, and a bias circuit configured to bias a gate of the fourth transistor and a gate of the second transistor. The charge pump also includes an amplifier having a first input coupled to the output of the charge pump, a second input coupled to the drain of the third transistor, and the output coupled to the gate of the third transistor.

A voltage regulation method for a multi-converter parallel connection system is provided. The multi-converter parallel connection system includes N converters. Alternating-current sides of the N converters are connected to an alternating-current bus. N is an integer greater than or equal to 2. M converters among the N converters are switched from a current-source operation mode to a voltage-source operation mode to form an alternating-current bus voltage, when the N converters are disconnected from a power grid or the power grid fails. M is an integer less than or equal to N. Remaining N-M converters among the N converters are switched from the current-source operation mode to the voltage-source operation mode after the alternating-current bus voltage is formed.