Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

A spacing-assured gas discharge tube assembly is installed on a printed circuit board, which may be part of a motor controller. The discharge tube assembly includes a tube body and an electrostatic spacing shield disposed at least partially around the tube body. The shield is configured to prevent close physical proximity of adjacent structures having electrostatic fields that may alter the breakdown voltage of the tube body.

A method, device, and system for managing a mining facility including a plurality of systems. The method includes generating, on a simulation unit, system models for one or more systems from the plurality of systems of the mining facility. The system models are generated based on one of input signal, sensor data and output signal from the plurality of systems at the mining facility. The method further includes generating a facility model of the mining facility based on dependencies between the system models and managing the mining facility by simulating operation of the mining facility using the facility model.

A variable frequency motor drive comprises a converter including a rectifier having an input for connection to an AC power source and converting the AC power to DC power. A DC bus is connected to the rectifier circuit. At least one bus capacitor is across the DC bus. An inverter receives DC power from the DC bus and converts the DC power to AC power to drive a motor. A controller is operatively connected to the converter. The controller comprises a speed control controlling the inverter responsive to a speed command to maintain a desired motor speed. A speed foldback control measures DC bus ripple voltage and regulates the speed command responsive to the measured DC bus ripple voltage.

A control device is for a multi-level inverter. The control device determines whether a suppliable current value to the electronic equipment is less than a required current value of the electronic equipment, and controls, when it is determined that the suppliable current value is less than the required current value, the plurality of switches so that current flowing in the plurality of windings is larger than when the suppliable current value is determined to be equal to or greater than the required current value.

A motor driving apparatus includes a boosting section, a drive voltage output section, a detecting section, a storage section and a determining section. The boosting section generates a post-boosting voltage by boosting an input voltage. The drive voltage output section generates a drive voltage to drive a motor using the post-boosting voltage. The detecting section detects a value of the input voltage or a variation width relative to a reference value of the input voltage as variation power source variation information when there is power source variation. The storage section stores target value association information associating the power source variation information and a boosting target value of the post-boosting voltage. The determining section determines the boosting target value based on the power source variation information and target value association information. The target value association information is determined based on a range of operations of the drive voltage output section.

A spacing-assured gas discharge tube assembly is installed on a printed circuit board, which may be part of a motor controller. The discharge tube assembly includes a tube body and an electrostatic spacing shield disposed at least partially around the tube body. The shield is configured to prevent close physical proximity of adjacent structures having electrostatic fields that may alter the breakdown voltage of the tube body.

In some embodiments, an inverter control apparatus and a method for controlling the same are provided. The inverter control apparatus may speed up the discharging of the residual energy at an inverter driven with an input power when a safety signal is input to the inverter. The inverter control apparatus may include an input power switchgear supplying an input power to the inverter according to switching operation; an I/O unit inputting a safety signal to the inverter according to a user control input and outputting a failure output relay signal to the input power switchgear when the safety signal is generated; and a controller performing speeding up the discharge of residual energy at the inverter when the input power is interrupted.

In some embodiments, an inverter control apparatus and a method for controlling the same are provided. The inverter control apparatus may speed up the discharging of the residual energy at an inverter driven with an input power when a safety signal is input to the inverter. The inverter control apparatus may include an input power switchgear supplying an input power to the inverter according to switching operation; an I/O unit inputting a safety signal to the inverter according to a user control input and outputting a failure output relay signal to the input power switchgear when the safety signal is generated; and a controller performing speeding up the discharge of residual energy at the inverter when the input power is interrupted.