An outdoor device reset system includes a voltage regulation apparatus coupled to a power supply apparatus and an outdoor device coupled to the voltage regulation apparatus. The voltage regulation apparatus is configured to regulate a working voltage input to the outdoor device based on a feedback signal, a supply voltage from the power supply apparatus for the voltage regulation apparatus, and a reference voltage of the voltage regulation apparatus. The outdoor device is configured to determine a change amount of the working voltage, and perform a reset operation when the change amount is within a preset range.

The invention discloses a converter adaptable to a wide range output voltage and a control method thereof. The converter comprises a PWM half-bridge circuit. The control method comprises the steps of: controlling the PWM half-bridge circuit to enter into a discontinuous conduction mode by regulating a switching frequency; when the PWM half-bridge circuit is operated in the discontinuous conduction mode, oscillation occurs among the output inductor, a magnetizing inductor of the transformer and a parasitic capacitor of the PWM half-bridge circuit, and when a center point voltage of the primary switching bridge arm reaches a valley or a peak, turning on the corresponding power switch. The invention reduces switching loss by controlling the corresponding power switch in the PWM half-bridge circuit to turn on when a voltage across the power switch is oscillated to valley.

The invention discloses a converter adaptable to a wide range output voltage and a control method thereof. The converter comprises a PWM half-bridge circuit. The control method comprises the steps of: controlling the PWM half-bridge circuit to enter into a discontinuous conduction mode by regulating a switching frequency; when the PWM half-bridge circuit is operated in the discontinuous conduction mode, oscillation occurs among the output inductor, a magnetizing inductor of the transformer and a parasitic capacitor of the PWM half-bridge circuit, and when a center point voltage of the primary switching bridge arm reaches a valley or a peak, turning on the corresponding power switch. The invention reduces switching loss by controlling the corresponding power switch in the PWM half-bridge circuit to turn on when a voltage across the power switch is oscillated to valley.

An assembly for connection to a high-voltage system has multiple single-phase transformers each having a transformer tank which is filled with a fluid and in which a core with at least one winding is situated. At least some of the windings of the single-phase transformers are connected to one another, forming a neutral point. A short-circuit voltage curve or impedance of the assembly can be adapted to different requirements. The windings are each connected to the neutral point via a switchover unit and a choke winding. The choke winding has multiple tappings, and the switchover unit is configured to select the tapping via which the winding in question is connected to the neutral point.

An assembly for connection to a high-voltage system has multiple single-phase transformers each having a transformer tank which is filled with a fluid and in which a core with at least one winding is situated. At least some of the windings of the single-phase transformers are connected to one another, forming a neutral point. A short-circuit voltage curve or impedance of the assembly can be adapted to different requirements. The windings are each connected to the neutral point via a switchover unit and a choke winding. The choke winding has multiple tappings, and the switchover unit is configured to select the tapping via which the winding in question is connected to the neutral point.

There is disclosed new topology for an Electronic Voltage Regulator (EVR) which can apply additive or subtractive (aka boost or buck) voltages to compensate for an increase or decrease in system voltages. This regulator employs a ladder of power capacitors which are in series and connected across the input voltage to apply different levels of voltages to a controlled or regulated transformer. Considering this, the proposed EVR can be utilized as a replacement for conventional electromechanical type on-load tap changers or (OLTCs) commonly used in power transformers, and meant to compensate voltage changes in a system. Electromechanical tap changers have some significant issues, such as defined time durations when switching to different taps, as determined by the spring-loaded mechanism's operation; a high malfunction rate due to mechanical switching when causing arcing, and thereby decreasing the operating lifetime of transformers. In this EVR instead of electromechanical taps, a combination of capacitors and TRIACs are used at each voltage level to eliminate arcing effects while increasing the speed of the tap changing process. Furthermore, the electronic regulator can improve the load power factor due to the presence of capacitors. Other advantages over conventional OLTC's is the elimination of a reactor, if used, and the elimination of a tap winding with its numerous tap leads and having correspondingly higher cost. This will reduce the overall size of the active part of the main transformers and improve efficiency by reducing operating losses. In addition, a new failure detection method is included that detects a failed TRIAC to enable the system to continue operating. The failure detection circuit is seamlessly incorporated within the main circuit and has a high-speed detection rate.

There is disclosed new topology for an Electronic Voltage Regulator (EVR) which can apply additive or subtractive (aka boost or buck) voltages to compensate for an increase or decrease in system voltages. This regulator employs a ladder of power capacitors which are in series and connected across the input voltage to apply different levels of voltages to a controlled or regulated transformer. Considering this, the proposed EVR can be utilized as a replacement for conventional electromechanical type on-load tap changers or (OLTCs) commonly used in power transformers, and meant to compensate voltage changes in a system. Electromechanical tap changers have some significant issues, such as defined time durations when switching to different taps, as determined by the spring-loaded mechanism's operation; a high malfunction rate due to mechanical switching when causing arcing, and thereby decreasing the operating lifetime of transformers. In this EVR instead of electromechanical taps, a combination of capacitors and TRIACs are used at each voltage level to eliminate arcing effects while increasing the speed of the tap changing process. Furthermore, the electronic regulator can improve the load power factor due to the presence of capacitors. Other advantages over conventional OLTC's is the elimination of a reactor, if used, and the elimination of a tap winding with its numerous tap leads and having correspondingly higher cost. This will reduce the overall size of the active part of the main transformers and improve efficiency by reducing operating losses. In addition, a new failure detection method is included that detects a failed TRIAC to enable the system to continue operating. The failure detection circuit is seamlessly incorporated within the main circuit and has a high-speed detection rate.

An isolation transformer boost system. The system includes a power supply and an isolation transformer. The isolation transformer includes a primary winding electrically connected to the power supply, a secondary winding, a first voltage tap, and a second voltage tap. Wherein the isolation transformer is configured to, in response to a command from an electronic processor, disconnect a connection from the second voltage tap and establish a second connection from the first voltage tap, wherein the command is based on an electrical characteristic measurement of the power supply exceeding an upper limit threshold for a predetermined period of time.

An isolation transformer boost system. The system includes a power supply and an isolation transformer. The isolation transformer includes a primary winding electrically connected to the power supply, a secondary winding, a first voltage tap, and a second voltage tap. Wherein the isolation transformer is configured to, in response to a command from an electronic processor, disconnect a connection from the second voltage tap and establish a second connection from the first voltage tap, wherein the command is based on an electrical characteristic measurement of the power supply exceeding an upper limit threshold for a predetermined period of time.

A system and method are provided for regulating a voltage level at a load. A current source generates a current and a voltage control mechanism provides a portion of the current to regulate the voltage level at the load. When the voltage level at the load is greater than a maximum voltage level, the current source is decoupled from the load and the current source is coupled to a current sink to reduce the voltage level at the load. An electric power conversion comprises the current source and the voltage control mechanism. A downstream controller is configured to control the voltage control mechanism to decouple the current source from the load and couple the current source to a current sink to reduce the voltage level at the load when the voltage level at the load is greater than a maximum voltage level.