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 provided a transformer system (10) for converting a grid voltage (V.sub.grid) to a regulated voltage (V.sub.regulated) and output the regulated voltage (V.sub.regulated) to a power line (30), the transformer system (10) comprising: a first transformer (40) configured to step down the grid voltage (V.sub.grid) to an unregulated voltage (V.sub.unregulated) and provide the unregulated voltage (V.sub.unregulated) at an output of the first transformer (40); a shunt coupling transformer (50) connected in parallel with the output of the first transformer (40) and further connected to power electronics circuitry (60); and a series coupling transformer (70) connected in series with the output of the first transformer (40) and further connected to the power electronics circuitry (60). The power electronics circuitry (60) adds, via the series coupling transformer, a conditioning voltage (V.sub.conditioning) in series to the unregulated voltage (V.sub.unregulated) to generate the regulated voltage (V.sub.regulated). The first transformer, the series coupling transformer and the shunt coupling transformer are housed in a single transformer tank (80), and the power electronics circuitry is housed in a power electronics enclosure (90) separate from the transformer tank. Each of the transformer tank and the power electronics enclosure comprises one or more openings (95) through which electrical connections (97) between the shunt coupling transformer (50), the series coupling transformer (70) and the power electronics circuitry (60) pass.

A power supply conversion topology of a multiphase switch capacitor resonant cavity conversion circuit with full-wave output rectification. The power supply conversion topology includes at least k conversion switch capacitors and one output switch capacitor which are sequentially connected in series through conductors and are connected to two ends of input power supply. When a transformer ratio N is an even number, k=N/2; when transformer ratio N is not an even number, k is smallest integral greater than N/2; and lower end of output switch capacitor is grounded, and two ends of output switch capacitor are connected with output interfaces. Power supply conversion topology further includes k switch resonant cavity converters. When transformer ratio N is even number, k=N/2; and when transformer ratio N is not even number, k is smallest integral greater than N/2. The invention further discloses two power supply conversion structures based on power supply conversion topology.

A power conversion device includes a power converter including at least a first converter for converting battery power output by a battery into first output power of a first voltage waveform based on an input or set output waveform profile and outputting the first output power from a first terminal pair and a second converter for converting the battery power into second output power of a second voltage waveform of a rectangular shape and outputting the second output power from a second terminal pair and configured to supply a load with third output power of an alternating current (AC) control waveform generated by adding the first output power to the second output power, and a controller configured to output a voltage command value for outputting the first output power as the output waveform profile to the first converter to the power converter on the basis of the input request command value of output power for the load and the voltage value of the third output power output by the power converter.

A control circuit, a control chip and a power supply device are disclosed by the present invention. The control circuits are used for control of a constant-voltage closed-loop which causes a voltage of a voltage feedback signal obtained from an output voltage to approach a voltage of a reference voltage signal obtained from a base voltage and thereby achieves a constant-voltage output. In addition, when a sampled current obtained from an output current is higher than a predetermined current, or when output power is higher than a predetermined power, the control circuit increases the voltage feedback signal or decreases the reference voltage signal, causing the constant-voltage closed loop to decrease the output voltage and the output current and thereby achieving a limited output current and limited output power.

According to the present embodiment, a DC transformation system includes a rectifier, a first power conversion device, a second power conversion device, and a control device. The rectifier rectifies AC power supplied from an AC power source and outputs a first DC voltage. The first power conversion device is connected in series to the rectifier and outputs a second DC voltage. The second power conversion device is connected in parallel to the rectifier and converts power supplied from the rectifier to supply the converted power to the first power conversion device. The control device controls the first power conversion device to cause an addition/subtraction voltage of the first DC voltage and the second DC voltage to be a predetermined voltage.

A DC-DC auto-converter module includes a positive source terminal, a negative source terminal, a positive load terminal, a negative load terminal, and a DC-DC converter. The negative source terminal cooperates with the positive source terminal to facilitate electrical connection of a DC power source thereto. The negative load terminal cooperates with the positive load terminal to facilitate connection of an electrical load thereto. The isolated DC-DC converter comprises an input circuit and an output circuit that is galvanically isolated from the input circuit. The DC-DC converter includes a positive input terminal, a negative input terminal, a positive output terminal, and a negative output terminal. At least one of the positive input terminal, the negative input terminal, the positive output terminal, and the negative output terminal is galvanically connected to at least one of the positive source terminal, the negative source terminal, the positive load terminal, and the negative load terminal.

A power supply system and method. The power supply system includes: a first branch on which a first string is located, a second branch on which a second string is located, a transfer switch unit, a first voltage compensation unit, and a controller. The transfer switch unit is configured to connect the first voltage compensation unit to the first branch based on a voltage compensation enabling signal received from the controller, where the voltage compensation enabling signal is generated by the controller based on an operating state parameter of the first string and an operating state parameter of the second string. The first voltage compensation unit is configured to compensate for an output voltage of the first branch. Thus the system and method can prevent the voltage compensation unit from causing an unnecessary system loss in the branch requiring no voltage compensation, and reduce system costs.

In accordance with disclosed embodiments, a power conversion system and method are provided. The power conversion system comprises a main power source configured to deliver drive power to a load and an add-on power module. The add-on power module comprises an isolated DC/DC converter and a low voltage source coupled in series with a high voltage source. The add-on power module is coupled to the main power source and the load and configured to output boost power to the load. The power conversion system further comprises a controller coupled to the main power source and the add-on power module, wherein the controller is configured to: determine that the load requires power from the main power source, and if so, direct boost power from the add-on power module to the load; and direct drive power from the main power source to the load when boost power falls below a predetermined threshold.

According to some embodiments, an electronic drive circuit is disclosed. The electronic drive circuit includes an energy storage device and a first bridge circuit coupled to the energy storage device. The first bridge circuit includes at least one leg having two switches. The electronic drive circuit also includes a transformer. The transformer includes a first winding coupled to the first bridge circuit and a second winding coupled to the energy storage device through a center tap. The electronic drive circuit further includes a second bridge circuit coupled to the second winding of the transformer. The second bridge circuit includes a pair of switches operable to conduct in both directions and block voltage in both directions. The electronic drive circuit additionally includes a DC bus coupled to the second bridge circuit and a controller, which is configured to buck or boost a DC voltage from the energy storage device to supply to the DC bus as well as buck or boost a DC voltage from the DC bus to supply to the energy storage device.