A grid interactive uninterruptible power supply (UPS) is provided. The grid interactive UPS includes a first path including a rectifier, an inverter coupled in series with the rectifier, and a battery coupled in parallel with the inverter. The grid interactive UPS further includes a second path in parallel with the first path, wherein the grid interactive UPS is operable to supply power from the battery to a grid coupled to an input of the grid interactive UPS.

A static volt-ampere reactive (VAR) compensator apparatus includes a capacitor electrically coupled between a phase conductor and a neutral conductor. The apparatus further includes a first switch electrically coupled between the phase conductor and an intermediate node. The apparatus also includes an inductor electrically coupled between the intermediate node and the neutral conductor in series with the first switch. The apparatus includes a second switch electrically coupled between the intermediate node and the neutral conductor in parallel with the inductor. The apparatus further includes a controller configured to transmit signals to the first switch and the second switch that cause the apparatus to modulate between a first state, in which the first switch is open and the second switch is closed, and a second state, in which the first switch is closed and the second switch is open.

A method of assembling a switching module may arrange a first pressing member on a first supporting member, stack a plurality of switches and a plurality of cooling plates on the first pressing member along a vertical direction, arrange a second pressing member and a supporting member on the uppermost cooling plate, support the first supporting member and a second supporting member using a plurality of supporting rods, press the first pressing member using a pressing device to separate between the first pressing member and the first supporting member, and insert a third pressing member between the first pressing member and the first supporting member.

In the presented solution reactive power is compensated for in connection with a power transmission line with an arrangement which comprises at least one transformer and at least one reactive power compensator. The at least one reactive power compensator comprises a voltage source converter and switched elements. The switched elements may be thyristor switched capacitors and/or thyristor switch reactors, for example. The voltage source converter may provide reactive power in a linear or step less manner. The transformer is a three winding transformer having a high voltage side connectable to the power transmission line, a first low voltage side connected to the voltage source converter and a second low voltage side connected to the switched elements.

A method for online limit early-warning to a shunt capacitor bank, and the method comprises: performing harmonic monitoring to the shunt capacitor bank; obtaining a measured voltage and a measured current, based on raw data obtained by the harmonic monitoring; obtaining a first parameter representing a ratio of the measured voltage to a rated voltage and a second parameter representing a ratio of the measured current to a rated current, based on the measured voltage and the measured current; obtaining a relation between an impedance correlation quantity of the shunt capacitor bank and a background harmonic voltage ratio, based on the first parameter, the second parameter, and an obtained series reactance ratio of a detected capacitor circuit; and performing online limit early-warning to the shunt capacitor bank, based on the relation. The present invention also discloses a device for online limit early-warning to a shunt capacitor bank.

A reactive power system comprises a plurality of electrical capacitor banks, with each electrical capacitor bank electrically connected in series with an electrical switch. The electrical switches may be electrically connected to a system such as, for example, an electrical induction motor starter system. A controller is coupled with the motor starter system and each of the electrical switches. The controller, in response to receiving a signal from the motor starter system, determines which of the plurality of electrical capacitor banks from which electrical power should be provided for the motor starter system. For the determined or identified electrical capacitor bank(s), the controller identifies the corresponding electrical switch(es) and communicates a signal to close the switch(es). Closing the switches results in the capacitors in the corresponding electrical capacitor banks to be electrically connected to the motor starter system and to provide current to the motor starter system.

A method for optimizing consumption of reactive power in an electrical network includes a system for monitoring and adjusting electrical power supply, the system including an electrical generator, electrical loads, a power compensation system, an electric transmission line, an electro-digital processor and a remote-readable meter. The method further includes: measuring the dataset of the electrical loads via at least one remote-readable meter; collecting the dataset of the electrical loads and transmitting it to the electro-digital processor in order to establish data curves; calculating a power factor of the electrical loads; enabling reactive power compensation by setting the type and configuration of the compensation systems to be installed, when the calculated power factor has a value lower than or equal to a predefined threshold value; and compensating for reactive power by actuating the installed compensation systems.

Provided is a hybrid control device for a static synchronous compensator (STATCOM), the device including: a first arithmetic operation unit calculating the deviation between a reference voltage desired to be controlled by the STATCOM and output voltage to be output so as to output the same; a proportional integral (PI) controller performing PI control on the deviation output from the first arithmetic operation unit within a range between a new inductive reactive current maximum value and a new capacitive reactive current maximum value, so as to output a reactive current output value; and a second arithmetic operation unit adding the preset reactive current set value to the reactive current output value output from the PI control unit so as to output a reactive current reference value.

A reactive power system comprises a plurality of electrical capacitor banks, with each electrical capacitor bank electrically connected in series with an electrical switch. The electrical switches may be electrically connected to a system such as, for example, an electrical induction motor starter system. A controller is coupled with the motor starter system and each of the electrical switches. The controller, in response to receiving a signal from the motor starter system, determines which of the plurality of electrical capacitor banks from which electrical power should be provided for the motor starter system. For the determined or identified electrical capacitor bank(s), the controller identifies the corresponding electrical switch(es) and communicates a signal to close the switch(es). Closing the switches results in the capacitors in the corresponding electrical capacitor banks to be electrically connected to the motor starter system and to provide current to the motor starter system.

A switch assembly of a reactive power compensation apparatus may include a first switching module having a first stack structure perpendicular to a supporting module, and a second switching module having a second stack structure perpendicular to the supporting module, the second switching module being connected in parallel with the first switching module. Each of the first and second switching modules may include a plurality of cooling plates stacked along a vertical direction with respect to the supporting module, and a plurality of switches disposed between the plurality of cooling plates. The cooling plate may include an engagement portion disposed on one side of the upper surface to be located at a normal position by guiding the switch.