In an on-load tap changer (10) for controlling voltage of a tapped transformer (15) it is provided that the tapped transformer (15) has at least one regulatable phase (16) that has a first winding (20) and a second winding (30); the first winding (20) has a regulating winding (21) with even-numbered winding taps (23) and a main winding (22), and the second winding (30) has a regulating winding (31) with odd-numbered winding taps (33) and a main winding (32); the first winding (20) and the second winding (30) having the regulating windings (21, 31) of the even-numbered and of the odd-numbered winding taps (23, 33), are inductively coupled; the on-load tap changer (10) has a selector (40) for the alternating power-free preselection of the even-numbered or odd-numbered winding taps (23, 33) to be switched.

An electric power system includes an OLTC transformer including a plurality of primary and secondary windings inductively coupled to each other. The electric power system includes at least one on-load tap changer coupled to at least one of the primary and secondary windings that is selectively configurable to regulate the portion of the primary and secondary windings inductively coupled to each other. The electric power system also includes a plurality of buses coupled to the transformer and are positioned downstream therefrom. The electric power system further includes at least one processor coupled to the tap changer configured to regulate a voltage bandwidth of the tap changer as a function of estimated voltage values of at least one bus as estimated based on a priori values of power/current transmitted through each bus. The a priori values are substantially based on measured power/current transmission through the on-load tap changer.

An electric power system includes an OLTC transformer including a plurality of primary and secondary windings inductively coupled to each other. The electric power system includes at least one on-load tap changer coupled to at least one of the primary and secondary windings that is selectively configurable to regulate the portion of the primary and secondary windings inductively coupled to each other. The electric power system also includes a plurality of buses coupled to the transformer and are positioned downstream therefrom. The electric power system further includes at least one processor coupled to the tap changer configured to regulate a voltage bandwidth of the tap changer as a function of estimated voltage values of at least one bus as estimated based on a priori values of power/current transmitted through each bus. The a priori values are substantially based on measured power/current transmission through the on-load tap changer.

A terminal I thereof is respectively connected with transition switches, and a terminal II is respectively connected with transition switches; the other terminals of the transition switches are jointly connected and are connected with the terminal through a saturable reactor and a thyristor switch; the other terminals of the transition switches are jointly connected and are connected with the terminal through a linear reactor, a saturable reactor and an overvoltage triggering thyristor circuit; an odd-numbered side main contact is respectively connected with the terminal I and a common terminal, and an even-numbered side main contact is respectively connected with the terminal II and the common terminal; the terminals of non-common terminals of a main path and a transition path are further connected with a bidirectional voltage stabilizing circuit.

A terminal I thereof is respectively connected with transition switches, and a terminal II is respectively connected with transition switches; the other terminals of the transition switches are jointly connected and are connected with the terminal through a saturable reactor and a thyristor switch; the other terminals of the transition switches are jointly connected and are connected with the terminal through a linear reactor, a saturable reactor and an overvoltage triggering thyristor circuit; an odd-numbered side main contact is respectively connected with the terminal I and a common terminal, and an even-numbered side main contact is respectively connected with the terminal II and the common terminal; the terminals of non-common terminals of a main path and a transition path are further connected with a bidirectional voltage stabilizing circuit.

Method and apparatus for cleaning pollution control equipment, such as particulate removal devices, including wet electrostatic precipitators (WESP). The apparatus may include a housing having a chamber, at least one process gas inlet in fluid communication with the chamber, a process gas outlet spaced from the at least one process gas inlet and in fluid communication with the chamber, one or more ionizing electrodes in the housing and one or more collection electrodes or plates in the housing. Sealing liquid is provided and introduced into the chamber in an amount sufficient to submerge the at least one process gas inlet and stop the flow of contaminated gas into the chamber.

Method and apparatus for cleaning pollution control equipment, such as particulate removal devices, including wet electrostatic precipitators (WESP). The apparatus may include a housing having a chamber, at least one process gas inlet in fluid communication with the chamber, a process gas outlet spaced from the at least one process gas inlet and in fluid communication with the chamber, one or more ionizing electrodes in the housing and one or more collection electrodes or plates in the housing. Sealing liquid is provided and introduced into the chamber in an amount sufficient to submerge the at least one process gas inlet and stop the flow of contaminated gas into the chamber.

A control system may include a first tap changer, a second tap changer, and a third tap changer, wherein each of the first tap changer, the second tap changer, and the third tap changer associated with a respective phase line. The control system may include an electronic processor configured to: determine whether a voltage level of the first phase line exceeds a threshold, control power to the first tap changer with power converted from the first phase line to affect a tap change on the first phase line when the voltage level of the first phase line exceeds the threshold; and control power to the first tap changer with power converted from the second phase line to affect a tap change on the first phase line when the voltage of the first phase line does not exceed the threshold.

A control system may include a first tap changer, a second tap changer, and a third tap changer, wherein each of the first tap changer, the second tap changer, and the third tap changer associated with a respective phase line. The control system may include an electronic processor configured to: determine whether a voltage level of the first phase line exceeds a threshold, control power to the first tap changer with power converted from the first phase line to affect a tap change on the first phase line when the voltage level of the first phase line exceeds the threshold; and control power to the first tap changer with power converted from the second phase line to affect a tap change on the first phase line when the voltage of the first phase line does not exceed the threshold.

An electric power system including an on-load tap changing (OLTC) transformer is provided. The OLTC transformer includes a primary winding and a secondary winding. A portion of the at least one primary winding and at least one of the secondary windings are inductively coupled to each other. Further, the electric power system includes at least one on-load tap changer coupled to the at least one primary winding or the at least one secondary winding of the OLTC transformer. The on-load tap changer is configured to regulate the portion of the at least one primary winding or the at least one secondary winding that are inductively coupled to each other. Furthermore, the system includes at least one controller coupled to the on-load tap changer. The controller is configured to determine a permissible voltage range defined by a bandwidth around a voltage set-point at the at least one on-load tap changer, where the bandwidth is a function of one or more electrical network states.