SU1304122A1 - Electric power installation - Google Patents

Abstract

The invention relates to electrical engineering, in particular to devices for insulation insulation. The purpose of the invention is to improve the energy characteristics by utilizing the energy of the higher harmonic components of the current for the DRYING isolation of motor windings during their stopping. Having disconnected the electric motor 3 by the switching unit 2 from the mains supply, the unit 2 connects the motor windings to the windings of the reactor. After connecting, unit 2 opens the point of zero potential of the power resonant filter or capacitor bank. When the motor is turned on in the network, the switching unit 2 closes the point of zero potential of the filter and disconnects the motor windings from the power resonant filter or capacitor bank without disturbing the operation of the filter or capacitor bank. In the event of a power supply voltage being removed and its subsequent supply, the switching unit 2 automatically puts into operation a power resonant filter or a capacitor bank, closing the zero point, and protects the electric motor from self-starting. 4 and.h. i W ild iii SO O 4 Yu Yu

Description

one

The invention relates to electric power industry, in particular to electric power installations of alternating current, including electric motors and resonant filters, based on the higher harmonic components of the current.

The purpose of the invention is to improve the energy performance by utilizing the energy of the higher harmonic components of the current to dry and prevent the insulation of the motor windings from wetting during their shutdowns.

FIG. 1 shows a block diagram of the connection of the switching unit of the elements of the resonant filter and the motor winding to the resonant filter circuit; in fig. 2-4 - power supply device, examples of implementation.

The electric power installation includes a high-harmonic power resonance filter (or a capacitor bank) and main and additional switching elements arranged in a switching unit. The power resonance filter (capacitor banks) 1, the switching unit 2 are connected to the mains, the second input of the switching unit 2 is connected to the power resonant filter 1. The output of the unit 2 is connected to the electric motor 3.

The source of the current of the new frequency used for drying the insulation of the windings of electric motors in an electric power installation is a power resonance filter made on the basis of successively switched on batteries of capacitors, reactors with windings of an electric motor or windings without reactors.

The switching unit 2 consists of contacts 4 of the magnetic starter 5, which provides the switching off and on of the electric motor 3 to the supply mains, contacts 6 and 7 of the magnetic starters 8 and 9, and contacts 0 of the time relay 11, providing 1 connection to the windings of the electric motor 3 current source of increased frequency, and therefore, the passage of current 0-th harmonic through them The current of the fth harmonic heats the windings, drying them or protecting them from moisture. The buttons “Stop 12,“ Start 13 ”are used for switching the motor to a state of operation or protection against humidification under operating conditions. The contacts 14 of the relay 15, the buttons “Start 16,“ Stop 17 serve to prevent the self-launch of the electric digger. Bulbs 18 and 19 signal the mode in which the electric motor is located.

Electric power plant (Fig. 2-4) works as follows.

After switching off the electric motor 3 by the switching unit 2 from the mains supply, the unit 2 connects the motor windings to the windings of the reactor if the resistance of the electric motor is much less than the resistance of the reactor

1304122

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(Fig. 2), to the capacitor bank (Fig. 3) in the event that the reactors are not installed. If the resistances of the reactor and the engine are approximately equal, the windings are connected instead of the reactor (Fig. 4). The connection of the motor windings occurs with a time delay during which all electromagnetic and mechanical transients are terminated in the motor. After switching by the switching unit 2 windings of the electric motor 3, the unit 2 opens the point of zero potential of the power resonant filter (Fig. 2) or capacitor banks (Fig. 3), and the windings of the electric motor become an inductive element of the power resonant filter. The newly obtained resonant power filter remains a source of reactive power and a device that improves the quality of electricity, and also additionally provides a source of increased frequency current to heat the electric windings of the motor, resulting in drying or protection of the motor windings from moisture. When the motor is turned on, the switching unit 2 closes the point of zero potential of the filter and disconnects the motor windings from the power resonant filter (Fig. 2) and; 1 and the capacitor batteries (Fig. 3), not napyujBH while the filter or the capacitor bank are working. In the case of the removal of the mains supply voltage and the next; supplying it to it, the switching unit 2 automatically puts into operation a power resonance filter or a capacitor bank, closing the zero point, and protects the electric motor from self-starting.

When operating in accordance with the scheme of FIG. 4, the switching unit 2, after disconnecting the electric motor 3 from the power supply network with a time delay, disconnects the reactors and instead connects the windings of the electric motor 3. When the electric motor 3 is turned on in the network, switching operations occur in the reverse order.

The proposed device makes it possible to use for the drying and preventing the damping of the insulation of the windings of the electric motors during their stops the energy of the HIHI harmonic components of the current, which improves the energy characteristics of the power supply device.

Claims (1)

Invention Formula An electrical installation comprising an AC source and electromotors and resonant filters connected to it through switching elements, characterized in that, in order to improve the energy performance by utilizing the energy of the higher harmonic components of the current to dry the insulation of the motor windings during their stopping, equipped with additional switching elements connected between the motor and the resonant filter. (R .J m - f rrjrtn jl. M „Squeak 76 P„ Stop “Start“ Table ” 11 75 If 77 P /  Gtr ,,Stop 13T.J five y ;; 511 -h five y ;; eri2.