RU202818U1 - Voltage dips compensation device - Google Patents

Abstract

This utility model relates to the field of electrical engineering and can be implemented in the form of a device installed at the supply input of equipment to compensate for supply voltage dips. The voltage dips compensation device includes a booster transformer, one of the high voltage windings of which is connected to a controlled inverter, and the other low voltage winding connected to the network between the supply network and the consumer. The active rectifier is directly connected to the consumer circuit. Between the controlled inverter and the active rectifier, an energy storage device is connected to the DC link, which provides compensation for medium and deep voltage drops in the supply network. Control system, based on information about voltage values at the points of connection of the voltage dip compensation device to the supply network and to the consumer, by acting on the contactor, controlled inverter and active rectifier, it switches between modes. voltage dip compensation provides the ability to work in at least three modes, namely, compensation for shallow voltage drops, compensation for medium-depth voltage dips and compensation for deep voltage dips.

Description

The present utility model relates to the field of electrical engineering and can be implemented in the form of a device installed at the supply input of the equipment to compensate for supply voltage dips.

Known transformer-thyristor compensator for voltage and reactive power deviations (Patent for FROM RF № / 2158953 from 10.11.2000 H02J 3/00),

The compensator contains a network reactive power sensor and a load voltage deviation sensor, the first and second three-phase voltage inverters with individual control systems, the first and second three-phase booster transformers, the primary windings of which are connected in series and included in the load circuit, and their secondary windings are respectively connected to outputs of the first and second three-phase voltage inverters, while the inputs of the first and second three-phase voltage inverters are combined and connected to the load through a three-phase recuperative rectifier, the three-phase recuperative rectifier includes a valve block with a control system, a three-phase automatic device and an output inductive-capacitive filter, and a control the input of the control system for the first three-phase voltage inverter is connected to the output of the reactive power sensor of the network.

The disadvantage of the device is the impossibility of maintaining the voltage in the load in the event of a voltage failure in the network, a limited range of reactive power compensation, low speed, high harmonic distortion due to the operation of thyristors, the presence of more than two electronic power units of comparable power, the presence of two voltage boost transformers.

The closest in technical essence and the achieved result is the DYNAMIC VOLTAGE COMPENSATOR under the patent for invention of the Russian Federation No. 2656372 dated 06/05/2018, H02J 3/00

The booster transformer of the dynamic voltage compensator is configured to operate in at least two operating modes. In one of which at least one high voltage winding is connected to a controlled inverter, and another winding or group of windings is connected in series to the network between the current source and the consumer. At the same time, in the second of the possible modes of operation, the low-voltage windings of the booster transformer, which are switched by means of at least one controlled switching device, are connected to an electrical circuit with the possibility of ensuring the operation of the booster transformer without being connected to the mains, while the inverter is connected to the energy storage and transmission link with the possibility of supplying a booster transformer.

The disadvantages of this technical solution include the overestimation of the power of the booster transformer, since in the mode of complete loss of the supply network, all the power from the energy storage will be transmitted through the booster transformer, as well as the lack of a power supply circuit of the storage unit with deep voltage dips (up to 20% of the nominal voltage ).

A technical problem is the creation of a voltage dip compensation device that provides the ability to operate in at least three modes, namely, compensation for shallow voltage drops, compensation for medium-depth voltage dips and compensation for deep voltage dips.

The technical result of the utility model is to ensure the operation of the device in an additional mode of compensation for average voltage dips.

The technical problem is solved and the technical result is achieved by the fact that the voltage dip compensation device includes a booster transformer, one of the high voltage windings of which is connected to a controlled inverter, and the other low voltage winding is connected to the network between the supply network and the consumer.

The active rectifier is directly connected to the consumer circuit.

An energy storage device is connected to the DC link between the controlled inverter and the active rectifier, which compensates for medium and deep voltage drops in the supply network.

The device is connected to the control system, with the possibility of acting on the high-speed contactor. Based on the information about the voltage values at the connection points of the voltage drop compensation device to the supply network and to the consumer, by acting on the contactor, controlled inverter and active rectifier, it switches between modes.

FIG. 1 shows a block diagram of a voltage dip compensation device, where

booster transformer VDT - 1;

contactor K - 2;

energy storage device - 3

controlled inverter - 4

active rectifier - 5

switches QF1, QF2, QF3 - 6,7,8

control system - 9

The voltage dip compensation device contains:

Contactor K (2) - connected between the supply network and the low voltage winding of the RCCB (1);

VDT (1), one winding is connected through a high-speed contactor K between the supply network and the consumer, and the other winding is connected to a controlled inverter (4);

Switches QF2, QF3 (7, 8) - input and output switches, respectively, for connecting the supply network and the consumer to the device.

Circuit breaker QF1 (6) is a bypass circuit breaker. Voltage dips compensation device operation

In normal or standby mode, the contactor (2) and the switches (7, 8) are on; switch (6) - off;

With shallow voltage drops when the contactor (2) is on, the controlled inverter (4) and the active rectifier (3) are switched on, whereby, through the circuit, the active rectifier (5) - controlled inverter (4) - RCCB (1) into the network to the consumer voltage is added to maintain the voltage at the nominal level indefinitely;

With medium-deep voltage dips with the contactor (2) on, the controlled inverter (4) and the active rectifier (3) are switched on, whereby, through the circuit, the active rectifier (5) - energy storage (3) - controlled inverter (4) - RCCB (1) voltage is added to the network to the consumer to maintain the voltage at the nominal level for a time limited by the capacity of the energy storage units;

In case of deep voltage dips, the contactor (2) is disconnected and the active rectifier (5) is turned on, whereby, through the energy storage circuit (3) - active rectifier (5) - switch (8), the consumer is powered at rated voltage for a time limited capacity of energy storage.

Thus, the developed voltage dip compensation device can operate in at least three modes:

- compensation of shallow voltage drops through the active rectifier circuit (5) - controlled inverter (4) - RCCB (1);

- compensation of voltage dips of average depth through the active rectifier circuit (5) - energy storage (3) - controlled inverter (4) - VDT (1);

- compensation of deep voltage drops through the energy storage circuit (3) - active rectifier (5) - switch (8).

Claims (1)

A voltage dip compensation device, characterized by the presence of a booster transformer, one of the high voltage windings of which is connected to a controlled inverter, and the other low voltage winding is connected to the network between the supply network and the consumer, the active rectifier is directly connected to the consumer circuit, the device is also characterized by the presence of an energy storage device, providing compensation for medium and deep voltage dips in the supply network connected to the DC link between the controlled inverter and the active rectifier, while the contactor, the controlled inverter and the active rectifier are configured to receive commands from the control system to ensure switching between the device operation modes.

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