CN202309082U - Automatic stepless voltage regulating type reactive power compensator - Google Patents

Abstract

The utility model provides an automatic stepless voltage regulating reactive power compensation device, which includes a capacitor bank and its control part. An adjustable reactor is connected in series on the line where the capacitor bank is connected to the power grid. The adjustable reactor includes a capacitor bank connected in series with the The primary side coil KL1 between the power grids, the adjustable reactor is provided with the secondary side control coil KL2, and the two ends of the secondary side control coil KL2 are connected to the bidirectional thyristor VT, and the control pole of the bidirectional thyristor VT is connected to the intelligent controller ZKQ; The grid reactive current detection device JC is set on the line connecting the group to the grid, and the output of the grid reactive current detection device JC is connected to the intelligent controller ZKQ. The utility model can automatically adjust the capacity of the capacitor group steplessly through closed-loop control without any impact on the power grid, and can adapt to the automatic tracking and compensation of rapidly changing loads in the power grid; the capacitor group has long life and high reliability, and can be used for power grids and large electrical equipment Reactive fast compensation.

Description

Automatic stepless pressure regulation reactive power compensation device

technical field

The utility model relates to an automatic stepless voltage regulating reactive power compensation device, which is used for fast reactive power compensation of power grids and large electrical equipment. It belongs to the technical field of reactive power compensation.

Background technique

There are two types of electrical equipment in the power grid, one is the transformer, and the other is the motor. The transformer uses the principle of electromagnetic induction to exchange and change different voltage systems to obtain the required voltage and current. For example: the 110KV voltage system can be reduced to a 35KV or 10KV system through a step-down transformer, and then the 35KV or 10KV voltage can be reduced to our daily civilian 380V/220V voltage system through a distribution transformer, so as to meet the electricity demand of thousands of households.

The electric motor is the main electrical equipment for industrial driving and control. Its main function is to convert electric energy into mechanical energy required for industrial production. The electric energy consumed by electric motors in industrial production accounts for about 70% of the national power generation.

Both transformers and motors need reactive power to function properly. The transformer needs reactive power to make the primary coil of the transformer generate a magnetic field, so that the secondary coil can induce voltage; the motor needs reactive power to establish and maintain a rotating magnetic field, so that the motor rotor rotates, thereby driving the mechanical movement.

Reactive power is mainly used for the exchange of electric field and magnetic field in the circuit, and the electric power that establishes and maintains the magnetic field in electrical equipment. All electrical equipment with electromagnetic coils will consume reactive power to establish a magnetic field.

When the electrical equipment absorbs active power from the grid, it also absorbs reactive power from the grid. If the reactive power provided by the grid is insufficient, the electrical equipment does not have enough reactive power to establish a normal electromagnetic field. These electrical equipment It will not be able to play the rated power normally to work normally. The rated power of the motor will decrease; the power supply capacity of the transformer will decrease; the voltage loss of the power supply line will increase and the power loss will increase.

To make up for the lack of reactive power in the grid, it is necessary to add additional reactive power compensation equipment. At present, the most effective and economical compensation method is to use capacitor bank for reactive power compensation.

There are two main ways of traditional reactive power compensation:

1. Put in or cut off the capacitor bank through the contactor;

2. The capacitor bank is fixedly connected to the power grid.

In the first type of traditional compensation, the increase and decrease of capacitor capacity is realized by switching on or cutting off the capacitor bank by the contactor. The main disadvantage is that the change of capacitor capacity is graded, and the input or removal has a certain impact on the power grid; secondly, it takes a certain time to input or remove the contactor, so it cannot keep up with the rapid changes in reactive power (for example, punching, laser welding, During the working process of equipment such as rolling mills, the reactive power will change rapidly).

In the second type of traditional compensation, the capacity of the capacitor is fixed and does not change. Its main disadvantage is that when the grid load is too heavy, the reactive power compensation capacity is insufficient; on the contrary, when the grid load is light, the grid will overcompensate. Insufficient compensation capacity will reduce the power factor of the grid; overcompensation of compensation capacity will decrease the power supply capacity of the grid and affect the security of the grid.

Contents of the invention

The purpose of this utility model is to overcome the shortcomings of the above-mentioned traditional compensation technology and provide an automatic stepless voltage regulation reactive power compensation device. Good performance, high reliability and long service life.

The technical scheme of the utility model is: the automatic stepless voltage regulation reactive power compensation device of the utility model includes a capacitor bank and its control part, and an adjustable reactor is connected in series on the line connecting the capacitor bank to the power grid, and the adjustable reactor includes The primary side coil KL1 is connected in series between the capacitor bank and the grid, and the adjustable reactor is provided with a secondary side control coil KL2, and a bidirectional thyristor VT is connected between the two ends of the secondary side control coil KL2, and the control pole of the bidirectional thyristor VT is connected to the intelligent controller ZKQ connection; a grid reactive current detection device JC is installed on the line where the capacitor bank is connected to the grid, and the output of the grid reactive current detection device JC is connected to the intelligent controller ZKQ.

The beneficial effects of the utility model are: 1. The voltage on the capacitor terminal can be automatically adjusted steplessly through closed-loop control, so that the capacity of the capacitor bank can be changed arbitrarily within the rated capacity range; 2. The change of the capacity of the capacitor bank has no impact on the power grid; 3. , Can adapt to the automatic tracking compensation of fast changing loads in the power grid; 4, Since the capacitor bank is limited to work below the rated voltage, the capacitor bank has a long life and high reliability. 5. It has a wide range of applications and can replace the existing high and low voltage tuned reactive power compensation devices.

Description of drawings

Fig. 1 is a schematic diagram of the electrical principle of the utility model.

Detailed ways

Embodiments of the present utility model will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the electrical principle of the utility model.

In the automatic stepless voltage regulating reactive power compensation device of the present invention, an adjustable reactor is connected in series on the line connecting the capacitor bank C1 to Cn to the power grid. The side coil KL1 and the adjustable reactor are provided with the secondary control coil KL2, and the two ends of the secondary control coil KL2 are connected with the triac VT, and the control pole of the triac VT is connected with the intelligent controller ZKQ; The grid reactive current detection device JC is set on the line, and the output of the grid reactive current detection device JC is connected to the intelligent controller ZKQ. In the figure QF is a circuit breaker.

The traditional reactor has only one coil per phase. After the reactor is manufactured in the factory, since the cross section of the iron core, the number of coil turns, and the air gap of the iron core column have been determined, the reactance value XL of the reactor cannot be changed, and the reactor voltage The UL is basically unchanged, and the voltage on the terminal of the capacitor bank connected in series with it is constant, and the capacity is also constant.

In the utility model, a secondary side control coil KL2 is added to each phase of the traditional reactor, and a group of bidirectional thyristors VT are connected in series at its head and end. The magnitude of the passed current I2 is also different, so that the main magnetic flux Φm generated by the current I1 on the primary coil KL1 of the reactor changes, the inductance Lm generated by the main magnetic flux Φm changes, and the reactance XL changes accordingly. The adjustable reactor The voltage at both ends changes accordingly, the voltage at both ends of the capacitor bank connected in series changes accordingly, and the capacity of the capacitor bank changes accordingly, so as to achieve the purpose of adjusting the reactive power compensation capacity.

The opening adjustment of the bidirectional thyristor conduction angle is completed by the intelligent controller ZKQ. The intelligent controller ZKQ receives the reactive current signal through the reactive current detection device JC, calculates the power factor through the microcomputer and compares it with the set value, and then sends out a signal to control the conduction angle of the bidirectional thyristor.

The capacitor bank is composed of several single capacitors C1, C2...Cn connected in series (when the capacity or voltage is required). A reactor with adjustable reactance is installed at its front end, and it cooperates with the control device to make it an automatic stepless voltage regulating capacitor bank.

Claims (1)

1. An automatic stepless voltage regulating reactive power compensation device, including a capacitor bank and its control part, characterized in that: an adjustable reactor is connected in series on the line where the capacitor bank is connected to the power grid, and the adjustable reactor includes a capacitor connected in series The primary side coil KL1 between the group and the grid, the adjustable reactor is provided with a secondary side control coil KL2, the two ends of the secondary side control coil KL2 are connected to a bidirectional thyristor VT, and the control pole of the bidirectional thyristor VT is connected to the intelligent controller ZKQ; A grid reactive current detection device JC is installed on the line where the capacitor bank is connected to the grid, and the output of the grid reactive current detection device JC is connected to the intelligent controller ZKQ.

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