CN213990153U - No-load reactive power control device for transformer - Google Patents

Abstract

The utility model relates to a transformer no-load reactive power treatment device belongs to electrical control technical field. The main structure of the device comprises a power generator and a balance control system; the power generator consists of a plurality of resistance load units, is connected with a power supply grid through a switching unit circuit, and the balance control system consists of an arithmetic processor CPU and a human-computer touch screen; the utility model discloses both can improve the compensation to idle, also can do the part active, make it produce monitoring current, under the certain circumstances of apparent power rated power of transformer, let active and idle effectual balance to reach power factor's improvement.

Description

No-load reactive power control device for transformer

Technical Field

The utility model relates to a transformer no-load reactive power treatment device belongs to electrical control technical field.

Background

Through market research, when a transformer is installed, the transformer with the corresponding capacity is generally configured according to the factory power plan, and in the actual process, the influence of off-season production, upgrading and reconstruction, holidays and peak-shifting power utilization is often inevitable, so that the power load is very low, and the transformer is in a no-load or light-load running state. The low power factor presents the following hazards: the loss of the line is increased, and the section of the lead must be increased in order to avoid excessive loss, and the investment of a power grid is correspondingly increased; the transmission capacity of the power grid is increased, the corresponding line voltage drop is increased, and the voltage quality of a user is reduced; the generator set generates a large amount of idle work, and the active power output is limited, so that the utilization rate of the generator set is reduced; grid companies generally punish for enterprises with too low a power factor. The power factor of the enterprise is low, reactive power output can be generated to adjust the fine fee of the electric charge, and the electricity utilization cost of the enterprise is increased.

For a transformer of a special transformer, national grid power companies and south grid power companies generally require high supply and high count, and loss of the transformer needs to be recorded. In a no-load or light-load state, the transformer is an inductive load, and not only active power but also reactive power is consumed. Because the power factor is often not up to standard when the transformer is in no-load or light-load operation, the reactive power output adjustment electric charge is produced, the lower the power factor is, the higher the penalty force is, especially for users with large capacity of the transformer, the monthly reactive power output adjustment electric charge can be different from thousands of yuan to ten thousand yuan, and the production cost of enterprises is greatly increased. The current conventional low-voltage compensation device needs sampling current and voltage signals from the low-voltage side of the transformer, and although the power factor on the high-voltage side of the transformer is low, the reactive compensation controller cannot be automatically started, and the capacitor cannot be put into operation. If a group of capacitors is forcibly put into use manually, overcompensation is generated, the generated reactive power is far larger than that in no-load, and the power factor of the high-voltage side of the transformer is lower. The traditional capacitance compensation defect: the scheme of the controller and the capacitor can only compensate the reactive power of the low-voltage side, and the reactive power requirement of the high-voltage side cannot be met on the basis of the reactive power of the low-voltage side. Aiming at the electricity utilization scheme of high-meter high-control, the sampling is all on the high-voltage side, the power factor is low, and therefore high reactive penalty is generated.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a transformer no-load reactive power administers device. The reactive power compensation can be improved and compensated, partial active power can be also made, the monitoring current is generated, and the active power and the reactive power are effectively balanced under the condition that the apparent power rated power of the transformer is certain, so that the power factor is improved.

In order to realize the purpose, the utility model discloses a technical scheme is: a transformer no-load reactive power treatment device comprises a power generator and a balance control system; the method is characterized in that: the power generator consists of a plurality of resistive load units, and each resistive load unit is tightly attached to the radiator for heat dissipation; the balance control system consists of an arithmetic processor CPU and a man-machine touch screen, an input interface of the arithmetic processor CPU is connected with a current transformer and a voltage transformer of the power supply grid, the current and the voltage of the power supply grid are sampled, and real-time active and reactive parameters are judged; the man-machine touch screen provides manual and automatic control related parameter setting and switching commands for the CPU; the number of the switching resistance load units of the switching unit circuit is controlled by the CPU; the CPU of the operation processor is also provided with a data storage sharing interface, a 12M memory card can be inserted, variable information in a main station is monitored, the variable information can be selectively set to be transmitted to a designated cloud terminal in a single phase, the monitoring center can monitor the running state of the equipment in real time, fault information can be known at the first time when a fault occurs, and the on-site maintenance can be timely and pertinently carried out.

Further, the switching unit circuit is an IGBT switching circuit.

Further, the radiator is used for cooling and radiating the semiconductor.

Use the utility model discloses a transformer no-load reactive treatment device can be a power generator unit when utilizing the no-load, provides certain load loss PC value, can overcome reactive compensation controller and can not automatic start, and the unable technical problem who drops into the operation of condenser, when the idle reactive loss of electric wire netting is certain, thereby increase the effective output of load loss PC value and reach the improvement of the power factor of big high-pressure side, the utility model discloses compromise the reactive compensation of intelligence, contained devices such as idle generator, can improve the compensation to idle, also can be partial active, make it produce monitoring current, under the certain condition of transformer apparent power rated power, let active and idle effectual balance to reach the improvement of power factor.

Drawings

FIG. 1 is a schematic diagram of high pressure metering with low pressure compensation.

Fig. 2 is a vector diagram of a reactive power formula and a characteristic diagram of transformer loss.

Fig. 3 is a schematic diagram of the transformer no-load reactive power treatment device.

Fig. 4 is a control schematic diagram of the transformer no-load reactive power treatment device.

Wherein: the system comprises a current transformer A, a voltage transformer B, a human-computer touch screen C, an operation processor CPU D, a switching unit circuit E, a resistance load unit F and a data storage sharing interface G.

Detailed Description

The preferred embodiments of the present invention will be further explained with reference to the accompanying drawings.

A transformer no-load reactive power treatment device comprises a power generator and a balance control system; the method is characterized in that: the power generator consists of a plurality of resistive load units (F), and each resistive load unit (E) is tightly attached to the radiator for heat dissipation; the balance control system is composed of an arithmetic processor CPU (D) and a man-machine touch screen (C), an input interface of the arithmetic processor CPU (D) is connected with a current transformer (A) and a voltage transformer (B) of the power supply grid, the current and the voltage of the power supply grid are sampled, and real-time active and reactive parameters are judged; the human-computer touch screen (C) provides manual and automatic control related parameter setting and switching commands for an arithmetic processor CPU (D); the number of the switching resistance load units (F) of the switching unit circuit (E) is controlled by an arithmetic processor CPU (D); the CPU (D) of the operation processor is also provided with a data storage sharing interface (G) into which a 12M memory card can be inserted to monitor the variable information in the main station, the variable information can be selectively transmitted to a designated cloud terminal in a single phase, the monitoring center can monitor the running state of the equipment in real time, the fault information can be known at the first time when a fault occurs, and the equipment can be timely and pertinently maintained on site.

The switching unit circuit (E) is an IGBT switching circuit.

1. Traditional compensation power utilization scheme

In fig. 1, for high voltage measurement, low voltage compensation is adopted, and it is obvious that the compensation needs to be operated, and the operation can be performed only by depending on the power factor generated by the low voltage sampling voltage current transformer, but the operation cannot be performed when the transformer is in no-load or light-load and no current exists.

2. The characteristics of a reactive power formula vector diagram and transformer loss are as follows:

S=√3 UI=√(P^2+Q^2 )

P=√3 UIcosφ

Q=√3 UIsinφ

it is clear from FIG. 2 that as we decrease, the P value increases and the Q value decreases. Therefore, the active output needs to be controlled besides the compensation of reactive loss;

loss characteristic of transformer

P0-no-load loss, mainly iron loss, including hysteresis loss and eddy current loss;

hysteresis loss is proportional to frequency; proportional to the hysteresis coefficient to the power of the maximum magnetic flux density;

the eddy current loss is in direct proportion to the product of the frequency, the maximum magnetic flux density and the thickness of the silicon steel sheet;

PC-load loss, mainly the loss on the resistance when load current passes through the winding, commonly called copper loss;

the magnitude of the current is changed along with the load current and is in direct proportion to the square of the load current; (and expressed in standard coil temperature scalars);

the load loss is also influenced by the temperature of the transformer, and meanwhile, the leakage magnetic flux caused by the load current can generate eddy current loss in the winding and generate stray loss at the metal part outside the winding;

total loss Δ P = P0-PC of transformer

Transformer loss ratio = PC/P0

Transformer efficiency = PZ/(PZ Δ P), expressed in percentage; wherein PZ is the secondary side output power of the transformer.

The reactive compensation scheme of the embodiment:

FIG. 3 illustrates: the transformer no-load reactive power treatment device can be a resistance load unit (E) when the transformer is no-load, a certain load loss PC value is provided, when the no-load reactive power loss is certain, the effective output of the load loss PC value is increased, so that the power factor of a large high-voltage side is improved, the intelligent reactive power compensation is considered in the embodiment mode, devices such as a reactive generator are included, the reactive power compensation can be improved, partial active power can be also realized, the monitoring current is generated, and the active power and the reactive power are effectively balanced under the condition that the apparent power rated power of the transformer is certain, so that the improvement of the power factor is achieved.

4. The intelligent field of the reactive power treatment device is expanded.

The product of the embodiment can be used as a fixed balance module unit aiming at transformers with different capacities. And the intelligent arithmetic unit can also be adjusted at any time in a complex way.

Claims (3)

1. A transformer no-load reactive power treatment device comprises a power generator and a balance control system; the method is characterized in that: the power generator consists of a plurality of resistive load units (F), and each resistive load unit (F) is tightly attached to the radiator for heat dissipation; the balance control system is composed of an arithmetic processor CPU (D) and a man-machine touch screen (C), an input interface of the arithmetic processor CPU (D) is connected with a current transformer (A) and a voltage transformer (B) of the power supply grid, the current and the voltage of the power supply grid are sampled, and real-time active and reactive parameters are judged; the human-computer touch screen (C) provides manual and automatic control related parameter setting and switching commands for an arithmetic processor CPU (D); the number of the switching resistance load units (F) of the switching unit circuit (E) is controlled by an arithmetic processor CPU (D); the CPU (D) of the operation processor is also provided with a data storage sharing interface (G) into which a 12M memory card can be inserted to monitor the variable information in the main station, the variable information can be selectively transmitted to a designated cloud terminal in a single phase, the monitoring center can monitor the running state of the equipment in real time, the fault information can be known at the first time when a fault occurs, and the equipment can be timely and pertinently maintained on site.

2. The transformer no-load reactive power management device of claim 1, wherein: the switching unit circuit (E) is an IGBT switching circuit.

3. The transformer no-load reactive power management device of claim 1, wherein: the radiator is used for semiconductor refrigeration and heat dissipation.

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