CN215933361U

CN215933361U - High-voltage switch transformer combined electrical apparatus capable of being switched frequently

Info

Publication number: CN215933361U
Application number: CN202121079355.6U
Authority: CN
Inventors: 包红旗; 孙茂有; 张国良; 张闪; 李玉林
Original assignee: Clp Xinyuan Langfang Electric Group Co ltd
Current assignee: Clp Xinyuan Langfang Electric Group Co ltd
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2022-03-01
Anticipated expiration: 2031-05-20

Abstract

The utility model relates to the field of new energy, in particular to a high-voltage switch transformer combined electrical appliance capable of being switched frequently, which comprises an isolating switch, wherein the current entering a transformer is enabled to pass through a resistor through the switching of the isolating switch, so that the magnetizing inrush current is limited, or the current directly enters the transformer without passing through the resistor after the magnetizing inrush current tends to be stable. By adopting the scheme, the purposes of putting the transformer immediately after use and cutting the transformer when not used can be achieved.

Description

High-voltage switch transformer combined electrical apparatus capable of being switched frequently

Technical Field

The utility model relates to the field of new energy, in particular to a high-voltage switch transformer combined electrical appliance capable of being switched frequently.

Background

With the goal that China promises carbon to reach peak and neutralize carbon to the world, the construction of renewable energy resources has been developed on a large scale. However, wind power and photovoltaic power generation are unstable due to natural conditions, and can cause huge impact on a power grid. With the increasing of the proportion of new energy in the power grid, the impact of the new energy on the power grid can reach an intolerable degree. The problem can be well solved by building corresponding energy storage power stations. In energy storage plants there are a large number of transformers supplying the energy storage units. Because the energy storage unit is charged for energy storage when the electricity is used at night at the trough, and is discharged for peak shaving when the electricity is used at the peak in the daytime, the working time of the energy storage unit is shorter every day, and generally, the charging time and the discharging time are respectively 4 hours every day. However, the transformer is limited by surge current, and frequent switching on and off (switching) operations are not allowed, so that the transformer must be in an idle running state for a long time. Generally, the no-load loss of a transformer is between 0.1% and 0.5% of the rated capacity, taking the capacity of the transformer as 2500kVA as an example, the no-load loss can reach at least 2.5kW, and the no-load operation time of the transformer reaches 16 hours per day, so that the electric quantity of the no-load loss of a single transformer per day is 2.5X 16-40 kW · h (degrees). 36 transformers are needed for a 50MW energy storage power station, so the total no-load loss electricity per day is 40X 36-1440 degrees, and the loss per year is 1440X 365-52.56 ten thousand degrees. Therefore, the no-load loss of the transformer has become a main factor influencing the economic benefit of the energy storage power station.

Therefore, the inventor further researches the above and develops a high-voltage switch transformer combined electrical apparatus capable of being switched frequently, and the present invention is generated based on the above.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a high-voltage switch transformer combined electrical appliance capable of being switched frequently, which can achieve the purpose of switching a transformer immediately after use and switching the transformer when not used.

In order to achieve the purpose, the technical scheme of the utility model is as follows:

a high-voltage switch transformer combined electrical appliance capable of being switched frequently comprises

The isolating switch is switched to enable the current entering the transformer to pass through the resistor or limit the magnetizing inrush current, or enable the current not to directly enter the transformer through the resistor after the magnetizing inrush current tends to be stable.

The current enters the transformer after flowing through the resistor, and the closing current (excitation inrush current) of the transformer is limited to an acceptable degree because of flowing through the resistor, under the condition, after several cycles after closing, the closing current is stabilized, and the excitation of the transformer is completed; the switching-on current (excitation surge current) tends to be stabilized to the no-load current of the transformer, the action of the resistor is completed at the moment, the input current of the transformer is increased due to the fact that a load is added on the low-voltage side, and if the current passes through the resistor, the resistor can continuously absorb energy to cause the resistor to be overheated and explode, so that the resistor needs to be timely withdrawn from operation, and the purposes of putting the transformer immediately after use and cutting when not used are achieved.

Further, when the disconnecting switch is opened, current enters from the cable, sequentially passes through the circuit breaker, the three-position switch and the resistor, and then enters the transformer.

Further, when the isolating switch is switched on, current enters from the cable, sequentially passes through the circuit breaker, the three-position switch and the conductor, and then enters the transformer.

Furthermore, when the transformer quits operation, the breaker is disconnected, and the isolating switch is opened.

Further, a circuit breaker closing control signal simultaneously gives a closing instruction to the resistor short circuit isolating switch through a time relay, so that the resistor short circuit isolating switch is closed after the circuit breaker is closed by delay time t set by the relay, and the resistor exits from operation.

After adopting the scheme, compared with the prior art, the utility model has the following advantages:

through accurate configuration of the resistance value and reasonable control strategy of the short-circuit isolating switch, the influence of switching-on impact surge current on a transformer insulation system during transformer power transmission can be greatly reduced, and the transformer body is allowed to be frequently operated.

Drawings

FIG. 1 is a schematic diagram of the disconnecting switch of the present invention when it is opened;

FIG. 2 is an equivalent circuit diagram of FIG. 1;

FIG. 3 is a schematic diagram of the disconnector when closed;

FIG. 4 is an equivalent circuit diagram of FIG. 3;

description of the reference symbols

A disconnecting switch 1, a transformer 2, a resistor 3, a breaker 4, a three-position switch 5,

conductor 6, permanent magnetic mechanism 7, cable incoming end 8.

Detailed Description

The utility model is further described with reference to the following figures and specific embodiments.

As shown in the figure, the transformer 2 and the switch combined electrical appliance adopt the same base, high-voltage sleeves are directly connected, and when the oil type transformer 2 is selected, oil gas sleeves are adopted for connection; when the dry type transformer 2 is selected, a cable connection is adopted.

The switch combined electrical apparatus comprises a disconnecting switch 1, a circuit breaker 4, a three-position switch 5, a resistor 3 and a conductor 6 which are connected in parallel, wherein a cable access end 8 is connected with the circuit breaker 4, the circuit breaker 4 is connected with the three-position switch 5, the resistor 3 and the conductor 6 are connected in parallel and then connected in series with the three-position switch 5, the conductor 6 is linked with the disconnecting switch 1, and when the disconnecting switch 1 is connected with the conductor 6 under the action of a permanent magnetic mechanism 7, the resistor 3 is short-circuited or current is limited to a circuit.

The working principle is as follows:

when the transformer 2 is put into operation, the resistor 3 is in short circuit with the isolating switch 1 in an open state, and the breaker 4 is switched on to carry out excitation charging on the transformer 2, as shown in the attached figure 1;

after the circuit breaker 4 is switched on, the high-voltage side voltage is applied to the high-voltage coil of the transformer 2 through the resistor 3, and the magnetizing inrush current of the transformer 2 is greatly reduced due to the current limiting effect of the resistor 3, and the magnetizing inrush current performs an R/L slow charging process on the transformer 2 until the rated voltage is reached on the high-voltage coil of the transformer 2;

after the magnetizing inrush current is stable (more than tens of milliseconds), in order to avoid damage of the resistor 3 due to overheating, the resistor 3 is in short circuit with the disconnecting switch 1 switched on to carry out short circuit on the resistor 3, and the voltage on the high-voltage side is not passed through the resistor 3 any more, but is directly applied to the high-voltage coil of the transformer 2, as shown in the attached figure 3; at this time, the whole commissioning process of the transformer 2 is completed; at that time, the low-voltage side of the transformer 2 is loaded and normally operated.

When the transformer 2 is out of operation, the circuit breaker 4 is directly disconnected, then the resistor 3 is in short circuit with the isolating switch 1 for opening, and preparation is made for next transformer 2 operation;

the action of opening and closing the resistor 3 to short circuit the isolating switch 1 is automatically completed through a secondary interlocking loop of the circuit breaker 4, namely before the transformer 2 is put into operation, the circuit breaker 4 is in an opening state, at the moment, the resistor 3 is in a short circuit the isolating switch 1 is also in an opening state, when the circuit breaker 4 is closed, a closing control signal of the circuit breaker 4 simultaneously gives a closing instruction to the resistor 3 to short circuit the isolating switch 1 through a time relay, so that the resistor 3 is closed through the delay time t set by the relay after the circuit breaker 4 is closed, and the resistor 3 is closed to short circuit the isolating switch 1 and quits from operation.

The high-voltage switch combined electrical apparatus is according to non-maintaining design, and life is 30 years, in order to satisfy the requirement of transformer 2 frequent switching, the operating device who selects long-life work (20000 times more) for circuit breaker 4 and resistance 3 short circuit isolator 1's operating device.

The above description is only an embodiment of the present invention, and all the terms such as "upper", "lower", "left", "right", "middle", etc. in the present invention are used as reference and not absolutely limited, and all the insubstantial modifications made by the present invention shall fall within the scope of infringing the present invention.

Claims

1. The utility model provides a high tension switchgear transformer combined electrical apparatus that can frequently switch which characterized in that: comprises an isolating switch, a circuit breaker, a three-position switch, and a resistor and a conductor which are mutually connected in parallel,

when the isolating switch is switched off, current enters from the cable, sequentially passes through the circuit breaker, the three-station switch and the resistor, and then enters the transformer;

when the isolating switch is switched on, current enters from the cable, sequentially passes through the real circuit breaker, the three-position switch and the conductor, and then enters the transformer.

2. The high-voltage switch transformer combined electrical apparatus capable of being switched frequently according to claim 1, characterized in that: when the transformer is out of operation, the breaker is disconnected, and the isolating switch is opened.