Scope of application

The characteristics of rural electricity use in China: strong seasonality of electricity consumption, large fluctuations in load, concentrated electricity consumption, and low annual average load rate. During the busy season and the Spring Festival in summer and autumn, most of the transformers are in full load or overload operation, and the failure rate of the transformer increases. The rest of the time is the low season of electricity consumption. The load is mainly lighting power. At this time, the load rate is low and appears again. The phenomenon of "big horse car" has caused a lot of electric energy to be wasted. In addition, in urban residential quarters and Changbai class enterprises and institutions, the difference in electricity load during day and night is also large.

The on-load capacity-adjusting voltage-regulating distribution transformer is a kind of rated capacity of two sizes. It can be automatically detected and judged by the controller according to the load of the user, and the special on-load capacity-adjusting voltage regulating switch can be used in the transformer without power failure. In the state, the two capacities of the transformer are automatically switched, and the transformer capacity is automatically adjusted during the operation to realize the automatic conversion of the two rated capacity modes. When the grid voltage changes, the on-load voltage regulation is also realized through the switch to ensure the stability of the secondary voltage.

Executive standard

GB 6451-2008 "Three-phase oil-immersed power transformer technical parameters and requirements"

GB 1094.1 "Power Transformers Part I General Rules"

GB 1094.2 "Power Transformer Part 2 Temperature Rise"

GB 1094.3 "Power transformers - Part 3: Insulation level and insulation test"

GB 1094.5 "Power transformer fifth part ability to withstand short circuit"

JB/T 10778 "Three-phase oil immersed transformer"

JB/T 3837 "Transformer Product Numbering Method"

JB/T 501 "Power Transformer Test Guide"

Features

A. Loaded and convenient, quick and easy

The rated output capacity of the distribution transformer can be automatically changed by tracking the load change, and the power supply can be ensured at an appropriate time, so that the no-load loss of the transformer is reduced by about 40-50% compared with the same type of distribution transformer. It can improve the grid power factor, reduce the reactive component in the distribution network, and reduce network loss.

B. On-load voltage regulation, high quality power supply

When the voltage of the distribution network changes, the non-excitation voltage regulation method often has shortcomings such as untimely voltage regulation and large workload, and it is difficult to ensure the quality of power supply. The on-load voltage regulation can be monitored at any time through the controller, and the voltage is regulated in time to keep the supply voltage constant to improve the power supply quality and extend the service life of the equipment.

C. Integrated switch, beautiful use

The on-load adjustable pressure regulating switch is a vertical cylindrical structure; the switch moving and static contacts are fastened on the insulating cylinder, there is no jamming during the switching process, and the contact resistance is small; there is a glass observation port at the top of the switch, which can be clear Observing the action position of the switch, the oil seal ring at the switch and the cover, ensuring that the switch and the transformer are not permeable to oil and the safety of the operating mechanism; the switch has both manual and automatic functions, and is usually set in an automatic state.

D. Energy efficient, safe and reliable

The transformer core is made of high-quality oriented cold-rolled silicon steel sheet. The punching can ensure that the no-load loss is reduced by 30% and the no-load current is reduced by 70% compared with the S9 product of the same specification. The windings are all cylindrical and have good impact voltage distribution. The oil passage has high heat dissipation efficiency.

E. Extended function (optional)

It is recommended to use with our low voltage reactive power compensation device to achieve the following functions:

1. Precise microcomputer protection function: It can realize precise over-current and quick-break protection functions, the protection setting can be continuously adjusted and support remote modification, overload, short circuit,

Protection functions such as phase loss, undervoltage, overvoltage, slowly varying leakage, and sudden leakage. It solves the problem that the conventional power distribution station area trips over or burns out due to inaccurate protection.

2. "Four remote" and remote power selling function: cooperate with the distribution operation management system to send GPRS commands to realize real-time monitoring, viewing and modification of the "four remote" function and prepaid management functions of fixed value, wireless remote power transmission and delivery, and solved With the problem of automatic control of the radio area.

3. Accurate reactive power compensation: It can realize 30-channel pole difference 1kVar precision reactive power compensation, adopting single-chip intelligent thyristor zero-crossing switching, and low power consumption.

Model Description

Transformer dimensions

Performance and structural parameters of S11-ZT type on-load capacity regulating transformer

注：括号内为小容量参数

S13-M-ZT型有载调容变压器性能参数及外形

Note: small capacity parameters in parentheses

Comprehensive economic analysis

Take the S11 energy-saving transformer of an energy-saving company of the State Grid as an example: the load characteristic of the transformer is basically no power failure within one year, and it is close to full-load operation (90 days) during the busy season and the Spring Festival in summer and autumn, and the load for the rest of the time is rated. 30% of capacity. If this batch of transformers is changed to the on-load capacity-adjusting transformer of the corresponding specification, the economic analysis will be carried out from the aspects of annual operation savings and investment recovery years:

Annual operating cost savings:

The annual operating cost of the transformer can be calculated as follows:

Cy=[8600*(P0+0.05*Sn/100)+2200*(Pk+0.05*Uk*Sn/100)]*0.8

In the above formula, Cy is the annual operating cost of the transformer (yuan); P0 is the no-load loss (kW); Pk is the load loss (kW); Sn is the rated capacity (kVA); Uk is the short-circuit impedance percentage (%); 0.8 is Electricity price (yuan/kW·h); 8600, 2200 are the transformers' annual no-load, equivalent full load (load factor 0.25) hours. Substituting the corresponding P0, Pk and Uk values in the international form into the above formula, the Cy of the S11 type energy-saving transformer and the S11-ZT load-carrying transformer can be calculated separately, and the annual electricity cost △Cy is calculated as follows:

Investment recovery period:

According to the comparison between the market price of the S11-ZT type load-carrying transformer and the ordinary S11 energy-saving distribution transformer and the annual electricity saving, it is estimated that the S11-ZT type load-carrying transformer is used to replace the S11 energy-saving transformer under different capacities. The recycling period is shown in the following table:

It can be seen from the above table that the static investment recovery period of S11-ZT type load-carrying transformer instead of S11 energy-saving transformer is about 4 years. If S13-ZT type load-carrying transformer is adopted, its energy saving effect is better, investment recovery The age is shorter.