CN209844626U

CN209844626U - Distribution transformer monitoring devices power with MPPT function

Info

Publication number: CN209844626U
Application number: CN201921082382.1U
Authority: CN
Inventors: 黄剑岚; 朱扬
Original assignee: Nanjing Tianyuan Intelligent Electric Co Ltd
Current assignee: Nanjing Tianyuan Intelligent Electric Co Ltd
Priority date: 2019-07-11
Filing date: 2019-07-11
Publication date: 2019-12-24
Anticipated expiration: 2029-07-11

Abstract

The utility model discloses a distribution transformer monitoring devices power with MPPT function, including the distribution transformer box, the top of distribution transformer box is provided with thermoelectric generator, the equal adhesion in upper and lower both sides of thermoelectric generator has heat conduction silica gel pad. According to the distribution transformer monitoring device power supply with the MPPT function, the thermoelectric generator, the heat conduction silica gel pad, the radiator and the power generation controller are arranged at the top end of the distribution transformer box body respectively and are used in a matched mode, the method that power generation is achieved by means of the top of the distribution transformer box body and the environmental temperature difference and power is provided for the distribution transformer monitoring device is achieved, the high-voltage line is not required to be modified, the construction difficulty is reduced, and the material cost and the construction cost are reduced. Meanwhile, the power supply is completely isolated from the high-voltage line, so that overvoltage which is possibly introduced into the monitoring device due to lightning stroke of the 10kV line is thoroughly avoided, and the safe operation of the device is ensured.

Description

Distribution transformer monitoring devices power with MPPT function

Technical Field

The utility model belongs to the technical field of distribution transformer monitoring, concretely relates to distribution transformer monitoring devices power with MPPT function.

Background

The distribution network of the power system has wide distribution range, multiple equipment types and severe operating environment. In order to perform online monitoring on the devices of the power distribution network, timely discover hidden dangers existing in operation or remotely operate the power distribution devices, an online monitoring device needs to be installed at some important positions of the power distribution network devices.

The existing power supply of the distribution transformer monitoring device is taken from a 10kV overhead line, the voltage is reduced from 10kV to 100V or 57V by installing a small-capacity voltage transformer, and then the required power supply is provided by a switching power supply arranged in the device. There are two major problems with this conventional approach:

one is as follows: the field installation is complicated and the cost is high. The constructor must lap-joint at least one phase power supply to the high-voltage terminal of the voltage transformer on the existing 10kV line. A proper position must be found for installing a supporting structure for the voltage transformer, and the safe insulation distance of the system cannot be reduced;

the second step is as follows: it is easy to introduce overvoltage of the primary system into the monitoring device. A large number of distribution network lines are erected on the top of an electric power tower, although the lightning protection problem can be considered in the design stage of the electric power lines, the proportion of the current lightning fault station distribution network faults still exceeds 70 percent (different in each region) due to the defects of design or equipment in practice. One important effect of lightning strikes is the generation of relatively high lightning overvoltage in the distribution network, which can directly introduce 10kV system overvoltage into the secondary low voltage system via an electromagnetic voltage transformer, which can cause irreparable damage to fragile electronic monitoring equipment.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a distribution transformer monitoring devices power with MPPT function to solve the problem that proposes in the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a distribution transformer monitoring devices power with MPPT function, includes the distribution transformer box, the top of distribution transformer box is provided with thermoelectric generator, the upper and lower both sides of thermoelectric generator all adhere there is the heat conduction silica gel pad, the top of heat conduction silica gel pad is provided with the radiator, the top symmetrical welding of distribution transformer box has two lead screws, the tip of lead screw runs through the both sides of radiator, and threaded connection has the nut on the lead screw, the top fixedly connected with power generation controller of distribution transformer box, thermoelectric generator passes through wire and power generation controller electric connection.

Preferably, the size of the heat-conducting silica gel pad is equal to that of the top end of the thermoelectric generator, and the thickness of the heat-conducting silica gel pad is not less than two centimeters.

Preferably, the radiator is a heat radiation fan, and the radiator is vertically arranged on the upper side of the thermoelectric generator.

The utility model discloses a technological effect and advantage: according to the distribution transformer monitoring device power supply with the MPPT function, the thermoelectric generator, the heat conduction silica gel pad, the radiator and the power generation controller are arranged at the top end of the distribution transformer box body respectively and are used in a matched mode, the method that power generation is achieved by means of the top of the distribution transformer box body and the environmental temperature difference and power is provided for the distribution transformer monitoring device is achieved, the high-voltage line is not required to be modified, the construction difficulty is reduced, and the material cost and the construction cost are reduced. Meanwhile, the power supply is completely isolated from the high-voltage line, so that overvoltage which is possibly introduced into the monitoring device due to lightning stroke of the 10kV line is thoroughly avoided, and the safe operation of the device is ensured.

Drawings

FIG. 1 is a schematic view of the thermoelectric power generation of the present invention;

FIG. 2 is a schematic diagram of the power supply for generating power by using the environmental temperature difference of the distribution transformer of the utility model;

FIG. 3 is a functional block diagram of the thermoelectric generation controller of the present invention;

fig. 4 is a flow chart of Maximum Power Point Tracking (MPPT) of thermoelectric generation.

In the figure: 1. a distribution transformer tank; 2. a thermoelectric generator; 3. a heat-conducting silica gel pad; 4. a heat sink; 5. a screw rod; 6. a nut; 7. and a power generation controller.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides a distribution transformer monitoring devices power with MPPT function as shown in fig. 1-4, including distribution transformer box 1, distribution transformer box 1's top is provided with thermoelectric generator 2, the equal adhesion in the upper and lower both sides of thermoelectric generator 2 has heat conduction silica gel pad 3, heat conduction silica gel pad 3's top is provided with radiator 4, distribution transformer box 1's top symmetric welding has two lead screws 5, the tip of lead screw 5 runs through the both sides of radiator 4, and threaded connection has nut 6 on the lead screw 5, distribution transformer box 1's top fixedly connected with electricity generation controller 7, thermoelectric generator 2 passes through wire and electricity generation controller 7 electric connection.

Specifically, the size of the heat-conducting silica gel pad 3 is equal to the size of the top end of the thermoelectric generator 2, and the thickness of the heat-conducting silica gel pad 3 is not less than two centimeters.

Specifically, the heat sink 4 is a heat dissipation fan, and the heat sink 4 is vertically disposed on the upper side of the thermoelectric generator 2.

This distribution transformer monitoring devices power with MPPT function, when using, through set up thermoelectric generator 2 respectively on the top of distribution transformer box 1, heat conduction silica gel pad 3, radiator 4 and power generation controller 7's cooperation is used, realized utilizing the method that distribution transformer box 1 top and environmental temperature difference realized generating electricity and provide the power for distribution transformer monitoring devices exempts from to the transformation of high voltage circuit (need not follow 10kV circuit and overlap the power, also need not install the structure that supports high voltage transformer), reduced the degree of difficulty of construction, reduced material cost and construction cost. Meanwhile, the power supply is completely isolated from the high-voltage line, so that overvoltage which is possibly introduced into the monitoring device due to lightning stroke of the 10kV line is thoroughly avoided, and the safe operation of the device is ensured.

As shown in fig. 2, a represents a thermoelectric generation module, B represents a distribution transformer online monitoring device, C represents a thermoelectric generation controller, and D represents a lithium battery, and firstly, the temperature difference is based on the temperature of the working environment of the distribution transformer and the temperature of the oil at the top of the distribution transformer in operation; secondly, the thermoelectric generation principle of the semiconductor; finally, the principle of the maximum power tracking technology is adopted;

the main components of the distribution transformer comprise a metal shell, a transformer coil completely surrounded by the metal shell, and transformer insulating oil filled in the shell of an oil-immersed transformer (the distribution transformer is mostly in an oil-immersed type). When the transformer works, copper loss and iron loss are generated, wherein the copper loss is caused by consumption of load current on coil resistance, and the iron loss is caused by leakage flux of coils inside the transformer on a transformer iron core. Both copper and iron losses are manifested in the form of heat, which is reflected in the temperature rise of the coil and core. The temperature rise of the coil and the iron core can cause the temperature rise of the insulating oil and the shell of the transformer due to heat conduction, heat convection and heat radiation. According to national standards, for sealed oil-immersed transformers: the oil top layer temperature rise limit value can reach 60K, and the top layer oil temperature can reach 60+40 degrees to 100 degrees by considering the maximum environment temperature of 40 degrees. Even considering a maximum ambient temperature of 40 degrees, the temperature difference between the ambient temperature and the top oil temperature is still 60 degrees. Of course, the top oil temperature of the transformer is typically less than 100 degrees due to the varying magnitude of the load current. However, unless the transformer is shut down (no load current), the temperature at the top of the transformer must be significantly higher than ambient temperature (typically above 30 degrees) due to iron and copper losses;

because the loss of the distribution transformer and the temperature rise at the top of the transformer generated by the loss of the distribution transformer are changed along with the load current and other factors of the transformer, the environmental temperature can also be changed along with the time (such as the temperature difference between the morning and the evening, the condition changes of ventilation, heat dissipation and the like), and the temperature difference sensed at the two ends of the temperature difference power generation module cannot be fixed and unchanged. The output of the temperature difference power generation module is directly related to the temperature difference, and the change of the output is reflected by the change of the internal impedance. According to the principle of impedance matching, if the maximum output power of the thermoelectric generation module is desired, the impedance of the load must match the impedance of the power generation module. Such load impedance matching must be dynamically adjusted by a computer. Based on the thermoelectric generation maximum power tracking circuit, a program for tracking maximum power is designed. The tracking circuit monitors the charging current of the thermoelectric generation to the battery, dynamically adjusts the duty ratio of a DC-DC converter (the converter is positioned between the thermoelectric generation module and the battery and between the thermoelectric generation module and a load circuit), and the change of the duty ratio directly changes the impedance of the input end of the converter so as to realize the impedance matching with the thermoelectric generation module, thereby realizing the aim of maximum power generation.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and variations can be made in the embodiments or in part of the technical features of the embodiments without departing from the spirit and the scope of the invention.

Claims

1. The utility model provides a distribution transformer monitoring devices power with MPPT function, includes distribution transformer box (1), its characterized in that: the top of distribution transformer box (1) is provided with thermoelectric generator (2), the upper and lower both sides of thermoelectric generator (2) all adhere and have heat conduction silica gel pad (3), the top of heat conduction silica gel pad (3) is provided with radiator (4), the top symmetric welding of distribution transformer box (1) has two lead screws (5), the tip of lead screw (5) runs through the both sides of radiator (4), and threaded connection has nut (6) on lead screw (5), the top fixedly connected with power generation controller (7) of distribution transformer box (1), thermoelectric generator (2) pass through wire and power generation controller (7) electric connection.

2. The distribution transformer monitoring device power supply with MPPT function of claim 1, wherein: the size of the heat-conducting silica gel pad (3) is equal to that of the top end of the thermoelectric generator (2), and the thickness of the heat-conducting silica gel pad (3) is not less than two centimeters.

3. The distribution transformer monitoring device power supply with MPPT function of claim 1, wherein: the radiator (4) is a radiating fan, and the radiator (4) is vertically arranged on the upper side of the thermoelectric generator (2).