WO2020077641A1

WO2020077641A1 - On-site test method and system for no-load/load loss of vehicle-mounted power transformer

Info

Publication number: WO2020077641A1
Application number: PCT/CN2018/111100
Authority: WO
Inventors: 戴迎宏; 李永飞; 陈威; 汤国龙; 闫培渊; 周际; 王蔚; 何洋; 彭一鸣; 何应齐; 董旺; 施源; 刘晓丽; 胡华峰
Original assignee: 国网电力科学研究院武汉南瑞有限责任公司
Priority date: 2018-10-19
Filing date: 2018-10-19
Publication date: 2020-04-23
Also published as: KR102596181B1; KR20210078535A

Abstract

The present invention relates to the field of electrical technology, and more particularly, to an on-site test method and system for no-load/load loss of a vehicle-mounted power transformer. The on-site test method uses an on-site test system for no-load/load loss of a vehicle-mounted power transformer. The on-site test system comprises: a test system and a side-open carriage. The test system is located in the side-open carriage. The test system comprises: a test connection end for connecting a transformer under test, a power supply device for providing a test voltage to the transformer under test, a measurement instrument for obtaining measurement data of the transformer under test, and a measurement control device for controlling the measurement instrument. The power supply device, the measurement instrument, and the measurement control device are all located on a test circuit where a test connection end is located. The input end of the power supply device is connected to a power supply at a test site. By means of the present invention, on-site test for no-load and load of a large power transformer can be implemented.

Description

On-site test method and system for on-board power transformer empty and load loss

Technical field

The present invention relates to the field of electrical technology, and more specifically, to an on-site test method and system for empty and load losses of a vehicle-mounted power transformer.

Background technique

According to JB / T501-2006 "Guidelines for Power Transformer Test", there are many test projects for power transformers installed or operated on site, and the existing technology and utility model patent 201320007072.X "Substation Equipment Test Platform" can be completed Conventional tests such as insulation resistance, winding DC resistance, winding, bushing dielectric loss and capacitance, transformation ratio, polarity and group, operating characteristics of on-load tap changer, frequency response of winding deformation, etc .; invention patent 201710257472.9 A wing-open deployment type partial discharge voltage test vehicle "can complete the induction voltage test and partial discharge measurement test of power transformers. But neither of these two test platforms (vehicles) can complete the empty and load tests of the transformer.

For the empty and load field tests of power transformers, the existing technology only supports the empty and load field tests of small distribution transformers; and when performing on-site testing in the existing technology, testers need to transport various test equipment to the site, Then locate the test equipment on the site, connect each test equipment, and then test the transformer. In this way, there are the following problems: the test equipment is difficult to handle, the test efficiency is low, various hidden safety problems may exist in the connection process of the test equipment, and the labor intensity of the test personnel is large.

For the empty and load tests of large transformers, the existing technologies do not support on-site testing. Usually, only large-scale transformers can be tested in the laboratory or factory. If they are installed in a specific power grid environment, the test equipment needs to be moved to On-site and assembly problems cannot be tested. Therefore, if there is an abnormality in the large transformer, etc., a more complete on-site test cannot be conducted.

Summary of the invention

The technical problem to be solved by the present invention is to provide an on-site test method and system for empty and load losses of vehicle-mounted power transformers, which can complete 110kV, 220kV three-phase power transformers and 500kV single-phase power transformers on-site. No load, load loss test.

The technical solutions adopted by the present invention to solve its technical problems are:

An on-site test method for on-board power transformer empty and load loss, the on-site test system for on-board power transformer empty and load loss used in this test method includes: a single or multiple wing opening vehicle using a loading test system, and a test connection terminal Connect the tested transformer, use the power supply device to provide the test voltage or test current for the tested transformer, use the measuring instrument to obtain the measured data of the tested transformer, use the measurement control device to control the measuring instrument, and use the compensation capacitor bank to provide capacitive compensation;

The wing-opened vehicle travels to a location near the tested transformer with a wing-opened vehicle deployment space and stops;

The wing opening doors on both sides of the vehicle open automatically;

Connect the ground wire;

Connect the connecting cable of the capacitor bank;

Connect 380V or 10kV power supply according to the on-site power supply situation;

Connect the test test wire to the high-voltage side or low-voltage side of the transformer under test;

On-site supervisors conduct safety inspections;

Use no-load test method to carry out no-load test;

Use load test method to carry out no-load test;

The test is completed, the data is automatically saved, and the test report is printed;

Discharge, ground knife gate ground;

Disconnect the power supply;

Remove the test test wire, the connection of the compensation capacitor bank and the isolation knife gate, and the ground wire;

Wing opening The wing opening doors on both sides of the vehicle close automatically.

The test method of the no-load test is as follows:

1) Input the basic parameters of the transformer under test at the input terminal of the industrial control machine, including the capacity of the transformer under test, high-voltage and low-voltage rated voltage;

2) According to the input transformer parameters, by controlling the variable frequency power supply, the intermediate transformer gear, and using the automatic switching control method of the compensation capacitor capacity, a voltage is applied on the low voltage side of the transformer under test to achieve the test voltage equal to the rated voltage;

3) Obtain corresponding values through precision current transformers, voltage transformers, and power meters, and automatically calculate no-load loss, excitation impedance, excitation resistance and other parameters through the built-in software of the test system;

The test method of the load test is as follows:

2) According to the input transformer parameters, by controlling the variable frequency power supply, the intermediate transformer gear, and using the automatic switching control method of the compensation capacitor capacity, a current is applied on the high-voltage side of the transformer under test to achieve the test current equal to the rated current;

3) Obtain corresponding values through precision current transformers, voltage transformers, and power meters, and automatically calculate parameters such as load loss, short-circuit impedance, short-circuit resistance, and short-circuit voltage through the built-in software of the test system;

The automatic switching control method of compensation capacitor capacity is as follows:

2) Set the applied voltage or current according to the test regulations;

3) According to the set test current and voltage, the required gear of the intermediate transformer and capacitor is automatically calculated by the built-in software of the test system, and the automatic switching gear is switched by the PLC;

4) Obtain the current of the intermediate transformer from the precision current transformer;

5) The test current, the current of the intermediate transformer, and the voltage level of the capacitor are obtained by a certain formula algorithm to obtain the capacity of the compensation capacitor, and the capacity of the capacitor required for automatic switching through the PLC is switched on;

A vehicle-mounted power transformer empty and load loss on-site test system, including: a test system (130), a wing-open deployment car (110) and a drive device (120) that drives the wing-open door; the test system (130) is located on the wing-open In the unfolding car (110); the driving device 120 is located in the unfolding wing-opening car, and is connected with the wing-opening door to provide a driving force for the wing-opening door and a supporting force for keeping the wing-opening door open. It is characterized by,

The test system (130) includes a test connection terminal (131) for connecting to the transformer under test, a power supply device (132) for providing a test voltage for the transformer under test, and a measuring instrument (133) for acquiring measurement data of the transformer under test ) And a measurement control device (134) for controlling the measuring instrument (133), a compensation capacitor bank (135) providing capacitive compensation;

The power supply device (132), the measuring instrument (133), the measurement control device (134) and the compensation capacitor group (135) are all located on the test circuit where the test connection terminal (131) is located;

The input terminal of the power supply device (132) is connected to the power supply at the test site.

The power supply device (132) includes: a variable frequency power supply (210), an intermediate transformer (220), and a filter (260);

The input terminal of the variable frequency power supply (210) is the input terminal of the power supply device (132), and the variable frequency power supply (210) is used to convert the power supply at the test site into a voltage signal of a predetermined frequency;

The input terminal of the intermediate transformer (220) is connected to the output terminal of the variable frequency power supply (210), and the intermediate transformer (220) is used to convert a voltage signal of a predetermined frequency into a voltage required by the transformer under test.

The filter (260) is connected between the variable frequency power supply (210) and the intermediate transformer (220), and is used for filtering voltage signals outside the predetermined frequency range, and transmitting the filtered voltage signals to the intermediate transformer Input.

The measuring instrument (133) includes: a transformer (230) and a power analyzer 233;

The transformer (230) includes: a precision voltage transformer (231) and / or a precision current transformer (232).

The measurement control device (134) includes: an industrial control computer (1), a power supply device controller (2), and a compensation capacitor bank controller (3);

The industrial control computer (1), the power supply device controller (2) and the compensation capacitor group controller (3) are connected to each other through a bus;

The industrial control computer (1) is connected to a measuring instrument (133).

The power supply device controller is used to control the power supply output control of the power supply device (132);

The compensation capacitor group controller controls the compensation capacitor group (135) to provide capacitive compensation during the load test of the transformer under test;

The compensation capacitor group includes: a three-phase compensation capacitor group (1351) and a single-phase compensation capacitor group (1352);

The three-phase capacitor bank (1351) is used to provide three-phase compensation during the load test of the transformer under test;

The single-phase capacitor bank (1352) is used to provide single-phase compensation when the transformer under test is subjected to load testing;

The test system further includes: an isolation protection device (240);

The isolation protection device (240) is located on the test circuit where the test connection terminal (131) is located, and is arranged between the transformer under test and the measuring instrument (133);

The test system also includes a lighting system and a monitoring system for assisting on-site testing of the transformer.

The beneficial effects of the invention:

1. Adopt on-site test method and system of on-board power transformer empty and load loss, can complete 110kV, 220kV three-phase power transformer and 500kV single-phase power transformer field no-load and load loss test.

2. The test method of no-load test is adopted, and the parameters such as no-load loss, excitation impedance and excitation resistance can be automatically calculated through the built-in software of the test system.

3. The test method of load test is adopted, and the parameters such as load loss, short-circuit impedance, short-circuit resistance, and short-circuit voltage can be automatically calculated through the built-in software of the test system.

4. The automatic switching control method of the compensation capacitor capacity can be used to automatically calculate the capacity of the compensation capacitor according to the parameters of the tested transformer and automatically switch on; the compensation capacitor group is used to provide capacitive compensation during the load test of the tested transformer, which reduces Test the power capacity.

5. Integrate the test system inside the wing-open unfolding car, and the car will bring the test system to any test site. Only the transformer to be tested can be connected to the test connection end to perform on-site testing, avoiding the need to move each car on site. The interconnection between the test equipment and the test equipment reduces potential safety hazards and also reduces the labor intensity of the test site staff.

BRIEF DESCRIPTION

The present invention will be further described below with reference to the drawings and embodiments. In the drawings:

Figure 1 is a schematic diagram of the structure of the present invention;

2 is a functional block diagram of the test system in the present invention;

3 is a side view of the vehicle A in the embodiment of the present invention;

4 is a plan view of the vehicle A in the embodiment of the present invention;

5 is a side view of the vehicle B in the embodiment of the present invention;

6 is a plan view of the vehicle B in the embodiment of the present invention;

7 is a schematic diagram of the measurement control device of the present invention;

8 is a rear view of vehicles A and B in a transport state in an embodiment of the present invention;

Fig. 9 is a rear view of vehicles A and B in the working state in the embodiment of the present invention.

detailed description

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings.

As shown in FIGS. 1, 2 and 7, the vehicle-mounted power transformer field and load loss on-site test system provided by the present invention includes a test system 130 and a wing-opening and unfoldable car 110 with openable and closable doors. The test system 130 Located in the wing-open deployment car 110;

The test system 130 includes a test connection terminal 131 for connecting to the transformer under test, a power supply device 132 for providing a test voltage for the transformer under test, a measuring instrument 133 for acquiring measurement data of the transformer under test, and a control measuring instrument 133 The measurement control device 134;

The power supply device 132, the measuring instrument 133 and the measurement control device 134 are all located on the test circuit where the test connection terminal 131 is located;

The input terminal of the power supply device 132 is connected to the power supply at the test site.

In FIG. 2, the measurement control device 134 is omitted. As can be seen from FIG. 7, the measurement control device 134 is connected to the measuring instrument 133.

Since there are many test devices in the test system 130, it is difficult to accommodate them in one car. Therefore, in this embodiment, there are two wing-open deployment cars 110, which are the car of vehicle A and the car of vehicle B, respectively. Vehicles A and B are loaded with different test equipment.

In this embodiment, the test connection end 131 is disposed on the side close to the movable box. For example, there may be multiple test connection ends 131, and the test connection ends are provided near the multiple movable boxes. In this way, after the vehicle travels to the site, it is possible to simply connect to the transformer under test without intentionally correcting the positional relationship between itself and the transformer under test. Thereby, the problem of insufficient cables or complicated wiring crossover caused by the poor position of the vehicle relative to the transformer under test is reduced, thereby simplifying the connection with the transformer under test.

In some embodiments, the test connection terminal may be composed of one or more connection terminals, and these connection terminals may be sequentially distributed on the same wiring panel.

Further, the power supply device 132 includes: a variable frequency power supply 210 and an intermediate transformer 220;

The input end of the variable frequency power supply 210 is the input end of the power supply device 132, and the variable frequency power supply 210 is used to convert the power supply at the test site into a voltage signal of a predetermined frequency;

The input terminal of the intermediate transformer 220 is connected to the output terminal of the variable frequency power supply 210. The intermediate transformer 220 is used to convert a voltage signal of a predetermined frequency into a voltage required by the transformer under test.

The power supply device is located on the test circuit where the test connection terminal is located, and is used to provide the voltage required for the test to the transformer under test through the test circuit, that is, to provide the test voltage required for the field test to the transformer under test For example, the test transformer is provided with a no-load test voltage in a no-load state, and / or the test transformer is provided with a test voltage in a load state connected with a load.

Optionally, as shown in FIGS. 4 and 5, the power supply device includes:

Frequency conversion power supply 210, located on the test circuit where the test connection end is located, is configured to provide a voltage signal of a predetermined frequency to the transformer under test;

The intermediate transformer 220 is connected to the variable frequency power supply 210 and is used to convert the voltage signal to provide a voltage of the volt value required for the test of the transformer under test.

The variable frequency power supply 210 is connected to the test circuit where the test connection terminal is located, and is used to provide an AC voltage signal of the required frequency to the transformer under test. In this way, the transformer has a voltage source for transforming the voltage.

Optionally, the variable frequency power supply 210 includes: an input terminal for receiving power from the power supply at the test site; a frequency converter device connected to the input terminal for converting the received power supply into a voltage signal of a predetermined frequency; The terminal is connected to the frequency conversion device for outputting the voltage signal.

The intermediate transformer 220 is connected to the variable frequency power supply 210 and is used to convert the voltage signal to provide a voltage at a frequency and a volt required by the transformer under test. For example, the intermediate transformer 220 may be used to increase the voltage value of the voltage signal provided by the variable frequency power supply 210. For example, the intermediate transformer 220 may be an excitation transformer.

In some embodiments, the input end of the variable frequency power supply 210 is connected with a transfer switch, and the transfer opening switches between two voltage sources through its own state. If the power supply at the test site can provide three-phase 380V AC power, the transfer switch can turn on the first input circuit so that the voltage is input to the variable frequency power supply 210. If the three-phase 10kV power provided by the power supply at the test site can be converted into a voltage of 380V by a distribution transformer, the 10kV power is first input to the variable frequency power supply 210.

The voltage values provided by the first and second power supplies above are examples, and the specific implementation is not limited to the above examples. In some embodiments, if the voltage provided by the power supply is within an input voltage range that can be received by the variable frequency power supply 210, the power supply directly supplies power to the variable frequency power supply 210 if the voltage provided by the power supply is not within the input voltage range Within, the voltage input to the variable frequency power supply 210 is within its input voltage range through the voltage conversion of the distribution power supply.

Furthermore, the power supply device 132 further includes: a filter 260;

The filter 260 is connected between the variable frequency power supply 210 and the intermediate transformer 220.

The filter 260, located between the variable frequency power supply 210 and the intermediate transformer 220, is configured to filter voltage signals outside the predetermined frequency range, and transmit the filtered voltage signal to the input terminal of the intermediate transformer .

In this embodiment, the filter 260 is located between the variable frequency power supply 210 and the intermediate transformer 220, and is used to filter the noise frequency signal. The noise signal here is a voltage signal outside the predetermined frequency range, for example, an excessively high noise signal. The filter 260 may be a high-voltage low-pass filter, which may allow a high-voltage voltage signal lower than a predetermined frequency to pass through. For example, the cut-off frequency of the high-voltage low-pass filter is 100 Hz, 110 Hz, 90 Hz, and so on. The cut-off frequency can be set as needed, and is not limited to any one of the above values.

As shown in FIGS. 2 to 4 and 7 in the above technical solution, the measuring instrument 133 includes: a transformer 230;

The transformer 230 includes: a precision voltage transformer 231 and / or a precision current transformer 232.

In this embodiment, the measuring instrument 133 includes at least one of the following:

Precision current transformer 232 for measuring current;

Precision voltage transformer 231 for detecting voltage;

Power analyzer 233 to detect power output, signal frequency, harmonic components and other parameters;

In short, the measurement instrument in this embodiment may include a plurality of instruments or detection devices directly or indirectly connected to the test circuit.

In this embodiment, the measuring instrument 133 can be used to detect at least one of the following: voltage effective value; current effective value, voltage average value, current average value, active power, reactive power, power factor, frequency, voltage harmonics Wave, current harmonics, total harmonic content of voltage, total harmonic content of current.

As shown in FIGS. 5 and 6, preferably, the device further includes: a compensation capacitor bank 310;

The compensation capacitor group 310 is located on the test circuit where the test connection terminal 131 is located, and is used to provide capacitive compensation when the transformer under test is subjected to a no-load test.

The compensation capacitor bank 310 may include one or more capacitors in this embodiment. During the load test of the transformer under test, the coil of the transformer under test will make the test circuit inductive, and the transformer under test can also be tested without the addition of a compensation circuit set, but it may produce a large To a certain extent, the reactive power will increase the power design requirements of the variable frequency power supply 210 and the intermediate transformer 220. In this embodiment, a compensation capacitor bank 310 is introduced into the test circuit. Because the capacitor is capacitive, it can offset part of the inductance of the transformer under test, thereby reducing the reactive power of the test circuit and reducing the power supply of the variable frequency power supply 210 and the intermediate transformer 220 The power design requirements of the equipment reduce the overall hardware cost of the test system 130.

As shown in FIG. 7, in the above technical solution, the measurement control device 134 includes: an industrial control computer 1, a controller 320 of a compensation capacitor group, and a power supply device controller 2;

The industrial control computer 1, the controller 320 and the power supply device controller 2 are connected to each other through a bus;

The industrial control computer 1 is connected to the measuring instrument 133.

Further, the controller 320 includes: a single-phase capacitor bank controller 321 and / or a three-phase capacitor bank controller 322;

The single-phase capacitor bank controller 321 is used to control the single-phase compensation of the compensation capacitor bank 310;

The three-phase capacitor bank controller 322 is used to control the three-phase compensation of the compensation capacitor bank 310;

The single-phase capacitor bank controller 321 and the three-phase capacitor bank controller 322 are connected to each other through a bus;

The single-phase capacitor bank controller 321 includes: an isolated power supply 3211, a processing module 3212, a first communication module 3213, a second communication module 3214, and a digital input / output module 3215;

The first communication module 3213 is connected to the bus;

The second communication module 3214 is connected to the measuring instrument 133;

The three-phase phase capacitor bank controller 322 includes: an isolated power supply 3221, a processing module 3222, a first communication module 3223, a second communication module 3224, and a digital input and output module 3225;

The first communication module 3223 is connected to the bus;

The second communication module 3224 is connected to the measuring instrument 133.

Further, the power supply controller 2 includes: an isolated power supply 21, a processing module 22) a first communication module 23, a second communication module 24, a switching input and output module 25, an analog output module 26 and a temperature measurement module 27;

The first communication module 23 is connected to the bus;

The second communication module 24 is connected to the measuring instrument 133.

The measurement control device 134 may be composed of one or more personal computers (Personal Computers, PCs) or programmable arrays (Programmable Logic Controllers, PLCs), etc. Measurement control device 134: multiple control modules, which can be connected to the main controller via a bus, and different control modules can control different test equipment or different test functions of the test equipment.

The industrial control computer 1 can be connected to a power analyzer 233 in a test instrument through a communication interface such as an RS232 interface, and the power analyzer 233 is connected to a precision current transformer 232 and a precision voltage transformer 232.

The controller 320 of the capacitor bank can be used to control the compensation of the compensation capacitor. The controller 320 of the capacitor bank is shown in FIGS. 5 and 6.

The power supply device controller 2 serves as the main controller of the measurement system. Here, the controller 320 of the capacitor bank and the power supply device controller 2 may be collectively referred to as a controller of the test system.

These three can be connected through a communication bus, for example, through an 8-port 10 / 100M adaptive switch.

The capacitor bank controller 320 includes a single-phase capacitor bank controller 321 and / or a three-phase capacitor bank controller 322.

The single-phase capacitor bank controller 321 can be used to control single-phase compensation of the compensation capacitor. The three-phase capacitor bank controller 322 can be used to control the three-phase compensation of the compensation capacitor. Alternatively, the single-phase capacitor bank controller 321 may be a single-phase capacitor bank controller PLC. The three-phase capacitor bank controller 322 may be a three-phase capacitor bank controller PLC.

The single-phase capacitor bank controller 321 may include: an isolated power supply 3211 (power module) isolated from the variable-frequency power supply 210, a processing module 3212 (eg, CPU or DSP), a first communication module 3213 (eg, Ethernet communication module), a first Two communication modules 3214 (for example, MODBUS modules) and binary input / output modules 3215. The processing module 3212 is used for information processing. The second communication module 3214 is used for receiving various measurement values from various measuring instruments, for example, receiving the output current of the single-phase compensation circuit from the digital quantity sensor. The second communication module 3214 is connected to the bus, so that it can transmit its own information to the industrial control computer 1 and / or receive various information from the industrial control computer 1.

The three-phase capacitor bank controller 322 may include: an isolated power supply 3221 (power module) isolated from the variable frequency power supply 210, a processing module 3222 (eg, CPU or DSP), a first communication module 3223 (eg, Ethernet communication module), and a third Two communication modules 3224 (for example, MODBUS modules) and digital input / output modules 3225. The processing module 3222 is used for information processing. The second communication module 3224 is used for receiving various measured values from various measuring instruments, for example, receiving the output current of the three-phase compensation circuit from the digital quantity sensor. The second communication module 3224 is connected to the bus, so that it can transmit its own information to the industrial control computer 1 and / or receive various information from the industrial control computer 1.

The digital input / output module 3215 and the digital input / output module 3225 in the controller 320 of the capacitor bank are connected to various switches. For example, the digital input / output module 3215 and the digital input / output module 3225 can be controlled by corresponding pneumatic isolating switch solenoid valves, respectively, to control the pneumatic isolating switch. The digital input / output module 3215 and the digital input / output module 3225 each include: a corresponding receiving switch state of the switch, and / or, outputting a switch command to control the switch state switching of the switch to the switch.

Similarly, the power supply controller 1 may also be a system general control PLC.

The power supply device controller 1 may include: an isolated power supply 21 (power supply module) isolated from the variable frequency power supply 210, a processing module 22 (e.g., CPU or DSP), a first communication module 23 (e.g., Ethernet communication module), and a second communication Module 24 (for example, MODBUS module), switch input and output module 25 and analog output module 26, and temperature measurement module 27 (for example, PT100 temperature measurement module).

The processing module 22 is used for information processing. The second communication module 24 is used to control the measurement of various measuring instruments, control the digital sensor to perform the output voltage and current test of the variable frequency power supply 210, the voltage and current test of the power supply, and the switching control of the variable frequency power supply 210. The second communication module 24 is connected to the bus, so that it can transmit its own information to the industrial control computer 1 and / or receive various information from the industrial control computer 1. The temperature measurement module 27 can be used for test ambient temperature measurement, power circuit breaker switching control, precision measurement transformer range adjustment control, and intermediate transformer 220 tap switch control. Through the tap changer control of the intermediate transformer 220, the voltage value of the voltage output from the power supply device can be adjusted.

In some embodiments, the measurement control system may be installed on the control cabinet (the controller 320 of the capacitor bank) as shown in FIGS. 5 and 6.

Preferably, the device further includes: an isolation protection device 240;

The isolation protection device 240 is located on the test circuit where the test connection terminal 131 is located, and is disposed between the transformer under test and the measuring instrument 133;

The isolation protection device 240 may include one or more isolation protection switches. The isolation protection switch protects the test circuit and the test equipment in the test circuit through its own switch state.

The isolation protection device 240 may include at least one of the following: an overvoltage protector; an undervoltage protector; a current interruption protector and the like. It is shown in FIGS. 3 and 4 that the isolation knife gate 240 may be one of the isolation protection devices.

The device also includes a test lighting system and a video monitoring system for on-site testing of the transformer.

The test auxiliary system is used for on-site testing of auxiliary transformers. For example, the test auxiliary system includes at least one of the following: a lighting subsystem configured to provide test lighting; and a video monitoring subsystem configured to perform video monitoring of the test.

For example, the video monitoring subsystem is connected to the control system and can be used for monitoring by testers. In some cases, the video monitoring subsystem may also establish a wireless connection with the tester's mobile device to implement wireless monitoring.

Preferably, a driving device 120 is installed on the wing opening deployable car 110 for driving the opening and closing of the door of the wing opening deployable car 110.

In this embodiment, the compartment 110 may be a compartment 110 fixedly installed on the chassis of the vehicle, or a compartment 110 movably installed on the chassis of the vehicle. If it is movably installed on the chassis of the vehicle, it can be The car 110 containing the complete test system 130 is transferred to a normal car chassis by a crane or the like, so that the field test system 130 of the on-board transformer can be driven into the transformer site as scheduled to complete the test.

As shown in FIGS. 8 and 9, in this embodiment, the box side panel of the compartment 110 is movable. For example, the movable door may include: a side movable door (wing door 410) on the side of the car 110, a fixed end connected to the top of the frame body, and the movable end can rotate around the fixed end. The movable door also includes a movable door at the rear of the car (folding door 420).

After the carriage 110 is transported to the site where the transformer under test is opened, the movable door is opened, and the connection between the transformer under test and the test system 130 can be performed, and the measurement can be performed after the connection.

In this embodiment, the reason why the frame body is provided with a movable door is that, on the one hand, the opening and closing of the movable door can reveal and hide the test system 130, and on the other hand, after the movable door is opened, a test is provided The system 130 has sufficient test space to meet the safety distance required for the test.

In some embodiments, the driving device 120 is drivingly connected to the movable door through a transmission device, and the driving device 120 transmits the driving force provided by itself to the movable door through the transmission device, thereby driving the movable door to move. The driving device 120 adopts a hydraulic driving device. The hydraulic driving device has a smooth driving force and can support the movable box to stay in any position of opening. Fig. 8 shows a hydraulic drive device, which includes a hydraulic cylinder, a hydraulic station, and a hydraulic line.

In some embodiments, the driving device 120 may be provided with a travel switch, etc., which can control the movable box to stay at several predetermined positions, for example, a closed position, a maximum opened position, and an intermediate opened position, if the movable box is at the maximum opened position , The movement of the movable box relative to the frame reaches its maximum.

In this embodiment, the test system 130 itself is located in the car 110 and does not need to be transported to the handling equipment, which simplifies the handling of the transformer testing system 130. Since the test system 130 is preset in the car 110 and the connection is automatically completed, there is no need to go to the transformer test site to connect the test equipment, which can improve the test efficiency. And once the test system 130 is connected, it can be used without disassembly and can be used for multiple field tests of transformers or multiple transformers.

The following provides in combination with any of the above embodiments: A few specific examples:

Example 1:

The embodiment of the present invention provides an on-site test system for empty and load losses of a vehicle-mounted power transformer:

The test system 130 uses a vehicle as a carrier, and integrates various test equipment and measuring instruments required for the test of the test system 130 on the vehicle body to form a set of on-board power transformer no-load and load field test system 130.

The test system 130 can independently complete the transformer no-load and load loss tests on the vehicle. The test equipment does not get off the vehicle, no secondary assembly is required, and there is no need to repeat the wiring between the test equipment. The required safety insulation distance and heat dissipation requirements can greatly shorten the power outage time, reduce the labor intensity of the test personnel, and improve the test efficiency.

The vehicle-mounted power transformer empty and load loss field test system includes the vehicle body, the test system 130, and the auxiliary system. The vehicle body is composed of two wing-open special vehicles; the test system 130 includes a test power supply, a frequency conversion power supply 210, a filter 260, an intermediate transformer 220, a compensation capacitor group 310, a measurement control device 134, and an isolation protection device connected in sequence through a line 240 etc .;

Optionally, as shown in FIGS. 3 to 6 and FIGS. 8 to 9, the vehicle body includes a wing-open van-specific vehicle A and a wing-open van-specific vehicle B; the wing-open van-specific vehicle A is sequentially placed Power input cable reel 250, variable frequency power supply 210 (including input control switch, output high voltage filter); high frequency switch cabinet and distribution transformer are placed on the side of variable frequency power supply 210; intermediate transformer 220 is placed at the rear of variable frequency power supply 210, output terminal of variable frequency power supply 210 and The input terminal of the intermediate transformer 220 is connected with a cable, and the output terminal of the intermediate transformer 220 is led out on the other side. The casing is arranged diagonally so that the position of the terminal block is parallel to the position of the A and C phase precision measurement transformers. connection. In the wing-opening van-type special vehicle B, a three-phase capacitor bank (compensation capacitor bank 310) is placed in order from inside to outside, and a PLC control and air source cabinet (capacitor bank controller 320) are placed at the rear of the vehicle. The compensation capacitor bank 310 is controlled by a pneumatic switch, and compressed gas is provided by the gas source cabinet to control the switching state of the pneumatic switch.

The power input cable reel 250 can be formed by coiling the cable, and can be used to connect the system with the power supply at the test site.

Optionally, the measurement control device 134 includes a precision voltage transformer 231, a precision current transformer 232, a power analyzer, etc. 233. Reference measurement data includes: three-phase voltage and current output by variable frequency power supply 210, and three-phase current by capacitor bank; precise measurement data includes: phase voltage effective value, line voltage effective value, phase voltage average value, line voltage average value, current effective value , Active power, Q reactive power, power factor, frequency, 1 to 19th voltage and current harmonics, voltage and current total harmonic content and current total harmonic content (THD), etc.

Optionally, the measurement control device 134 is specifically configured to implement at least one of the following:

Frequency converter power 210 output AC contactor on and off control;

Intermediate transformer 220 gear adjustment;

231 gear adjustment control of measuring precision voltage transformer,

232 gear adjustment control of measuring precision current transformer;

The voltage of the variable frequency power supply 210 changes fast, slow and step-down control.

Optionally, the isolation protection device 240 may include: a high-voltage isolation switch, an emergency stop button, an alarm bell, etc .; protection items include: more than 210 electronic protection of frequency conversion power supply; over-range protection of precision measurement transformer; Variable frequency power supply 210 zero-voltage boost protection; over-voltage and over-current protection of the tested product; over-compensation and under-compensation protection of load loss measurement test; setting of warning lights, alarm bells and emergency stop buttons.

The electronic protection may include one or more of input overvoltage protection, output overcurrent protection, output short circuit protection, and the like.

Optionally, the test power supply can be an external power supply, which is not installed on the vehicle. A three-phase 380V test power supply can be selected according to the situation of the on-site test power supply, or a three-phase 10kV power supply can be connected to the high-voltage cabinet and passed through The test power supply after the step-down of the distribution transformer is selected by the transfer switch.

Optionally, the wing-open special vehicle includes a car body and a wing-open deployable car 110 at the rear of the car body; the wing-open deployable car 110 is composed of roof ribs and symmetrically arranged on both sides The wing door 410 is composed of a split door 420 at the rear; one end of the wing door 410 (which is one of the aforementioned movable boxes) is hinged to the roof rib by a hinge, and the wing door 410 is driven by a wing door hydraulic cylinder Unfold.

The test system 130 provided in this embodiment further includes: an auxiliary system. The auxiliary system may include a lighting unit, a video monitoring unit, a hydraulic support unit, a hydraulic control unit, and the like.

This embodiment can independently complete the transformer no-load and load loss tests. The test equipment does not get off the vehicle and does not need to be reassembled. There is no need to repeat the wiring between the test equipment. The test vehicle can be automatically deployed to the test state to meet the safety insulation required for the test The distance and heat dissipation requirements can greatly shorten the power outage time, reduce the labor intensity of the test personnel, and improve the test efficiency.

Implementation steps:

This example provides a mobile field test device for no-load and load loss of power transformers. The steps of field test are as follows:

The vehicles arrive at the test site and are parked in sequence;

The vehicle automatically unfolds the compartment 110;

Connect the ground wire;

Connect the compensation capacitor 310 connection cable;

Connect the power supply cable;

Connect the test test line (to the transformer under test);

The tester turns on the control computer and selects the test plan based on the transformer nameplate parameters;

On-site supervisors conduct safety inspections;

The tester operates the computer to conduct the test;

After the test is completed, the data is automatically saved;

Discharge, ground knife gate ground;

Disconnect the power supply;

Remove the test wiring and disconnect the tested transformer from the test system 130;

The vehicle automatically closes the compartment 110.

Example 2:

This example provides an on-site test method of vehicle-mounted power transformer empty and load loss. The test method uses an on-board power transformer empty and load loss field test system including: a single or multiple wing opening vehicle using a loading test system, using The test connection is connected to the transformer under test, the power supply device is used to provide the test voltage or test current for the transformer under test, the measurement instrument is used to obtain the measurement data of the transformer under test, the measurement control device is used to control the measurement instrument, and the compensation capacitor bank is used to provide capacitive compensation; Proceed as follows:

The wing opening doors on both sides of the vehicle open automatically;

Connect the ground wire;

Connect the connecting cable of the capacitor bank;

On-site supervisors conduct safety inspections;

Use no-load test method to carry out no-load test;

Use load test method to carry out no-load test;

Discharge, ground knife gate ground;

Disconnect the power supply;

In some embodiments, the test method of the no-load test is as follows:

3) Obtain corresponding values through precision current transformers, voltage transformers and power meters, and automatically calculate no-load loss, excitation impedance, excitation resistance and other parameters through the built-in software of the test system.

In some embodiments, the test method of the load test is as follows:

2) According to the input transformer parameters, the frequency conversion power supply and the intermediate transformer gear are controlled by the switch, and the automatic switching control method of the compensation capacitor capacity is applied, and the current is applied on the high voltage side of the transformer under test to achieve the test current equal to the rated current;

3) Obtain corresponding values through precision current transformers, voltage transformers, and power meters, and automatically calculate parameters such as load loss, short-circuit impedance, short-circuit resistance, and short-circuit voltage through the built-in software of the test system.

In some embodiments, the automatic switching control method of the compensation capacitor capacity is as follows:

2) Set the applied voltage or current according to the test regulations;

5) The test current, the current of the intermediate transformer, and the voltage level of the capacitor are obtained through a certain formula algorithm to obtain the capacity of the compensation capacitor, and the capacity of the capacitor required for automatic switching through the PLC is automatically switched.

Example 3:

This example provides an on-board power transformer empty and load loss on-site test system, including: a test system (130), a wing-open deployment car (110), and a drive device (120) that drives the wing-open door; a test system (130) Located in the wing-open deployable compartment (110); the drive device 120, located in the wing-open deployable compartment, is connected to the drive of the wing-opening door, provides driving force for the wing-opening door, and provides support for maintaining the wing-opening door open force,

In some embodiments, the power supply device (132) includes: a variable frequency power supply (210), an intermediate transformer (220), and a filter (260);

The input terminal of the intermediate transformer (220) is connected to the output terminal of the variable frequency power supply (210), and the intermediate transformer (220) is used to convert a voltage signal of a predetermined frequency into the voltage required by the transformer under test;

In some embodiments, the measurement instrument (133) includes: a transformer (230) and a power analyzer 233;

In some embodiments, the measurement control device (134) includes: an industrial control computer (1), and a power supply device controller (2), a compensation capacitor bank controller (3);

The industrial control computer (1) is connected to a measuring instrument (133);

The compensation capacitor bank controller controls the compensation capacitor bank (135) to provide capacitive compensation during the load test of the transformer under test.

In some embodiments, the compensation capacitor bank includes: a three-phase compensation capacitor bank (1351) and a single-phase compensation capacitor bank (1352);

The single-phase capacitor bank (1352) is used to provide single-phase compensation when the transformer under test is subjected to a load test.

In some embodiments, the test system further includes: an isolation protection device (240);

The isolation protection device (240) is located on the test circuit where the test connection terminal (131) is located, and is disposed between the transformer under test and the measuring instrument (133).

In some embodiments, the test system further includes: a lighting system and a monitoring system for assisting on-site testing of the transformer.

The embodiments of the present invention have been described above with reference to the drawings, but are not limited to the specific embodiments described above. The specific embodiments described above are only schematic and are not limiting. Those of ordinary skill in the art Under the enlightenment of the present invention, many forms can be made without departing from the scope of the present invention and the scope of the claims, all of which fall within the protection of the present invention.

Claims

An on-site test method of vehicle-mounted power transformers for empty and load losses, characterized by:

The test method uses the on-board power transformer empty and load loss on-site test system including: using a single or multiple wings to load the test system to open the vehicle, using the test connection terminal to connect the tested transformer, and using the power supply device to provide test for the tested transformer For voltage or test current, use a measuring instrument to obtain the measured data of the transformer under test, a measuring control device to control the measuring instrument, and a compensation capacitor bank to provide capacitive compensation; the test steps are as follows:

The wing-opened vehicle travels to a location near the tested transformer with a wing-opened vehicle deployment space and stops;

The wing opening doors on both sides of the vehicle open automatically;

Connect the ground wire;

Connect the connecting cable of the capacitor bank;

Connect 380V or 10kV power supply according to the on-site power supply situation;

Connect the test test wire to the high-voltage side or low-voltage side of the transformer under test;

On-site supervisors conduct safety inspections;

Use no-load test method to carry out no-load test;

Use load test method to carry out no-load test;

The test is completed, the data is automatically saved, and the test report is printed;

Discharge, ground knife gate ground;

Disconnect the power supply;

Remove the test test wire, the connection of the compensation capacitor bank and the isolation knife gate, and the ground wire;

Wing opening The wing opening doors on both sides of the vehicle close automatically.
The on-site test method for no-load and load loss of a vehicle-mounted power transformer according to claim 1, wherein the test method for the no-load test is as follows:

1) Input the basic parameters of the transformer under test at the input terminal of the industrial control machine, including the capacity of the transformer under test, high voltage and low voltage rated voltage;

2) According to the input transformer parameters, by controlling the variable frequency power supply, the intermediate transformer gear, and using the automatic switching control method of the compensation capacitor capacity, a voltage is applied on the low voltage side of the transformer under test to achieve the test voltage equal to the rated voltage;

3) Obtain corresponding values through precision current transformers, voltage transformers and power meters, and automatically calculate no-load loss, excitation impedance, excitation resistance and other parameters through the built-in software of the test system.
The on-site test method for on-board power transformer empty and load loss according to claim 1, wherein the test method for the load test is as follows:

1) Input the basic parameters of the transformer under test at the input terminal of the industrial control machine, including the capacity of the transformer under test, high-voltage and low-voltage rated voltage;

2) According to the input transformer parameters, the frequency conversion power supply and the intermediate transformer gear are controlled by the switch, and the automatic switching control method of the compensation capacitor capacity is applied, and the current is applied on the high voltage side of the transformer under test to achieve the test current equal to the rated current;

3) Obtain corresponding values through precision current transformers, voltage transformers, and power meters, and automatically calculate parameters such as load loss, short-circuit impedance, short-circuit resistance, and short-circuit voltage through the built-in software of the test system.
The on-site test method for empty and load loss of a vehicle-mounted power transformer according to claim 1, wherein the automatic switching control method of the compensation capacitor capacity is as follows:

1) Input the basic parameters of the transformer under test at the input terminal of the industrial control machine, including the capacity of the transformer under test, high-voltage and low-voltage rated voltage;

2) Set the applied voltage or current according to the test regulations;

3) According to the set test current and voltage, the required gear of the intermediate transformer and capacitor is automatically calculated by the built-in software of the test system, and the automatic switching gear is switched by the PLC;

4) Obtain the current of the intermediate transformer from the precision current transformer;

5) The test current, the current of the intermediate transformer, and the voltage level of the capacitor are obtained through a certain formula algorithm to obtain the capacity of the compensation capacitor, and the capacity of the capacitor required for automatic switching through the PLC is automatically switched.
A vehicle-mounted power transformer empty and load loss on-site test system, including: a test system (130), a wing-open deployment car (110) and a drive device (120) that drives the wing-open door; the test system (130) is located In the unfolding compartment (110); the driving device 120 is located in the unfolding wing-opening compartment and is connected to the wing opening door to provide a driving force for the wing opening door and a supporting force for keeping the wing opening door open.

The test system (130) includes a test connection terminal (131) for connecting to the transformer under test, a power supply device (132) for providing a test voltage for the transformer under test, and a measuring instrument (133) for acquiring measurement data of the transformer under test ) And a measurement control device (134) for controlling the measuring instrument (133), a compensation capacitor bank (135) providing capacitive compensation;

The power supply device (132), the measuring instrument (133), the measurement control device (134) and the compensation capacitor group (135) are all located on the test circuit where the test connection terminal (131) is located;

The input terminal of the power supply device (132) is connected to the power supply at the test site.
The vehicle-mounted power transformer empty and load loss field test system according to claim 5, characterized in that the power supply device (132) includes: a variable frequency power supply (210), an intermediate transformer (220) and a filter (260);

The input terminal of the variable frequency power supply (210) is the input terminal of the power supply device (132), and the variable frequency power supply (210) is used to convert the power supply at the test site into a voltage signal of a predetermined frequency;

The input terminal of the intermediate transformer (220) is connected to the output terminal of the variable frequency power supply (210), and the intermediate transformer (220) is used to convert a voltage signal of a predetermined frequency into the voltage required by the transformer under test;

The filter (260) is connected between the variable frequency power supply (210) and the intermediate transformer (220), and is used for filtering voltage signals outside the predetermined frequency range, and transmitting the filtered voltage signals to the intermediate transformer Input.
The on-board power transformer empty and load loss on-site testing system according to claim 5, characterized in that the measuring instrument (133) includes: a transformer (230) and a power analyzer 233;

The transformer (230) includes: a precision voltage transformer (231) and / or a precision current transformer (232).
The on-board power transformer empty and load loss field test system according to claim 5, characterized in that the measurement control device (134) includes: an industrial control computer (1), and a power supply device controller (2), compensation Capacitor bank controller (3);

The industrial control computer (1), the power supply device controller (2) and the compensation capacitor group controller (3) are connected to each other through a bus;

The industrial control computer (1) is connected to a measuring instrument (133);

The power supply device controller is used to control the power supply output control of the power supply device (132);

The compensation capacitor bank controller controls the compensation capacitor bank (135) to provide capacitive compensation during the load test of the transformer under test.
The on-board power transformer empty and load loss on-site test system according to claim 5, wherein the compensation capacitor group comprises: a three-phase compensation capacitor group (1351) and a single-phase compensation capacitor group (1352);

The three-phase capacitor bank (1351) is used to provide three-phase compensation during the load test of the transformer under test;

The single-phase capacitor bank (1352) is used to provide single-phase compensation when the transformer under test is subjected to a load test.
The on-site test method for the empty and load loss of the vehicle-mounted power transformer according to claim 1, wherein the on-site test system for the empty and load loss of the vehicle-mounted power transformer further comprises: an isolation protection device (240);

The isolation protection device (240) is located on the test circuit where the test connection terminal (131) is located, and is disposed between the transformer under test and the measuring instrument (133).
The on-vehicle power transformer empty and load loss field test system according to claim 5, characterized in that the test system further comprises: a lighting system and a monitoring system for auxiliary field test of the transformer.