CN104698319A - Comprehensive tester for transformer parameters - Google Patents

Abstract

The invention relates to a transformer parameter comprehensive tester, which cooperates with a control host to complete the DC resistance test, insulation resistance test and transformation ratio test of the transformer, which includes a central control module connected with the control host and transmitting control signals. Under the control of the control signal transmitted by the central control module, the input single-phase AC power is converted into an excitation source module that is output in the form required for testing, and the range is switched under the control of the control signal transmitted by the central control module. An adaptive signal conditioning module that measures the return signal of the transformer, and a self-assembly module that adjusts the connection terminals of the transformer under the control of the control signal transmitted by the central control module. The invention integrates the testing of various parameters of the transformer, and completes the testing of the transformer through cooperation with a control host, and has a simple structure, easy integration, small size and high portability.

Description

Transformer parameter comprehensive tester

technical field

The invention relates to a portable and multifunctional parameter comprehensive testing instrument used for testing the transformer, which is the main equipment in the power system.

Background technique

The transformer is one of the main equipment in the power system, and its performance directly affects the safe operation of the power system, so the detection of the transformer is particularly important. The detection of transformers generally needs to measure the DC resistance of the transformer winding and bushing, so that the welding quality of the wire joint inside the winding, the welding quality of the lead wire and the winding joint, each tap position of the voltage tap changer, and the relationship between the lead wire and the bushing can be checked. Whether the contact is good, whether the parallel branch connection is correct, whether there is a short circuit in the current-carrying part of the transformer, and whether there is a short circuit in the winding; in addition, in the transformer short circuit test and temperature rise test, in order to provide accurate winding resistance, DC Measurement of resistance. Secondly, measure the transformation ratio of the transformer to check whether the transformation ratio is consistent with the nameplate to ensure the correct transformation of the voltage; check whether the position of the tap changer is correct; after the transformer fails, check the winding turns by measuring the transformation ratio Whether there is an inter-turn short circuit between turns, and judge whether the transformer can be operated in parallel.

At present, there are two ways to test transformers at home and abroad, one is to use the transformer comprehensive test bench, and the other is to use different special instruments for testing. The transformer comprehensive test bench is bulky, which is not conducive to movement and has no portability. Many of them cannot be used when on-site testing is required. Although the special instruments are portable, most of them can only test some items of the transformer alone. Therefore, to test a transformer, it is necessary to carry several special test instruments, and different instruments may come from different manufacturers. Managing test data brings inconvenience. Therefore just need a kind of volume is small, light in weight, portable transformer comprehensive tester.

Contents of the invention

The object of the present invention is to provide a transformer parameter comprehensive tester which has multiple parameter test functions and is easy to carry.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A transformer parameter comprehensive tester, which cooperates with a control host to complete the DC resistance test, insulation resistance test and transformation ratio test of the transformer. The transformer parameter comprehensive tester includes phase signal connection with the control host and transmission control The central control module of the signal, under the control of the control signal transmitted by the central control module, converts the input single-phase AC power supply into the power supply in the form required for testing and outputs the excitation source module. Under the control of the control signal transmitted by the control module, the adaptive signal conditioning module performs range switching and measures the return signal of the transformer, and adjusts the range under the control of the control signal transmitted by the central control module. The wiring self-assembly module of the wiring terminal of the transformer, the excitation source module is connected to the transformer through the wiring self-assembly module, and the transformer is connected to the self-adaptive signal conditioning module, The adaptive signal conditioning module is signal-connected with the control host.

The excitation source module includes three conversion units, which are respectively the first conversion unit that converts the single-phase AC power supply into the 1-5A constant DC current power supply required for the DC resistance test, and converts the The single-phase AC power supply is converted into the second conversion unit of the 0-5kV high-voltage low-current DC power supply required for the insulation resistance test, and the single-phase AC power supply is converted into the 0-5kV required for the transformation ratio test. The third conversion unit of the -400V three-phase AC power supply.

The excitation source module further includes a feedback unit for feeding back the power signal output by the conversion unit, and a feedback control unit for controlling the conversion unit according to the signal of the feedback unit.

The adaptive signal conditioning module includes three measuring units, which are respectively the first measuring unit for measuring the volt-level voltage signal returned by the DC resistance test, and the milliampere-level current for measuring the returned insulation resistance test. The second measurement unit for the signal, and the third test unit for measuring the AC voltage between the three-phase lines returned by the transformation ratio test.

The self-assembled module includes a terminal matrix corresponding to the terminals in the transformer and capable of combined wiring.

Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art: the present invention integrates the testing of various parameters of the transformer, and completes the testing of the transformer by cooperating with the control host, and its structure is simple. Easy to integrate, small size, high portability.

Description of drawings

Accompanying drawing 1 is the functional block diagram of transformer parameter comprehensive tester of the present invention.

Accompanying drawing 2 is the schematic diagram of the first conversion unit of the excitation source module in the transformer parameter comprehensive tester of the present invention.

Accompanying drawing 3 is the schematic diagram of the second conversion unit of the excitation source module in the transformer parameter comprehensive tester of the present invention.

Accompanying drawing 4 is the schematic diagram of the third conversion unit of the excitation source module in the transformer parameter comprehensive tester of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

Embodiment 1: As shown in accompanying drawing 1, a kind of transformer parameter comprehensive tester that cooperates with the control host to complete the DC resistance test, insulation resistance test and transformation ratio test of the transformer, it includes a central control module, an excitation source module, Adaptive signal conditioning modules and wiring self-assembly modules.

The central control module is used to transmit the control signal issued by the control host, and the control signal includes information such as the type of test to be performed. The input terminal of the central control module is connected with the control host for signal, which can be wired or wireless. The central control module has three output terminals, which are respectively connected with the excitation source module, the self-adaptive signal conditioning module and the wiring self-assembly module.

The excitation source module is used to convert the single-phase AC power into the power required by the test under the control of the control signal transmitted by the central control module. Transformer DC resistance test needs to use 1-5A steady DC current power supply, transformer insulation resistance test needs 0-1-2.5-5kV high voltage and small current DC power supply, transformer ratio error test needs a 0-400V three-phase AC power supply, so , the excitation source module includes three conversion units, which are respectively the first conversion unit for converting single-phase AC power into 1-5A constant and stable DC power required for DC resistance testing, and the first conversion unit for converting single-phase AC power into insulation resistance testing. The second conversion unit for the required 0-5kV high-voltage low-current DC power supply, and the third conversion unit for converting the single-phase AC power supply to the 0-400V three-phase AC power supply required for the transformation ratio test. The excitation source module has an input terminal, three output terminals and a control terminal. output of the conversion unit. When it receives the control signal, it starts different conversion units to convert and output power according to the test required in the control signal, thus realizing the purpose of one power input and three different nature excitation power outputs. In the third conversion unit corresponding to the transformation ratio test, the three-phase AC power is output, so that the transformation ratio data can be directly calculated and processed from the basic principle, without the need to perform single-phase to three-phase related work. The excitation source module also includes a feedback unit that feeds back the power signal output by the conversion unit, and a feedback control unit that controls the conversion unit according to the signal of the feedback unit. Each conversion unit can be equipped with a feedback control unit and can be equipped with a corresponding protection circuit.

The wiring ad hoc module is used to adjust the wiring mode of the terminals of the transformer according to the control signal, and the excitation source module is connected with the transformer through the wiring ad hoc module. The wiring ad hoc module includes a terminal matrix corresponding to the terminals in the transformer and capable of combined wiring. During the DC resistance test of the transformer, the effective wiring is between the two terminals of the winding on one side of the transformer, and the other terminals should be kept electrically disconnected. In the transformer insulation resistance test, when performing one side to the other side and ground test, all terminals on the excitation power side must be short-circuited for pressurization, while the other side is all short-circuited and grounded. When conducting the transformer ratio error test, the three terminals on the high-voltage side of the transformer have three-phase 400V AC power input, and it is necessary to measure the voltage of three high-voltage lines at the same time, and the three terminals on the low-voltage side also need to measure the three-phase line value. At this time, six All transformer terminals are used. Therefore, the terminal matrix in the wiring self-assembly module is temporarily considered as 3*3. When performing any of the test items, the terminal reorganization is carried out according to the requirements of the central control module, and the corresponding correct test wiring is realized according to different test items.

The adaptive signal conditioning module is used to switch the range and measure the return signal of the transformer under the control of the control signal. Its input terminal is connected with the transformer, and its output terminal is connected with the phase signal of the control host. The measurement return signal of the transformer DC resistance test is the voltage signal between the terminals of the tested transformer, which belongs to the volt-level DC voltage signal; the test return signal of the transformer insulation resistance is the DC mA level current signal; the measurement return signal of the transformer ratio error test The signals are the three-phase line-to-line AC voltage of 400V on the high-voltage side and the three-phase line-to-line AC voltage of 400/K (K is the actual transformation ratio of the transformer) on the low-voltage side. Therefore, the adaptive signal conditioning module includes three measurement units, which are the first measurement unit for measuring the volt-level voltage signal returned by the DC resistance test, and the second measurement unit for measuring the milliampere-level current signal returned by the insulation resistance test. 1. A third test unit for measuring the AC voltage between the three-phase lines returned by the transformation ratio test. Therefore, the adaptive signal conditioning module can perform wide range switching and accurate measurement according to the amplitude range of the AC voltage. For example, if a DC high voltage excitation signal is detected, it will automatically switch to the mA current detection and conditioning module to work. The circuits of each measuring unit in the adaptive signal conditioning module can be implemented by selecting corresponding circuits according to actual conditions.

The transformer parameter comprehensive tester of the present invention only integrates the central control module, the excitation source module, the self-adaptive signal conditioning module and the wiring self-assembly module, through its cooperation with the control host, various testing tasks on the transformer can be completed. The control host uses G language programming to process the obtained signals such as voltage and current, and obtains relevant test results by relevant algorithms, which can be displayed on the display to complete the entire test function. The transformer parameter comprehensive tester is small in size and easy to carry, has multiple functions, and has a wide range of applications.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (5)

1. A transformer parameter comprehensive tester, which cooperates with the control host to complete the DC resistance test, insulation resistance test and transformation ratio test of the transformer, it is characterized in that: the described transformer parameter comprehensive tester includes and described control host Phase signals are connected to the central control module that transmits the control signal, and under the control of the control signal transmitted by the central control module, the input single-phase AC power is converted into the form of power required for testing and output as an excitation source module , under the control of the transmitted control signal of the central control module, the adaptive signal conditioning module that performs range switching and measures the return signal of the transformer, and transmits the control signal of the central control module Under the control of the self-assembly module for adjusting the wiring terminals of the transformer, the excitation source module is connected to the transformer through the self-assembly module, and the transformer is connected to the self-adaptive The signal conditioning module is connected, and the self-adaptive signal conditioning module is signal-connected with the control host. 2. The transformer parameter comprehensive tester according to claim 1, characterized in that: said excitation source module comprises three conversion units, which are respectively converted from said single-phase AC power to said DC resistance test The first conversion unit for the required 1-5A constant and stable DC power supply, the second conversion unit for converting the single-phase AC power supply into the 0-5kV high-voltage low-current DC power supply required for the insulation resistance test, and the The third conversion unit for converting the single-phase AC power into the 0-400V three-phase AC power required for the transformation ratio test. 3. The transformer parameter comprehensive tester according to claim 2, characterized in that: the excitation source module also includes a feedback unit that feeds back the power signal output by the conversion unit, according to the signal control of the feedback unit The feedback control unit of the conversion unit. 4. The transformer parameter comprehensive tester according to claim 1, characterized in that: said self-adaptive signal conditioning module comprises three measuring units, respectively for measuring the volt-level voltage signal returned by said DC resistance test The first measurement unit, the second measurement unit for measuring the milliamp level current signal returned by the insulation resistance test, and the third test unit for measuring the AC voltage between the three-phase lines returned by the transformation ratio test. 5 . The transformer parameter comprehensive tester according to claim 1 , wherein the self-assembly module includes a terminal matrix corresponding to the terminals in the transformer and capable of combined wiring. 5 .