CN111983329A - Device and method for testing dielectric loss of transformer to ground - Google Patents
Device and method for testing dielectric loss of transformer to ground Download PDFInfo
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- G01R27/2694—Measuring dielectric loss, e.g. loss angle, loss factor or power factor
Abstract
The invention provides a device and a method for testing dielectric loss of a transformer to the ground, wherein the device comprises the following components: the device comprises a controller, a three-channel high-voltage relay switching module, a three-channel current acquisition module, a three-channel voltage acquisition module and three channels; the output end of the controller is connected with the input end of the three-channel high-voltage relay switching module, and the input end of the controller is connected with the output ends of the three-channel current acquisition module and the three-channel voltage acquisition module; the output end of the three-channel high-voltage relay switching module is connected with the input end of the three channel through a three-channel current acquisition module and a three-channel voltage acquisition module; the output ends of three channels are respectively connected with the high, middle and low voltage windings of the transformer to be tested. According to the invention, each channel is flexibly configured to be high-voltage output or low-voltage input through the high-voltage relay, and the current acquisition module is connected in series with each channel, so that the current of each channel can be measured, and meanwhile, the voltage acquisition module of each channel can acquire the voltage of each channel.
Description
Technical Field
The invention relates to the field of dielectric loss measurement, in particular to a device and a method for testing transformer to ground dielectric loss.
Background
The transformer is used as a core device of the power system, and has the functions of voltage conversion, energy transmission and electric energy distribution, the quality of the insulation performance of the transformer is directly related to the operation reliability of the power system, and accidents caused by the insulation system account for more than 85% of the accidents of the transformer. Dielectric loss is an important parameter reflecting the insulation condition thereof. Generally, an excitation signal (such as a high-voltage direct-current signal in a polarization depolarization PDC method and a high-voltage alternating-current signal in a frequency domain FDS method) is applied to a sample to be tested, voltage and current responses under excitation are measured, characteristic quantities such as dielectric loss are obtained, the size of the insulation power loss of equipment is reflected, information such as aging and water content of an insulation material of the equipment can be provided, and the quality of an insulation system is evaluated according to the information.
In the medium response testing instrument in the prior art, only one output channel is provided, and the current measuring module is generally arranged in an input channel at a low-voltage side, so that although the dielectric loss between windings can be effectively measured, and the damp state of an oil paper insulation system between the windings can be evaluated (an output excitation signal is added into a medium-voltage winding, 2 current measuring modules are respectively connected into a low-voltage winding and a high-voltage winding, and the dielectric loss between medium-low and medium-high and the moisture content of the oil paper insulation can be effectively measured), when the dielectric loss of each winding (three windings of high-voltage winding, medium-voltage winding and low-voltage winding) of a three-winding transformer to the ground is measured, only the three windings can be connected into a whole in a short mode, the dielectric loss of the whole three windings to the ground is tested, and the dielectric loss. Or only the excitation signal can be output to one winding, such as a medium-voltage winding, and when the other two windings are grounded, the dielectric loss to the ground is measured. However, this "dielectric loss to ground" is not a pure dielectric loss to ground of the medium voltage windings, and this "dielectric loss to ground" introduces the influence of dielectric loss of the insulation system between the windings, and therefore, in a strict sense, dielectric loss to ground of each winding cannot be obtained. When a certain winding has insulation fault to the ground, the connection of the dielectric loss instrument with each winding and the ground needs to be switched repeatedly, and the fault winding can be determined through multiple tests, so that the testing efficiency is seriously influenced. If and only if the insulation of the medium-voltage winding to the ground is failed (other windings are normal to the ground, and the insulation between the windings is normal), multiple measurements are needed to lock the insulation of the medium-voltage winding to the ground.
Disclosure of Invention
Embodiments of the present invention provide a device and a method for testing dielectric loss of a transformer to ground, which overcome the above problems or at least partially solve the above problems. The method is used for solving the problems that in the prior art, when the dielectric loss of each winding (three windings of high voltage, medium voltage and low voltage) of a three-winding transformer to the ground is measured, only the three windings can be connected into a whole in a short mode, the dielectric loss of the whole three windings to the ground is tested, and the dielectric loss of each winding to the ground cannot be obtained respectively.
In a first aspect, an embodiment of the present invention provides a device for testing dielectric loss of a transformer to ground, where the device includes: the device comprises a controller, a three-channel high-voltage relay switching module, a three-channel current acquisition module, a three-channel voltage acquisition module and three channels; the output end of the controller is connected with the input end of the three-channel high-voltage relay switching module, and the input end of the controller is connected with the output ends of the three-channel current acquisition module and the three-channel voltage acquisition module; the output end of the three-channel high-voltage relay switching module is connected with the input end of the three channel through a three-channel current acquisition module and a three-channel voltage acquisition module; the output ends of three channels are respectively connected with the high, middle and low voltage windings of the transformer to be tested; the three-channel high-voltage relay switching module is used for switching the input end to an excitation signal or a ground signal according to a switching signal received from the controller; the three-channel current acquisition module is used for acquiring current data of each channel; the three-channel voltage acquisition module is used for acquiring voltage data of each channel; the controller is used for respectively calculating the dielectric loss value to the ground of each winding in the transformer according to the current data and the voltage data.
Furthermore, the testing device for the dielectric loss of the transformer to the ground also comprises a power module; the input end of the three-channel high-voltage relay switching module is respectively connected with the power module and a GND ground, the power module is used for generating the excitation signal, and the GND ground is used for generating a ground signal.
Furthermore, the testing device for the dielectric loss of the transformer to the ground also comprises a communication module; the communication module is connected with the controller, and the controller is used for receiving the issued instruction through the communication module so as to generate the switching signal.
Furthermore, the three-channel high-voltage relay switching module comprises three high-voltage relays, and each high-voltage relay is respectively configured in one channel; the high voltage relay is used for switching an excitation signal or a ground signal so that each channel can be configured as a high voltage output or a low voltage input.
Furthermore, the three-channel current acquisition module comprises three current measurement modules, so that the three-channel voltage acquisition module comprises three voltage measurement modules; each current measuring module and each voltage measuring module are configured in one channel;
in each channel, the input end of the current measuring module is connected with the output end of the high-voltage relay, the output end of the current measuring module is connected with the input end of the channel, and the voltage measuring module is respectively connected with the input end of the channel and the GND ground.
In a second aspect, an embodiment of the present invention provides a method for testing dielectric loss of a transformer to ground by using the above testing apparatus, where the method includes: the input end of the three-channel high-voltage relay switching module is controlled by the controller to be switched to an excitation signal; acquiring current data of each channel through a three-channel current acquisition module, and acquiring voltage data of each channel through a three-channel voltage acquisition module; and respectively calculating the dielectric loss to ground value of each winding in the transformer according to the current data and the voltage data through the controller.
According to the device and the method for testing the dielectric loss of the transformer to the ground, provided by the embodiment of the invention, each channel is flexibly configured to be high-voltage output or low-voltage input through the high-voltage relay, and the fact that each channel is connected in series with the current acquisition module is realized, so that the current of each channel can be measured, and meanwhile, the voltage acquisition module of each channel can acquire the voltage of each channel. Based on the method, a user can measure the dielectric loss of the high-voltage winding, the medium-voltage winding and the low-voltage winding of the three-winding transformer to the ground without being influenced by the potential difference among the windings, so that an accurate dielectric loss value of each winding to the ground is obtained. Meanwhile, each channel can be flexibly configured to be an output channel or an input channel according to the needs of customers and the actual wiring on site, so that great flexibility and better user experience are achieved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from these without inventive effort.
Fig. 1 is a schematic structural diagram of a testing apparatus for dielectric loss of a transformer to ground according to an embodiment of the present invention;
fig. 2 is an overall configuration diagram of a testing apparatus for dielectric loss of a transformer to ground according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a channel 1 of a testing apparatus for dielectric loss between a transformer and ground according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a high-voltage relay switching module of the testing apparatus for dielectric loss of a transformer to ground according to the embodiment of the present invention;
fig. 5 is a schematic diagram of a current collection module of the testing apparatus for dielectric loss between a transformer and ground according to the embodiment of the present invention;
fig. 6 is a schematic diagram of a voltage acquisition module of the device for testing dielectric loss of a transformer in the embodiment of the present invention;
fig. 7 is a schematic structural diagram of a controller of a testing apparatus for dielectric loss between a transformer and ground according to an embodiment of the present invention;
fig. 8 is a schematic flowchart of a method for testing dielectric loss between transformer and ground according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments, but not all embodiments, of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
In the medium response testing instrument in the prior art, only one output channel is provided, and the current measuring module is generally arranged in an input channel at a low-voltage side, so that although the dielectric loss between windings can be effectively measured, and the damp state of an oil paper insulation system between the windings can be evaluated (an output excitation signal is added into a medium-voltage winding, 2 current measuring modules are respectively connected into a low-voltage winding and a high-voltage winding, and the dielectric loss between medium-low and medium-high and the moisture content of the oil paper insulation can be effectively measured), when the dielectric loss of each winding (three windings of high-voltage winding, medium-voltage winding and low-voltage winding) of a three-winding transformer to the ground is measured, only the three windings can be connected into a whole in a short mode, the dielectric loss of the whole three windings to the ground is tested, and the dielectric loss. Or only the excitation signal can be output to one winding, such as a medium-voltage winding, and when the other two windings are grounded, the dielectric loss to the ground is measured. However, this "dielectric loss to ground" is not a pure dielectric loss to ground of the medium voltage windings, and this "dielectric loss to ground" introduces the influence of dielectric loss of the insulation system between the windings, and therefore, in a strict sense, dielectric loss to ground of each winding cannot be obtained. When a certain winding has insulation fault to the ground, the connection of the dielectric loss instrument with each winding and the ground needs to be switched repeatedly, and the fault winding can be determined through multiple tests, so that the testing efficiency is seriously influenced. If and only if the insulation of the medium-voltage winding to the ground is failed (other windings are normal to the ground, and the insulation between the windings is normal), multiple measurements are needed to lock the insulation of the medium-voltage winding to the ground.
Therefore, the embodiment of the invention provides a testing device for dielectric loss of a transformer to the ground, which flexibly configures each channel as high-voltage output or low-voltage input through a high-voltage relay, and realizes that each channel is connected in series with a current acquisition module, so that the current of each channel can be measured, and meanwhile, the voltage acquisition module of each channel can acquire the voltage of each channel. Based on the method, a user can measure the dielectric loss of the high-voltage winding, the medium-voltage winding and the low-voltage winding of the three-winding transformer to the ground without being influenced by the potential difference among the windings, so that an accurate dielectric loss value of each winding to the ground is obtained. Meanwhile, each channel can be flexibly configured to be an output channel or an input channel according to the needs of customers and the actual wiring on site, so that great flexibility and better user experience are achieved. The following description and description of various embodiments are presented in conjunction with the following drawings.
Fig. 1 is a schematic structural diagram of a testing apparatus for dielectric loss of a transformer to ground according to an embodiment of the present invention; fig. 2 is an overall configuration diagram of a testing apparatus for dielectric loss between a transformer and ground according to an embodiment of the present invention. Referring to fig. 1-2, the device comprises a controller, a three-channel high-voltage relay switching module, a three-channel current collecting module, a three-channel voltage collecting module and three channels; the output end of the controller is connected with the input end of the three-channel high-voltage relay switching module, and the input end of the controller is connected with the output ends of the three-channel current acquisition module and the three-channel voltage acquisition module; the output end of the three-channel high-voltage relay switching module is connected with the input end of the three channel through a three-channel current acquisition module and a three-channel voltage acquisition module; the output ends of three channels are respectively connected with the high, middle and low voltage windings of the transformer to be tested; the three-channel high-voltage relay switching module is used for switching the input end to an excitation signal or a ground signal according to a switching signal received from the controller; the three-channel current acquisition module is used for acquiring current data of each channel; the three-channel voltage acquisition module is used for acquiring voltage data of each channel; the controller is used for respectively calculating the dielectric loss value to the ground of each winding in the transformer according to the current data and the voltage data.
Fig. 3 is a schematic structural diagram of a channel 1 of a testing apparatus for dielectric loss between a transformer and ground according to an embodiment of the present invention. Referring to fig. 3, the principle of the testing device provided by the embodiment of the present invention is illustrated: each channel of the dielectric response instrument can be independently configured as either a high voltage (output) or a low voltage (input) by configuring a high voltage relay at each channel for switching either an excitation signal or a ground signal. At the same time, each channel is provided with a current measuring module, which will be placed floating on the high voltage side, or on the low voltage side, which is grounded, according to the switching of the above-mentioned relay, as shown in fig. 3, which exemplifies channel 1.
In one embodiment, the test apparatus further comprises a power module; the input end of the three-channel high-voltage relay switching module is respectively connected with the power module and the GND ground, the power module is used for generating an excitation signal, and the GND ground is used for generating a ground signal.
In particular, the excitation signal may be generated by a power portion (i.e., a power module) of the dielectrically responsive device. And the high-voltage relay can switch and select the excitation signal or GND according to the control of the MCU controller. And the relay output part is connected in series with an ammeter, namely a current measuring module, and is connected in parallel with a voltmeter, namely a voltage measuring module. And finally, connecting to the tested object through a CH channel.
In one embodiment, the test device further comprises a communication module; the communication module is connected with the controller, and the controller is used for receiving the issued command through the communication module and generating a switching signal.
Referring to fig. 2, as an alternative embodiment, the three-channel high-voltage relay switching module includes three high-voltage relays, and each high-voltage relay is configured in one channel; the high voltage relay is used to switch either the excitation signal or the ground signal so that each channel can be configured as either a high voltage output or a low voltage input. The three-channel current acquisition module comprises three current measurement modules, so that the three-channel voltage acquisition module comprises three voltage measurement modules; each current measuring module and each voltage measuring module are configured in one channel; in each channel, the input end of the current measuring module is connected with the output end of the high-voltage relay, the output end of the current measuring module is connected with the input end of the channel, and the voltage measuring module is respectively connected with the input end of the channel and the GND ground.
Based on the structure of the testing device, the testing principle of the testing device is summarized as follows: when the relay is switched to an excitation signal (the channel is equivalent to an output channel of a traditional dielectric loss instrument), the ammeter is suspended and placed on the high-voltage side, so that the purpose of measuring current on the high-voltage side is achieved; when the relay is switched to GND ground (the channel is equivalent to the input channel of the traditional dielectric loss meter), the ammeter is arranged on the low-voltage side. The current meter can measure the current flowing out of or into the channel regardless of how the relay switches.
Specifically, when the relay is switched to an excitation signal (the channel is equivalent to an output channel of a traditional dielectric loss instrument), the ammeter is suspended and placed on a high-voltage side, the excitation signal is designed to be the ground potential of a current measurement part at the moment, the current signal is changed into a voltage signal through an I-V conversion circuit, and then the high-voltage signal is transmitted to a low-voltage measurement part through an optical coupler device, so that the purpose of measuring the current of the high-voltage side is achieved; when the relay is switched to the GND ground (the channel is equivalent to the input channel of the traditional dielectric loss meter), the ammeter is arranged on the low-voltage side, and the reference potential of the current measuring part is the GND ground potential. Regardless of how the relay is switched, the ammeter is free to switch the "ground" potential of the measurement portion, thereby further measuring the current flowing out of or into the channel.
And when the dielectric loss of the three windings to the ground is measured, a command (which can be received by a communication module) issued by a user is received through a human-computer interaction interface, so that the MCU controls (namely, the controller) to conduct the high-voltage relay nodes in 3 channels with excitation signals, therefore, CH1/2/3 (three channels) are the same excitation signals and are respectively added to the high-medium and low-voltage windings. Because the three windings are equipotential, the windings have no current between each other. The response current obtained by measuring through the ammeter (current testing module) connected in series with each channel is the response current of each channel to the ground, and meanwhile, the voltmeter (voltage measuring module) of each channel collects the voltage of each voltmeter, so that the dielectric loss value of each winding to the ground can be calculated.
To sum up, the device for testing dielectric loss of transformer to ground provided by the embodiment of the present invention flexibly configures each channel as high voltage output or low voltage input through the high voltage relay, and realizes that each channel is connected in series with the current collection module, so that the current of each channel can be measured, and the voltage collection module of each channel can collect the voltage of each channel. Based on the method, a user can measure the dielectric loss of the high-voltage winding, the medium-voltage winding and the low-voltage winding of the three-winding transformer to the ground without being influenced by the potential difference among the windings, so that an accurate dielectric loss value of each winding to the ground is obtained. Meanwhile, each channel can be flexibly configured to be an output channel or an input channel according to the needs of customers and the actual wiring on site, so that great flexibility and better user experience are achieved.
In one embodiment, referring to fig. 4, the embodiment of the present invention provides a structure of a high-voltage relay switching module, where VOH is a high-voltage excitation source generated by a power module, and since the configuration of 3 channels is completely the same, only channel 1 will be described below, and GNDH1 represents a high-voltage or low-voltage ground of CH1 channel. The excitation signal can be selected to be turned on by controlling K1, i.e. the channels are configured to be in output mode, the GND signal can be selected to be turned on by controlling K3, and the conduction of K1 and K3 are in mutual exclusion relationship. U1 is the driver chip ULN2803ADW of the relay. The pins 18 and 19 of the MCU STM32F103C8T6 control signals IO _ VOH _ CH1 and IO _ GND _ CH1 respectively, and the high-voltage relay is controlled after the signals pass through the driving chip U1. The high-voltage relay has the following types: CRSTHV24V, winding on voltage 24V, junction withstand voltage 15kV, which covers substantially all of the range of dielectric response excitation voltages. When the MCU pin 18 is high and the pin 19 is low, that is, the pin 1 IO _ VOH _ CH1 of the driver chip U1 is high and the pin 2 is low, the pin 18 RE _ VOH _ CH1 of the U1 is low and the pin 19 is high, at this time, the relay K1 is turned on, the relay K3 is turned off, and the GNDH1 voltage is the excitation signal VOH. When pin 1 IO _ VOH _ CH1 of the driver chip U1 is low and pin 2 is high, pin 18 of U1 is high (24V) and pin 19 is low, at this time, the relay K1 is not turned on, and due to K2, GNDH1 is GND ground.
In one embodiment, referring to fig. 5, the embodiment of the present invention provides a structure of a current collecting module, which also takes channel 1 as an example. The model of the ultra-low bias current operational amplifier U11 is OPA129, and the 3-pin GNDH1 and GNDH1 of U11 are used as the reference ground of a current sampling part; pin 2 of U11 is CH1_ OUT, which is electrically connected to the input/output port of CH1 for loading on the test object. Resistor R11 is 5.1 Ω), the designed current sampling range is less than 20mA because the dielectric loss current is generally small. Therefore, the U11, the resistor R11 and the corresponding circuit can convert the current signal into a voltage signal of +/-0.1V and below (relative to GNDH1), and R13100 omega and C41nF form a first-order low-pass filter with the cut-off frequency of about 159kHz, so that the high-frequency noise interference can be filtered. U9 is optical coupler amplifier AMC1300B, and its magnification is about 8 times, and 7 feet of U9 after isolating and amplifying high voltage signal is + -0.8V (relative to low voltage ground GND). U10 is instrument operational amplifier AD620AN, and its pin 5 connects 1.65V voltage, and R12 is 49.9k omega, so the magnification of instrument operational amplifier equals approximately 2 times, can be with the output of U11 + -0.8V voltage, convert SAMP _ IO _ CH1 voltage signal, (+ -0.8) x 2+1.65, belong to [0,3.3V ] interval, and send this signal into MCU's ADC pin namely MCU's 11 pins, supply MCU's ADC module to sample, thereby obtain CH1_ OUT's current size.
In an embodiment, referring to fig. 6, an embodiment of the present invention provides a structure of a voltage acquisition module, for a voltage CH1_ OUT of a channel 1, in the present design, an excitation voltage range is ± 500V, U2 is an operational amplifier OPA277, a resistor R3 is a 50M Ω glass glaze resistor, R2 is a 150k Ω resistor, and a magnification factor is: 150k/50M is 0.003, so the voltage of ± 500V can be converted into a voltage of ± 1.5V. D1 is a switch diode for protecting the operational amplifier U2. R4100 Ω and C11nF constitute a low-pass filter. U3 is an instrument operational amplifier AD620AN, 5 pins of U3 are connected to 1.65V, so that the output voltage SAMP _ VO _ CH1 on 6 pins (± 1.5) +1.65 belongs to the [0,3.3V ] interval, and an ADC module of the MCU can sample the voltage. And a pin 6 of the U3 is connected with a pin 14 of the U5MCU for collecting voltage.
In one embodiment, referring to fig. 7, the embodiment of the present invention provides a controller structure, the model number of U5 control is STM32F103C8T6, the current of channel 1/2/3 is collected from pin 11 to pin 13, and the voltage of channel 1/2/3 is collected from pin 14 to pin 16. Pins 34 and 37 are the download ports for programming, pins 18 and 19 are used to control the two relays for channel 1, pins 20 and 39 are used to control the two relays for channel 2, and pins 40 and 41 are used to control the two relays for channel 3. The pins 21 and 22 are used for data interaction with the communication module. And the pin 5 is a crystal oscillator signal input pin. Y1 is a 25M active crystal oscillator.
Fig. 8 is a schematic flow chart of a method for testing dielectric loss to ground of a transformer according to an embodiment of the present invention, and referring to fig. 8, the embodiment of the present invention provides a method for testing dielectric loss to ground of a transformer using the apparatus according to the above embodiment, including, but not limited to, the following steps:
102, acquiring current data of each channel through a three-channel current acquisition module, and acquiring voltage data of each channel through a three-channel voltage acquisition module;
and 103, calculating the dielectric loss to ground value of each winding in the transformer respectively according to the current data and the voltage data through the controller.
Specifically, when dielectric loss of the three windings to the ground is measured, a command issued by a user is received through a human-computer interaction interface, so that the MCU controls high-voltage relay nodes in 3 channels to be conducted with excitation signals, and therefore CH1/2/3 are the same excitation signals and are respectively added to the high-voltage winding, the medium-voltage winding and the low-voltage winding. Because the three windings are equipotential, the windings have no current between each other. The response current obtained by measuring through the ammeter (current testing module) connected in series with each channel is the response current of each channel to the ground, and meanwhile, the voltmeter (voltage measuring module) of each channel collects the voltage of each voltmeter, so that the dielectric loss value of each winding to the ground can be calculated.
According to the method for testing the dielectric loss of the transformer to the ground, provided by the embodiment of the invention, each channel is flexibly configured to be high-voltage output or low-voltage input through the high-voltage relay, and the current acquisition module is connected in series with each channel, so that the current of each channel can be measured, and meanwhile, the voltage acquisition module of each channel can acquire the voltage of each channel. Based on the method, a user can measure the dielectric loss of the high-voltage winding, the medium-voltage winding and the low-voltage winding of the three-winding transformer to the ground without being influenced by the potential difference among the windings, so that an accurate dielectric loss value of each winding to the ground is obtained. Meanwhile, each channel can be flexibly configured to be an output channel or an input channel according to the needs of customers and the actual wiring on site, so that great flexibility and better user experience are achieved.
The embodiments of the present invention can be arbitrarily combined to achieve different technical effects.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (6)
1. A transformer is to test device that decreases that situated between ground, its characterized in that includes: the device comprises a controller, a three-channel high-voltage relay switching module, a three-channel current acquisition module, a three-channel voltage acquisition module and three channels; the output end of the controller is connected with the input end of the three-channel high-voltage relay switching module, and the input end of the controller is connected with the output ends of the three-channel current acquisition module and the three-channel voltage acquisition module; the output end of the three-channel high-voltage relay switching module is connected with the input ends of the three channels through the three-channel current acquisition module and the three-channel voltage acquisition module; the output ends of three of the three channels are respectively connected with high, middle and low voltage windings of the transformer to be tested;
the three-channel high-voltage relay switching module is used for switching an input end to an excitation signal or a ground signal according to a switching signal received from the controller;
the three-channel current acquisition module is used for acquiring current data of each channel;
the three-channel voltage acquisition module is used for acquiring voltage data of each channel;
and the controller is used for respectively calculating the dielectric loss to ground value of each winding in the transformer according to the current data and the voltage data.
2. The apparatus of claim 1, further comprising a power module;
the input end of the three-channel high-voltage relay switching module is respectively connected with the power module and a GND ground, the power module is used for generating the excitation signal, and the GND ground is used for generating a ground signal.
3. The device of claim 1, further comprising a communication module;
the communication module is connected with the controller, and the controller is used for receiving the issued instruction through the communication module so as to generate the switching signal.
4. The apparatus of claim 1, wherein the three-channel high-voltage relay switching module comprises three high-voltage relays, each high-voltage relay being respectively configured to one channel; the high voltage relay is used for switching an excitation signal or a ground signal so that each channel can be configured as a high voltage output or a low voltage input.
5. The apparatus of claim 4, wherein the three-channel current collection module comprises three current measurement modules, so the three-channel voltage collection module comprises three voltage measurement modules; each current measuring module and each voltage measuring module are configured in one channel;
in each channel, the input end of the current measuring module is connected with the output end of the high-voltage relay, the output end of the current measuring module is connected with the input end of the channel, and the voltage measuring module is respectively connected with the input end of the channel and the GND ground.
6. A method for testing dielectric loss to ground of a transformer by using the device of any one of claims 1-5, comprising:
the input end of the three-channel high-voltage relay switching module is controlled by the controller to be switched to an excitation signal;
acquiring current data of each channel through a three-channel current acquisition module, and acquiring voltage data of each channel through a three-channel voltage acquisition module;
and respectively calculating the dielectric loss to ground value of each winding in the transformer according to the current data and the voltage data through the controller.
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Citations (5)
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| CN103018576A (en) * | 2012-12-03 | 2013-04-03 | 杭州西湖电子研究所 | Method for measuring dielectric loss factor and insulation resistance of power transformer |
| CN107367637A (en) * | 2017-07-14 | 2017-11-21 | 国网福建省电力有限公司 | The automatic testing method of Transformer Winding insulaion resistance and dielectric loss detecting instrument |
| CN207248948U (en) * | 2017-09-07 | 2018-04-17 | 国家电网公司江苏省电力公司扬州供电公司 | Transformer measurement intelligence switching line apparatus |
| CN207866906U (en) * | 2018-03-07 | 2018-09-14 | 杭州高电科技有限公司 | A kind of multichannel precision dielectric loss measuring instrument |
| CN208689116U (en) * | 2018-05-28 | 2019-04-02 | 云南电网有限责任公司曲靖供电局 | A kind of main transformer test device |
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- 2020-08-25 CN CN202010865810.9A patent/CN111983329A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103018576A (en) * | 2012-12-03 | 2013-04-03 | 杭州西湖电子研究所 | Method for measuring dielectric loss factor and insulation resistance of power transformer |
| CN107367637A (en) * | 2017-07-14 | 2017-11-21 | 国网福建省电力有限公司 | The automatic testing method of Transformer Winding insulaion resistance and dielectric loss detecting instrument |
| CN207248948U (en) * | 2017-09-07 | 2018-04-17 | 国家电网公司江苏省电力公司扬州供电公司 | Transformer measurement intelligence switching line apparatus |
| CN207866906U (en) * | 2018-03-07 | 2018-09-14 | 杭州高电科技有限公司 | A kind of multichannel precision dielectric loss measuring instrument |
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