CN104991127A - Relative dielectric loss and capacitance tester - Google Patents

Abstract

The invention provides a relative dielectric loss and capacitance tester, which includes a portable box body and a circuit device installed in the portable box body; the circuit device includes an operation panel, a battery power management unit, a wireless communication unit, a measurement unit and a display control unit; The display control unit is electrically connected with the wireless communication unit and the measurement unit with two-way signals; the battery power management unit provides power when in use; the measurement unit is responsible for the collection of PT secondary side voltage and final screen leakage current data under the control of the display control unit during operation and digital signal processing; the display control unit completes human-computer interaction through the keyboard, controls the measurement unit to start measurement and reads the measurement data of the measurement unit in real time for real-time display, storage, and printout; when necessary, the display control unit transmits the data in real time through the wireless communication unit Upload to the supporting host computer for synchronous monitoring. The invention has the advantages of compact structure, portability, comprehensive functions, high testing precision and convenient operation.

Description

Relative dielectric loss and capacitance tester

technical field

The invention relates to the technical field of power system test tools, in particular to a relative dielectric loss and capacitance tester for measuring the relative dielectric loss factor and capacitance ratio of capacitive equipment in a power supply system.

Background technique

The insulation status of capacitive equipment such as capacitive current transformers, capacitive voltage transformers, coupling capacitors, capacitive bushings, and metal oxide arresters is related to the safe operation of power supply equipment and power supply safety, because capacitive equipment is prone to moisture due to insulation , oil quality deterioration and other reasons make the insulation damaged, so it is necessary to conduct live tests on the insulation state of the capacitive equipment in operation on a regular basis; the current common detection method is to use the corresponding device to detect the state parameters such as the relative dielectric loss factor of the capacitive equipment and Analyze it, and then judge and evaluate the insulation state of the tested capacitive equipment. The so-called relative dielectric loss factor refers to the value obtained by measuring the difference of two current vectors at the end of the capacitor when two capacitive devices are connected in parallel or at the same voltage with different phases, and the difference is calculated by positive switching.

At present, the common devices used for relative dielectric loss and capacitance testing have problems such as incomplete functions, low test accuracy, and inconvenient portability and operation. Therefore, it is necessary to develop a relative Dielectric loss and capacitance testing is very necessary to improve the speed and quality of testing capacitive equipment in the power supply department and ensure the safety of power supply.

Contents of the invention

The purpose of the present invention is to provide a relative dielectric loss and capacitance tester that is compact in structure, easy to carry, comprehensive in use, high in test accuracy and easy to operate in view of the problems in the prior art.

The technical solution of the present invention is: the relative dielectric loss and capacitance tester of the present invention, its structural feature is: comprise portable case body and the circuit device installed in portable case body; Above-mentioned circuit device comprises operation panel, battery power management unit , a wireless communication unit, a measurement unit and a display control unit;

The display control unit is respectively electrically connected with the wireless communication unit and the measurement unit for two-way signals; the battery power management unit is used to provide working power when in use;

The above measurement unit includes a reference voltage interface, a reference current interface, a current interface of the device under test, a reference voltage/current conditioning module, a measured current conditioning module, a second-order anti-aliasing low-pass filter, an AD conversion module, and FFT digital signal processing a module and a second serial interface;

The reference voltage interface, reference current interface and the current interface of the tested equipment are respectively set on the operation panel; the reference voltage/current conditioning module is electrically connected to the reference voltage interface and the reference current interface respectively; the tested current conditioning module is connected to the current interface of the tested equipment Electrical connection; the second-order anti-aliasing low-pass filter is electrically connected to the reference voltage/current conditioning module and the measured current conditioning module; the AD conversion module is electrically connected to the second-order anti-aliasing low-pass filter; the AD conversion module is connected to the FFT The digital signal processing module is electrically connected to the bidirectional signal; the FFT digital signal processing module is electrically connected to the second serial interface to the bidirectional signal;

The display control unit includes a main control module, a keyboard module, a liquid crystal display module, a storage module, a printer module, a wireless communication interface, a measurement communication interface, a host computer communication interface and a U disk interface;

The keyboard module, liquid crystal display module, upper computer communication interface and U disk interface are all set on the operation panel; the printer module is set on the portable box;

The main control module is electrically connected with the signal of the keyboard module; the liquid crystal display module and the printer module are respectively connected with the signal and electricity of the main control module; the main control module is respectively connected with the storage module and the U disk interface bidirectional signal; The communication unit communicates; the measurement communication interface of the main control module is electrically connected with the second serial interface of the measurement unit for bidirectional signals.

A further solution is: the above-mentioned wireless communication unit includes a second control module, a first serial interface, a radio frequency communication module, a radio frequency power amplifier module and an antenna;

The second control module is respectively electrically connected with the first serial interface and the radio frequency communication module for bidirectional signals; the radio frequency power amplifier module is respectively electrically connected with the radio frequency communication module and the antenna for bidirectional signals.

A further solution is: the above-mentioned battery power management unit includes a first control module, an on/off detection module, a charging management module, a lithium battery, an on/off control module, a DC-DC step-down module, a charging interface and a power switch; the charging interface and The power switch is set on the operation panel;

The first control module is provided with an on/off detection signal input terminal, a charging management signal communication terminal, an on/off control signal output terminal, and a power output control terminal; the on/off detection module is provided with a signal input terminal and a signal output terminal; the charging management module is provided with Charging power input terminal, charging control signal communication terminal and power output terminal; lithium battery is provided with charging power input terminal and power output terminal; switch machine control module is provided with control signal input terminal, power input terminal and power output terminal; DC-DC The step-down module is provided with a control signal input terminal, a power input terminal and a power output terminal;

The switch detection signal input terminal of the first control module is electrically connected with the signal output terminal signal of the switch detection module; the charging management signal communication terminal of the first control module is electrically connected with the charging control signal communication terminal of the charging management module with a bidirectional signal; the switch The signal input end of the machine detection module is electrically connected to the power switch; the charging power input end of the charging management module is electrically connected to the charging interface; the charging power input end of the lithium battery is electrically connected to the power output end of the charging management module; The control signal input terminal is electrically connected to the switch control signal output terminal of the first control module; the power input terminal of the switch control module is electrically connected to the power output terminal of the lithium battery; the control signal input terminal of the DC-DC step-down module is connected to the The power output control terminal signal of the first control module is electrically connected; the power input end of the DC-DC step-down module is electrically connected with the power output end of the switch machine control module; the power output end of the DC-DC step-down module outputs working power when used .

A further solution is: the reference voltage/current conditioning module of the above measurement unit includes multi-level sampling resistors and variable gain amplifiers; the second-order anti-aliasing low-pass filter includes a second-order Butterworth active low-pass filter and a first-order passive RC low-pass filter.

A further solution is: the core device of the AD conversion module of the above-mentioned measurement unit is an ultra-low power consumption 16-bit microcontroller of the MSP430AFE253 model; the core device of the FFT digital signal processing module is a CPU of the STM32F405 model with a floating-point unit.

A further solution is: the core device of the main control module of the above-mentioned display control unit is a high-performance microprocessor of the S3C44B0 type based on ARM7TDMI core; the core device of the printer module is a miniature thermal printer with 8-bit parallel port communication.

A further solution is: the core component of the radio frequency communication module of the above wireless communication unit is a radio frequency chip of the SI4463 type based on the 433MHz frequency band.

A further solution is: the charging management module of the above-mentioned battery power management unit includes an external power supply detection circuit, a PWM charging circuit, a battery voltage detection circuit and a charging current detection circuit; the core device of the first control module is an MSP430F2012 single-chip microcomputer; DC-DC The core device of the step-down module is a high-efficiency switching power supply chip of the LM2675 model.

The present invention has positive effects: (1) The relative dielectric loss and capacitance tester of the present invention adopts a portable box body, and the circuit device is installed in the portable box body. It has a compact structure and is easy to carry, and is suitable for outdoor operations in power supply departments. (2) The relative dielectric loss and capacitance tester of the present invention can be connected and operated on the operation panel during use, and the operation interface is intuitive and clear; the large-screen dot-matrix liquid crystal display can display various measurement data in real time during operation; the measurement data is automatically Save; the miniature thermal printer can print out the measurement results; an external U disk can be used for auxiliary storage; the operation is very convenient and easy for operators to use. adopted composition. (3) The relative dielectric loss and capacitance tester of the present invention has the measurement functions of absolute method and relative method, which can be flexibly selected according to the site conditions; it has a variety of detection functions, and can detect the dielectric loss, capacitance and The resistive current and capacitive current parameters of the zinc oxide arrester can be used and verified as a conventional dielectric loss test instrument; it has comprehensive functions. (4) The relative dielectric loss and capacitance tester of the present invention can automatically track the frequency of the test signal when it is used, and can adapt to the measurement of dielectric loss in the range of 45Hz to 65Hz power frequency; the sampling signal is effectively filtered by a high-precision model The digital converter performs synchronous high-speed sampling of the reference signal and the tested signal, and then performs FFT transformation on the signal, and after a digital filtering algorithm, the capacitance ratio and dielectric loss value between the tested product and the reference tested product are obtained; the test data is not affected by harmonics. Influence, strong anti-interference ability; high test accuracy. (5) The relative dielectric loss and capacitance tester of the present invention has a built-in large-capacity lithium-ion battery, which can work continuously for 8 hours without being limited by the on-site power supply; and has an automatic shutdown function, which will automatically shut down if there is no operation within ten minutes. shutdown.

Description of drawings

Fig. 1 is a schematic block diagram of the circuit structure of the present invention;

FIG. 2 is a schematic block diagram of the circuit structure of the battery power management unit in FIG. 1;

Fig. 3 is a schematic block diagram of the circuit structure of the wireless communication unit in Fig. 1;

Fig. 4 is a schematic block diagram of the circuit structure of the measuring unit in Fig. 1;

FIG. 5 is a schematic block diagram of the circuit structure of the display control unit in FIG. 1 .

The reference signs in the above-mentioned accompanying drawings are as follows:

Battery power management unit 1, first control module 11, switch detection module 12, charging management module 13, lithium battery 14, switch control module 15, DC-DC step-down module 16, charging interface 17, power switch 18;

A wireless communication unit 2, a second control module 21, a first serial interface 22, a radio frequency communication module 23, a radio frequency power amplifier module 24, and an antenna 25;

Measuring unit 3, reference voltage interface 31, reference current interface 32, tested device current interface 33, reference voltage/current conditioning module 34, measured current conditioning module 35, second-order anti-aliasing low-pass filter 36, AD conversion module 37, FFT digital signal processing module 38, second serial interface 39;

Display control unit 4, main control module 41, keyboard module 42, liquid crystal display module 43, storage module 44, printer module 45, wireless communication interface 46, measurement communication interface 47, upper computer communication interface 48, U disk interface 49.

Detailed ways

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

(Example 1)

As shown in Fig. 1, the relative dielectric loss and capacitance tester of this embodiment is mainly composed of a portable box and a circuit device installed in the portable box. The circuit device mainly includes an operation panel, a battery power management unit 1 , a wireless communication unit 2 , a measurement unit 3 and a display control unit 4 .

The display control unit 4 is electrically connected to the wireless communication unit 2 and the measurement unit 3 with two-way signals, and the battery power management unit 1 is used to provide working power to other units when in use; in this embodiment, the display control module 4 is connected to the measurement module 3 and The communication mode of the wireless communication module 2 preferably adopts RS232 bus communication.

2, the battery power management unit 1 is mainly composed of a first control module 11, a switch detection module 12, a charging management module 13, a lithium battery 14, a switch control module 15, a DC-DC step-down module 16, a charging interface 17 and Power switch 18 is formed.

The first control module 11 is provided with an on/off detection signal input end, a charging management signal communication end, an on/off control signal output end, and a power output control end; the on/off detection module 12 is provided with a signal input end and a signal output end; the charging management module 13 is provided with charging power input terminal, charging control signal communication terminal and power output terminal; lithium battery 14 is provided with charging power input terminal and power output terminal; switch machine control module 15 is provided with control signal input terminal, power input terminal and power output terminal terminal; the DC-DC step-down module 16 is provided with a control signal input terminal, a power input terminal and a power output terminal; the charging interface 17 and the power switch 18 are arranged on the operation panel;

The switch detection signal input terminal of the first control module 11 is electrically connected with the signal output terminal signal of the switch detection module 12; Electrical connection; the signal input end of the switch machine detection module 12 is electrically connected with the power switch 18; the charging power input end of the charging management module 13 is electrically connected with the charging interface 17; the charging power input end of the lithium battery 14 is connected with the power supply of the charging management module 13 The output terminal is electrically connected; the control signal input end of the switch machine control module 15 is electrically connected with the switch machine control signal output terminal signal of the first control module 11; Connection; the control signal input end of the DC-DC step-down module 16 is electrically connected to the power output control end signal of the first control module 11; the power input end of the DC-DC step-down module 16 is connected to the power output end of the switch control module 15 Electrical connection; the power output terminal of the DC-DC step-down module 16 is used to provide working power to other units.

The core device of the first control module 11 preferably adopts MSP430F2012 single-chip microcomputer in the present embodiment, and its main frequency is 16MHz, has PWM timer, can produce the PWM signal that frequency is 62.5KHZ 8-bit resolution, multi-channel 10-bit AD modulus The converter can collect battery voltage and current.

The on/off detection module 12 is used to detect whether the power switch 18 is pressed and transmit the detected signal to the first control module 11 to determine whether to power on or off.

The charging management module 13 includes a detection circuit for external power supply, a PWM charging circuit, a battery voltage detection circuit and a charging current detection circuit; the charging management module 13 charges and manages the lithium battery 14 under the control of the first control module 11 .

The switch machine control module 15 can cut off the power supply to the DC-DC step-down module 16 under the control of the first control module 11 to realize automatic shutdown; the core device of the DC-DC step-down module 16 is preferably LM2675 high-efficiency in this embodiment Switching power supply chip, its output is 5V.

Referring to FIG. 3 , the wireless communication unit 2 is mainly composed of a second control module 21 , a first serial interface 22 , a radio frequency communication module 23 , a radio frequency power amplifier module 24 and an antenna 25 .

The second control module 21 is respectively electrically connected with the first serial interface 22 and the radio frequency communication module 23 for bidirectional signals; the radio frequency power amplifier module 24 is respectively electrically connected with the radio frequency communication module 23 and the antenna 25 for bidirectional signals.

The core device of the radio frequency communication module 23 preferably adopts the wireless radio frequency chip SI4463 based on the 433MHz frequency band in this embodiment; the first serial interface 22 adopts a UART serial interface for communicating with the display control unit 4; the purpose of setting the radio frequency power amplifier module 24 It is used to realize long-distance reliable communication with the supporting host computer to realize data interaction. In this embodiment, the line-of-sight distance of the wireless communication can reach 2 kilometers under open conditions.

As shown in Figure 4, the measurement unit 3 is mainly composed of a reference voltage interface 31, a reference current interface 32, a device current interface 33 under test, a reference voltage/current conditioning module 34, a measured current conditioning module 35, and a second-order anti-aliasing low-pass filter 36. It consists of an AD conversion module 37, an FFT digital signal processing module 38 and a second serial interface 39.

The reference voltage interface 31, the reference current interface 32 and the tested equipment current interface 33 are respectively set on the operation panel; the reference voltage/current conditioning module 34 is electrically connected with the reference voltage interface 31 and the reference current interface 32 respectively; the measured current conditioning module 35 is electrically connected to the current interface 33 of the device under test; the second-order anti-aliasing low-pass filter 36 is electrically connected to the reference voltage/current conditioning module 34 and the measured current conditioning module 35; the AD conversion module 37 is connected to the second-order anti-aliasing Low-pass filter 36 is electrically connected; AD conversion module 37 is electrically connected with FFT digital signal processing module 38 bidirectional signals; FFT digital signal processing module 38 is electrically connected with second serial interface 39 bidirectional signals; second serial interface 39 and display The control unit 4 communicates.

The reference voltage/current conditioning module 34 includes multi-level sampling resistors and variable gain amplifiers, which can realize ultra-wide range measurement of input signals.

The second-order anti-aliasing low-pass filter 36 includes a typical second-order Butterworth active low-pass filter and a first-order passive RC low-pass filter for efficient digital filtering.

The core device of the AD conversion module 37 is preferably used in this embodiment, the MSP430AFE2xx series metering analog front end (AFE) ultra-low power consumption 16-bit microcontroller launched by Texas Instruments TI for metering and smart grid applications.

The core device of the FFT digital signal processing module 38 preferably adopts the CPU of the STM32F405 model of the Cortex-M4 band floating-point unit that STMicroelectronics ST produces in the present embodiment.

5, the display control unit 4 is mainly composed of a main control module 41, a keyboard module 42, a liquid crystal display module 43, a storage module 44, a printer module 45, a wireless communication interface 46, a measurement communication interface 47, a host computer communication interface 48 and a U disk. The interface 49 is composed.

The keyboard module 42, the liquid crystal display module 43, the upper computer communication interface 48 and the U disk interface 49 are respectively arranged on the operation panel; the printer module 45 is arranged on the portable box.

The main control module 41 is electrically connected with the keyboard module 42 signals; the liquid crystal display module 43 and the printer module 45 are respectively electrically connected with the main control module 41 signals; the main control module 41 is respectively electrically connected with the storage module 44 and the U disk interface 49 bidirectional signals; The control module 41 is electrically connected with the first serial interface 22 of the wireless communication unit 2 through the wireless communication interface 46 for bidirectional signals; the main control module 41 is electrically connected with the second serial interface 39 of the measurement unit 3 for bidirectional signals through the measurement communication interface 47; The main control module 41 can be selectively electrically connected with the corresponding host computer via the host computer communication interface 48 via wired signals.

The core device of the main control module 41 is preferably a high-performance microprocessor of the model S3C44B0 based on the ARM7TDMI core of Samsung in this embodiment. The core component of the printer module 45 is preferably a miniature thermal printer with 8-bit parallel port communication in this embodiment.

(Application example)

The relative dielectric loss and capacitance tester of the aforementioned embodiments, its working principle and working process when in use are briefly described as follows:

The battery power management unit 1 is responsible for charge and discharge management of the lithium battery 14 built in the instrument, as well as generating the working power of each module and controlling the power switch; the display control unit 4 is responsible for human-computer interaction, responsible for monitoring the operation of the user through the keyboard module 42 and making corresponding actions. Display, and control the measurement unit 3 to measure and read the measurement data and perform operations such as display, storage, and printing, and is responsible for sending the measurement data to the wireless communication unit 2; the wireless communication unit 2 is responsible for on-line communication with the supporting host computer. Upload the measurement data to the host computer. The display control unit 4 communicates with the measurement unit 3 and the wireless communication unit 2 in the form of RS232, and the display control unit 4 is responsible for coordinating and controlling the work of each module in the whole instrument.

The relative dielectric loss and capacitance tester of the foregoing embodiments supports the absolute measurement method of taking the voltage as a reference from the PT secondary side or the relative measurement method of taking the same phase sample as a reference; when in use, according to the object to be measured After the wiring is correct, press the power switch 18 to turn it on, and the instrument can work automatically:

The measurement unit 3 is mainly responsible for the acquisition and digital signal processing of the PT secondary side voltage and the leakage current data of the last screen; the reference voltage/current conditioning module 34 or the measured current conditioning module 35 of the measurement unit 3 obtains signals from the corresponding interface through the second stage The anti-aliasing low-pass filter 36 sends the signal to the AD conversion module 37 after effective digital filtering; the AD conversion module 37 converts the analog signal into a digital signal under the control of the FFT digital signal processing module 38 and automatically sends the digital quantity to The FFT digital signal processing module 38 calculates and processes the data. The FFT digital signal processing module 38 calculates parameters such as voltage, current effective value, frequency, and phase difference through fast Fourier transform (FFT) and spectrum leakage correction algorithm.

The display control unit 4 receives keyboard commands through the keyboard module 42 to complete human-computer interaction; the display control unit 4 communicates with the measurement unit 3, controls the measurement unit 3 to start measurement and reads the measurement data of the measurement unit 3 in real time, on the one hand through the liquid crystal display module 43 carries out real-time display; Storage module 44 stores, also can utilize U disk to store data by U disk interface 49 if necessary; The supporting host computer implements synchronous monitoring.

The relative dielectric loss and capacitance tester of aforementioned embodiment, its function characteristic when using has:

① It has the measurement functions of absolute method and relative method at the same time, which can be flexibly selected according to the situation on site;

② With multiple detection functions, it can detect the dielectric loss and capacitance of capacitive equipment and the resistive current and capacitive current parameters of zinc oxide arrester while it is live, and can be used and verified as a conventional dielectric loss test instrument (external power supply) ;

③It can measure and display the capacitance ratio and relative dielectric loss value of the tested equipment and the reference equipment, and also put the test data of the reference equipment first, and directly read the capacitance and dielectric loss value of the tested equipment, which is convenient for comparison with the power failure test data ;

④ Internal high-precision analog-to-digital converters are used to perform synchronous high-speed sampling of the reference signal and the tested signal, and then perform FFT transformation on the signal. After a digital filtering algorithm, the capacitance ratio and dielectric loss value between the tested product and the reference sample are obtained; The test data is not affected by harmonics, and has strong anti-interference ability;

⑤ It can automatically track the frequency of the test signal, and can adapt to the measurement of dielectric loss within the power frequency range of 45Hz to 65Hz;

⑥Real-time display of each measurement data, and continuous measurement can be saved as a data report; up to 4000 sets of measurement data can be saved in the machine, and the measurement results can also be stored in an external U disk; the miniature thermal printer can print out the measurement results;

⑦Built-in large-capacity lithium-ion battery, can work continuously for 8 hours, convenient to carry around for measurement, not limited by on-site power supply; with automatic shutdown function, it will automatically shut down without any operation within ten minutes;

⑧Large-screen dot-matrix liquid crystal display, which can be clearly displayed in sunlight; the operation interface is intuitive and clear, and the user only needs to operate according to the prompts;

⑨With RS232 and USB interface, the software can be upgraded by U disk.

Relative dielectric loss and capacitance tester, its main technical indicators in use are as follows:

Power supply: built-in large-capacity 12-cell lithium-ion battery;

Charging power supply: AC100V ～ 220V 50Hz/60Hz;

Working environment temperature: -10°C～50°C;

Working environment humidity: 30%～85%;

Current measurement range: 100uA～1A;

Current measurement range: 1mA～1A;

Current measurement accuracy: ±(0.5% reading+10uA);

Reference voltage input range: 1～300V;

Dielectric loss measurement range: -200%～+200%, minimum resolution 0.001%;

Dielectric loss measurement accuracy: ±(1% reading+0.0005);

Capacitance ratio measurement range: 1.000E-4～1.000E+4;

Capacitance ratio measurement accuracy: ± (0.5% reading + 5 digits);

Capacitance measurement range: 10pF～0.5uF;

Capacitance measurement accuracy: ±(0.5% reading+1pF);

Full current measurement range: 100uA～1A;

Resistive current measurement range: 10μA～100mA;

Resistive current measurement accuracy: ±(reading×5%+5uA);

Capacitive current measurement range: 100μA～500mA;

Capacitive current measurement accuracy: ±(reading×5%+5uA);

Phase measurement range: 0°～360°;

Phase measurement accuracy: ±0.1°;

Ground current measurement range: 5mA～30A;

Ground current measurement accuracy: ±(1% reading+1mA);

Frequency measurement range: f=45Hz～65Hz;

Frequency measurement accuracy: ±0.5Hz.

The above embodiments are descriptions of specific implementations of the present invention, rather than limitations of the present invention. Those skilled in the relevant technical fields can also make various transformations and changes without departing from the spirit and scope of the present invention. Corresponding equivalent technical solutions, therefore all equivalent technical solutions should fall into the patent protection scope of the present invention.

Claims (8)

1. relative dielectric loss and a capacitance tester, is characterized in that: comprise carrying case and be arranged on the circuit arrangement in carrying case; Described circuit arrangement comprises guidance panel, battery power management unit (1), wireless communication unit (2), measuring unit (3) and indicative control unit (4);

Indicative control unit (4) is electrically connected with wireless communication unit (2) and measuring unit (3) two-way signaling respectively; Battery power management unit (1) is used for providing working power when using;

Described measuring unit (3) comprises reference voltage interface (31), reference current interface (32), tested device current interface (33), reference voltage/current conditioning module (34), tested current regulating module (35), the anti-aliasing low-pass filter of second order (36), AD conversion module (37), FFT digital signal processing module (38) and the second serial line interface (39);

Reference voltage interface (31), reference current interface (32) and tested device current interface (33) are arranged on guidance panel respectively; Reference voltage/current conditioning module (34) is electrically connected with reference voltage interface (31) and reference current interface (32) respectively; Tested current regulating module (35) is electrically connected with tested device current interface (33); The anti-aliasing low-pass filter of second order (36) is electrically connected with reference voltage/current conditioning module (34) and tested current regulating module (35) respectively; AD conversion module (37) is electrically connected with the anti-aliasing low-pass filter of second order (36); AD conversion module (37) is electrically connected with FFT digital signal processing module (38) two-way signaling; FFT digital signal processing module (38) is electrically connected with the second serial line interface (39) two-way signaling;

Indicative control unit (4) comprises main control module (41), Keysheet module (42), LCD MODULE (43), memory module (44), printer module (45), wireless communication interface (46), measures communication interface (47), host computer communication interface (48) and USB flash disk interface (49);

Keysheet module (42), LCD MODULE (43), host computer communication interface (48) and USB flash disk interface (49) are arranged on guidance panel respectively; Printer module (45) is arranged on carrying case;

Main control module (41) is electrically connected with Keysheet module (42) signal; LCD MODULE (43) and printer module (45) are electrically connected with main control module (41) signal respectively; Main control module (41) is electrically connected with memory module (44) and USB flash disk interface (49) two-way signaling respectively; Main control module (41) is communicated with wireless communication unit (2) by wireless communication interface (46); The measurement communication interface (47) of main control module (41) is electrically connected with the second serial line interface (39) two-way signaling of measuring unit (3).

2. relative dielectric loss according to claim 1 and capacitance tester, is characterized in that: described wireless communication unit (2) comprises the second control module (21), the first serial line interface (22), radio-frequency communication module (23), radio frequency power amplification modules (24) and antenna (25);

Second control module (21) is electrically connected with the first serial line interface (22) and radio-frequency communication module (23) two-way signaling respectively; Radio frequency power amplification modules (24) is electrically connected with radio-frequency communication module (23) and antenna (25) two-way signaling respectively.

3. relative dielectric loss according to claim 1 and capacitance tester, is characterized in that: described battery power management unit (1) comprises the first control module (11), switching on and shutting down detection module (12), charge management module (13), lithium battery (14), switching on and shutting down control module (15), DC-DC voltage reduction module (16), charging inlet (17) and power switch (18); Charging inlet (17) and power switch (18) are arranged on guidance panel;

First control module (11) is provided with switching on and shutting down detection signal input end, Charge Management signal communication ends, switching on and shutting down control signal output terminal and power supply output control terminal; Switching on and shutting down detection module (12) is provided with signal input part and signal output part; Charge management module (13) is provided with charge power supply input end, charging control signal communication ends and power output end; Lithium battery (14) is provided with charge power supply input end and power output end; Switching on and shutting down control mould (15) and are provided with control signal input end, power input and power output end; DC-DC voltage reduction module (16) is provided with control signal input end, power input and power output end;

The switching on and shutting down detection signal input end of the first control module (11) is electrically connected with the signal output part signal of switching on and shutting down detection module (12); The Charge Management signal communication ends of the first control module (11) is electrically connected with the charging control signal communication ends two-way signaling of charge management module (13); The signal input part of switching on and shutting down detection module (12) is electrically connected with power switch (18); The charge power supply input end of charge management module (13) is electrically connected with charging inlet (17); The charge power supply input end of lithium battery (14) is electrically connected with the power output end of charge management module (13); The control signal input end that switching on and shutting down control mould (15) is electrically connected with the switching on and shutting down control signal output end signal of the first control module (11); The power input that switching on and shutting down control mould (15) is electrically connected with the power output end of lithium battery (14); The control signal input end of DC-DC voltage reduction module (16) is electrically connected with the power supply output control terminal signal of the first control module (11); The power output end that power input and the switching on and shutting down of DC-DC voltage reduction module (16) control mould (15) is electrically connected; The output power supply when power output end of DC-DC voltage reduction module (16) uses.

4. relative dielectric loss according to claim 1 and capacitance tester, is characterized in that: the reference voltage/current conditioning module (34) of described measuring unit (3) comprises many grades of sample resistances and variable gain amplifier; The anti-aliasing low-pass filter of second order (36) comprises 1 second order Butterworth active low-pass filter and 1 passive RC low-pass filter of single order.

5. relative dielectric loss according to claim 1 and capacitance tester, is characterized in that: the core devices of the AD conversion module (37) of described measuring unit (3) is super low-power consumption 16 8-digit microcontroller of MSP430AFE253 model; The core devices of FFT digital signal processing module (38) is the CPU of the STM32F405 model of band Float Point Unit.

6. relative dielectric loss according to claim 1 and capacitance tester, is characterized in that: the core devices of the main control module (41) of described indicative control unit (4) is the high-performance microprocessor of the S3C44B0 model based on ARM7TDMI core; The core devices of printer module (45) is the minitype thermal printer of 8 parallel port communications.

7. relative dielectric loss according to claim 2 and capacitance tester, is characterized in that: the core devices of the radio-frequency communication module (23) of described wireless communication unit (2) is the radio frequency chip of the SI4463 model based on 433MHz frequency range.

8. relative dielectric loss according to claim 3 and capacitance tester, is characterized in that: the charge management module (13) of described battery power management unit (1) comprises external power supply testing circuit, PWM charging circuit, battery voltage detection circuit and charging current detecting circuit; The core devices of the first control module (11) is MSP430F2012 single-chip microcomputer; The core devices of DC-DC voltage reduction module (16) is the high efficiency switch power supply chip of LM2675 model.